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FIELD OF THE INVENTION
[0001] This invention relates to high resolution imaging of a surface using a scanning probe microscope (SPM). In particular, this invention relates to a probe for such a microscope.
BACKGROUND TO THE INVENTION
[0002] The Atomic Force Microscope (AFM) has been widely used to image surfaces at a resolution of fractions of a nanometer. The AFM typically comprises a cantilever having a sharp tip at one end that is used to scan the sample surface. When the tip is brought into proximity with the surface, forces between the tip and the sample lead to deflection of the cantilever. Measurement of this deflection is used to create an image of the surface. To alleviate the risk that the tip collides with the surface during scanning, which may cause damage, a feedback mechanism is typically employed to maintain a constant distance between the tip and the surface.
[0003] In order for the tip to be close enough to the surface for short-range forces to become detectable, while preventing the tip from sticking to the surface, the AFM cantilever is typically operated in “tapping” mode. This also avoids damage caused by dragging of the sharp tip across the surface in “contact” mode AFM. In tapping mode, the cantilever is oscillated such that during each cycle the tip comes in contact with the surface, and a restoring force provided by the cantilever detaches the tip from the surface. This is usually achieved by attaching a piezoelectric block to the other end of the cantilever, remote from the tip, which drives the cantilever assembly up and down at its resonant frequency, usually at frequencies of up to tens of kHz.
[0004] Tapping mode AFM generally relies upon differentiation of the phase of the tip from that of the driver. A typical AFM setup is shown in FIG. 1 and described in EP0397496A. A compliant cantilever 101 is attached at one end to a probe 102 having a sharp tip 103 , and at its other end to a driver 104 for oscillating the probe in the z direction. Means (not shown) are provided for x-y scanning of the probe 102 across the sample surface 105 . Deflection of the cantilever in the z direction is measured by optical interferometry. The output of a laser 106 is directed via a beam splitter 107 , set at 45 degrees to the beam axis, and a lens 108 to a reflecting surface 109 provided on the probe end of the cantilever 101 and separately to a plane mirror 110 . Light incident on the plane mirror 110 is reflected back to the beam splitter 107 , and light incident on the reflecting surface 109 is reflected back to the beam splitter 107 . The two reflected beams meet and interfere at the beam splitter 107 and the resultant fringe pattern is directed to a light detector 111 via lens 112 . The electrical output of the light detector 111 is applied to one input of a phase detector 113 forming part of a phase locked loop 114 . The other input to the phase detector 113 is taken from a loop voltage controlled oscillator (VCO) 115 . The output from the VCO 115 is also applied to the driver 104 . The control voltage for the VCO is developed from the output of the phase detector 113 by means of a loop filter 116 .
[0005] The tip 103 attached to, or integral with, the end of the cantilever 101 is deemed to have an egregious atom which interacts with the Van der Waals forces of the atoms of the sample surface 105 . The compliance of the cantilever 101 allows a phase discrepancy to exist between the driver 104 and the tip as a result of such interaction. The detection of this discrepancy in the output from loop filter 116 is used to control the height of the tip 103 , via a z height controller, at a constant distance from the surface 105 from which the contour is derived in a raster scan to produce a topographic x,y image of the surface.
[0006] Tuning the oscillator frequency of the VCO 115 to the resonant frequency of the cantilever assembly, in its free/un-biased state, improves sensitivity and noise performance. However, the amplitude and frequency of the oscillation in tapping mode AFM are clearly constrained by the resonant frequency and mechanical properties of the cantilever, leading to limited scan speeds. Harmonic operation is theoretically possible to increase scan speed, but virtual world modelling suggests that distortion and twisting of the cantilever occurs easily in this mode, particularly where the tip is influenced by lateral forces.
[0007] While tapping mode AFM has worked well enough in air, the effect of a liquid environment, as for electrochemical and live cell studies, is to lower the resonant frequency of the cantilever by a factor of five or more, and to introduce cavitation and turbulence into the liquid environment near the surface. The time taken to scan even a limited area is extended considerably and thermal fluctuations cause drifts in laser alignment.
[0008] In an article by A. G. Onaran, et al, entitled “A new atomic force microscope probe with force sensing integrated readout and active tip” published in Review of Scientific Instruments 77, 023501 (2006) an alternative to the conventional cantilever probe is described. The probe described in this article comprises a sharp probe tip provided on a micromachined optically reflective membrane, The membrane is, in turn, mounted on a transparent substrate incorporating a diffraction grating resulting in an integrated phase-sensitive structure. Thus, probe tip displacement is monitored by illuminating the diffraction grating and monitoring the intensity of the reflected diffraction orders. The tip of the probe is moved by electrostatic forces applied to the membrane with the transparent substrate as a rigid actuator electrode.
[0009] A further alternative to the conventional cantilever probe is described in an article by Toshu An, et al, entitled “Atomically-resolved imaging by frequency-modulation atomic force microscopy using a quartz length-extension resonator” published in Applied Physics Letters 87, 133114 (2005). This article describes the use of a quartz rod as a resonator to which a probe tip is attached. Shifts in the resonance frequency of the probe are representative of the interactive force between the probe tip and the sample surface and thus by applying a small oscillation amplitude to the resonator, characteristics of the surface of the sample may be imaged.
[0010] There is therefore a need in the art for an improved SPM to address at least some of the drawbacks evident in AFM.
SUMMARY OF THE INVENTION
[0011] According to a first aspect of this invention, there is provided a scanning probe microscope for topographical imaging of a surface, comprising an elongate probe having a longitudinal axis oriented substantially orthogonal to the surface, the probe having a tip, a driver and a compliant elastic module disposed between the driver and the tip, the driver being adapted to axially oscillate the tip.
[0012] According to a second aspect of this invention, there is provided a method for topographical imaging of a surface using the scanning probe microscope of the first aspect, comprising bringing the probe in proximity with the surface and driving the probe tip in axial oscillation.
[0013] In the absence of external forces acting on the tip, the tip will vibrate with a constant phase relationship to the driver. By bringing the probe into close proximity with the surface, any interaction of the tip with the surface, i.e. by virtue of Van der Waals forces or sticking, will change this mechanical phase relationship due to the compliance of the elastic module disposed between the tip and the driver, orthogonal to the surface. In the context of this document reference to the module being compliant is to be understood as reference to the module elastically deforming under the forces generally encountered in probe microscopy.
[0014] Detection of this change in phase relationship may be used to control the height of the tip, via a z height controller, at a constant distance from the surface from which the contour is derived in a raster scan to produce a topographic image of the surface. Due to the elimination of the cantilever used in AFM, raster scan speeds can be high enough to result in real time imaging capability, impossible to achieve using AFM. The upper limit of the frequency of operation will be determined by the resonant frequency of the elastic module. The tip oscillation may be user defined up to tens of thousands of kHz, three orders of magnitude greater than that for AFM.
[0015] Preferably, the elastic module has a tapering cross-section along its length towards the tip. In a preferred example of the present invention, the elastic module is an acoustic transformer of hyperbolic section. This transforms the high force, low amplitude motion of the driver into a low force, high amplitude motion at the tip, which can be better matched to the tip/surface interaction force levels.
[0016] The elastic module can take many forms and may be a spring, an elastomeric member or a fluid filled tube. The driver can also take many different forms and may include piezo-electric, magneto-constrictive or electromagnetic drive means. The principles of this invention are therefore far reaching and may be applied to a wide variety of probes, adapted for a similarly wide variety of uses.
[0017] Monitoring of the axial tip position is preferably by optical interferometry, in a similar way to that described above for AFM, using a laser source and an array of photodiodes. However, deflection of the tip can be measured by any sufficiently sensitive technique, e.g. tunnelling microscope, capacitance or inductance changes. For example, the position of the tip itself, or a ferromagnetic bead attached to it, could be assessed from signals from adjacently mounted inductors.
[0018] The SPM of this invention is far less constrained than cantilever AFM. In particular, imaging under liquid becomes less intrusive. The tip can be arbitrarily long, limited only by inertial considerations, with diameters as small as is consistent with mechanical stability, which makes possible imaging which cannot be achieved using cantilever AFM. For example, this invention allows imaging with minimal disturbance in liquids. Not only does this invention lead to an expansion of the areas in which SPM can be used but also enables the principles of this invention to be used in conjunction with both optically inverted and non-inverted microscopy techniques to produce combination images that have not previously been possible, at the micro, nano and atomic scale.
[0019] For example, the SPM of this invention can be combined with Near Field Scanning Optical Microscopy (SNOM), Fluorescence Resonance Energy Transfer (FRET), Total Internal Reflection Microscopy (TIRF), Surface-Enhanced Raman Scattering (SERS), Scanning Ion Conductance Microscopy (SICM), Surface Plasmon Resonance (SPR), or Magnetic Force Microscopy (MFM).
[0020] The SPM of this invention preferably includes an array of such probes, each probe being associated with an area of the sample surface. The probes are preferably moved simultaneously across the surface, such that each probe scans across its associated area. Subdivision of the surface in this manner leads to reduced scan times.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Preferred examples of the present invention will now be described with reference to the accompanying drawings, in which:
[0022] FIG. 1 shows a block diagram of an optical interferometric cantilever AFM system of the prior art;
[0023] FIG. 2 shows a first example of a probe of an SPM of this invention;
[0024] FIG. 3 shows a second example of a probe of an SPM of this invention;
[0025] FIG. 4 shows a third example of a probe of an SPM of this invention;
[0026] FIG. 5 shows a fourth example of a probe of an SPM of this invention;
[0027] FIG. 6 shows a fifth example of a probe of an SPM of this invention;
[0028] FIG. 7 shows a sixth example of a probe of an SPM of this invention;
[0029] FIG. 8 shows a seventh example of a probe of an SPM of this invention; and
[0030] FIGS. 9 (a ), 9 ( b ), 10 ( a ), 10 ( b ), 11 ( a ) and 11 ( b ) illustrate the phase differences generated using three sample probes in accordance with the present invention at a range of driving frequencies.
DETAILED DESCRIPTION
[0031] The SPM of this invention differs from the exemplary optical interferometric cantilever AFM system shown in FIG. 1 in that the driven cantilever and attached tip is replaced with an elongate probe having a longitudinal axis oriented substantially orthogonal to the sample surface. The probe has a tip, a driver and a compliant elastic module disposed between the driver and the tip. Thus, the SPM employs a non-cantilever probe.
[0032] In the first example of this invention, shown in FIG. 2 , the probe 10 includes a helical coil spring 11 , of which one end is attached to a driver 12 and the other end is attached to a sharp tip 13 . The driver 12 is adapted to mechanically oscillate the spring 11 , as the compliant elastic module, along the longitudinal axis of the spring 11 and is positioned at the opposite end of the compliant elastic module to the sharp tip 13 , symmetric about the longitudinal axis of the module. The tip 13 is adapted to interact with a sample surface.
[0033] The low forces involved in the interaction between the tip 13 and the sample surface, at the pico newton level, suggest that the probe 10 will be on the micro scale, and would be most readily micro-machined from materials such as, but not limited to, silicon, silicon nitride, aluminium nitride, or some alloys.
[0034] The probe 10 further includes a mirror 14 acting as a reflecting surface for an optical interferometric tip monitoring system. In other words, the mirror 14 is analogous to the reflective surface 107 of FIG. 1 . The mirror 14 conveniently acts as a radial supporting bridge between the helical spring 11 and the axially disposed tip 13 .
[0035] Stability of the probe may be improved and micro-machining of the spring more readily realised by adapting the spring geometry. FIG. 3 shows the probe 20 of the second example of this invention. The probe 20 includes a conical spiral spring 21 , attached between a driver 22 and a tip 23 . The spring 21 may be formed as a flat spiral, deformed into the conical form. The probe further includes a mirror 24 supported by the tip 23 and acting as the reflecting surface. This geometry would more readily be capable of being made in an array form, with micro-mirror readout of the tip height change.
[0036] In the third example of this invention, shown in FIG. 4 , the probe 30 includes an elastomeric block 31 as the compliant elastic module, shaped as a rectangular parallelepiped, of which one end is attached to a driver 32 and the other end is attached to a sharp tip 33 . The block 31 may be made, for example, of rubber material. In order to optically monitor probe tip height changes, the driver 32 may include an aperture (not illustrated) for use in combination with an optical fibre to monitor the probe tip.
[0037] In the fourth example of this invention, shown in FIG. 5 , the probe 40 includes a compressible elastic fluid 41 contained within a cylindrical vessel 45 having a sealed upper end attached to a driver 42 . The lower end of the cylindrical vessel 45 is closed by a membrane or piston 46 , to which a sharp tip 43 is attached. The cylindrical vessel 45 and the membrane/piston 46 together form the compliant elastic module of this invention. Attached to the membrane/piston 46 or the tip 43 is a reflecting surface 44 . The driver 42 is adapted to drive the cylindrical vessel 45 in axial oscillation, which moves the membrane/piston to which the tip 43 is attached, up and down.
[0038] As can be seen from the first through fourth examples above, the compliant elastic module can take many different shapes and forms. However, there are advantages to forming the compliant elastic module as an acoustic transformer, usually of hyperbolic section, between the driver and the tip. This transforms the high force, low amplitude motion of the driver into a low force, high amplitude motion at the tip, which can be better matched to the tip/surface interaction force levels.
[0039] One such geometry is shown in FIG. 6 , which represents the fifth example of this invention. The probe 50 includes a compliant elastic module 51 between a driver 52 and a sharp tip 53 , the elastic module being made entirely of elastomer and having a hyperbolic section, such that the elastic module 51 tapers towards the tip end.
[0040] In the sixth example of this invention, shown in FIG. 7 , the hyperbolic geometry is achieved with a fluid assembly, instead of the elastomer of the fifth example. The probe 60 includes a compressible elastic fluid 61 contained within a hyperbolic section vessel 65 having a sealed upper end attached to a driver 62 . The lower end of the hyperbolic section vessel 65 is closed by a membrane or piston 66 , to which a sharp tip 63 is attached. The fluid filled hyperbolic transformer of the sixth embodiment is therefore based upon the principles of the fourth and fifth examples.
[0041] The entirely elastomeric component of the fifth example could instead be formed as a laminated structure to change the characteristics of the compliant elastic module. One such structure is shown in FIG. 8 , which represents the seventh example of this invention. The probe 70 includes a hyperbolic transformer made of one or more laminations of elastomer 71 and solid material 75 , between a driver 72 and a sharp tip 73 .
[0042] The driver, as in all the above examples can be, but is not restricted to, piezo-electric, magneto-constrictive, or electromagnetic. In all cases it will be apparent that the compliant elastic module is provided solely to act as an oscillation bridge, transmitting oscillations to the probe tip which have been applied to the module externally by a separate driver. The compliant elastic module does not generate its own oscillations and instead requires the oscillations to be externally applied.
[0043] In all of the above examples, the materials can be transparent to aid in the transmission of light for optical monitoring of the axial tip position. The probe may include a reflective surface, as shown in the above examples, for use in optical interferometric monitoring of the axial tip position similar to the setup described for cantilever AFM with reference to FIG. 1 .
[0044] Alternatively, the optical SiGNUM™ system sold by Renishaw plc, Wotton-under-Edge, Gloucestershire, UK, in which a grating is projected on to a grating attached to, or adjacent, the probe tip may be used to give positional information accurate to the nm region which is needed for this application. The axial position of the tip itself, or a ferromagnetic bead attached to it, could alternatively be assessed from signals from adjacently mounted inductors.
[0045] The mechanical phase change which will develop between motion of the tip and the driver when Van der Waals forces come into play, when the tip is brought into proximity with the sample surface, is used in a feedback loop to control the height of the probe tip relative to the surface to maintain the tip at a constant distance from the surface from which the contour is derived from combining a series of height adjustments collected during a raster scan to produce a topographic image of the surface.
[0046] A conventional three-axis piezo system such as that typically employed in cantilever AFM systems may be used to control movement of the probe scanwise in the x and y directions and also in the z height direction.
[0047] The upper limit to the frequency of operation will be determined by the resonant frequency of the compliant elastic module, be it elastomer or fluid filled tube. This would be when a standing wave is set up within it, and is a function of the velocity of sound within the fluid or elastomer. This would be frustrated in the hyperbolic geometries.
[0048] If the fluid is air, the velocity of sound at 20 degrees Celsius is 300 m/s, ie a standing wave would be set up at about 10 kHz for a fluid filled tube 1.5 cm long. For a 1.5 cm long elastomeric block, the sound velocity would be 1800 m/s, and so resonance would be 60 kHz.
Experimental Results
[0049] Several formers were machined in aluminium alloy into acoustic transformer shapes with base diameters ranging from less than 10 mm to more than 20 mm. These were used in conjunction with a two part silicone based elastomer to create moulds. Vacuum degassed heat curable silicone rubber was poured into the moulds to create compliant elastic modules in the form of acoustic transformer modules covering a range of sizes and with differing shore hardness values. One source of these elastomeric materials is Nusil Silicone Technology (USA). Two part liquid silicone elastomers LS1-6941 (Type A durometer 53), R21-2615 (Type A durometer 75) and R2620 (Type A durometer 63) were typical elastomers used in the viability stage of testing.
[0050] The base of each acoustic transformer module was coupled to a piezoelectric driver. Accoustic waves generated using a signal generator travelled through the module to its tip. A signal receiver was positioned at the tip of the module which converted the motion into an electric signal. Both the input and output waveform signals were compared directly using a picoscope to assess the phase difference when the compliant elastomeric module was either in contact or out of contact with a surface.
[0051] Some of the curves generated in this way are shown in FIGS. 9 to 11 . The figures illustrate the phase difference that can be generated with different input frequencies and the amplitude variation in the output signal when the tip is in contact with a surface. These variations in the signal will be used to drive the module at a constant distance from the surface.
[0052] FIG. 9( a ) illustrates the measured response of a conical elastomer made of compound EC13 (very elastic) when driven at 3.7 kHz and with no contact with the motion detector. FIG. 9( b ) illustrates the measured response of the same conical elastomer at the same frequency but with the tip of the elastomer in contact with the motion detector. In each case line A represents the input signal, line B the output signal.
[0053] FIG. 10( a ) illustrates the measured response of a conical elastomer made of compound EC07 (very elastic) when driven at 31.2 kHz and with no contact with the motion detector. FIG. 10 (b ) illustrates the measured response of the same conical elastomer at the same frequency but with the tip of the elastomer in contact with the motion detector. In each case line A represents the input signal, line B the output signal.
[0054] FIG. 11( a ) illustrates the measured response of a conical elastomer made of compound EC05 (high durability) when driven at 115 kHz and with no contact with the motion detector. FIG. 11( b ) illustrates the measured response of the same conical elastomer at the same frequency but with the tip of the elastomer in contact with the motion detector. In each case line A represents the input signal, line B the output signal.
Imaging Modes
[0055] The SPM of this invention can be operated in dynamic mode or “tapping” mode by which the tip is oscillated at a user defined nominal frequency and not limited to the resonance frequency of a cantilever as in AFM. The frequency range can therefore be in the region of 0 to tens of thousands of kHz. Thus, with the present invention real time/video rate imaging of a sample is achievable.
[0056] The SPM of this invention can also be operated in “altitude mode” in which a line is raster scanned in tapping mode, as above, and subsequently by a repeated raster scan following the contours at a predetermined distance above the surface for, but not limited to, electrochemical, magnetic and conductance measurements.
Applications
[0057] The tip can be arbitrarily long, limited only by inertial considerations, with diameters as small as is consistent with mechanical stability, which makes possible imaging which cannot be achieved using cantilever AFM. For example, this invention allows imaging with minimal disturbance in liquids. Not only does this invention lead to an expansion of the areas in which SPM can be used but also enables the principles of this invention to be used in conjunction with both optically inverted and non-inverted microscopy techniques to produce combination images, at the micro, nano and atomic scale.
[0058] For example, the SPM of this invention can be combined with Near Field Scanning Optical Microscopy (SNOM), Fluorescence Resonance Energy Transfer (FRET), Total Internal Reflection Microscopy (TIRF), Surface-Enhanced Raman Scattering (SERS), Scanning Ion Conductance Microscopy (SICM), Surface Plasmon Resonance (SPR), or confocal fluorescence.
Isolating Enclosures
[0059] Another feature of the use of long tips is the ease with which operation in an isolating enclosure can be set up, giving the option of scanning not only in air and aqueous media, but also in heterogeneous media-heterogeneous imaging mode. Two phase or sequential imaging in, e.g. air/fluid environments can be done to reveal the effects of one, then the other on the properties of a surface both for biological and electrochemical studies.
[0060] Disposing the SPM probe in a humidified enclosure would enable, e.g. accelerated corrosion studies, and the deterioration of drugs or organic/inorganic crystals to be examined.
[0061] Where the SPM probe is enclosed in an inert atmosphere or even a vacuum, oxidisable species may be studied to image directly surfaces which at present need Scanning Electron Microscopy (SEM) or Transmission Electron Microscopy (TEM). The latter rely on the deposition of metallic coatings to image organic materials, inevitably compromising the structures.
Magnetic Field Measurements
[0062] The probe tip may be magnetic or magnetised so that a magnetic field image can be delivered by Magnetic Force Microscopy (MFM) to be superimposed on the SPM topographic image derived from the Van der Waals interaction.
Biological
[0063] The coating or functionalisation of the tip can result in a specific interaction with the surface to either image the distribution of a given species or to manipulate it, e.g. for protein unfolding studies, cell membrane manipulation and the measurement of properties such as elasticity.
[0000] Hollow tips
[0064] Despite decreasing the resolution, a hollow tip would allow the delivery of light, biomolecules, reagents and fluids.
Nanolithography
[0065] Patterning and manipulation of the surface can be achieved using a number of approaches including, but not limited to, oxidation, scratching and deposition.
Nanoindentation
[0066] Mechanical testing of materials and coatings using nanoindentation, applying force and adding modules for hardness and wear testing using, for example Berkovitch, cube corner and spherical indentation can be done.
Force Curves
[0067] Due to the force induced phase displacement which occurs as the probe tip approaches the surface, force-distance curves can be constructed which allow the measurement of, for example, elasticity, mechanical stimulation and protein unfolding of softer materials than for nanoindentation.
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An elongate probe ( 50 ) for use in probe microscopy comprises a module ( 51 ) provided between a probe tip ( 53 ) and a driver ( 52 ). In use the driver ( 52 ) applies oscillations to the module ( 51 ) which are transmitted by the module to the tip ( 53 ). With the probe tip ( 53 ) positioned close to the surface of a sample, any phase variance in the oscillation of the tip with respect to the driving oscillation is representative of an interaction between the tip and the sample surface. The elongate arrangement of the probe ( 50 ) is particularly beneficial when used to probe samples which require a liquid environment.
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FIELD OF THE INVENTION
[0001] The present invention relates to a high damage tolerant Al—Cu alloy product having a high toughness and an improved fatigue crack growth resistance while maintaining good strength levels, to a method for producing such a rolled high damage tolerant Al—Cu alloy product having a high toughness and an improved fatigue crack growth resistance and further to a rolled alloy sheet product for aeronautical applications. More specifically, the present invention relates to a high damage tolerant Al—Cu—Mg alloy designated by the Aluminum Association (“AA”)2xxx-series for structural aeronautical applications with improved properties such as fatigue crack growth resistance, strength and fracture toughness. The invention also relates to a rolled alloy product which is suitable used as fuselage skin or lower wing skin of an aircraft.
BACKGROUND OF THE INVENTION
[0002] It is known in the art to use heat treatable aluminum alloys in a number of applications involving relatively high strength such as aircraft fuselages, vehicular members and other applications. The aluminum alloys 2024, 2324 and 2524 are well known heat treatable aluminum alloys which have useful strength and toughness properties in T3, T39 and T351 tempers.
[0003] The design of a commercial aircraft requires various properties for different types of structures on the aircraft. Especially for fuselage skin or lower wing skin it is necessary to have properties such as good resistance to crack propagation either in the form of fracture toughness or fatigue crack growth. At the same time the strength of the alloy should not be reduced. A rolled alloy product either used as a sheet or as a plate with an improved damage tolerance will improve the safety of the passengers, will reduce the weight of the aircraft and thereby improve the fuel economy which translates to a longer flight range, lower costs and less frequent maintenance intervals.
[0004] It is known in the art to have AA2×24 alloy compositions with the following broad compositional range, in weight percent:
[0005] Cu: 3.7-4.4
[0006] Mg: 1.2-1.8
[0007] Mn: 0.15-0.9
[0008] Cr: 0.05-0.10
[0009] Si: ≦0.50
[0010] Fe: ≦0.50
[0011] Zn: ≦0.25
[0012] Ti: ≦0.15
[0013] the balance aluminum and incidental impurities.
[0014] U.S. Pat. No. 5,593,516 discloses a high damage tolerant Al—Cu alloy with a balanced chemistry comprising essentially the following composition (in weight %):
[0015] Cu: 2.5-5.5
[0016] Mg: 0.1-2.3
[0017] Cu max : −0.91 Mg+5.59
[0018] CU min : −0.91 Mg+4.59
[0019] Zr: up to 0.2, or
[0020] Mn: up to 0.8
[0021] balance aluminum and unavoidable impurities. It also discloses T6 and T8 tempers of such alloys which gives high strength to a rolled product made of such alloy.
[0022] U.S. Pat. No. 5,897,720 discloses a high damage tolerant Al—Cu alloy with a “2024”-chemistry comprising essentially the following composition (in weight %):
[0023] Cu: 3.8-4.9
[0024] Mg: 1.2-1.8
[0025] Mn: 0.3-0.9
[0026] the balance aluminum and unavoidable impurities wherein the alloy is annealed after hot rolling at a temperature at which the intermetallics do not substantially dissolve. The annealing temperature is between 398° C. and 455° C.
[0027] U.S. Pat. No. 5,938,867 discloses a high damage tolerant Al—Cu alloy with a “2024”-chemistry comprising essentially the following composition (in weight %):
[0028] Cu: 3.8-4.9
[0029] Mg: 1.2-1.8
[0030] Mn: 0.3-0.9
[0031] balance aluminum and unavoidable impurities wherein the ingot is inter-annealed after hot rolling with an anneal temperature of between 385° C. and 468° C.
[0032] EP-0473122, as well as U.S. Pat. No. 5,213,639, disclose an aluminum base alloy comprising essentially the following composition (in weight %):
[0033] Cu: 3.8-4.5, preferably 4.0-4.5
[0034] Mg: 1.2-1.8, preferably 1.2-1.5
[0035] Mn: 0.3-0.9, preferably 0.4-0.7
[0036] Fe: ≦0.12
[0037] Si: ≦0.10.
[0038] the remainder aluminum, incidental elements and impurities, wherein such aluminum base is hot rolled, heated and again hot rolled, thereby obtaining good combinations of strength together with high fracture toughness and a low fatigue crack growth rate. More specifically, U.S. Pat. No. 5,213,639 discloses an inter-anneal treatment after hot rolling the cast ingot with a temperature between 479° C. and 524° C. and again hot rolling the inter-annealed alloy wherein the alloy contains one or more elements from the group consisting of Cr, V, Hf, Cr, Ag and Sc, each within defined ranges. Such alloy is reported to have a 5% improvement over the above mentioned conventional 2024-alloy in T-L fracture toughness and an improved fatigue crack growth resistance at certain ΔK-levels.
[0039] EP-1 170394-A2 discloses an aluminum sheet product with improved fatigue crack growth resistance having an anisotropic microstructure defined by grains having an average length to width aspect ratio of greater than about 4 to 1 and comprising essentially the following composition, (in weight %):
[0040] Cu: 3.5-4.5
[0041] Mg: 0.6-1.6
[0042] Mn: 0.3-0.7
[0043] Zr: 0.08-0.13,
[0044] the remainder substantially aluminum, incidental elements and impurities. The examples show a Zr-level in the range of 0.10 to 0.12 while maintaining an Mg-level of more than 1.30. Such alloy has an improvement in compressive yield strength properties which is achieved by respective sheet products in comparison with conventional 2524-sheet products. Furthermore, the strength and toughness combinations of such sheet products with high Mn variants have been described better than those of 2524-T3. Throughout the high anisotropy in grain structure the fatigue crack growth resistance could be improved.
[0045] Furthermore, it is described that low copper-high manganese samples exhibited higher properties than high copper-low manganese samples. Results from tensile strength measurements showed that high manganese variants exhibited higher strength values than the low manganese variants. The strengthening effect of manganese was reported to be surprisingly higher than that of copper.
SUMMARY OF THE INVENTION
[0046] It is a preferred object of the present invention to provide a high damage tolerant 2024-series type alloy rolled product having a high toughness and an improved fatigue crack growth resistance while maintaining good strength levels of conventional 2024, 2324 or 2524 alloys. It is another preferred object of the present invention to provide an aluminum alloy sheet product having an improved fracture toughness and resistance to fatigue crack growth for aircraft applications such as fuselage skin or lower-wing skin.
[0047] Yet a further preferred object of the present invention is to provide rolled aluminum alloy sheet products and a method for producing those products so as to provide structural members for aircrafts which have an increased resistance to fatigue crack growth and to provide an improved fracture toughness while still maintaining high levels of strength.
[0048] More specifically, there is a general requirement for rolled AA2000-series aluminum alloys within the range of 2024 and 2524 alloys when used for aeronautical applications that the fatigue crack growth rate (“FCGR”) should not be greater than a defined maximum. A FCGR which meets the requirements of high damage tolerance 2024-series alloy products is, e.g., FCGR below 0.001 mm/cycles at ΔK=20 MPa{square root}m and 0.01 mm/cycles at ΔK=40 MPa{square root}m.
[0049] The present invention preferably solves one or more of the above mentioned objects.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] The foregoing and other features and advantages of the alloy according to the invention will become readily apparent from the following detailed description of preferred embodiments. Some of the enhanced high damage tolerant properties are shown in the appended drawings, in which:
[0051] [0051]FIG. 1 shows the fatigue crack growth properties versus a 2524 reference alloy; and
[0052] [0052]FIG. 2 shows the Kahn-tear versus yield strength properties compared to 2024-T351 commercially available alloys and 2024-T351 pure grade alloys; and
[0053] [0053]FIG. 3 shows the Kahn-tear versus yield strength properties as shown in FIG. 2 but in average L-T and T-L direction.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] In accordance with the invention there is disclosed a high damage tolerant Al—Cu alloy having a high toughness and an improved fatigue crack growth resistance by maintaining high levels of strength which comprises essentially the following composition (in weight %):
[0055] Cu: 3.8-4.7
[0056] Mg: 1.0-1.6
[0057] Zr: 0.06-0.18
[0058] Mn: >0-0.50, and preferably >0.15-0.50
[0059] Cr: <0.15
[0060] Fe: ≦0.15, preferably ≦0.10
[0061] Si: ≦0.15, preferably ≦0.10,
[0062] and Mn-containing dispersoids and Zr-containing dispersoids, the balance essentially aluminum and incidental elements and impurities, wherein the Mn-containing dispersoids are at least partially replaced by Zr-containing dispersoids. The alloy contains Mn-containing dispersoids and Zr-containing dispersoids.
[0063] It has surprisingly been found that lower levels of manganese result in a high toughness and an improved fatigue crack growth resistance specifically in areas where the toughness and fatigue crack growth resistance under tensile load are critical. The alloy of the instant invention in a T3 temper has significant improved high damage tolerance properties by lowering the amount of manganese and by partially replacing manganese-containing dispersoids by zirconium containing dispersoids. At the same time it is important to carefully control the chemistry of the alloy.
[0064] The main improvement of the alloy according to the present invention is an improved fatigue crack growth resistance at the lower ΔK-values which leads to significant longer lifetimes. The balance of high damage tolerance properties and mechanical properties of the alloy of the present invention is better than the balance of conventional 2024 or 2524-T3 alloys. At the same time the toughness levels are equal or better to 2524 alloy levels. It has been found that the high damage tolerance properties such as fracture toughness or strength may be further improved by adding zirconium.
[0065] The amount (in weight %) of manganese is preferably in a range of 0.20 to 0.45%, most preferably in a range of 0.25 to 0.30%. Mn contributes to or aids in grain size control during operations. The preferred levels of manganese are lower than those conventionally used in conventional AA2×24 alloys while still resulting in sufficient strength and improved damage tolerance properties. In order to optimize the improved high damage tolerance properties the chemical composition of the alloy of the present invention preferably meets the proviso that Zr≧0.09 when Mn≦0.45 and Cu≧4.0.
[0066] The amount (in weight %) of copper is in a range of 4.0 to 4.4, preferably in a range of 4.1 to 4.3. Copper is an important element for adding strength to the alloy rolled product. It has been found that a copper content of 4.1 or 4.2 results in a good compromise in strength, toughness, formability and corrosion performance while still resulting in sufficient damage tolerance properties.
[0067] The preferred amount (in weight %) of magnesium is in a range of 1.0 to 1.4, most preferably in a range of 1.1 to 1.3. Magnesium provides also strength to the alloy rolled product.
[0068] The preferred amount (in weight %) of zirconium is in a range of 0.09 to 0.15 thereby partially replacing Mn-containing dispersoids. The balance of manganese and zirconium influences the recrystallisation behavior. Throughout the addition of zirconium more elongated grains may be obtained which also results in an improved fatigue crack growth resistance. Zirconium may also be at least partially replaced by chromium wherein [Zr]+[Cr]≦0.20. Preferred amounts (in weight %) of chromium and zirconium are in a range of 0.05 to 0.15, preferably in a range of 0.10 to 0.13. The balance of zirconium and chromium as well as the partial replacement of Mn-containing dispersoids and Zr-containing dispersoids result in an improved recrystallisation behavior and more elongated grains.
[0069] A preferred alloy composition of the present invention comprises the following composition (in weight %):
[0070] Cu: 4.0-4.2
[0071] Mn: 0.20-0.50
[0072] Mg: 1.0-1.3.
[0073] Another preferred alloy according to the present invention consists of the following composition (in weight %):
[0074] Cu: 4.0-4.2
[0075] Mg: about 1.2
[0076] Zr: 0.10-0.15
[0077] Mn: 0.20-0.50
[0078] Fe: ≦0.10
[0079] Si: ≦0.10.
[0080] Even more preferred, an alloy according to the present invention consists of the following composition (in weight %):
[0081] Cu: 4.1 or 4.2
[0082] Mg: about 1.2
[0083] Zr: about 0.14
[0084] Mn: 0.20-0.50
[0085] Fe: ≦0.10
[0086] Si: ≦0.10.
[0087] The balance in the rolled alloy product according to the invention is aluminum and inevitable impurities and incidental elements. Typically, each impurity element is present at 0.05% maximum and the total of impurities is 0.20% maximum. Preferably the alloy product is substantially Ag-free. The best results are achieved when the alloy rolled products have a recrystallised microstructure meaning that 75% or more, and preferably more than 80% of the grains in a T3 temper, e.g. T39 or T351, are recrystallised. In a further aspect of the microstructure it has the grains have an average length to width aspect ratio of smaller than about 4 to 1, and typically smaller than about 3 to 1, and more preferably smaller than about 2 to 1. Observations of these grains may be done, for example, by optical microscopy at 50× to 100× in properly polished and etched samples observed through the thickness in the longitudinal orientation.
[0088] The alloy according to the present invention may further comprise one or more of the elements Zn, Hf, V, Sc, Ti or Li, the total amount less than 1.00 (in weight %). These additional elements may be added to further improve the balance of the chemistry and enhance the forming of dispersoids.
[0089] In another aspect the invention provides a method for producing a rolled high damage tolerant Al—Cu alloy product having a composition as set out above and having a high toughness and an improved fatigue crack growth resistance according to the invention comprises the steps of:
[0090] a) casting an ingot having a composition as set out above and set forth in the claims,
[0091] b) homogenizing and/or pre-heating the ingot after casting,
[0092] c) hot rolling the ingot and optionally cold rolling into a rolled product,
[0093] d) solution heat treating,
[0094] e) quenching the heat treated product,
[0095] f) stretching the quenched product, and
[0096] g) naturally ageing the rolled and heat-treated product.
[0097] After hot rolling the ingot it is possible to anneal and/or re-heat the hot rolled ingot and again hot rolling the rolled ingot. It is believed that such re-heating or annealing enhances the fatigue crack growth resistance by producing elongated grains which—when recrystallized—maintain a high level of toughness and good strength. It is furthermore possible to conduct a surface heat treatment between hot rolling and cold rolling at the same temperatures and times as during homogenisation, e.g. 1 to 5 hours at 460° C. and about 24 hours at 490° C. The hot rolled ingot is preferably inter-annealed before and/or during cold rolling to further enhance the ordering of the grains. Such inter-annealing is preferably done at a gauge of about 4.0 mm for one hour at 350° C. Furthermore, it is advisable to stretch the rolled and heat-treated product in a range of 1 to 5%, preferably in a range of 1 to 3%, and then naturally aging the stretched product for more than 5 days, preferably about 10 to 20 days, and more preferably for 10 to 15 days, to provide a T3 temper condition, in particular a T351 temper condition.
[0098] The present invention provides a high damage tolerant rolled Al—Cu alloy sheet product which has high toughness and an improved fatigue crack growth resistance with the above described alloy composition which is preferably produced in accordance with the above described method. Such rolled alloy sheet product has preferably a gauge of around 2.0 mm to 12 mm for applications such as fuselage skin and about 25 mm to 50 mm for applications such as lower-wing skin. The present invention thereby provides an aircraft fuselage sheet or an aircraft lower-wing member sheet with improved high damage tolerance properties. In particular when used as aircraft fuselages, the sheet may be unclad or clad, with preferred cladding layer thickness of from about 1 to about 5 percent of the thickness of the sheet.
[0099] The foregoing and other features and advantages of the alloy according to the invention will become readily apparent from the following examples. Some of the enhanced high damage tolerant properties are shown in the appended drawings, in which:
[0100] [0100]FIG. 1 shows the fatigue crack growth properties versus a 2524 reference alloy; and
[0101] [0101]FIG. 2 shows the Kahn-tear versus yield strength properties compared to 2024-T351 commercially available alloys and 2024-T351 pure grade alloys; and
[0102] [0102]FIG. 3 shows the Kahn-tear versus yield strength properties as shown in FIG. 2 but in average L-T and T-L direction.
EXAMPLES
[0103] On an industrial scale 7 different aluminum alloys have been cast into ingots having the following chemical composition as set out in Table 1.
TABLE 1 Chemical composition of the DC-cast aluminum alloys, in weight %, Si about 0.05%, Fe about 0.06%, balance aluminum and inevitable impurities. Alloying Element Alloy Cu Mn Mg Zr Cr AA2024 4.4 0.59 1.5 0 0 AA2524 4.3 0.51 1.4 0 0 1 4.4 0.40 1.3 0.06 0 2 4.3 0.41 1.3 0.09 0 3 4.2 0.43 1.2 0.14 0 4 4.1 0.31 1.2 0.14 0 5 4.1 0.21 1.2 0.14 0 6 4.4 0.21 1.4 0.10 0 7 4.4 0.21 1.3 0 0.08
[0104] The alloys have been processed to a 2.0 mm sheet in the T351 temper. The cast ingots were homogenized at about 490° C., and subsequently hot rolled at about 410° C. The plates were further cold rolled, surface heat treated and stretched by about 1%. All alloys have been tested after at least 10 days of natural aging.
[0105] Then the ultimate tensile strength properties and the unit propagation energy as well as the Kahn-tear has been measured in the L and T-L direction. The testing has been done in accordance with ASTM-B871 (1996) for the Kahn tear tests, and EN-1 0.002 for the tensile tests.
TABLE 2 Tensile properties and toughness of Alloys 1 to 7 of Table 1 in the L and T-Ldirection. L PS UTS UPE T-L Alloy (MPa) (MPa) (kJ/m2) TS/Rp AA2024 344 465 162 1.74 AA2524 338 447 331 1.99 1 324 441 355 1.92 2 335 446 294 1.95 3 338 449 322 2.02 4 337 449 335 1.98 5 320 419 335 1.98 6 332 442 266 1.91 7 337 449 289 1.92
[0106] As identified in Table 2 and shown in FIGS. 2 and 3 the Kahn-tear versus yield strength properties of the alloys according to the present invention are better than those of conventional 2024-T351 in commercially available form or pure form. Furthermore, the preferred minimum level of manganese is in between 0.21 and 0.31 while at a level of 0.21 the strength level is still good.
[0107] In order to identify the fatigue crack growth rate (“FCGR”) all alloys were tested according to ASTM E-647 on 80 mm wide M(T) panels at R=0.1 at constant load and a frequency of 8 Hz. The lifetime as shown in Table 3 is defined as the time (in number of cycles) that the crack grows from a length of 5 mm to 20 mm. The maximum stress was 54 MPa. The initial notch was 4.1 mm. Anti-buckling device are not used. The results are presented in Table 3 and FIG. 1.
[0108] From the results of Table 3 and FIG. 1 it can be seen that the preferred amount of Mn is in a range of 0.25 to 0.45 (in weight %) and the preferred range of Zr is in between 0.09 and 0.15 (in weight %). Copper is most preferably present in an amount below 4.3 and magnesium is preferably present in an amount below 1.3 (in weight %).
[0109] From the results of Table 3 and according to FIG. 1 (Region A) it can be seen that alloys 3 and 5 have a significantly improved lifetime over conventional AA2024 alloys preferably at ΔK-levels in a range of 5 to 15 MPa{square root}m. Hence, the fatique crack growth resistance at those lower ΔK-values results in significant longer lifetimes of the alloy and enhances its usefulness for aeronautical applications.
TABLE 3 Fatigue crack growth rate with ΔK-level is MPa✓m for all alloys compared with commercially available AA2024 alloy (=baseline). Cycles between Improvement in lifetime over Alloy a = 5 and 20 mm AA2024 AA2024 163830 baseline AA2524 216598 32% 1 338468 107% 3 526866 222% 5 416750 154% 6 272034 66% 7 284609 74%
[0110] Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made without departing from the spirit or scope of the invention as hereon described.
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Disclosed is a high damage tolerant Al—Cu alloy of the AA2000 series having a high toughness and an improved fatigue crack growth resistance, including the following composition (in weight percent) Cu 3.8-4.7, Mg 1.0-1.6, Zr 0.06-0.18, Cr<0.15, Mn>0-0.50 , Fe≦0.15, Si≦0.15, and Mn-containing dispersoids, the balance essentially aluminum and incidental elements and impurities, wherein the Mn-containing dispersoids are at least partially replaced by Zr-containing dispersoids. There is also disclosed a method for producing a rolled high damage tolerant Al—Cu alloy product having a high toughness and an improved fatigue crack growth resistance, and applications of that product as a structural member of an aircraft.
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This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/587,047, filed on Jan. 16, 2011,
BACKGROUND OF THE INVENTION
1. Field of the Invention
Present invention is directed toward the attachment of retracting device to a web strap or MOLLE system found on Military and Tactical vests.
2. Description of the Related Art
Retractable Tethering Devices currently are being attached to a person through use of common art attachment mechanisms such as Snap Clips, Velcro Straps, Pin Mounting Systems, Bracket Mounting devices and Belt Clipping devices. Examples of these retractable devices can be seen in U.S. Pat. No. 6,966,519, U.S. Pat. No. 7,478,776, and U.S. Pat. No. 7,665,684, all to Salentine and Collin, and all assigned to Hammerhead Industries, Inc., the same assignee as the present application.
The MOLLE vest system was first introduced around 1997, but it did not see widespread use until after the Sep. 11, 2001 attacks when it was used by U.S. troops serving in Afghanistan and, later, Iraq. MOLLE (pronounced MOLLY as in the female name) is an acronym for MOdular Lightweight Load-carrying Equipment. It is used to define the current generation of load-bearing equipment and rucksacks utilized by the United States armed forces, especially the United States Army, and its use is also growing in the British Army in the form of the Osprey Modular systems. The system's modularity is derived from the use of Pouch Attachment Ladder System (PALS) webbing, which can comprise a grid of grid of webbing used to attach smaller equipment onto load-bearing platforms, such as vests and backpacks. It was first used on MOLLE rucksacks, but is now found on a variety of tactical equipment, such as the American Improved Outer Tactical Vest, Interceptor body armor, USMC Improved Load Bearing Equipment backpack and Modular Tactical Vest. It is used to attach items such as holsters, magazine pouches, radio pouches, knife sheathes, and other gear. A wide variety of pouches are commercially available, allowing soldiers to customize their kit. This method of attachment has become a standard for modular tactical gear, replacing the click and stick system used in the earliest modular vest systems (which is still in use with most Western police departments).
For some military and tactical applications, a Velcro strap that loops can be used to attach accessories, with the strap cinches around the web strap of the MOLLE system on tactical vests. In other arrangements, snap clips are used. Both of these mount systems allows for the retracting device to pivot from the person's body in the extended direction of the gear, thereby minimizing line/cable wear and resistance. One disadvantage of the above listed mounting systems is that the retracting device is hung from the mounting position, and may have an undesirable dangle length and excessive movement of the gear when not in use. These systems may require further mechanisms to further secure the gear to the person.
A rotating mount, such as a rotating belt clip is desirable from minimizing the dangle length of the retractor and undesirable movement of the gear when not in use. The disadvantage of most belt clip mounting systems is that they are not secure enough for the extreme tactical environment so as not to come dislodged.
Further, any such mount that is semi-permanently affixed, usually takes too much time and effort to install or remove. A disadvantage of current art belt clipping devices is that they restrict the ability for the retracting device to pivot in the direction of cable extension, thereby causing excessive resistance and cable flexing or fatigue which results in reduced overall life of the product.
Belt Clipping, pinning and Bracketing Systems are desirable to reduce the dangle length and gear movement. However, if they are a fixed mount with no rotating feature they will cause excessive line/cable wear and resistance when using the gear away from the body. Furthermore, due to the design of the MOLLE system, most of these mounts if they are easy to install are not secure enough or they are simply too difficult to install.
SUMMARY OF THE INVENTION
The present invention is generally directed to a retractor that is capable of mounting to a user, and has a housing that allows for rotation of the retractor housing about the retractor's attachment mechanism. More particularly the present invention is directed to retractors and vests having the retractors, wherein the retractor can be attached by an attachment mechanism to a web system on the vest. An accessory can be attached to a line within the retractor, and the user can extend the line from the retractor housing when the accessory is in use. When the line is extended from the housing, the retractor housing rotates so it is in alignment with the extended line. This alignment of the housing and line significantly reduces the stresses on the line, which in turn extends the reliability and lifespan of the retractor. Further, the line can be under have a retraction force that retracts the line back into the retractor housing when the extension force is released. The retraction force can be strong enough to prevent the line from extending from under weight of the accessory. The retractor can also minimize the dangle length of the retracting device to the attachment point to minimize movement when not in use.
One embodiment of a retractor according to the present invention comprises a retractor housing an attachment mechanism for attaching to directly to a web strap, wherein the attachment mechanism is coupled to the retractor housing, such that the housing can rotate about the attachment mechanism. A line is included that is capable of being extended and retracted from and back into the retractor housing, and a connector is on the line for connecting to an accessory.
Another embodiment of a retractor according to the present invention comprises a retractor housing and an attachment mechanism for attaching to a web strap. A rotation mechanism is included that cooperates with the housing and attachment mechanism to allow rotation of the housing about the attachment mechanism. A line is included capable of being extended and retracted from and back into the retractor housing.
On embodiment of a vest according to the present invention comprises a web strap system for the mounting of accessories to the vest and a retractor mounted to said web system. The retractor comprises a retractor housing an attachment mechanism for attaching to directly the web strap system and wherein the retractor housing is capable of rotating about the attachment mechanism. A line is included capable of being extended and retracted from and back into the retractor housing, and a connector is on the line for connecting to an accessory.
These and other further features and advantages of the invention would be apparent to those skilled in the art from the following detailed description, taken together with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of one embodiment of a retractable tether according to the present invention, mounted to a web strap;
FIG. 2 is a perspective exploded view of one embodiment of retractable tether according to the present invention;
FIG. 3 is another perspective exploded view of the retractable tether shown in FIG. 2 ;
FIG. 4 is a perspective exploded view of another embodiment of retractable tether according to the present invention; and
FIG. 5 is another perspective exploded view of the retractable tether shown in FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to a rotating retractor that is arranged to be mounted on in many different locations and to many different articles of clothing. In particular, the present invention is adapted for mounting on vests, such as to a web strap provided on MOLLE type vests. In some embodiments, the present invention can be adapted for mounting to PALS webbing that can be found on a different types of vests, including MOLLE vests, but it is understood that the present invention can also be arranged to mount on many other types of mounting systems or webbing.
The retractors according to the present invention can be arranged with an attachment mechanism or connection point to reliably attach to a web strap or webbing system, and to allow for an accessory to be attached to a connector on the retractor. The attachment mechanism holds the retractor to the vest, while at the same time allowing for its quick and easy removal from the vest. The connector on the retractor can also be coupled to a line that can be extended from the retractor housing under a pulling force from, such as from the user. The line can then retract into the retractor housing when the pulling force is removed or released, with the connector preventing the line from fully retracting into the retractor housing. The retractor also comprises a rotation mechanism that allows for the retractor about the connection point. The different retractors can be arranged to rotate with different ranges about the connection point, with some embodiment having ranges up to 180°. Other embodiments can have rotation ranges up to 270°, while others can allow for a full rotation of 360° about the connection point. The rotation of the retractor housing allows for the line of the retractor to align with extended line to reduce stress, wear and tear on the extended line.
The present invention is described herein with reference to certain embodiments, but it is understood that the invention can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is further understood that different embodiments can comprise different materials arranged in different ways, and can comprise different features. Different embodiments can also be arranged for mounting to different types of apparatus beyond vests, and can be arranged to attach to different features of the vests.
It will be understood that when an element is referred to as being “on” or “in contact with” another element, it can be directly on, or in contact with the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly on”, or “directly in contact with” another element, there are no intervening elements present. Although the terms first, second, etc. may be used herein to describe various elements, and/or sections, these elements and/or sections should not be limited by these terms. These terms are only used to distinguish one element, or section from another element, or section. Thus, a first element or section discussed herein could be termed a second element, or section without departing from the teachings of the present invention.
Embodiments of the invention are described herein with reference to perspective view illustrations that are schematic illustrations of an embodiment of the invention. As such, the actual thickness of components can be different, and variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances are expected. Embodiments of the invention should not be construed as limited to the particular shapes as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. A region illustrated or described as square or rectangular will typically have rounded or curved features due to normal manufacturing tolerances. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region of a device and are not intended to limit the scope of the invention.
FIG. 1 shows one embodiment of a rotating retractor 10 according to the present invention, mounted to web strap 12 such as those provided on MOLLE vest system 14 . The retractor 10 provides a coupling mechanism 16 (or connection point) that can be used for connecting to the user, and in the embodiment shown is compatible with the web strap on the vest system 14 , and holds the rotating mechanism securely to the vest system 14 . It is understood that many different coupling mechanisms can be used in different embodiments, with only two of the many different alternatives being described below.
The retractor 10 comprises a rotation mechanism (also described below) that allows the retractor body 18 to rotate about the coupling mechanism 16 as shown by arrows 20 . As mentioned above, the retractor body 18 can rotate about connection point through different rotation ranges, with the embodiment shown having a retractor body 18 that rotates a full 360° about the coupling mechanism 18 .
The retractor 10 can also comprise a connector having an attachment ring 22 for holding an accessory, and a quick release mechanism 24 that securely holds the accessory to the retractor 10 , but can also be operated by the user for disengaging the accessory from the retractor 10 . The retractor 10 can be arranged to hold many different accessories, including but not limited to a flashlight, laser pointer, medic shear, compass, handgun, knife, GPS, FRS radio and other electronic devices. It is understood that these are only some of the many accessories that can be attached to a web strap using the retractors according to the present invention.
FIGS. 2 and 3 show another embodiment of a rotating retractor 30 according to the present invention, comprising a housing 32 and a coupling mechanism 34 . The housing 32 houses the line/tether (“tether”) that protrudes from the housing through opening 36 (also shown in FIG. 1 ). The housing 32 can also include an internal mechanism that biases the tether to retract back into the housing 32 . Many different biasing mechanisms can be used, with some embodiment utilizing a spring. The quick release mechanism 24 (shown in FIG. 1 ) can be attached to the end of the tether to prevent the tether from fully retracting into the housing 32 . The tether can be pulled and extended from the housing 32 by the user against the bias of the internal biasing mechanism, and automatically retracts into the housing 32 when the pulling force is released. Tethers of different length can be used, with one embodiment having a tether that extends approximately 36 inches from the housing 32 . The internal spring can have different levels of retraction force, with one embodiment having a retraction force of approximately 6 ounces. Other embodiments can have a lower retraction force, while still other embodiments can have a greater retraction force, such as 12 or 18 ounces, or more.
The coupling mechanism 34 is designed to cooperate with a web strap to reliably hold the retractor to the web strap. In the embodiment shown, the coupling mechanism comprises first and second strap notches 38 a , 38 b , and first and second strap slots 40 a , 40 b . A web strap can be fed through each of the notches 38 a , 38 b until it is allowed to expand and substantially fill the one of its slots 40 a , 40 b , with the web strap running behind the coupling mechanism 34 . This arrangement securely holds the coupling mechanism 34 to the web strap.
The coupling mechanism is also arranged to allow for rotation of the retractor housing, and different embodiment can have different features to allow for this rotation. Retractor 10 comprises a coupling mechanism 34 having a mushroom shaped post 42 , with larger diameter upper section 44 , and smaller diameter lower section 46 . The present invention also comprises a rotation mechanism 48 that is arranged to cooperate with the coupling mechanism 34 to allow the housing 32 to rotate about the coupling mechanism 34 . The rotation mechanism has a slot 50 with a larger diameter section sizes for the post's larger section 46 to pass, and a smaller section sized for the post's smaller diameter section 48 to fit. During assembly of the retractor 30 , the post's larger section 46 can be inserted through the slot's larger diameter portion, and the rotation mechanism is slid such that the post's smaller section 48 is in the slot's smaller section. This engages the rotation mechanism 48 with the coupling mechanism 34 , with the mounting mechanism 48 rotating about the coupling mechanism 34 on the post 42 .
To hold the post 42 in the desired position in the slot 50 , a holding plug 54 is included that is sized to fit in the cavity 58 of the rotation mechanism 48 . The plug 50 has a post hole 56 sized and positions to hold the posts larger section 46 when the post is in the desired position in the slot 50 . The holding plug 54 can then be bonded or mounted to the rotation mechanism 48 , with the coupling mechanism 34 mounted to the rotation mechanism 48 . The rotation mechanism 48 can then be bonded or mounted to the housing 32 using many different methods or mechanisms. In the embodiment shown, the mounting mechanism 48 is mounted to the housing screws (not shown) that pass through four screw holes 60 .
FIGS. 4 and 5 show still another embodiment of a rotating retractor 70 according to the present invention that is similar to the retracting tether 30 above, and for similar features that same reference numbers will be used. The retractor 70 comprises a housing 32 , rotation mechanism 48 and holding plug 54 . This embodiment, however, comprises a different mounting mechanism in the form of a U-shaped belt clip 72 . The belt clip 72 comprises a post 74 that passes through a belt clip hole 76 to engage and cooperate with the rotation mechanism 48 as described above. The post 74 comprises a larger diameter upper section 77 and lower diameter lower section 78 , and is held in place by the holding plug 54 as described above. The belt clip is designed to hold a web strap, with the end tab 80 helping to retain the web strap.
While different embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art, such as utilizing the present invention for attaching to many different devices and for use with many different accessories. Such variations and alternate embodiments are contemplated, and can be made without departing from the spirit and scope of the invention as described herein.
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Retractors and vests having retractors are disclosed, wherein the retractor can be attached by an attachment mechanism to a web system on the vest. An accessory can be attached to a line within the retractor, and the line can be extended from the retractor housing during accessory use. When the line is extended from the housing, the retractor housing rotates so it aligns with the extended line. This alignment of the housing and line reduces stresses on the line, which extends the reliability and lifespan of the retractor. Further, a retraction force can retract the line back into the retractor housing when the extension force is released. The retraction force can be strong enough to prevent the line from extending from under weight of the accessory. The retractor can also minimize the dangle length of the retracting device to the attachment point to minimize movement when not in use.
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BACKGROUND OF THE INVENTION
1. Technical Field
This invention is related to carrying devices that aid in the physical engagement or lifting and transporting dimensionally large unyieldly objects such as material panels.
2. Description of Prior Art
Prior art devices of this type have been developed to allow for lifting and moving large objects by hand, see for example U.S. Pat. Nos. 4,113,160, 6,102,462, Design Patents D317,703, D423,309.
In U.S. Pat. No. 4,113,160 a sheet sling can be seen having a pair of identical elongated material engagement elements adjustably secured to one another for selective reversal edge engagement of a sheet to be transported.
U.S. Pat. No. 6,102,462 illustrates a mattress and sheet material carrying apparatus having a main strap with a pair of dependent load support strap members extending therefrom allowing two individuals to group oppositely disposed strap ends and lift the material load between them.
U.S. Pat. No. 8,251,421 claims a panel carrier having a flexible shape with an attached rigid handle secured to a contoured U-shaped panel receiving platform.
U.S. Design Patent D317,703 discloses an ornamental design for a drywall carrier having a rigid handle with an eccentric extending shaft and a spade like end defining a material engagement lip there along.
U.S. Design Patent D423,309 claims an ornamental design for a handle for carrying wall board having a flexible cord and attached grip with a material engagement element attached to its oppositely disposed end.
SUMMARY OF THE INVENTION
A handle enabled carrying device having a panel receiving end element and a flexible lifting strap with an adjustable handle thereon. A panel engagement body member has a panel receiving platform with oppositely disposed impact positioning portion and vertically spaced, oppositely disposed extending impact engagement release elements to assist in removing the device from engagement with the panel. A centralized apertured lifting tab is formed in a vertically offset orientation on the body member to accommodate panel positioning and from which the flexible lifting strap extends with the handle which is adjustable on the strap to afford angular inclination lifting capabilities.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the carrier engagement portion of the primary panel carrier of the device.
FIG. 2 is a rear elevational view thereof on lines 3 - 3 of FIG. 1 .
FIG. 3 is a front elevational view of the panel carrier in use engaged for illustration purposes by a user's hand representation.
FIG. 4 is an end elevational view of the primary form of the panel carrier in solid lines with an engaged material sheet positioned within shown in broken lines for illustration.
FIG. 5 is a top elevational view of the primary panel carrier of the invention with the material sheet engaged therein shown in broken cut-away lines.
FIG. 6 is a perspective view of an alternate form of the material carrier of the invention with repositioned spaced strap engagement apertured tabs and a central impact release tab there between.
FIG. 7 is a front elevational view thereof with strap representation shown in broken lines.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 3 of the drawings, a panel carrying device 10 can be seen having a cylindrical handle 11 with a hand engagement central portion 11 A and oppositely disposed open ends 11 B and 11 C.
A flexible strap 12 extends through the handle engagement portion 11 A having oppositely disposed ends 12 A and 12 B secured centrally to a panel engagement lifting bracket 13 of the panel carrying device 10 as will be described in detail hereinafter.
The flexible strap 12 can be of any suitable material configuration that has significant strength to accommodate a wide variety of lifting applications.
The panel carrying device has a primary one piece panel engagement and lift bracket 13 formed of a general angle iron configuration main body member 14 with an elongated material receiving platform portion 15 extending at right angles from a corresponding upstanding portion 16 as best seen in FIGS. 1 and 2 of the drawings.
A pair of spaced oppositely disposed parallel impact release tabs 17 and 18 are formed inwardly from their respective ends of the upstanding portion 16 in opposing orientation to the material receiving platform portion 15 .
The release tabs 17 and 18 are formed by cutting and bending respective end portions towards one another at right angles to form the pair of spaced parallel impact release tabs 17 and 18 . A lifting strap aperture attachment tab 19 is formed in the upstanding portion 16 midway between the hereinbefore described impact release tabs 17 and 18 . The attachment tab 19 is formed by a pair of parallel longitudinally spaced cuts at 20 in a longitudinal edge 21 of the upstanding portion 16 allowing for bending angular deflection thereof to define the tab 19 outwardly in opposed relation to the release tabs 17 and 18 .
An opening at 22 is formed in the attachment tab 19 through which respective ends 12 A and 12 B of the flexible lift strap 12 extend and are secured, in this example, by tying as best seen in FIG. 3 of the drawings. The attachment tab 19 is formed, as noted, by bending a portion of the upstanding body member portion 16 outwardly from its vertical plane towards material receiving platform 15 . It will be evident, therefore, that angular inclination of the attachment tab 19 will effectively adjust to a vertical panel orientation during engagement as seen in FIG. 4 of the drawings that is conducive to lifting a panel P so engaged due to the geometry of the handgrips and its offset point of attachment by the strap 12 .
Referring now to FIGS. 3 and 4 of the drawings, the panel carrying device 10 of the invention can be seen positioned for and in use under the bottom edge of a panel P to be lifted and transported by imparting manual lifting force to the handle 11 shown by force arrows F.
Typically the user (not shown) would use their foot, for example, to engage the impact portion of the upstanding portion 16 for positioning the platform 15 under the panel P. A leading edge 15 A of the platform portion 15 is tapered so as to assist in the insertion under the panel P in this application.
Once engaged, the hereinbefore described flexible strap 12 and the attached handle 11 allows for a secure and proper extended grip for lifting the angled shaped main body member 14 of the panel carrying device 10 and the panel positioned thereon.
Once the panel P is positioned at its destination it can be easily released from the receiving platform 15 by tapping either one or both of the hereinbefore described impact and release tabs 17 and 18 sequentially dislodging the carrying device 10 of the invention out from under the panel P as described.
The preferred embodiment of the panel carrier 10 is constructed preferably of an integral piece of metal such as steel or aluminum for durability and strength given its use requirements and ease of angle and tab formation.
It will be evident, therefore, that given the universal nature of the receiving platform portion 15 , it will be easily adapted to other engaging and lifting venues having engagement surface edges such as appliances, not shown, providing a safe, simple, portable and self-contained material engagement and lifting aid with an adjustable handle configuration to afford an effective grip and maneuvering of large material such as panels and the like.
Referring now to FIGS. 6 and 7 of the drawings, an alternate form of the invention 30 can be seen with a modified lifting bracket body. In this form of the invention a material receiving platform 32 extends at right angle to a corresponding upstanding bracket portion 33 as in the primary form of the invention.
A pair of longitudinally spaced apertured lift attachment tabs 34 are formed by cutting and outwardly bending respective end portions of the upstanding bracket portion 33 . The alternate lift tabs 34 are foreshortened and apertured for receiving the free ends of a corresponding flexible strap and handle assembly representation 36 illustrated by broken lines in FIG. 7 of the drawings.
An alternate tap and release tab 37 is formed centrally in the upstanding bracket portion 33 between and is bent outwardly similar to the lift tabs 34 , but in opposition relation thereto. The tap and release tab 37 is defined by cutting and bending, as in the hereinbefore described lift tabs 34 .
It will be evident that tap release tab 37 performs the function as the hereinbefore described multiple release tabs 17 and 18 in the primary form of the invention allowing the user, not shown, to physically tap or impact there against to unseat the receiving platform 32 from engagement under the lifting material after lifting, positioning and transporting has occurred.
The advantages of the alternate material carrier of the invention as described are that of the lift tabs 34 being spaced in relation to one another on the lifting bracket body member 31 by providing two independent spaced stabilizing attachment points for the flexible strap ends and handle assembly 36 .
Such an orientation may be of increased value when engaging a variety of material to lift, but not limited only to sheet material, but other bulky items, as hereinbefore noted.
It will thus be seen that a unique and novel panel carrying device has been illustrated and described and it will be evident to those skilled in the art that various changes and modifications may be made thereto without departing from the spirit of the invention.
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A carrying device for large panels, such as drywall, plywood and the like. The carrying device includes a rigid one-piece panel receiving bracket with a dual flexible strap and adjustable handle extending therefrom. The panel is received on a platform portion of the bracket which has multiple impact surfaces for positioning, engaging and releasing the bracket from the panel so positioned thereon and a panel positioning strap handle attachment extending therefrom.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an adsorbing capacity determining system in an exhaust emission control unit for an internal combustion engine in which an unburned component adsorbing means is provided for temporarily adsorbing an unburned component in the exhaust gas from the engine.
2. Description of the Prior Art
An exhaust emission control unit is conventionally known, for example, as in Japanese Utility Model Application Laid-open No. 105925/92. The exhaust emission control unit includes an unburned component adsorbing means provided in an exhaust system for temporarily adsorbing an unburned component in the exhaust gas in order to prevent the unburned component from being released to the atmosphere when an exhaust emission control catalyst is inactivated during a cold start of an internal combustion engine or at other times.
The unburned component adsorbing means is constructed using granular activated carbon or zeolite and adsorbs an unburned component of the exhaust gas comprising hydrocarbon(s). When the capacity for adsorbing the unburned component is reduced due to a secular change or the like, there is a possibility that the unburned component is directly released into the atmosphere without adsorption.
SUMMARY OF THE INVENTION
The present invention has been accomplished with such circumstance in view, and it is an object of the present invention to provide a capacity determining system in an exhaust emission control unit for an internal combustion engine, wherein the adsorbing capacity of the unburned component adsorbing means can be easily and reliably determined to prevent the unburned component from being released to the atmosphere.
To achieve the above object, the present invention provides a capacity determining system in an exhaust emission control unit for an internal combustion engine. An unburned component adsorbing means is provided in an exhaust system in the internal combustion engine for temporarily adsorbing an unburned component in the exhaust gas. The capacity determining system comprising: upstream and downstream air-fuel ratio detecting means connected respectively upstream and downstream of the unburned component adsorbing means, for detecting air-fuel ratios in the exhaust gas at locations upstream and downstream of the unburned component adsorbing means; an unburned component adsorbing state detecting means for detecting a state in which the unburned component adsorbing means is in an adsorbing state for adsorbing the unburned component or in a adsorbing state for adsorbing the unburned component; and a determining means for determining the adsorbing capacity of the unburned component adsorbing means on the basis of values detected by the upstream and downstream air-fuel ratio detecting means when the unburned component adsorbing state detecting means has detected that the unburned component adsorbing means is in an adsorbing state or in a desorbing state.
With the above arrangement, it is possible to reliably determine or judge the adsorbing capacity or ability of the unburned component adsorbing means. Thus, it is possible to prevent the unburned component from being released to the atmosphere by replacing the adsorbent with a new adsorbent upon determining that the adsorbing capacity has deteriorated.
The above and other objects, features and advantages of the invention will become apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of intake and exhaust systems in an internal combustion engine; and
FIG. 2 is a flow chart illustrating a method for determining the adsorbing capacity at the adsorbing means in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention will now be described by way of a preferred embodiment with reference to the accompanying drawings.
Referring first to FIG. 1, an intake system 5 includes an air cleaner 2, a throttle valve 3 and a fuel injection valve 4. The intake system is connected to an intake port 1 in an internal combustion engine E. An unburned component adsorbing means 8 for temporarily adsorbing an unburned component in the exhaust gas, and an exhaust emission control catalytic converter 9 are incorporated into an exhaust system 7 connected to an exhaust port 6 in the internal combustion engine E. The unburned component adsorbing means 8 includes an adsorbent 10 such as granular activated carbon and zeolite within a casing, and the exhaust emission control catalytic converter 9 includes a ternary catalyst 11 within a casing.
In the exhaust system 7, an upstream air-fuel ratio detecting means 12 for detecting an air-fuel ratio (A/F) U in exhaust gas, is positioned upstream of the unburned component adsorbing means 8, and a downstream air-fuel ratio detecting means 13 is positioned between the unburned component adsorbing means 8 and the exhaust emission control catalytic converter 9, for detecting an air-fuel ratio (A/F) D .
The unburned component adsorbing means 8 is provided with a temperature detector 14 which functions as an unburned component adsorbing state detecting means for detecting if the unburned component adsorbing means 8 is in a desorbing state to desorb the unburned component. The adsorbent 10 in the unburned component adsorbing means 8 has a characteristic such that the unburned component (hydrocarbon) discharged into the exhaust system 7 is adsorbed during the cold start of the internal combustion engine E; the desorption of the unburned component is started when the temperature of the adsorbent 10 reaches a given desorption-starting temperature T 1 , and the desorption of the unburned component is substantially completed when the temperature of the adsorbent 10 reaches a given desorption-end temperature T 2 . Thus, a condition in which the temperature T detected by the temperature detector 14 is in a range of T 1 <T<T 2 indicates when the unburned component adsorbing means 8 is in the desorbing state.
Detection values detected by the upstream air-fuel ratio detecting means 12, the downstream air-fuel detecting means 13 and the temperature detector 14 are provided to a determining means 15 which comprises a computer. The determining means 15 judges or determines the adsorbing ability or capacity of the unburned component adsorbing means 8 on the basis of detection values detected by the upstream and downstream air-fuel ratio detecting means 12 and 13 when the temperature detector 14 determines that the unburned component adsorbing means 8 is in the desorbing state. In order to determine conditions for determining adsorbing capacity, the following detectors are connected to the determining means 15: an intake pressure detector 16 for detecting an intake pressure P B at a location downstream from the throttle valve 3; a water-temperature detector 17 for detecting a temperature of cooling water in the internal combustion engine E; and a revolution-number or engine speed detector 18 for detecting a number N E of revolutions per minute of the internal combustion engine E.
The determining means 15 determines the capacity according to the method shown in FIG. 2. The capacity determination is carried out, for example, at continuous predetermined time intervals after the start of the engine. At Step S1 in FIG. 2, it is determined whether or not all the following conditions (1) to (4) exist in order to decide whether to carry out the capacity determination:
T.sub.W <T.sub.WO (1)
N.sub.EL <N.sub.E <N.sub.EH (2)
P.sub.B <P.sub.BO (3)
T>T.sub.1 (4)
wherein T WO is a preset water temperature; N EL is a preset low number of revolutions per minute; N EH is a preset high number of revolutions per minute; and P BO is a preset intake pressure.
If it is decided at Step S1 that the conditions for carrying out the capacity determination are not established, various parameters, i.e., T WO , N E , P B and T, are reset at Step S2. If it is decided at Step S1 that the conditions have been established, the processing is advanced from Step S1 to Step S3 where it is determined whether or not T<T 2 is established. In other words, it is determined at Step S1 and Step S3 whether or not T 1 <T<T 2 , i.e., whether or not the unburned component adsorbing means 8 is in a desorbing state. If T<T 2 , the processing is advanced to Step S4.
At Step S4, an amount Q grams/sec (g/sec) of air drawn into the internal combustion engine E and the air-fuel ratios (A/F) U and (A/F) D at upstream and downstream sides of the unburned component adsorbing means 8 are provided. The amount Q (g/sec) of air drawn may be read from a map previously established in accordance with the number N E of revolutions per minute of the engine and the intake pressure P B , or may be detected by an air flow meter previously placed in the internal combustion engine E.
At Step S5, a desorption amount ΔD at every time interval Δt in execution of the processing shown in FIG. 2, is calculated according to a following expression (5):
ΔD=Q×[{1/(A/F).sub.U }-{1/(A/F).sub.D }]×Δt(5)
At Step S6, a value ΣD of the addition of the desorption amounts is calculated. More specifically, at Step S6, a total desorption amount ΣD is calculated for the period when T 1 <T<T 2 and the unburned component adsorbing means 8 is in the desorbing state.
When T≧T 2 after passage of the desorbing state, the processing is advanced from Step S3 to Step S7. When the total desorption amount ΣD exceeds a predetermined reference value at Step S7, it is decided at Step S8 that the adsorbing capacity of the unburned component adsorbing means 8 is normal. On the other hand, when the total desorption amount ΣD is equal to or less than the predetermined reference value, it is decided at Step S9 that the adsorbing capacity of the unburned component adsorbing means 8 has deteriorated.
The operation of this embodiment will be described below. When the temperature of the catalyst 11 in the exhaust emission control catalytic converter 9 does not reach an activating temperature as in a cold start of the internal combustion engine E, the unburned component in exhaust gas is adsorbed into the adsorbent 10 in the unburned component adsorbing means 8 and thus prevented from being released to the atmosphere. If the temperature of the adsorbent 10 in the unburned component adsorbing means 8 reaches the desorption starting temperature T 1 due to a rise in temperature of exhaust gas as a result of continuation of the operation of the internal combustion engine E, the desorption of the adsorbed unburned component from the adsorbent 10 is started. However, the temperature of the catalyst 11 has also risen and hence, the desorbed unburned component is converted in the exhaust emission control catalytic converter 9.
The determining means 15 ensures that in a condition in which it can be decided, on the basis of the detection value detected by the temperature detector 14, that the unburned component adsorbing means 8 is in the desorbing state to desorb the unburned component, the total desorption amount ΣD is calculated from the detection values of the air-fuel ratios (A/F) U and (A/F) D in the exhaust gas at the upstream and downstream sides of the unburned component adsorbing means 8. When the total desorption amount ΣD is equal to or less than the reference value, it is determined that the adsorbing capacity of the unburned component adsorbing means 8 has deteriorated. Thus, it is possible to reliably and easily determine the adsorbing capacity during operation of the internal combustion engine E. When it is determined that the adsorbing capacity has deteriorated, the replacement of the adsorbent 10 is indicated by an alarm means such as an alarm lamp, whereby the adsorbent can be replaced by new adsorbent to prevent the release of the unburned component to the atmosphere.
In the above-described embodiment, the upstream air-fuel ratio detecting means 12 for detecting the air-fuel ratio (A/F) U in the exhaust gas at the location upstream of the unburned component adsorbing means 8 is provided in the exhaust system 7. When a feedback control for controlling the air-fuel ratio in the exhaust to a given value in the desorbing state is carried out, the upstream air-fuel ratio detecting means 12 may be omitted, and the air-fuel ratio (A/F) U at the upstream side may be determined at a given value. In place of provision of the temperature detector 14 as the unburned component adsorbing state detecting means on the unburned component adsorbing means 8, the temperature may be estimated from a value of addition of the amounts of fuel injected by the fuel injection valve 4. Further, in place of determining of the adsorbing capacity of the unburned component adsorbing means 8 when in the desorbing state, an adsorption amount in the adsorbing state up to a time point when the temperature T reaches the desorption starting temperature T 1 , may be calculated to determine the adsorbing capacity.
The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are, therefore, to be embraced therein.
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An adsorbing capacity determining apparatus is provided for determining the adsorbing capacity of an unburned component adsorbing device in an exhaust system for an internal combustion engine. The adsorbing capacity determining apparatus comprises upstream and downstream air-fuel ratio detectors, respectively coupled upstream and downstream from the unburned component adsorbing device, a temperature sensor for sensing the temperature of the unburned component adsorbing means and a computer for determining the adsorption capacity as a function of the outputs of the system and downstream air-fuel ratio detectors, when the temperature is within a predetermined range.
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This application is a continuation of application Ser. No. 08/098,206, filed Jul. 28, 1993, abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to radiodiagnostic agents and reagents for preparing such agents, and also methods for producing radiolabeled radiodiagnostic agents. Specifically, the invention relates to technetium-99m ( 99m Tc) labeled agents, methods and kits for making the agents, and methods for using the agents to image pathological sites, including sites of infection, inflammation, cancer and atherosclerosis in a mammalian body. Specifically the agents and reagents are derivatives of oligosaccharides, more specifically β-glucans.
2. Description of the Prior Art
In the field of nuclear medicine, certain pathological conditions can be localized or the extent of such conditions determined by imaging the internal distribution of administered radioactively-labeled tracer compounds (i.e. radiotracers or radiopharmaceuticals) that accumulate specifically at the pathological site. This type of procedure is commonly known as radioimaging or scintigraphic imaging. Radioimaging has particular advantages over other methods of diagnosis in that it is essentially non-invasive, highly sensitive, highly specific, can be used to scan the entire body and is relatively cost-effective. A variety of radionuclides are known to be useful for radioimaging, including 67 Ga, 68 Ga, 99m Tc, 111 In, 123 I, 125 I or 201 Tl.
There is a clinical need to be able to determine the location and/or extent of sites of focal or localized infection. In a substantial number of cases conventional methods of diagnosis (such as physical examination, x-ray, CT and ultrasonography) fail to identify such sites (e.g., an abscess). In some cases, biopsy may be resorted to, but is preferably avoided at least until it is necessary in order to identify the pathogen responsible for an abscess at a known location. Identifying the site of such "occult" infection is important because rapid localization of the problem is critical to effective therapeutic intervention.
An abscess may be caused by any one of many possible pathogens, so that a radiotracer specific for a particular pathogen would have limited scope. On the other hand, infection is almost invariably accompanied by inflammation, which is a general response of the body to tissue injury. Therefore, a radiotracer specific for sites of inflammation would be expected to be useful in localizing sites of infection caused by any pathogen.
One of the main phenomena associated with inflammation is the localization of leukocytes (white blood cells), including macrophages, monocytes and neutrophils, at the site of inflammation. A radiotracer specific for leukocytes would be useful in detecting leukocytes at the site of a localized infection.
Currently approved nuclear medicine procedures for imaging sites of infection use either indium-111 labeled leukocytes ( 111 In-WBC) (see, e.g. Peters, 1992, J. Nucl. Med. 33: 65-67) or gallium-67 ( 67 Ga) citrate (see, e.g. Ebright et al., 1982, Arch. Int. Med. 142: 246-254).
A major disadvantage of using 111 In-labeled WBCs is that the preparation of the radiotracer requires sterile removal of autologous blood, sterile isolation of the leukocytes from the blood, sterile labeling of the leukocytes using conditions that do not damage the cells (since damaged WBC are taken up by the reticuloendothelial system when re-injected) and return (re-injection) of the (now labeled) leukocytes to the patient. Furthermore, a delay of 12 to 48 hours between injection and imaging may be required for optimal images. While 99m Tc labeled leukocytes have been used to shorten this delay period (see, e.g. Vorne et al., 1989, J. Nucl. Med. 30: 1332-1336), ex-corporeal labeling is still required. A preferred radiotracer would be one that does not require removal and manipulation of autologous blood components.
67 Ga-citrate can be administered by intravenous injection. However, this compound is not specific for sites of infection or inflammation. Moreover, a delay of up to 72 hours is often required between injection of the radiotracer and imaging. In addition, the γ-(gamma) emission energies of 67 Ga are not well suited to conventional gamma cameras.
Radiolabeled monoclonal and polyclonal antibodies raised against human leukocytes (including monocytes, neutrophils, granulocytes and others) have been developed. 99m Tc labeled antigranulocyte monoclonal antibodies (see, e.g. Lind et al., 1990, J. Nucl. Med. 31: 417-473) and 111 In-labeled non-specific human immunoglobulin (see, e.g. LaMuraglia et al., 1989, J. Vasc. Surg. 10: 20-28) have been tested for the detection of inflammation secondary to infection. 111 In-labeled IgG shares the disadvantages of 111 In-labeled WBC, in that 24-48 hours are required between injection and optimal imaging. In addition, antibodies are difficult to produce and are associated with safety concerns regarding potential contamination with biological pathogens (e.g. retroviruses).
In addition, the effective treatment of cancer by surgery or radiation therapy requires knowledge of the localization and extent of the disease. A means of monitoring the progression/regression of tumors following or during any form of therapy is also highly desirable. Advances in high-resolution imaging modalities such as CT and MRI allow the detection of many neoplasms. However certain tumors and their metastases are small and difficult to localize by these methods. Nuclear medicine offers a potentially more sensitive alternative. A radiotracer that selectively binds to or localizes to any and all cancerous tissue, sufficiently to allow easy external detection, might be considered to be the ultimate goal of radiodiagnostic oncology.
Also, despite remarkable advances in cardiology, coronary artery disease remains the leading cause of death in the U.S. The final event in this disease is usually fatal myocardial infarction caused by occlusive thrombosis of one or more coronary arteries usually at the site of a complicated atherosclerotic plaque. Therefore a means, preferably non-invasive, of determining the localization and/or extent of atherosclerotic plaque is highly desirable as an aid to selecting appropriate patient management. One of the most notable characteristics of atherosclerotic plaque is the accumulation of foam cells which are lipid-laden macrophages.
β-Glucans are oligoglucosides, which comprise 1,3 and 1,6 linked β-D-glucose residues, originally discovered as components of yeast and fungal cell walls (Bartnicki-Garcia in Ann Rev Microbiol. 1968, 22, 87). Originally obtained in an insoluble form, β-glucans have since been obtained as soluble, low molecular weight oligomers (Janusz, Austen and Czop, J. Immunol. (1989), 142, (959-965). They have been shown to be active in enhancing the host defense mechanisms of mammals by activating the alternative complement pathway through their specific binding to receptors (called β-glucan receptors) found on the cell-surfaces of monocytes, macrophages and neutrophils (Czop and Kay, J. Exp. Med. (1991), 173, 1511-1520, Czop et al, Biochemistry of the Acute Allergic Reactions: Fifth International Symposium. (1989), 287-296 and J. K. Czop, Pathol. Immunopathol. Res (1986), 5, 286-296, Czop and Austen, J. Immunol. (1985), 134, 2588-2593). The in vivo administration of particulate β-glucans has been shown to provide protection from many pathogens including bacteria, viruses and fungi as well as reducing tumor growth (Czop et al, Biochemistry of the Acute Allergic Reactions: Fifth International Symposium. 1989, 287-296). The smallest active β-glucan reported so far is a heptaglucoside (Janusz et al, J Immunol 1989, 142, 959. Onderdonk and co-workers (Infection and Immunity, 1992, 60, 1642-1647) describe the antiinfective properties of this small β-glucan. The β-glucans have also been shown to exhibit an anti-tumor growth effect, believed to occur by increasing the number of macrophages localizing to tumors (Di Luzio in Pathophysiology of the Reticuloendothelial System (Eds Altruo and Saba), Raven Press, NY, pp209-224).
Czop and Janusz, U.S. Pat. No. 5,057,503 (1991), claim a heptaglucoside capable of reacting with β-glucan receptors, their isolation and their therapeutic use.
Jamas et al, PCT/US90/03440 claim β-glucans as drug delivery vehicles and as adjuvants.
Jamas et al, PCT/US90/05022 claim a method of activating the immune system by administering β-glucans.
Jamas et al, PCT/US90/05041 claim a method of producing a soluble β-glucan.
Methods for preparing radiolabel-binding moieties and of labeling them with 99m Tc are disclosed in co-pending U.S. patent applications Ser. No. 07/653,012, now abandoned, which issued as U.S. Pat. No. 5,654,272; Ser. No. 07/757,470, now U.S. Pat. No. 5,225,180; Ser. No. 07/807,062, now U.S. Pat. No. 5,443,815; Ser. No. 07/851,074, now abandoned, which issued as U.S. Pat. No. 5,711,931; Ser. No. 07/871,282, a divisional of which issued as U.S. Pat. No. 5,720,934; Ser. No. 07/886,752, now abandoned, a continuation of which has been allowed as U.S. Ser. Nos. 08/273,274; 07/893,981, now U.S. Pat. No. 5,508,020; Ser. Nos. 07/955,466; 07/977,628, now U.S. Pat. No. 5,405,597; Ser. No. 08/019,525, now U.S. Pat. No. 5,552,525; Ser. No. 08/044,825, now abandoned, which issued as U.S. Pat. No. 5645,815; and Ser. No. 08/073,577, now U.S. Pat. No. 5,561,220; and PCT International Applications PCT/US92/00757, PCT/US92/10716, PCT/US93/02320, PCT/US93/03687, PCT/US93/04794, and PCT/US93/06029, which are hereby incorporated by reference.
SUMMARY OF THE INVENTION
The present invention provides scintigraphic imaging agents that are β-glucans which are radiolabeled with a radioisotope or are β-glucan-derived reagents radioactively-labeled with a radioisotope. The β-glucan-derived reagents of the invention are comprised of a β-glucan covalently linked to a radiolabel binding moiety. The scintigraphic imaging agents of this invention are useful for imaging pathological sites within a mammalian body including sites of infection, inflammation, cancer and atherosclerosis.
A first aspect of the invention comprises reagents for preparing scintigraphic imaging agents for imaging sites within a mammalian body, said reagents comprising a β-glucan having a 1,3 and 1,6 linked D-glucoside sequence, of molecular weight of up to about 2,000 kDa and a radiolabel-binding moiety.
In a second aspect, the scintigraphic imaging agent of the invention comprises a soluble β-glucan.
In a third aspect, the scintigraphic imaging agent of the invention comprises the radioisotope 99m Tc.
In another aspect of the invention the radiolabel-binding moiety is linked to the β-glucan via a 1-amino or 1-thio substituent.
In yet another aspect, the reagents of the invention comprise a β-glucan and a radiolabel-binding moiety of formula
Cp(aa)Cp I.
wherein Cp is a protected cysteine residue and (aa) stands for an amino acid, and wherein the radiolabel-binding moiety is covalently linked to the β-glucan. In a preferred embodiment, the amino acid is glycine. In another preferred embodiment, the radiolabel-binding moiety is linked to the β-glucan via a linker which forms either an ether, thioether or amine bond to the β-glucan.
In another aspect, the invention provides reagents comprising a radiolabel-binding moiety having the following structure: radioisotope complexing group comprising a single thiol moiety having the following structure
A--CZ (B)-- C(R.sup.1 R.sup.2)!.sub.n --X II.
wherein A is H, HOOC, H 2 NOC, (β-glucan)-(linker)-NHOC, (β-glucan)-(linker)-OOC or R 4 ; B is H, SH or --NHR 3 , --N(R 3 )-(linker)-(β-glucan) or R 4 ; X is SH or --NHR 3 , --N(R 3 )-(linker)-(β-glucan) or R 4 ; R 1 , R 2 , R 3 and R 4 are independently H or straight or branched chain or cyclic lower alkyl; n is 0, 1 or 2; and: (1) where B is --NHR 3 or --N(R 3 )-- (linker)-(β-glucan), X is SH and n is 1 or 2; (2) where X is --NHR 3 or --N(R 3 )-(linker)-(β-glucan), B is SH and n is 1 or 2; (3) where B is H or R 4 , A is HOOC, H 2 NOC, (β-glucan)-(linker)-NHOC or (β-glucan)-(linker)-OOC, X is SH and n is 0 or 1; (4) where A is H or R 4 , then where B is SH, X is --NHR 3 or --N(R 3 )-(linker)-(β-glucan) and where X is SH, B is --NHR 3 or --N(R 3 )-(linker)-(β-glucan); (5) where X is H or R 4 , A is HOOC, H 2 NOC, (β-glucan)-(linker)-NHOC or (β-glucan)-(linker)-OOC and B is SH; (6) where Z is methyl, X is methyl, A is HOOC, H 2 NOC, (β-glucan)-(linker)-NHOC or (β-glucan)-(linker)-OOC and B is SH and n is 0; and wherein the thiol moiety is in the reduced form.
In yet another aspect, the present invention provides reagents comprising β-glucans covalently linked to a radiolabel-binding moiety having the following structure: ##STR1## For purposes of this invention, radiolabel-binding moieties having structure III will be referred to as picolinic acid (Pic)-based moieties;
or ##STR2## For purposes of this invention, radiolabel-binding moieties having structure IV will be referred to as picolylamine (Pica)-based moieties; wherein X is H or a protecting group; (amino acid) is any amino acid. In a preferred embodiment, the amino acid is glycine and X is an acetamidomethyl protecting group.
In yet another embodiment of the invention, reagents are provided for preparing scintigraphic imaging agents for imaging sites within a mammalian body, comprising a β-glucan and a bisamino bisthiol radiolabel-binding moiety covalently linked to the β-glucan. The bisamino bisthiol radiolabel-binding moiety in this embodiment of the invention has a formula selected from the group consisting of: ##STR3## wherein each R 5 can be independently H, CH 3 or C 2 H 5 ; each (pgp) S can be independently a thiol protecting group or H; m, n and p are independently 2 or 3; A is linear or cyclic lower alkyl, aryl, heterocyclyl, combinations or substituted derivatives thereof; and X is (linker)-β-glucan; ##STR4## wherein each R 5 is independently H, lower alkyl having 1 to 6 carbon atoms, phenyl, or phenyl substituted with lower alkyl or lower alkoxy; m, n and p are independently 1 or 2; A is linear or cyclic lower alkyl, aryl, heterocyclyl, combinations or substituted derivatives thereof; V is H or --CO-(linker)-β-glucan; R 6 is H or a (linker)-β-glucan; provided that when V is H, R 6 is a (linker)-β-glucan and when R 6 is H, V is a --CO-(linker)-β-glucan. For purposes of this invention, radiolabel-binding moieties having these structures will be referred to as "BAT" moieties.
The invention comprises scintigraphic imaging agents that are complexes between β-glucans or the reagents of the invention and 99m Tc, and methods for radiolabeling the β-glucans and reagents of the invention with 99m Tc. Radiolabeled complexes provided by the invention may be formed by reacting β-glucans or the reagents of the invention with 99m Tc in the presence of a reducing agent. Preferred reducing agents include but are not limited to dithionite ion, stannous ion and ferrous ion. Complexes of the invention are also formed by labeling β-glucans or the reagents of the invention with 99m Tc by ligand exchange of a prereduced 99m Tc complex as provided herein.
The invention also provides kits for preparing scintigraphic imaging agents that are β-glucans or the reagents of the invention radiolabeled with 99m Tc. Kits for labeling the β-glucans or the reagents provided by the invention with 99m Tc are comprised of a sealed vial containing a predetermined quantity of a β-glucan or a reagent of the invention and a sufficient amount of reducing agent to label the β-glucan or reagent with 99m Tc.
This invention provides methods for using scintigraphic imaging agents that are radiolabeled β-glucans and reagents for imaging pathological sites, including infection, inflammation, cancer and atherosclerosis within a mammalian body by obtaining in vivo gamma scintigraphic images. These methods comprise administering an effective diagnostic amount of radiolabeled β-glucan or reagent of the invention and detecting the gamma radiation emitted by the radiolabel localized at the pathological site within the mammalian body.
Specific preferred embodiments of the present invention will become evident from the following more detailed description of certain preferred embodiments and the claims.
DETAILED DESCRIPTION OF THE INVENTION
The β-glucans of this invention have linear or branched 1,3 and 1,6 linked D-glucoside sequences. They comprise both insoluble and soluble molecular entities having molecular weights of up to about 2,000 kDa. In a preferred embodiment, the β-glucan is soluble. Most preferably the soluble β-glucan is a poly-β1-6-glucotriosyl-β1-3-glucopyranose.
In Cp(aa)Cp-containing β-glucan reagents, the Cp is a protected cysteine where the S-protecting groups are the same or different and may be but are not limited to:
--CH 2 -aryl (aryl is phenyl or alkyl or alkyloxy substituted phenyl);
--CH-(aryl) 2 , (aryl is phenyl or alkyl or alkyloxy substituted phenyl);
--C-(aryl) 3 , (aryl is phenyl or alkyl or alkyloxy substituted phenyl);
--CH 2 -(4-methoxyphenyl);
--CH-(4-pyridyl)(phenyl) 2 ;
--C(CH 3 ) 3 ;
--9-phenylfluorenyl;
--CH 2 NHCOR (R is unsubstituted or substituted alkyl or aryl);
--CH 2 --NHCOOR (R is unsubstituted or substituted alkyl or aryl);
--CONHR (R is unsubstituted or substituted alkyl or aryl);
--CH 2 --S--CH 2 -phenyl
The preferred protecting group has the formula --CH 2 --NHCOR wherein R is a lower alkyl having 1 and 8 carbon atoms, phenyl or phenyl-substituted with lower alkyl, hydroxyl, lower alkoxy, carboxy, or lower alkoxycarbonyl.
β-Glucans of the present invention can be obtained from natural sources, such as yeast, by methods well known in the art (e.g. see Manners, Masson and Patterson in J. Gen. Microbiol. (1974), 80, 411-417). Small soluble β-glucans can be obtained from larger β-glucans by methods known in the art (e.g. as described by Janusz, Austen and Czop in J. Immunol. (1989),142, 959-965 and Jamas et al, PCT/US90/05041) or can be obtained by chemical synthesis. Preferred soluble β-glucans are poly-β1-6-glucotriosyl-β1-3-glucopyranoses including those that are heptaglucosides.
The term soluble β-glucan is used herein to mean soluble in a physiologically compatible solution to about 10 mg/mL.
The reagents of this invention comprise a β-glucan covalently attached to a radiolabel-binding moiety. The radiolabel binding moiety can be attached directly to the β-glucan or it can be attached via a linker. The direct attachment of the radiolabel-binding moiety may be advantageously made by a 1-thioether or 1-amino group, or via an ester or ether bond to any hydroxyl group of the β-glucan (see for example, Her, Santikarn and Reinhold, J. Carbohydrate Chemistry (1987), 6, 129-139 and Bogwald, Seljelid and Hoffman, Carbohydrate research (1986), 148, 101-107). The linker is normally a small entity, of less than about 500 Da formula weight and may advantageously be a small (up to about 10 carbon atoms) linear or branched chain divalent alkyl, alkaryl or aryl group, optionally comprising a multiplicity of hetero atoms, preferably oxygens, and optionally substituted, preferably with hydrophilic moieties.
In forming a complex of radioactive technetium with the β-glucans and the reagents of this invention, the technetium complex, preferably a salt of 99m Tc pertechnetate, is reacted with the β-glucan or reagent in the presence of a reducing agent. Preferred reducing agents are dithionite, stannous and ferrous ions; the most preferred reducing agent is stannous chloride. Means for preparing such complexes are conveniently provided in a kit form comprising a sealed vial containing a predetermined quantity of a β-glucan or reagent of the invention to be labeled and a sufficient amount of reducing agent to label the reagent with 99m Tc. Alternatively, the complex may be formed by reacting a β-glucan or reagent of this invention with a pre-formed labile complex of technetium and another compound known as a transfer ligand. This process is known as ligand exchange and is well known to those skilled in the art. The labile complex may be formed using such transfer ligands as tartrate, citrate, gluconate or mannitol, for example. Among the 99m Tc pertechnetate salts useful with the present invention are included the alkali metal salts such as the sodium salt, or ammonium salts or lower alkyl ammonium salts.
The reaction of β-glucans and reagents of this invention with Tc-pertechnetate or preformed 99m Tc labile complex can be carried out in an aqueous medium at room temperature or with heating for a short period (from 5 to about 60 minutes). When an anionic complex having a charge of -1! is formed in the aqueous medium in the form of a salt with a suitable cation such as sodium cation, ammonium cation, mono, di- or tri-lower alkyl amine cation, etc. Any conventional salt of the anionic complex with a pharmaceutically acceptable cation can be used in accordance with this invention.
In a preferred embodiment of the invention, a kit for preparing 99m Tc-labeled β-glucans and β-glucan reagents is provided. An appropriate amount of the β-glucan or reagent is introduced into a vial containing a reducing agent, such as stannous chloride, in an amount sufficient to label the β-glucan or reagent with 99m Tc. An appropriate amount of a transfer ligand as described (such as tartrate, citrate, gluconate or mannitol, for example) can also be included. In forming the 99m Tc complexes, it is generally preferred to form radioactive complexes in solutions containing radioactivity at concentrations of from about 0.01 millicurie (mCi) to 100 mCi per ml.
Scintigraphic imaging agents of this invention can also be prepared by incubating radiolabeled β-glucans or radiolabeled β-glucan reagents with leukocytes, wherein the leukocytes take up the radiolabeled species and can then be administered as radiolabeled leukocytes.
The radiolabeled scintigraphic imaging agents provided by the present invention can be used for visualizing pathological sites including sites of inflammation and infection, including abscesses and sites of "occult" infection and inflammatory bowel disease. The imaging agents provided can also be used to image sites of atherosclerotic plaque and also tumors. In accordance with this invention, the scintigraphic imaging agents are administered in a single unit injectable dose. Any of the common carriers known to those with skill in the art, such as sterile saline solution or plasma, can be utilized after radiolabeling for preparing the injectable solution to diagnostically image various organs, tumors and the like in accordance with this invention. Generally, the unit dose to be administered has a radioactivity of about 0.01 mCi to about 100 mCi, preferably 1 mCi to 20 mCi. The solution to be injected at unit dosage is from about 0.01 ml to about 10 ml. After intravenous administration, imaging of the organ or tumor in vivo can take place in a matter of a few minutes. However, imaging can take place, if desired, in hours or even longer, after injecting into patients. In most instances, a sufficient amount of the administered dose will accumulate in the area to be imaged within about 0.1 of an hour to permit the taking of scintiphotos. Any conventional method of scintigraphic imaging for diagnostic purposes can be utilized in accordance with this invention.
The scintigraphic imaging agents provided by the invention may be administered intravenously in any conventional medium for intravenous injection such as an aqueous saline medium, or in blood plasma medium. Such medium may also contain conventional pharmaceutical adjunct materials such as, for example, pharmaceutically acceptable salts to adjust the osmotic pressure, buffers, preservatives and the like. Among the preferred media are normal saline and plasma.
The methods for making and labeling these compounds are more fully illustrated in the following Examples. These Examples illustrate certain aspects of the above-described method and advantageous results. These Examples are shown by way of illustration and not by way of limitation.
EXAMPLE 1
Reagent Synthesis
DMSO=dimethyl sulfoxide, DMF=N,N-dimethylformamide and DIEA=N,N-diisopropylethylamine.
Poly-β1-6-glucotriosyl-P1-3-glucopyranose (PGG) is obtained using the procedures described by Jamas et al (PCT/US90/05041).
N-α-Boc-lysyl-glycyl-(S-trityl)cysteine amide, glycyl-glycyl-(S-trityl)cysteine amide and chloroacetyl-(S,S'-bis-acetamidomethyl)cysteinyl-glycyl-cysteine amide are prepared by solid phase or solution phase peptide synthesis and are purified by reverse phase HPLC.
A conjugate with N 1 ,N 4 -bis(2-mercapto-2-methylpropyl)-1,4,10-triazadecane is obtained by reacting a β-glucan (e.g., PGG) at from about 1 to 100 mg/mL with about 1.5 mmol N 1 -(t-butoxycarbonyl)-N 1 ,N 4 -bis(2-methyl-2-triphenylmethylthiopropyl)-1,4,10-triazadecane in water, Cellosolve or mixtures thereof at approximately pH 7 at about 65° C. for from 1 to about 10 hours, followed by reduction with NaBH 3 CN followed by deprotection with trifluoroacetic acid. The product is purified by preparative HPLC.
Similarly conjugates of α-(lysyl-glycyl-cysteine amide) and glycyl-glycyl-cysteine amide are prepared from N-α-Boc-lysyl-glycyl-(S-trityl)cysteine amide and glycyl-glycyl-(S-trityl)cysteine amide respectively.
A conjugate of N 6 ,N 9 -bis(2-mercapto-2-methylpropyl)-6,9-diazanonanoic acid is prepared by reacting β-glucan (e.g. PGG) at from about 1 to 100 mg/mL in water, DMSO or DMF containing about 1.5 mmol DIEA and optionally containing about 0.15 mmol 4-dimethylaminopyridine, with about 1.5 mmol of the N-hydroxysuccinimide ester of N 9 -(t-butoxycarbonyl)--N 6 ,N 9 -bis(2-methyl-2-triphenylmethylthiopropyl)-6,9-diazanonanoic acid, at room temperature, followed by deprotection with TFA and purification by HPLC.
A conjugate of (S,S'-bis-acetamidomethyl)cysteinyl-glycyl-cysteine amide is prepared by reacting β-glucan (e.g. PGG) at from about 1 to 100 mg/mL in DMSO, with sodium methylsulfinylmethanide, or another suitable base, (approx. 1.6 mmol base/100 mg β-glucan) for from 1 to about 24 hours and reacting the resultant mixture with approx. 1.6 mmol chloroacetyl-(S,S'-bis-acetamidomethyl)cysteinyl-glycyl-cysteine amide for about 1 to 5 hours at between 20° and 50° C., followed by purification by HPLC.
EXAMPLE 2
A General Method for Radiolabeling with Tc-99m
1. About 0.1 mg of a β-glucan or a reagent prepared as in Example 1 is dissolved in 0.1 mL of water or 50/50 ethanol/water. Approximately 100 μg stannous salt as stannous chloride pre-dissolved in methanol, or stannous tartrate pre-dissolved in water is added followed by 1-10 mCi 99m Tc pertechnetate in approximately 0.1 mL. The mixture is allowed to stand for 15-30 minutes at room temperature or at 100° C. For soluble β-glucans the preparation is then filtered through a 0.2 μm filter and the Tc-99m labeled product purity is determined by HPLC. The purity of insoluble β-glucan products is assessed by ITLC developed in saline.
2. About 0.1 mg of β-glucan or reagent prepared as described in Example 1 is dissolved in 0.1 mL of water or 50/50 ethanol/water or phosphate-buffered saline or 50 mM potassium phosphate buffer (pH=5, 6 or 7.4). Tc-99m gluceptate was prepared by reconstituting a Glucoscan vial (E.I. DuPont de Nemours, Inc.) with 1.0 mL of Tc-99m sodium pertechnetate containing up to 200 mCi and allowed to stand for 15 minutes at room temperature. 25 μl of Tc-99m gluceptate was then added to the peptide and the reaction allowed to proceed at room temperature or at 100° C. for 15-30 min. For soluble β-glucans the preparation is then filtered through a 0.2 μm filter and the Tc-99m labeled product purity is determined by HPLC. The purity of insoluble β-glucan products is assessed by ITLC developed in saline.
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This invention relates to radiodiagnostic agents and reagents for preparing such agents, and also methods for producing radiolabeled radiodiagnostic agents. Specifically, the invention relates to technetium-99m ( 99m Tc) labeled agents, methods and kits for making the agents, and methods for using the agents to image pathological sites, including sites of infection, inflammation, cancer and atherosclerosis in a mammalian body. Specifically the agents and reagents are derivatives of oligosaccharides, more specifically β-glucans.
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This is a continuation-in-part of application Ser. No. 07/355,535, filed May 22, 1989 and now U.S. Pat. No. 4,924,987.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a viscous fluid coupling device. In particular, the present invention is concerned with a pressure-responsive fluid check valve and method for a viscous fluid clutch.
2. Statement of the Related Art
A thermostatically-controlled viscous fluid clutch assembly for driving and rotating a vehicle cooling fan is well-known. A multi-bladed fan is removably secured to a body of the clutch assembly. The fan and clutch assembly are installed between an accessory pulley of a vehicle engine (typically the water pump pulley) and a radiator. The clutch assembly drives the fan at high speeds close to input speed when cooling is required and permits the fan to rotate at low speeds when cooling is not required. Thermostatic control of the fan through the clutch assembly reduces the airflow noise caused by fan rotation and the load on an engine, resulting in horsepower gain and improved fuel economy.
Generally, a clutch plate, housed within the clutch assembly, having lands and grooves is mated to the body having complementary lands and grooves. A pump plate divides the assembly into a pair of internally-contained chambers, a working chamber and a reservoir. Gates in the pump plate permit selective flow of a viscous fluid from the reservoir to the working chamber and into a shear zone between the lands and grooves of the body and clutch plate. Fluid shear in the lands and grooves transfers input torque from the clutch plate to drive the body and the attached fan.
When cooling is not required, gates in the pump plate are closed and the fluid in the shear zone is pumped into a pumping chamber. Orifices in the pump plate permit passage of the fluid from the pumping chamber into the reservoir. The removal of a majority of the fluid from the shear zone substantially reduces the shear between the clutch plate and the body, thereby substantially reducing the rotation of the fan.
When an engine is not running, fluid in the reservoir may settle at an equilibrium level in a conventional clutch assembly. Fluid pressure may cause the migration of fluid from the reservoir into the pumping chamber through the pump plate orifices and into the shear zone. When an engine is next started, fluid that has migrated into the shear zone results in annoying high-speed operation of the fan. Such high-speed operation creates unwanted airflow noise from the fan blades. Also, excessive rotation of the fan of a cold engine increases the engine warm-up period.
The art continues to seek improvements. It is desirable that a viscous fluid clutch assembly provide thermostatic operation of a fan when cooling is required. Furthermore, it is desirable that a clutch assembly prevent the migration of fluid from a reservoir to the shear zone when the engine is not in operation, thereby eliminating high-speed operation and unwanted airflow noise when a cold engine is started.
SUMMARY OF THE INVENTION
The present invention includes a viscous fluid drive device particularly adaptable for a fan clutch assembly of a vehicle. The present fan clutch assembly utilizes a pressure-sensitive check valve to prevent the migration of fluid through a pump plate orifice from a reservoir into a pumping chamber, particularly when the engine is not running.
The present invention relates to a viscous fluid fan clutch assembly for a vehicle. The clutch assembly includes an internally-mounted pump plate for separating a working chamber from a reservoir. A plurality of pressure-sensitive fluid check valves are provided in the pump plate to permit only one-way fluid flow from a pumping chamber to the reservoir. Each check valve includes an interior chamber having a pair of angled side walls which terminate at a normally-closed outlet. When a predetermined fluid pressure is achieved in the pumping chamber, the side walls are forced apart to open the outlet. The closing of the outlet is not dependent upon fluid pressure in the reservoir.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a viscous fluid clutch assembly and attached fan incorporating a pump plate of the present invention.
FIG. 2 is an enlarged view of a portion of the clutch assembly of FIG. 1 wherein the pump plate has been rotated to illustrate a first embodiment of a pressure-sensitive check valve mounted on the pump plate.
FIG. 3 is a reduced rear elevational view of the present pump plate, removed from the clutch assembly of FIG. 1 for purposes of clarity of illustration, illustrating a pair of pressure-sensitive check valves and respective wipers.
FIG. 4 is a greatly enlarged sectional view of a portion of the pump plate of FIG. 2 illustrating fluid flow through the pressure-sensitive check valve.
FIG. 5 is a greatly enlarged front elevational view of a second embodiment of the present pressure-responsive check valve mounted on a pair of retention tabs provided in the partially-illustrated pump plate, wherein the pump plate has been removed from the clutch assembly for purposes of clarity of illustration.
FIG. 6 is a sectional view taken along line 6--6 of FIG. 5.
FIG. 7 is an end view taken along line 7--7 of FIG. 5.
FIG. 8 is a sectional view taken along line 8--8 of FIG. 5 including a partially-illustrated clutch plate.
FIG. 9 is a rear elevational view taken along line 9--9 of FIG. 7.
FIG. 10 is a sectional view taken along line 10--10 of FIG. 5.
FIG. 11 is a front elevational view of a portion of the pump plate illustrating a first step of a method for forming the orifice and retention tabs for receiving the check valve illustrated in FIGS. 5-10.
FIG. 12 is a sectional view taken along line 12--12 of FIG. 11.
FIG. 13 is a sectional view similar to FIG. 12 illustrating a second step of a method for forming the orifice and retention tabs for receiving the check valve of FIGS. 5-10.
FIG. 14 is a sectional view similar to FIG. 13 illustrating a third step for forming the orifice and retention tabs for receiving the check valve of FIGS. 5-10.
FIG. 15 is a front elevational view of the pump plate, orifice and retention tabs of FIG. 14.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A viscous fluid clutch assembly indicated generally at 20 is illustrated in FIG. 1. The clutch assembly 20 includes a rotatably driven shaft indicated generally at 21. The shaft 21, which can be provided with multiple steps as illustrated in FIG. 1, preferably terminates at its first or innermost end in a flange 22. The flange 22 can be secured to a conventional engine-driven water pump pulley (not illustrated) to drive the clutch assembly 20 as described below.
A clutch plate indicated generally at 23 includes a central hub portion 24 and an annular disk portion 25. The central hub portion 24 receives a knurled portion 26 of the shaft 21 to secure the clutch plate 23 on the shaft 21. In this construction, the rotational drive of the shaft 21 is transferred to the clutch plate 23. A second end of the shaft 21 can be machined as indicated at 27 to retain the clutch plate 23 on the shaft 21. It is appreciated that other constructions, e.g., splining, can be utilized to drivingly connect the clutch plate 23 with the shaft 21.
A housing indicated generally at 30 is a dished member having a hub 32 rotatably mounted on the shaft 21 by a bearing 34. A plurality of radially extending bosses 36 are formed on the exterior face of the housing 30. A multi-bladed fan 38, partially illustrated in FIG. 1, is attached by threaded fasteners 40 to the bosses 36. A plurality of fins 42 is provided on the outer surface of the housing 30 to dissipate heat transferred from a viscous fluid (not illustrated) contained by the assembly 20.
A cover indicated generally at 44 is mounted to a front face of and cooperates with the housing 30 to form a reservoir 46 for the viscous fluid as described below. The cover 44 is a dished member having an annular outer edge 48 secured to the housing 30 by an annular retainer lip 50 spun over from the material of the housing 30. An annular seal 52, e.g., a formed-in-place gasket, is interposed between the edge 48 and a front face of the housing 30 to prevent leakage from the interior of the assembly 20. A plurality of fins 54 is provided on the outer surface of the cover 44 to dissipate heat transferred from the fluid.
A disk-like pump plate 56 is installed in the interior of the assembly 20. The pump plate 56 is positioned on a shoulder 60 of the housing 30 and is drivingly secured to the housing 30 by the cover 44. The pump plate 56 divides the interior of the assembly 20 into a working chamber 62 and the fluid reservoir 46. In the view of FIG. 1, the working chamber 62 is the interior volume to the left of the pump plate 56, while the reservoir 46 is the interior volume to the right of the pump plate 56. For purposes of this specification, a first or rear surface 57 of the pump plate 56 is in communication with the working chamber 62 and a second or front surface 58 of the pump plate 56 is in communication with the reservoir 46. The pump plate 56 includes a central depression 64 which is fitted in the hub portion 20 of the clutch plate 23.
A pair of diametrically opposed gates or openings 66 are provided in the portion of the pump plate 56 outbound of the depression 64. Hydraulic pressure causes the flow of fluid through the gates 66 from the reservoir 46 into the working chamber 62.
A rotatable control arm 68 controls the fluid flow into the working chamber 62 by covering and uncovering the gates 66. The control arm 68 is drivingly connected to a shaft 70 rotatably mounted in a tubular hub 72 formed in the cover 44. An O-ring seal 73 is mounted in an annular groove in the shaft 70 and makes peripheral contact with the inner wall of the hub 72 to prevent fluid leakage to the exterior of the assembly 20.
A bimetallic coil 74 is mounted at a first end 76 in a slot 77 on the forward end of the shaft 70. The second end 78 of the bimetallic coil 74 is mounted in a tab 80 in the exterior of the cover 44. Preferably, the bimetallic coil 74 is recessed within a cavity 81 surrounding the hub 72. The bimetallic coil 74 responds to the ambient air temperature surrounding the cover 44. An increase in air temperature causes the coil 74 to expand, thereby rotating the control arm 68 to uncover the gates 66 in the pump plate 56. When the air temperature has decreased to a predetermined level, the bimetallic coil 74 contracts, causing the shaft 70 and control arm 68 to rotate back to their original positions, thereby covering the gates 66 in the pump plate 56 and blocking fluid flow.
A fluid shear zone 82 is formed by the space between the interleaved concentric annular lands or ridges 84 and grooves formed on a rear or inner surface of the disk portion 25 of the clutch plate 23 and corresponding concentric annular lands or ridges 86 and grooves formed on an interior surface of the housing 30. Fluid sheared in the shear zone 82 transmits input torque from the rotatably driven clutch plate 23 to provide hydraulic drive of the housing 30 and the attached fan 38.
Fluid flow through the shear zone 82 is illustrated best in FIG. 2. When the control arm 68 is rotated to uncover the gates 66, fluid flows from the reservoir 46 into the working chamber 62. Centrifugal forces of the rotating clutch assembly 20 direct the fluid into a radial flow as indicated at directional arrow 88 between the pump plate 56 and the clutch plate 23. A blocking ring 90, preferably formed from TEFLON or a similar material, is provided in an annular groove 92 in a front surface of the clutch plate 23. Radial flow 88 encounters the blocking ring 90 and is redirected to axial flow indicated at directional arrows 94 to flow through a plurality of passages 96 provided in the ridges 84 and grooves of the clutch plate 23. Centrifugal forces cause the fluid to be dispersed radially outwardly throughout the shear zone 82. Fluid friction in the shear zone 82 transmits the rotation of the clutch plate 23 to the housing 30. As the housing 30 rotates, the attached fan 38 is rotated to draw cooling air through a radiator (not illustrated) and cool an internal combustion engine in a well-known manner.
Fluid exits the shear zone 82 as indicated at directional arrow 97 into an annular pumping chamber 98 formed and bounded by the clutch plate 23, the pump plate 56 and the blocking ring 90. Fluid is pumped from the pumping chamber 98 back to the reservoir 46 through a plurality of fluid control elements provided in the pump plate 56 as described below.
A first preferred embodiment of the present fluid control element indicated generally at 100 is illustrated in FIGS. 2, 3 and 4. The fluid control element 100 comprises a resilient, generally cylindrical body 102 having a circumferential groove 104 for receiving the pump plate 56 at a circular opening 106. An interior chamber 108 having an inlet 110 in communication with the pumping chamber 98 is provided in the body 102. The interior chamber 108 includes a pair of angled side walls 112 and 114 which terminate at a normally-closed outlet 116. When the fluid pressure in the pumping chamber 98 reaches a predetermined level, fluid in the interior chamber 108 forces the side walls 112 and 114 apart so that fluid can flow through the outlet 116, as indicated by directional arrows 120 in FIG. 4.
The present fluid control element 100 is responsive to fluid pressure and operates during the entire operating temperature range of the fluid. The opening and closing of the normally-closed outlet 116 is a function of the pressure in the pumping chamber 98, and is not related to the pressure in the reservoir 46. Upon the application of a predetermined fluid pressure to the side walls 112 and 114, the outlet 116 opens. When the pressure is reduced to a predetermined level, the outlet 116 closes. Since the outlet 116 does not require any fluid pressure from the reservoir 46 to close, the fluid control element 100 can be referred to as a zero-pressure-to-close valve. It is also noted that fluid movement in the reservoir 46 does not interfere with actuation of the fluid control element 100. The closing of the outlet 116 is not related to fluid pressure in the reservoir 46.
It is preferred that the fluid control element 100 be molded from a resilient material, e.g., rubber. Preferably, the opening 106 is provided in a depression 122 formed in the pump plate 56 by stamping or the like so that an inlet surface 124 of the fluid control element 100 is substantially flush or planar with the rear surface 57 of the pump plate 56 so as not to impede the flow of fluid into the interior chamber 108.
The construction of the present fluid control element 100 provides an economical and effective check valve for preventing the migration of fluid from the reservoir 46 back into the pumping chamber 98 and the shear zone 82. When an engine is shut off, the clutch assembly 20 stops rotating. The prevention of fluid migration back into the shear zone 82 eliminates undesirable high-speed clutch operation when a cold engine is started, thereby significantly reducing annoying airflow noise created by the fan 38.
To improve pumping efficiency, a well-known wiper 126 can be mounted on the rear surface 57 of the pump plate 56 adjacent each fluid control element 100. Each wiper 126 can include a scoop surface 128 and is mounted upstream of the fluid control element 100. As viewed in FIG. 3, a counterclockwise rotation of the pump plate 56 forces fluid into the scoop surface 128, thereby increasing fluid pressure and fluid flow through the outlet 116. In other embodiments, the wipers 126 can be formed by any suitable means, e.g., as projecting elements stamped or pressed into the pump plate 56.
A second preferred embodiment of the present fluid control element indicated generally at 130 is illustrated in FIGS. 5-10. The fluid control element 130 is mounted on a disk-like pump plate 256 which is similar to and substituted for pump plate 56 in the assembly 20. For purposes of this description, the pump plate 256 includes rear face 257 in communication with the working chamber 62 and the pumping chamber 98 and a front face 258 in communication with the reservoir 46.
The fluid control element 130, preferably formed from a resilient material, comprises a generally rectangular body 132 having an interior chamber 134. An inlet 136 to the chamber 134 is provided in communication with the pumping chamber 98. The interior chamber 134 includes a pair of angled side walls 138 and 140 which terminate at a normally-closed outlet 142. As with similar elements in fluid control element 100, side walls 138 and 140 are forced apart to open outlet 142 when the pressure in the pumping chamber 98 reaches a predetermined level. When the fluid pressure drops below a predetermined level, the outlet 142 returns to its closed position.
The fluid control element 130 is received in an opening 146 (FIG. 11) provided in the pump plate 256 and mounted on a pair of retention tabs 150 and 151. The first retention tab 150 is formed as a depression in the pump plate 256 and projects into the pumping chamber 98. As illustrated in FIG. 8, the height H1 of the tab 150 must be less than the distance between the pump plate 256 and the clutch plate 23. The second retention tab 151 is formed on the opposite side of the opening 146 and projects into the reservoir 46. The height H2 of the tab 151 must be less than the distance between the pump plate 256 and the cover 44. The opening 146 is completed by opposite side walls 152 and 153 illustrated best in FIGS. 11 and 15.
For purposes of this specification, the fluid control element 130 is described from the orientation illustrated in FIG. 8. The fluid control element 130 is a generally rectangular member having a top surface 154 in communication with the reservoir 46 and a bottom surface 156 in communication with the pumping chamber 98. The top and bottom surfaces 154 and 156 are substantially parallel with the pump plate 256. A front surface 158 includes the inlet 136 and a rear surface 160 includes the outlet 142. A forwardly-projecting lip 162 is formed with the top surface 154 and provides a sealing surface overlapping and spanning an outer surface 164 of the second retention tab 151. The lip 162 extends over the second retention tab 151 in a pair of opposite side walls 166 and 168 formed with the top surface 154.
The bottom surface 156 of the fluid control element 130 includes an indentation or step 170 which is fitted on an inner surface 172 of the first retention tab 150. Forward of the step 170, the bottom surface 156 terminates in a pair of opposite locking flanges 174 and 176 (FIGS. 6, 7, 9 and 10) which project outwardly beyond the respective side walls 152 and 153 of the opening 146. When the fluid control element 130 is inserted into the opening 146, the locking flanges 174 and 176 are resiliently compressed until the step 170 is seated on the inner surface 172. Once in place, the locking flanges 174 and 176 expand to their original position and are positioned against the rear surface 257 of the pump plate 256 adjacent respective side walls 152 and 153.
A fluid encountering surface 178 is provided on the portion of the front face 158 between the inlet 136 and the bottom surface 156. The fluid encountering surface 178 projects into the pumping chamber 98 functioning as a fluid dam to create a pressure rise very similar to the wiper 126 described earlier, thereby improving pump-out through the fluid control element 130. While the fluid encountering surface 178 is shown as planar, it is appreciated that other shapes, including curved or scooped surfaces, are within the scope of this invention.
A method of forming the opening 146 and retaining tabs 150 and 151 for receiving the fluid control element 130 is illustrated in FIGS. 11-15. First, near the outer periphery of the pump plate 256, an opening 146 is pierced or stamped into the pump plate 256. While a rectangular opening 146 is illustrated, it is appreciated that other shapes are within the scope of this invention. Second, a forming operation with a punch and die draws a portion of the pump plate 256 adjacent the opening 146 into the first retaining tab 150. Third, a forming operation is performed on a portion of the pump plate 256 opposite the opening 146 from the first retaining tab 150 to draw the second retaining tab 151. If desired, these steps can be rearranged or combined.
Installation of the fluid control element 130 is accomplished by fitting the step 170 onto the inner surface 172 of the first retaining tab 150 and overlapping the lip 162 onto the outer surface 164 of the second retaining tab 151. As described above, the locking flanges 174 and 176 rest against the rear surface 257 at the opening 146 adjacent respective side walls 152 and 153. In operation, the force of fluid on the fluid encountering surface 178 and the resiliency of the body 132 act to hold the fluid control element 130 in place. As fluid indicated by direction arrow 180 (FIG. 8) flows through the fluid control element 130, sealing contact between the step 170 and first retention tab 150 is maintained. Any tendency of the fluid to force the fluid control element 130 away from the first retention tab 150 in a counterclockwise direction is resisted by the resiliency of the body 132 against the inner surface 172 and by the locking flanges 174 and 176 against the pump plate 256. Any tendency of the fluid to force the fluid control element 130 away from the second retention tab 151 in a clockwise direction is resisted by the resiliency of the lip 162 and the side walls 166 and 168 acting against the second retention tab 151.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A viscous fluid fan clutch assembly for a vehicle includes an internally-mounted pump plate for separating a working chamber from a reservoir. A plurality of pressure-sensitive fluid check valves are provided in the pump plate to permit only one-way fluid flow from a pumping chamber to the reservoir. Each check valve includes an interior chamber having a pair of angled side walls which terminate at a normally-closed outlet. When a predetermined fluid pressure is achieved in the pumping chamber, the side walls are forced apart to open the outlet. The closing of the outlet is not dependent upon fluid pressure in the reservoir.
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FIELD OF THE INVENTION
[0001] There is a need for substantial amounts of water for hydraulic fracturing operations. A potential exists in many areas to access and use a non-potable water aquifer formation for this purpose. An example would be the Debolt aquifer or the like, which was tested successfully.
BACKGROUND OF THE INVENTION
[0002] Nexen Inc. (“Nexen”), the assignee, has natural gas shale deposits in northeast British Columbia. Efficient and cost effective production of the natural gas shale deposits in the area is dependent upon the availability of water for fracturing operations. The expected daily gas production in the area will require an estimated annual volume of at least 1.3 MM m 3 of water with such water generally coming from natural above ground sources and/or pre-treated underground sources. In order to maximize the value of this natural gas reserve, a reliable supply of sufficient quantities of water for fracturing stimulation programs is necessary to enable the delivery of the projected production levels.
[0003] One of the opportunities for achieving value is to streamline the process for providing water for frac programs through the innovative use of non-potable water.
[0004] It is therefore a primary object of this invention to provide a method and process for fracturing a hydrocarbon reservoir utilizing water from an aquifer adjacent said reservoir. The suitable aquifer could also be nearby and be either shallower or deeper than the said reservoir.
[0005] It is another object of the invention to use the method and process when fracturing a natural gas reserve.
[0006] It is yet another object of the invention to avoid treating the aquifer water prior to using it for hydrocarbon fracturing.
[0007] It is a further object of the invention to use the Debolt aquifer as a source of water for the fracturing of a natural gas reserve.
[0008] It is another object of the invention to provide said fracturing pump with construction materials in alignment with the well known recommendations published for material performance criteria from for example NACE, ASTME or ANSI trim packaging or the like in view of the corrosive nature of the fluids being pumped).
[0009] Further and other objects of the invention will be apparent to one skilled in the art when considering the following summary of the invention and the more detailed description of the preferred embodiments described and illustrated herein along with the appended claims.
SUMMARY OF THE INVENTION
[0010] The Debolt subsurface formation or zone is an aquifer whose water contains approximately 22,000 ppm of total dissolved solids (“TDS”) and a small amount of hydrogen sulphide—H 2 S. The scope and volume of the Debolt formation is still being investigated, but it has the potential to be extensive. This aquifer has high permeability and porosity. A Debolt well at b-H18-1/94-O-8 was tested in May, 2010, with a 10.25″ 900 HP downhole electrical submersible pump (“ESP”). The well showed a Productivity Index of 107 m3/d per 1 kPa drawdown, indicating that the reservoir will provide a high enough rate of flow to support the volume and rate requirements needed to support well fracturing operations.
[0011] Debolt formation water contains sour gas in solution. When depressurized to atmospheric conditions, the Debolt water flashed off sour gas at a gas water ratio of 1.35 standard m 3 of gas to 1 m 3 of water. The flashed gas contained 0.5% H 2 S, 42% CO 2 and 57% CH 4 (methane). These gases are the same gases present in shale gas production being performed, which is normally in the range of 0.0005% H 2 S, 9% CO 2 , and 91% CH 4 (methane), and the use of raw Debolt water would have a negligible impact on the current percentage of shale gas components.
[0012] The challenge is how to use sour water, for example Debolt water, for fracing in a cost effective manner since current water fracturing equipment does not comply with the well known recommendations published for material performance criteria from for example NACE, ASTME or ANSI standards for trim packaging or the like. Current water frac contractors are reluctant to use Debolt water for fracturing operations. In part because current equipment is not NACE complian. But the primary reason relates to safety concerns with respect to H 2 S content of the Debolt water.
[0013] There are two different ways of using Debolt formation water for fracturing operations. The first is to construct and operate a water treatment plant to remove the H 2 S from Debolt water. This approach has been taken by other industry participants who have constructed an H 2 S stripping plant to remove the H 2 S from Debolt water. A recent paper published by Canadian Society for Unconventional Resources entitled “Horn River Frac Water: Past, Present, Future” discusses the technical and operational aspects of the Debolt Water Treatment Plant constructed and operated for the foregoing purposes. This paper states that a very expensive treatment plant is required to remove the H 2 S and other solution gases from the Debolt water.
[0014] The second approach is to maintain the aquifer water at a pressure above its saturation pressure (also known as the “Bubble Point Pressure” or “BPP”) on a continuous basis while being produced to surface and transported in pipelines to enable it to be used for fracturing. Tests conducted on the Debolt water properties indicates that as long as the Debolt water is maintained at a pressure high enough to keep the solution gas entrained in the water, the water is stable with no precipitates, and remains crystal clear in colour. Further the water is in the least corrosive state. These findings reveal that the Debolt aquifer fluid can be used in its natural state requiring no treatment. This is the basis of the proprietary Pressurized-Frac-on-Demand (“PFOD”) process.
[0015] The primary aspect of this invention is therefore to provide a method or process of fracturing a hydrocarbon deposit on demand comprising the steps of:
[0000] using as a source of water an underground aquifer which contains water which is stable and clear in the aquifer but which may include undesirable constituents that are in solution when subjected to surface conditions such as hydrogen sulfide and other constituents,
utilizing the water from the aquifer as a source of water to be used in a hydrocarbon fracturing process and to pump the water under pressure at a predetermined rate for the aquifer water and above the bubble point pressure (BPP) for the water contained in a particular aquifer to keep the water stable. We have found that the water becomes unstable when the pressure is reduced and gas is allowed to evolve out of the water. This depressuring and gas removal initiates a chemical reaction with the dissolved solids in the water to cause precipitates to form. To prevent these chemical reactions from occurring and causing the undesirable constituents of said water from falling out of solution,
maintaining said water pressure at a minimum required for each aquifer at all times during the fracturing process,
drilling a source well into the aquifer,
drilling a disposal well to the aquifer,
providing a pump capable of maintaining the required pressure needed to prevent the constituents of the aquifer water from coming out of solution only by maintaining the minimum pressure,
establishing a closed loop with a manifold, or a manifold and pumps, to keep the aquifer water circulating at all times until the fracturing operation begins when water will be supplied from that manifold,
providing the fracturing operation with water from the manifold so as to fracture a hydrocarbon reserve,
wherein in using water from an aquifer in the fracturing process and by maintaining said water under pressure at a minimum at all times, said water remains stable and the undesirable constituents remain in solution and the water remains clear thereby avoiding the necessity of treating the water from the aquifer prior to using it in a fracturing processes.
[0016] According to another aspect of the invention there is provided a method or process of high-pressure fracturing of a hydrocarbon deposit, for example a shale gas deposit on demand comprising the steps of using as a source of water from an underground aquifer such as the Debolt aquifer which contains sour water including H 2 S and other constituents,
[0000] utilizing the sour water from the aquifer as the water source to be used preferably on at least the clean side of a gas fracturing process and to pump said sour water under pressure at a minimum of for example 2310 kPa for Debolt water at approximately 38 degrees Celsius (which varies with the actual temperature of source water for each aquifer, and any surface cooling which may occur to such water) and above the BPP for the sour water contained in a particular aquifer to prevent H 2 S and other constituents of said sour water from falling out of solution,
maintaining said sour water pressure at a minimum required for each aquifer, for example for Debolt of 2310 kPa at all times during the fracturing process,
drilling a source well into the aquifer,
drilling a disposal well into the aquifer,
providing a pump capable of maintaining the required pressure needed to prevent the constituents of the sour water from coming out of solution only by maintaining the minimum pressure required which, for example, for Debolt water is 2310 kPa at 38 degrees Celsius, establishing a closed loop with a manifold to keep the sour water circulating at all times until the well fracturing operation begins when water will be supplied from that manifold, or a manifold and pumps,
providing the clean side of a well fracturing operation with sour water from the manifold so as to fracture a well reserve (normally an oil or gas zone reserve), wherein in using sour water from an aquifer such as Debolt for the gas fracturing process and maintaining said sour water under pressure at a minimum, as an example for Debolt water being at 2310 kPa and 38 degrees Celsius, said water remains stable and the constituents remain in solution and the water remains clear thereby avoiding the necessity of stripping out the hydrogen sulfide and other constituents as is required by other well fracturing processes.
[0017] In one embodiment of the invention said water source and method or process is utilized along with sand on the dirty side of the well fracturing operation with the addition of a high-pressure blender since the sour water must be maintained above its BPP, for example 2310 kPa for Debolt water at 38 degrees Celsius at all times thereby avoiding the constituents including the H 2 S from falling out of solution.
[0018] In a further embodiment of the method or process the necessary number of pumps and source wells and disposal water wells are provided with the method or process to enable a high-pressure fracturing operation on demand for a target number of fracs (which depends on the particular well design chosen for a reservoir stimulation or other purpose) for each well, or number of wells, stimulated as part of a program.
[0019] Preferably in the method or the process said water from the source aquifer is at an elevated temperature, for example for Debolt water a temperature under normal circumstances has been 38 degrees Celsius, which therefore requires no additional heating, or insulated piping, and which may be used as a source of sour water for the pressurized fracturing on demand process even during the colder winter months experienced in, for example, Western Canada or similar areas and which can contribute considerable cost savings when compared to utilizing surface water.
[0020] In yet another embodiment the method or process utilizes sour water from the Debolt aquifer and continuously circulates said water at a pressure above the BPP from the source well to the disposal well in an underground pipeline system accomplished by a back pressure control valve located downstream of the well to be fractured near the Debolt water circulation line and yet upstream of the disposal wells wherein when water is required for frac operations, water will be withdrawn from a manifold strategically located on this circulation line thereby feeding Debolt water to the frac operation under pressure, which is above the Debolt BPP.
[0021] According to yet another embodiment of the method or process the Debolt water is maintained at a pressure above its saturation pressure and is continuously used for fracing so that as long as the Debolt water is maintained at a high enough pressure to keep the solution gas entrained in the water, then the water remains stable, with no precipitates and is in the least corrosive state thus requiring that all frac operations (at least on the clean side) be conducted at pressures above the Debolt water BPP which is the basis for a successful PFOD process.
In yet another embodiment the method or process further comprises a NACE trim, preferably a High Pressure Horizontal Pumping System (“HPHPS”) frac pump capable of providing a discharge pressure of about 69 MPa. The pump construction uses materials in alignment with the recommendations published by the National Association of Corrosion Engineers (“NACE”) trim packaging in view of the corrosive nature of the fluids being pumped). Alternatively, materials may be selected from material performance criteria for a HPHPS frac pump or equivalent published by for example ASTME, ANSI or the like.
[0023] In order to carry out the process of this invention, a multistage centrifugal pump is built capable of delivering a discharge pressure or differential pressure between pump internal and external pressures to over 10,000 psi. A pressure sleeve or pump housing is designed to be the primary pressure containment. The sealing interface between the pump base and pump head is a metal on metal type achieved by using specialized thread. The diffusers are designed with openings to allow rapid pressure equalization across the diffuser outside edge to avoid failure from high differential pressure which could cause diffuser failure. A seal is used on the outside of the diffusers to prevent pressure communication, and fluid flow, between the outside of the individual diffusers enclosed within the housing. The pump connections to pump intake and discharge are upgraded to ring or gasket style sealing.
[0024] The present invention also relates to a multistage centrifugal pump design, which has the diffusers, impellors, and a shaft, inserted within a high pressure housing or barrel, wherein this assembly is fully enclosed within the housing, and the housing is of sufficient strength to be suitable for safe pressure containment of the fluids being pumped. This aspect of the invention describes the technical details used to reconfigure the known multistage centrifugal pump design to enable increase of the discharge pressure capabilities higher than the 6,000 psig of current designs. The design modifications discussed herein have been successfully tested at 10,000 psig discharge pressure. The 10,000 psig pressure capability provides a pressure suitable for fracturing formations penetrated by wellbores.
[0025] This style of pump unit is well suited to the hydrocarbon fracturing industry to be used to pump fluids at sufficient pressures, to stimulate oil and gas reservoirs.
[0026] The invention is a housing type of centrifugal pump, which is designed for operating at speeds of 30 to 90 hz, (1800 to 5400 rpm), with discharge pressures that may be 10,000 psig, and with a suction pressure that may be 15-600 psig. Fora 10,000 psig discharge pressure capability, such as this multistage centrifugal pump design enclosed within a housing, this is a more economical cost effective option as compared to prior structures such as a split casing multistage centrifugal pump.
[0027] Preferably said pump is utilizing pressure sleeve ( 21 ) on top of diffuser ( 22 ) wall for improved wall strength by compression fit between sleeve ( 21 ) and outside diameter of diffuser ( 22 ) wall.
[0028] Also preferably said pump is utilizing equalizations hole ( 23 ) in diffuser wall, resulting in zero deferential pressure across diffuser wall and also allows for rapid depressurizing.
[0029] Preferably to prevent stages from collapsing due to pressure transfer from one pump stage to another o-ring ( 31 ) style sealing is utilized between each diffuser ( 34 ) and housing ( 33 ).
[0030] In one embodiment sealing between pump housing ( 16 ) and both pump base ( 12 ) and pump head ( 19 ) is by specialized threads providing metal on metal sealing, eliminating all elastomeric and non-elastomeric seals through the use of proven metal-to metal thread sealing technology such as Base/Head Pin-Housing Connection).
[0031] The multistage centrifugal pump is designed for injecting fluids to a wellbore for purpose of fracturing this well.
[0032] According to that aspect of the invention there is provided a multiple stage centrifugal pump for fracturing hydrocarbon deposits capable to deliver discharge pressure or differential pressure between the pump internal and external pressure to be over 10,000 psi and including a pressure sleeve or pump housing designed for the primary pressure containment, sealing between the pump base and pump head is metal on metal type achieved by using specialized thread, diffusers are included designed with openings to allow rapid pressure equalization across the diffuser outside edge to avoid failure from high differential pressure which could cause diffuser failure, a seal is used on the outside of the diffusers to prevent pressure communication, and fluid flow, between the outside of the individual diffusers enclosed within the housing and the pump connections to pump intake and discharge are upgraded to ring or gasket style sealing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a PFOD Flow Schematic.
[0034] FIG. 2 is a PFOD Elevation View.
[0035] FIG. 3 is a drawing of a high pressure multistage centrifugal pump assembly illustrating and describing all key components used within the pump assembly.
[0036] FIG. 4 is a cross section drawing of the high pressure multistage centrifugal pump assembly describing the components used within assembly.
[0037] FIG. 5 is a cross sectional illustration showing a number of impellor and diffuser stages in the high pressure multistage centrifugal pump housing.
[0038] FIG. 6 is a cross sectional illustration of diffuser, for the high pressure multistage centrifugal pump assembly and diffuser details showing compression sleeve ( 21 ) on top of diffuser ( 22 ).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] Over the past two years, Nexen has been working on the PFOD process as outlined below, using Debolt water above its BPP for fracing thus eliminating the need for an expensive H 2 S removal process.
[0040] In order to guarantee a reliable source of water for its fracturing operations, it was necessary to identify ways to utilize the Debolt water as part of the frac water source. One of the options reviewed was to use Debolt water for only the clean side of the frac program.
[0041] In light of its requirements, Nexen designed and built a small flow HPHPS frac pump for testing. In June 2010, a 0.25 m 3 /min NACE trim HPHPS test frac pump capable of providing a discharge pressure of 69 MPa was tested on the b-18-1 pad in northeast British Columbia. Technicians were onsite to operate the Debolt water source well (“WSW”) ESP and the HPHPS test frac pump. Three chokes consisting of two bean types and one variable choke were piped up in series to provide the back pressure to test the HPHPS frac pump at fracturing pressure.
[0042] In the initial tests, the HPHPS test frac pump used freshwater from a tank truck. All the pump control parameters were set. In subsequent tests, Debolt water was used and fed by the Debolt WSW at b-H18-I/94-O-8 by ESP to the suction of the HPHPS test frac pump. The discharge from the test frac pump flowed through three chokes at various back pressures. The Debolt water then exited the chokes and flowed into a disposal water pipeline to the water disposal well (“WDW”) at b-16-I. The back pressure was progressively increased at 7000 kPa intervals and ran at that discharge pressure for approximately 30 to 60 minutes. When pump operations remained steady, the choke was adjusted to increase the discharge pressure of the pump.
[0043] The HPHPS frac test pump was successfully tested on July 7 and 8, 2010. It operated at a discharge pressure of 71 MPa. The pump was run using Debolt water for approximately 6 hours at 62 MPa to simulate a complete fracturing operation.
[0044] It is understood that for other aquifers will have different physical parameters. For example pump specifications will reflect different Bubble Point Pressures for alternative water sources. For the Debolt water source, the BPP of the aquifer water was 2310 kPag at 38 degrees Celsius.
[0045] In August 2010 during the completion of the 8 wells at pad b-18-1, the HPHPS test frac pump was integrated into six fracturing operation. Three of the 6 fracs ran using freshwater and three ran using Debolt water. The HPHPS test frac pump ran well for all 6 fracs and there were no operational or safety issues encountered.
[0046] Only one source water well and one disposal well are required for the initial testing of the PFOD system, and additional wells will provide increased capacity and backup to ensure minimum flow rate and injection capacities are available as required for the system to operate reliably with maximum system availability and use. Nexen is planning to drill and complete additional Debolt formation WSWs and additional Debolt WDW in the future as required to optimize the Debolt water system to support fracturing operations. Together with the existing b-H18-I Debolt WSW and the existing Debolt WDW b-16-I, these 2 initial wells plus any additional wells will form the basis of the PFOD water circulation system identified for such well fracturing program.
[0047] Nexen will continue to further evaluate the need to source and test a 1.25 m3/min full size 3000 kPa suction pressure for a trim plunger frac pump for the dirty side based on the well known recommendations published for material performance criteria from for example, NACE, ASTME or ANSI trim packaging or the like. This also includes the evaluation of the need for a pressurized blender, or another method for utilizing Debolt water for the dirty side.
[0048] Based on the Debolt water well tests conducted in June 2010, a feasibility study of the PFOD process, and initial field testing of a prototype NACE trim HPHPS frac pump in July and August of 2010, it was concluded:
It is technically and economically feasible to use Debolt water in its untreated state for fracturing operations. It is possible using the PFOD process to maintain pressures above 2310 kPa (BPP for Debolt water) thus keeping gases including H 2 S contained in solution. No compatibility issues have arisen using Debolt water for fracturing or injection into shale. A HPHPS NACE trim frac pump using Debolt water can be constructed and used on the clean side of fracturing operations. No operational or safety issues were identified during the testing and ultimate use in the field of the HPHPS frac pump. Freshwater may not be readily available for operations. Water from Debolt using PFOD process is readily available availability is not subject to spring and summer rainfall or suspension of licenses due to drought. For example, in August, 2010, government regulators in British Columbia suspended freshwater withdrawal licenses for hydrocarbon fracturing operations in the Montney area due to a drought in the Peace River watershed. There is experience in the pump industry in building a high suction pressure plunger style pump, with a NACE trim fluid end. There is no experience in the frac pump industry in building a high suction pressure (over 330 prig (2300 kpag)) plunger style frac pump, with a NACE trim fluid end, capable of pumping American Petroleum Institute (“API”) quality frac sand for the dirty side fracing. There is no apparent technical limitation or constraint to prevent the engineering and fabrication of a pressure blender to use Debolt water under pressure.
The PFOD Process
[0057] The PFOD process maintains Debolt water at a pressure above its BPP at all times in order to prevent gases (including H 2 S, CO 2 and CH 4 ) from coming out of solution. Based on Debolt well formation water and Pressure-Volume-Temperature (“PVT”) tests, the Debolt water BPP is 2310 kPa (335 Psi) at 38 degrees Celsius. When the Debolt water at 38 degrees Celsius was de-pressurized to atmospheric pressure, approximately 1.35 m 3 gas was released per m 3 of water. The flashed gas contained 0.5% H 2 S, 42% CO 2 and 57% CH 4 (methane). These are the same gases present in certain shale gas operations (normally 0.0005% H 2 S, 9% CO 2 , and 91% CH 4 (methane). The use of raw Debolt water would have negligible impact on the current percentage of shale gas components content.
[0058] For the typical PFOD system, a total of 3 Debolt WSWs and 2 Debolt WDWs will be required. These WSWs and WDWs will be centrally located for two to three identified well pads selected for development. Debolt water will be continuously circulated at a pressure above the BPP from the WSWs to the WDWs in an underground pipeline system. This will be accomplished by a back pressure control valve located downstream of the well to be fractured near the Debolt water circulation line and yet upstream of the disposal wells wherein when water is required for frac operations, water will be withdrawn from a manifold strategically located on this circulation line thereby feeding Debolt water to the frac operation under pressure, which is above the Debolt BPP. The two figures show a PFOD flow schematic and a subsurface elevation view. These figures demonstrate how the PFOD pipeline system would work.
[0059] The advantages of a PFOD process are numerous and include the following:
Fracturing operations can to be conducted on a continuous basis year round. Debolt water is typically at 38 degrees Celsius. This allows for the use of Debolt water in the winter months without requirement for heating or the other infrastructure often required for winter frac operations including insulated pipelines for water circulation. Furthermore, service contractors for fracturing operations tend to be more available during non-peak winter months. Year round fracing capability will allow for production flexibility relative to commodity demand and pricing. The PFOD process eliminates the intensive capital and operation costs associated with building, operating and maintaining water treatment facilities. The PFOD process also reduces the need for secondary facilities that are required as development of fracturing operations occurs at greater distances from the water treatment and H 2 S removal plants. The PFOD process eliminates the need for above ground treated water storage tanks or large holding ponds that would ordinarily be required to heat the water for an above ground treatment process. The Debolt aquifer therefore acts as a natural storage tank with no surface facilities, heating or maintenance required. The Debolt aquifer could also be used as the main storage location of excess fresh water to be used later during a fracturing operations.
PFOD Pump Details
[0066] FIG. 3 illustrates a High Pressure multistage centrifugal pump assembly describing all components used in a preferred embodiment as follows:
15 pump support—skid frame. 42 pump driver—electric motor. 43 thrust chamber to support shaft load from pump. 44 pump intake section example. 45 Shows a low pressure multistage centrifugal pump housings containing the diffusers, impellors and shaft. Two pump sections are shown. Maximum design was to 6,000 psi discharge pressure. 46 Shows the high pressure multistage centrifugal pump housing containing the diffusers, impellors and shaft. This is the inventive aspect that takes the pressure capability from 6,000 psig up to 10,000 psig discharge pressure. 47 High pressure discharge head for 10,000 psig. This is the invention aspect that takes the pressure capability from 6,000 psig up to 10,000 psig discharge pressure.
[0074] FIG. 4 is a cross section drawing of High Pressure multistage centrifugal pump assembly of the invention describing all components used within assembly including pump base ( 12 ) and pump head ( 19 ) threaded into pump housing ( 16 ). Pump stage is an assembly of impeller ( 13 ) and diffuser ( 14 ). The impellers ( 13 ) are install on pump shaft ( 15 ) and are the rotating part of the pump. The diffusers ( 14 ) are fixed in the pump assembly by being compressed by compression bearing ( 18 ) in the pump housing ( 16 ) and against pump base ( 12 ).
[0075] FIG. 5 is a cross section drawing showing a number of impellor and diffuser stages in the High Pressure multistage centrifugal pump housing ( 16 ). This invention includes the equalization hole ( 23 ) for rapid depressurizing, and the support sleeve ( 21 ) completely around the diffuser, which has grooves ( 25 ) to contain the O-Ring ( 31 ) to prevent pressure communication, and fluid flow, between the outside of the individual diffusers enclosed within the housing. This high pressure housing ( 33 ) is designed to safely contain pressures up to 10,000 psig.
[0076] FIG. 6 is a cross section drawing of the diffuser, for the High Pressure multistage centrifugal pump assembly and diffuser details showing compression sleeve ( 21 ) on top of diffuser ( 22 ). This invention includes the equalization hole ( 23 ) for rapid depressurizing, and the O-Ring ( 31 ) to prevent pressure communication, and fluid flow, between the outside of the individual diffusers enclosed within the housing
CONCLUSIONS
[0077] Any fracturing operation requires large volumes of water. The PFOD process provides an alternative to use of fresh or treated subsurface water. The Debolt formation in northeast British Columbia has proven to contain non-potable water at volumes necessary for fracturing operations. The PFOD process eliminates water treatment by maintaining gases and particulates in solution thus allowing for use of natural untreated sour aquifer water for example as found in the Debolt aquifer or the like. This is accomplished by maintaining water pressure above the BPP eliminating costly water treatment and secondary facilities, replacing the use of freshwater by non-potable subsurface sour water, and decreasing the environmental footprint of fracturing operation.
[0078] As many changes therefore may be made to the preferred embodiment of the invention without departing from the scope thereof. It is considered that all matter contained herein be considered illustrative of the invention and not in a limiting sense.
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Method of fracturing, hydrocarbon deposits comprising using as source of water an aquifer containing water stable and clear in the aquifer but which may include undesirable soluble chemical compounds that are not in solution when subjected to reduced pressures at surface conditions such as hydrogen sulfide,
utilizing aquifer source water in a fracturing process to pump water under pressure at above the water's bubble point pressure to prevent undesirable constituents thereof from separating, maintaining said pressure at a minimum at all times during fracturing, drilling a source and disposal well to/from the aquifer, providing a pump capable of maintaining the minimum pressure, establishing a closed loop, to keep the aquifer water circulating at all times and the undesirable constituents remaining in solution and the water remaining clear thereby avoiding the necessity of treating the water from the aquifer prior to using it in a fracturing processes.
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[0001] This U.S. application claims priority on the U.S. application Ser. No: 60/364,581 filed on Mar. 18, 2002.
BACKGROUND OF THE INVENTION
[0002] a) Field of the Invention
[0003] This invention relates to a new composition for inhibiting tumor growth and methods of treatment thereof.
[0004] (b) Description of Prior Art
[0005] Melanoma, a fatal skin cancer, now represents the fifth most common type of cancer in North America. The incidence rate of melanoma has risen dramatically in the last century in all countries with a white-skinned population, doubling every 10 years in many countries, and is now approximately 10 per 100,000 per annum in Europe, giving an approximate lifetime risk of 1 in 200 (Katsambas, A. & Nicolaidou, E. Cutaneous malignant melanoma and sun exposure. Arch. Dermatol. 132, 444-450 (1996)). It is also reported that at least 20% of people diagnosed with melanoma will experience advanced disease and die within 5 years of diagnosis (Beahers, O. H. , Henson, D. E. , Hutter, R. V. P. & Kennedy, B. J. Malignant melanoma of the skin (excluding eyelid). American Joint Committee on Cancer Manual for staging of cancer 4 th ed. Philadelphia: JB Lippincoft. 143-148 (1992)). At present there is no optimal treatment for this cancer. Adjuvant therapy with varying clinical results includes immunotherapy, such as interferon α-2b (Caraceni, A. et al. Neurotoxicity of interferon-α in melanoma therapy. Cancer 83, 482489 (1998)) levamisole, vaccines, chemotherapy, autologous bone marrow transplantation, biochemotherapy and chemoimmunotherapy (Johnson, T. M. , Yahanda, A. M. , Chang, A. E. , Fader, D. J. & Sondak, V. K. Advances in melanoma therapy. J. Am. Acad. Dermatol. 38, 731-741 (1998)). Thus, there is at present no conclusive method for the treatment of melanoma, a fatal skin cancer.
[0006] One unique characteristic is that tyrosine requirement for malignant melanomas is much higher than for normal cells since tyrosine is needed for both protein and melanin synthesis. Tyrosine is a semi-essential amino acid, derived from the liberation of tyrosine from hydrolysis of dietary or tissue protein. Dietary approach to lower tyrosine was not successful in human because it results in malnutrition in the severely sick cancer patients, its unpalatable nature also make compliance in human difficult, furthermore, it took a long time to lower systemic tyrosine (Johnson, T. M., Yahanda, A. M., Chang, A. E., Fader, D. J. & Sondak, V. K. Advances in melanoma therapy. J. Am. Acad. Dermatol. 38, 731-741 (1998)). The injection in human of an enzyme, tyrosinase, by itself was also not practical (Johnson, T. M., Yahanda, A. M., Chang, A. E., Fader, D. J. & Sondak, V. K. Advances in melanoma therapy. J. Am. Acad. Dermatol. 38, 731-741 (1998)) because the short half-life required repeated injection resulting in immunological problems from the bare enzyme.
[0007] It would be highly desirable to be provided with a new composition for inhibiting tumor growth.
SUMMARY OF THE INVENTION
[0008] In accordance with the present invention there is provided a new composition and method for inhibiting tumor growth.
[0009] In accordance with the present invention, there is provided a composition for inhibiting tumor growth, which comprises a tumor growth inhibiting enzymatic moiety in association with at least one protective carrier.
[0010] The composition in accordance with a preferred embodiment of the present invention, wherein the carrier is an oral encapsulation carrier to protect encapsulated enzymatic moiety from digestive enzyme degradation.
[0011] The composition in accordance with a preferred embodiment of the present invention, wherein the encapsulation carrier is a nanocapsule.
[0012] The composition in accordance with a preferred embodiment of the present invention, wherein the enzymatic moiety is selected from the group consisting of tyrosinase, asparaginase and glutaminase.
[0013] The composition in accordance with a preferred embodiment of the present invention, further comprising an oxygen binding molecule.
[0014] The composition in accordance with a preferred embodiment of the present invention, wherein the carrier is a molecule biologically active and protective that covalently bond to the enzymatic moiety.
[0015] The composition in accordance with a preferred embodiment of the present invention, wherein the molecule increase half-life of the enzymatic moiety.
[0016] The composition in accordance with a preferred embodiment of the present invention, wherein the molecule is an oxygen binding molecule.
[0017] The composition in accordance with a preferred embodiment of the present invention, wherein the molecule is hemoglobin or synthetic hemoglobin.
[0018] The composition in accordance with a preferred embodiment of the present invention, wherein the molecule is albumin or antineoplastic molecule.
[0019] The composition in accordance with a preferred embodiment of the present invention, wherein the antineoplastic molecule is selected from the group consisting of interleukin, interferon (α, interferon β and interferon γ.
[0020] In accordance with the present invention, there is provided a method for inhibiting tumor growth, the method comprising the step of administering the composition the present invention to a patient.
[0021] The method in accordance with a preferred embodiment of the present invention, wherein the enzymatic moiety is tyrosinase (or enzymes with tyrosinase-like activity for degrading tyrosinase) and the tumor is a skin cancer tumor.
[0022] The method in accordance with a preferred embodiment of the present invention, wherein the skin cancer is melanoma.
[0023] The method in accordance with a preferred embodiment of the present invention, wherein the enzymatic moiety is selected from the group consisting of asparaginase and glutaminase.
[0024] The method in accordance with a preferred embodiment of the present invention, wherein the tumor is selected from the group consisting of asparinase and gluataminase could be used in leukemia or lymphomas that depends on asparagines or glutamine for growing.
[0025] For the purpose of the present invention the following terms are defined below.
[0026] The term “oxygen carrying molecule” is intended to mean hemoglobin, synthetic hemoglobin, synthetic hemes or any other oxygen carrying molecules.
[0027] The term “protective carrier” is intended to mean a carrier that prevents degradation of the enzymatic moiety and therefore increase its half-life.
[0028] The term “molecule with enzymatic activity” is intended to mean synthetic enzyme, enzyme or functional fragment thereof.
[0029] The term “enzyme” is intended to mean tyrosinase, asparaginase, glutaminase or any other enzymes that can deplete any specific amino acid required for growth by any tumours.
[0030] All references herein referred to are incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] [0031]FIG. 1 illustrates the lowering of tyrosine by tyrosinase before and after crosslinking;
[0032] [0032]FIG. 2 illustrates the typical elution profile of PolyHb or PolyHb-tyrosinase;
[0033] [0033]FIG. 3 illustrates the activity of tyrosinase at 37° C. in vitro;
[0034] [0034]FIG. 4 illustrates the oxygen dissociation curve of pure bovine hemoglobin in free form and when it is crosslinked with tyrosinase to form the polyhemoglobin-tyrosinase complex;
[0035] FIGS. 5 A-D illustrate the activity of polyhemoglobin(polyHb)-tyrosinase at different time intervals: A-3.5 hr, B-24 hr, C-30 hr and D-48 hr ;
[0036] [0036]FIG. 6 illustrates the Tyrosine concentration in rat's plasma after injection of PolyHb-tyrosinase;
[0037] [0037]FIG. 7 illustrates in vitro growth curves of B16F10 cell lines when incubated with polyhemoglobin-tyrosinase;
[0038] [0038]FIG. 8 illustrates enzyme activity in artificial cells at different volumes concentrations;
[0039] [0039]FIG. 9A illustrates the activity of free tyrosinase (1020 U/3 ml) in different concentration of tyrosine;
[0040] [0040]FIG. 9B illustrates a double-reciprocal plot of free tyrosinase (1020 U/3 ml);
[0041] [0041]FIG. 10A illustrates the activity of encapsulated tyrosinase (1020 U/3 ml);
[0042] [0042]FIG. 10B illustrates a double-reciprocal plot of encapsulated tyrosinase (1020 U/3 ml);
[0043] [0043]FIG. 11 illustrates the activity of free tyrosinase and encapsulated tyrosinase at different pH;
[0044] [0044]FIG. 12 illustrates encapsulated tyrosinase activity after incubated at 37° C. for 1 hour at different pH;
[0045] [0045]FIG. 13 illustrates storage stability of free and encapsulated tyrosinase at 4° C.;
[0046] [0046]FIG. 14 illustrates storage stability of free and encapsulated tyrosinase at 37° C.;
[0047] FIGS. 15 A-C illustrates tyrosine concentration in rat's intestine juice after incubated with encapsulated tyrosinase (450 U/200 ul; 670 U/300 ul and 900 U/400 ul) in vitro;
[0048] [0048]FIG. 16 illustrates the body weight (g) of rats for control group fed with encapsulated Hb and test group fed with encapsulated Hb+tyrosinase twice a day for 21 days;
[0049] [0049]FIG. 17 illustrates the tyrosine level in test group in rat's plasma expressed as percentage of those in control group;
[0050] [0050]FIG. 18 illustrates the body weight (g) of rats for 22 days experiments;
[0051] [0051]FIG. 19 illustrates the tyrosine level in test group in rat's plasma expressed as percentage of those in control group; and
[0052] [0052]FIG. 20 illustrates the tyrosine concentration in rat's plasma (%).
DETAILED DESCRIPTION OF THE INVENTION
[0053] In accordance with the present invention, there is provided compositions and methods for inhibiting tumor growth.
[0054] It has been found that a novel polyhemoglobin-tyrosinase preparation can rapidly lower the body tyrosine level after one intravenous injection. In this form, the enzyme is covered by hemoglobin molecules and therefore has less immunological properties. Furthermore, polyhemoglobin is an oxygen carrier and being a solution, it can more easily reach the narrower capillaries of the melanoma cancer cells than red blood cells and can therefore bring more oxygen. The presence of high concentration of oxygen is important in radiotherapy for cancer cells. In vitro studies show that this novel polyhemoglobin-tyrosinase preparation inhibits the growth of melanoma cells in culture.
[0055] It also has been shown in accordance with the present invention that daily oral administration of encapsulated tyrosinase by itself for about 3-5 days, can lower the body tyrosine. The oral administration approach has the advantage that no intravenous injections are needed but takes a bit longer to lower the tyrosine level. A proposed encapsulation process is described in U.S. Pat. No. 5,084,350, which is incorporated by reference herein.
[0056] One intravenously injection of polyhemoglobin-tyrosinase followed by 3 times a day oral administration of encapsulated tyrosinase can lower the body tyrosine and maintain this low level as long as the oral administration is continued.
Polyhemoglobin-tyrosinase Preparation
[0057] Materials
[0058] L-tyrosine (98% TLC), hemoglobin from bovine (lyophilized powder), hemoglobin assay kit, tyrosinase from mushroom (3400 U/mg manufacturer's stated activity) were purchased from Sigma-Aldrich (Oakville, Canada). Collodion was obtained from Fisher Scientific (Nepean, Canada). Glutaraldehyde (25%) was obtained from Polyscienes (Warrington, Pa.). Purified bovine hemoglobin was purchased from Biopure Corporation (Boston, Mass.). All other reagents were of analytical grade.
[0059] Preparation of the novel PolyHb-Tyrosinase composition Reaction mixtures were prepared containing hemoglobin 10 gd/l, tyrosinase (6000 U/ml) in 0.1 M potassium phosphate buffer, pH 7.6. In PolyHb mixtures, an equivalent volume of buffer replaced enzyme condition. Prior to the start of crosslinking, 1.3 M lysine was added at a molar ratio of 7:1 lysine/hemoglobin. Crosslinking reaction was started with the addition of glutaraldehyde at molar ratio of 16:1 glutaraldehyde/hemoglobin. Glutaraldehyde was added in four equal aliquots over a period of 15 minutes. After 24 h under aerobic conditions with constant stirring, reaction was stopped with 2.0 M lysine at a molar ratio of 200:1 lysine/hemoglobin. Solutions were analyzed in physiological saline solution overnight and pass through sterile 0.45 μM filter. Aliquots (maximum 500 μl) of the 16:1 crosslinked preparation were concentrated using 100 kDa microconcentrators (Amicon, Beverly, Mass.). Samples were centrifuged at 2500 for 55 min at 23° C. Then, retentate was collected. Hemoglobin concentration was determined by cyanomethemoglobin at 540 nm. Final retentates were diluted to desired concentration at 7 g/dl and 4° C. fridge for later injection
Analysis of Hemoglobin-tyrosinase and Polyhemoglobin-tyrosinase Activity
[0060] This is to study the effects of crosslinking on the tyrosinase enzyme activity. In the study of the effect of glutaraldehyde ratio (one of the crucial reagents for crosslinking ) on tyrosinase activity, tyrosinase activity was tested with the addition of glutaraldehyde at different molar ratio of 8:1 and 16:1 glutaraldehyde/hemoglobin. Hemoglobin was considered with tyrosinase activity without addition of glutaraldehyde as 100% original activity. In table 1, after crosslinking, 99% of enzyme activity remained in PolyHb-Tyrosinase at gluataraldehyde molar ratio of 8:1. For PolyHb-tyrosinase at glutaraldehyde molar ratio of 16:1, 95% activity was obtained. Therefore, no significant difference in enzyme activity between these two groups. Then, hemoglobin was crosslinked with tyrosinase from 3 h to 24 h, and took samples for enzyme activity analysis every 2 h. Results showed that no significant difference in tyrosinase activity among these periods. It indicated that up to 24 h crosslinking time did not decrease enzyme activity significantly. In FIG. 1, the enzyme activity was measured before and after crosslinking. PolyHb served as control, then enzyme activity was tested before and after crosslinking or non-crosslinking which buffer instead of glutaraldehyde solution. From the results obtained, there was no significant change in enzyme activity before or after crosslinking. This further confirmed that crosslinking reaction does not affect enzyme activity significantly.
TABLE I Tyrosinase activity after crosslinking to form PolyHb-Tyrosinase Samples retained % Tyrosinase Hemoglobin + Tyrosinase 100 PolyHb-Tyrosinase at 8:1 99 Glut:Hb PolyHb-Tyrosinase at 16:1 95 Glut:Hb
[0061] Molecular Weight Distribution of PolyHb and PolyHb-Tyrosinase
[0062] To determine the degree of polymerization, samples were analyzed by gel filtration chromatography. At different reaction time, i.e. 3.5 h, 10 h, 24 h, 30 h, 48 h, run sample on a Sephadex G-200 1.6 cm×70 cm column. From the results obtained, the molecular weight distributions were the same for PolyHb and PolyHb-Tyrosinase (FIG. 2). In FIG. 2, typical elution profile of PolyHb or PolyHb-tyrosinase (1 ml sample) run on a Sephadex G-200 1.6 cm×70 cm column, VT=102 ml, equilibrated with 0.1 M Tris-HCI, pH 7.5, and eluted at 12 ml/hr.
[0063] Results showed that two main molecular weight distributions were found at 600 kDa and 60 kDa. The longer time the sample was crosslinked, the higher peek was found at or over 600 kDa. The ratio of hemoglobin to tyrosinase was 1:0.02. The added tyrosinase therefore is not expected to significantly change the molecular weight distribution after being crosslinked with hemoglobin. Table 2 shows the percentage of molecular weight distribution.
TABLE 2 Percentage of area under molecular distribution profiles Percentage of Molecular Weight Distribution (KD) Crosslinking Greater than Between 61 KD Less than Time (hours) Group 600 KD and 600 KD 60 KD 3.5 hours PolyHb 37% 33% 30% PolyHb- 37% 33% 30% Tyrosinase 10 hours PolyHb 55% 23% 22% PolyHb- 55% 23% 22% Tyrosinase 24 hours PolyHb 67% 20% 13% PolyHb- 67% 20% 13% Tyrosinase 30 hours PolyHb 69% 19% 12% PolyHb- 69% 19% 12% Tyrosinase 48 hours PolyHb 71% 18% 11% PolyHb- 71% 18% 11% Tyrosinase
[0064] The stability of PolyHb-tyrosinase at 37° C.
[0065] PolyHb-tyrosinase was incubated, free tyrosinase solution, buffer, PolyHb at 37° C. up to 6 hrs (FIG. 3). Results showed that enzyme activity in free tyrosinase solution decreased faster than PolyHb-tyrosinase at 37° C. At six hrs, 79% activity remained in PolyHb-tyrosinase compared to the activity at time 0. On the other hand, 60% activity was found in free tyrosinase solution after 6 h incubation.
Oxygen Affinity of Hemoglobin and PolyHb
[0066] This is to study the effect of crosslinking tyrosinase to hemoglobin on the oxygen carrying and release characteristics of hemoglobin. Hemoglobin solution served as control group to compare with the novel polyhemoglobin-tyrosinase preparation. There was no significant difference in the oxygen release characteristics between the novel polyhemoglobin-tyrosinase preparation and free hemoglobin solution (FIG. 4). In FIG. 4, oxygen dissociation curve of pure bovine hemoglobin in the free form and in the crosslinking form (Crosslink time 24 h). There is no significant difference in P 50 between the two groups. This shows that the novel polyhemoglobin-tyrosinase preparation retains the ability to carry and release oxygen.
The molecular Distribution of Tyrosinase Activity of PolyHb-tyrosinase Prepared by Different Degrees of Crosslinking
[0067] This is to study the molecular weight location of the tyrosinase in the polyhemoglobin-tyrosinase preparation. Hemoglobin was crosslinked with tyrosinase at 3.5 h, 24 h, 30 h and 48 h (FIGS. 5 A-D). Then, took 1 ml PolyHb-Tyrosinase sample at different time intervals, run through Sephadex G-200 1.6 cm×70 cm column, equilibrated with 0.1M Tris HCI, and eluted at 12 ml/hr. In FIG. 18, the results obtained indicated that the longer time the sample was crosslinked, the higher enzyme activity was found at the molecular distribution of the polyhemoglobin fraction of 600 kDa. With the lowest crosslinking time of 3.5 hours, much of the tyrosinase are not crosslinked to the polyhemoglobin. With 24 hours or more crosslinking, most of the tyrosinase molecules were cross-linked to the polyhemoglobin fraction of 600 kDa.
Animal Studies for Intravenous Injection
[0068] Fasted male Sprague-Dawley rats (245-260 g) were anaesthetized with intraperitoneal injection of pentobarbital (Somnotol, 65 mg/kg). Polyethylene cannulae were inserted and secured distal to the superficial epigastric branches in the femoral veins (PE-10, PE-50 Clay Adams). Take blood sample from each group at the beginning, then inject different samples through femoral vein. Connected femoral artery with vein and let blood circulate for a few seconds, then take blood samples from femoral artery at different time intervals.
Determination of Tyrosine in Rat's Plasma
[0069] Tyrosine concentration in plasma was analyzed by fluorometric method using Perkin Elmer Luminescence Spectrometer LS50B .
Statistical Analysis
[0070] The differences of tyrosine concentration in rat's plasma between two groups (control group and test group) at the same time point were determined by using Student's t-test within ANOVA and considered significant at P<0.05 35.
Intravenous Injection Study of PolyHb-tyrosinase in Rats
[0071] To investigate whether intravenous injection can lower tyrosine concentration in rats, polyhemoglobin-tyrosinase was injected at different hours and at different doses. Tyrosine level was rapidly decreased at the first hour after injection for all doses. However, the lowered levels were maintained more readily with the higher doses (FIG. 6).
Studies of Melanoma Cell Culture
[0072] Tumor Cells and Culture Conditions B16-F10 murine melanoma cells were obtained from American Type Tissue Collection, Manassas Va. The tumor cells were routinely cultured in DMEM (Life Technologies, Invitrogen Canada) supplemented with 10% heat-inactivated FBS, sodium pyruvate, nonessential amino acids, 2-fold vitamin solution, L-glutamine, 100 lU/ml penicillin, and 100 lU/ml streptomycin at 37° C. in a humidified atmosphere of 5% CO2. For passage, cells were detached with 0.05% Trypsin-EDTA and transferred to fresh medium every 3 days. The cells were used in vitro between passage 5 and passage 10. For experiment, melanoma cells were cultured in complete DMEM until they became 30-40% confluent. Then, appropriate aliquots of different samples (0.57 ml sample per 10 ml medium) were added to the medium. The cell viability was followed up to 4 days thereafter.
[0073] In Vitro Cell Growth Assays
[0074] Tumor cells were routinely monitored by phase microscopy. Cell counts were obtained daily with a hemacytometer. Cell viability was determined by trypan blue exclusion.
[0075] To study whether polyhemoglobin-tyrosinase can inhibit the growth of melanoma cells, B16F10melanoma cells were cultured in DMEM with adding appropriate aliquots of saline solution, PolyHb solution, PolyHb-tyrosinase solution and free tyrosinase solution respectively. Cell growth was determined by trypan blue exclusion every day. Cells were counted at day 0 before the medium was added samples and on each day following. From the results obtained, after day 1, melanoma cells in saline solution and PolyHb solution were growing up. On the other hand, the cell growth in PolyHb-tyrosinase solution and free tyrosinase solution was decreasing because tyrosinase inhibits the growth of melanoma cells (FIG. 7).
Encapsulated Tyrosinase for Oral Administration
[0076] Preparation of Microencapsules containing Tyrosinase for Oral Administration
[0077] One gram hemoglobin and 200 mg This was dissolved in 10 ml double distilled deionized water. Stir with a metal rod until everything is dissolved. Gravity filter the solution through a Waterman #42 filter into a Erlenmeyer flask. Take 2.5 ml of this 10 g/dl hemoglobin solution and was encapsulated within spherical, ultrathin, cellulose nitrate membrane. Without tyrosinase loaded microcapsules were administrated orally to control group. For tyrosinase loaded microencapsules, 1.5 mg of 3400 U/mg tyrosinase was dissolved in 2.5 ml 10% hemoglobin solution, then followed the methods described above to immobilize tyrosinase in collodion membrane microcapsules. Microcapsules prepared as a 50% suspension for later feeding. Tyrosinase loaded microencapsules were administered orally to test group. All microcapsules were prepared daily and stored in 1% v/v Tween 20 solution at 4° C. until use.
Analysis of Free Tyrosinase and Encapsulated Tyrosinase Activity
[0078] This is to optimize the preparation of encapsulated tyrosinase for use in oral administration. FIG. 8 shows the activity of free and encapsulated tyrosinase.
[0079] For free enzyme, increase in tyrosinase concentration resulted in increasing in reaction velocity. There is no significant difference in activity between free enzyme and free enzyme in hemoglobin solution. Thus, the interference due to the presence of hemoglobin component in the reaction mixture can be ruled out. For encapsulated enzyme, the reaction activity is increased when the concentration of tyrosinase inside the microcapsules is kept constant, but the volume of microcapsules is increased. However, the activity obtained is lower than enzyme in free solution. To study the reason for this, the membrane of encapsules was broken, then the activity of enzyme was tested. The results show that the activity of enzymes released from the encapsules is only very slightly higher than that of the intact microcapsules, showing that the decrease in activity is due to inactivity of some enzyme during the preparation procedure of microcapsules or some of enzyme entrapped inside the membranes rather than permeability restrictions. On the other hand, study was carried out when the tyrosinase concentration was increased stepwise but the volume of microcapsules was kept constant, the reaction activity is not increased corresponding to the concentration.
Studies in Vmax and Km
[0080] This is to characterize the enzyme kinetics of the preparation and comparing this encapsulated tyrosinse preparation to free tyrosinase. FIG. 9 shows the activity of free tyrosinase in different concentration of tyrosine. The Vmax for 1020 units/3 ml is 114.94 mg/dl-min, and Km is 4.65×104 M.
[0081] Next, the apparent Vmax and apparent Km value for encapsulated tyrosinase (1020 U/3 ml) were studied. The leakage of encapsulated tyrosinase is also measured. FIG. 10 gives the apparent Vmax is 49.02 mg/dl-min, and its apparent Km is 4.65×10-4 M. From the results obtained, the leakage of encapsulated tyrosinase in the supernatant can be ignored.
[0082] From the results obtained (Table 3), the value of apparent Km of micrencapsulated tyrosinase is the same as that of free tyrosinase because the Km value for one enzyme depends on the particular substrate and also environment conditions and ionic. Vmax of the encapsulated tyrosinase is 49.02 mg/dl.min, while that of tyrosinase in free solution is 114.94 mg/dl.min. The higher Vmax value in free tyrosinase than that in encapsulated tyrosinase is due to the inactivation of the enzyme activity during the preparation procedures of microencapsules.
TABLE 3 Summary of studies for V max and K m in free and encapsulated tyrosinase V max (mg/dl · min) K m (M) Free 114.94 4.65 × 10 −4 tyrosinase Apparent V max Apparent (mg/dl · min) K m (M) Encapsulated 49.02 4.65 × 10 −4 tyrosinase
[0083] pH studies in vitro
[0084] Orally administered microencapsulated tyrosinase passes through the stomach and intestine having different pH conditions. Thus it is important to analyze the effects of pH. FIG. 11 provides a comparison of free tyrosinase and encapsulated tyrosinase at different pH from 2 to 10. The enzyme activity at pH 7 were taken as 100% original activity, the other data were expressed as percentage of the original activity. At pH 6, encapsulated tyrosinase and free tyrosinase have 97% and 87% of the original activity respectively. At pH 4, encapsulated tyrosinase still has 21% activity, but only 2.3% activity was detected in free tyrosinase. When pH decreases to 2, there is no activity in free enzyme solution, but for encapsulated enzyme, there is still 14% activity remained. Only 0.4-0.6% activity can be tested in free tyrosinase when pH goes up from 8 to 10. For encapsulated tyrosinase, 49% activity remained at pH 8, even at pH 10, 17% activity can be tested. There are two reasons: first, artificial membranes protect enzyme inside, it separates macromolecules, such as proteins, enzyme from outside environment and the hemoglobin is maintained at a high concentration of 10 g/dl inside the microcapsules. Second, high concentration of hemoglobin solution inside artificial cells makes the enzyme more stable than the enzyme in free solution. Furthermore, the hemoglobin solution acts as a buffer, and it can bind hydrogen ions (H+). Thus, hemoglobin solution protects the enzyme inside microencapsules. For free tyrosinase, its activity is easily affected by pH changing.
[0085] To further simulate the physiological conditions, encapsulated tyrosinase was incubated at 37° C. for one hour at different pH, then washed and tested for enzyme activity at its optimal pH of 7 (FIG. 12). The results showed that at pH 6 to 9, the activity of encapsulated tyrosinase had more than 57% of original activity after one hour incubation at 37° C. FIG. 8 indicates tyrosinase is more sensitive to lower pH, i.e. pH2-4, than other pH range.
Temperature studies in vitro
[0086] It is important to know the temperature stability of the preparation before carrying out studies in the animal. FIGS. 13 and 14 show the difference for storage stability of free and encapsulated tyrosinase at 4° C. and 37° C. At 4° C. (FIG. 13), encapsulated tyrosinase maintained full activity in the first three days and after 15 days it still had 68% of the original activity. On the other hand, the activity of free tyrosinase went down from the beginning and only had 28% of original activity after 15 days.
[0087] At 37° C. (FIG. 14), encapsulated tyrosinase has 61% of original activity after 10 hours and 28% after 24 hours when incubated in water bath at 37° C. This would allow the encapsulated enzyme sufficient stability to carry out its function in the intestine after oral administration. Since the microcapsules stay in the small intestine for about 10-12 hours. For free tyrosinase, it only has 36% of original activity after 10 hours incubation and 7% after 24 hours. The activity of free enzyme decreases faster than that of encapsulated enzyme. Therefore, encapsulated tyrosinase is much more stable than free one under 4° C. and 37° C.
Incubation with Rat's Intestine Contents in vitro
[0088] This is to see the ability of the microencapsulated tyrosinase to lower tyrosinase in intestinal juice before using this for oral administration. Take 50 μl fresh intestine juice from anesthetized rat, then incubate with encapsulated tyrosinase at 37° C. in a shaker. Keep it shake gently in order to make tyrosinase microcapsules react with rat intestine juice completely. In the control group, same amount of microcapsules without enzyme were incubated with rat's intestine juice. Take sample at different time intervals, add 10% trichloroacetic acid (TCA) to stop the reaction, centrifuge it, then analyze the concentration of tyrosine in rat's intestine juice by fluorometric method. In this study, when the activity of encapsulated tyrosinase was increased, and lowering tyrosine level in rat's intestine contents were observed.
[0089] From the results obtained (FIG. 15), a significant different between control group and test group was observed. For the test group, tyrosine concentration in rat's intestine was from 200.25±10.16 mg/dl at the beginning decreased to 73.34±14.72 mg/dl in 30 minutes. Tyrosine level was decreased quickly when incubated with encapsulated tyrosinase for test group. The secretions of intestine contain high concentrations of proteins, enzymes, polypeptides, and peptides. Tryptic enzymes in the intestine break these down into amino acids. Therefore, tyrosine level in control group kept going up with time from 177.58±29.92 mg/dl at the beginning to 219.76±15.21 mg/dl at 30 minutes after an initial decrease due to equilibrate of tyrosine in the intestine juice and the microcapsules. When increasing the volume of encapsulated tyrosinase, tyrosine concentration in test group kept at low level during the experiment period.
Animal Studies for Oral Administration
[0090] Fasted male Sprague-Dawley rats (130-150 g) were used in this studied. All rats were kept in a controlled 12 h light/dark environment with food and water ad libitum. Two groups were studied: (1) control group: feed with artificial cells without enzyme; (2) test group: feed with artificial cells loaded with tyrosinase. Each experiment began on day 0 with blood taken, and no artificial cells were administered on that day. From that day on, and every subsequent day for 21 days, artificial cells were administered orally at 10:00 am, 2:00 pm, and 6:00 pm. Blood samples were taken on Day 4, 8, 11, 15, 18, 22 just after second feeding. Plasma in each blood sample was separated from the blood and placed in 1.5 ml microtube, then stored at −80° C. until analyzed.
Oral Administration Study in Rats
[0091] One-dose a day was not effective in lowering the tyrosine level. Two doses a day and three doses a day were experiment as follows:
Two-dose Experiment
[0092] As one dose oral administration of artificial cells could not bring any significant change in the tyrosine level in plasma, dosage was increased to two doses every day. Rats fed on regular rat food and administrated to artificial cells twice a day gained body weight with time during the 21-day experiment period (FIG. 16).
[0093] In this study, there was significant difference in tyrosine level in test group starting from the first week and no significant change in control group (FIG. 17). Plotting the results as percent of control group, at Day 7 the tyrosine concentration in the test group is decreased to 85% of that in control group. At Day 14 and Day 21, tyrosine concentration is further decreased in test group to 62.9% and 55.8% respectively. Results showed that encapsulated tyrosinase is effective to lower tyrosine level in the body and longer time is needed to reach this goal. The reason is that once the tyrosine concentration is decreased in plasma, tyrosine inside living cells will come out to compensate the loss of tyrosine in plasma. The basic theory for these experiments is that artificial cells loaded tyrosinase can remove tyrosine from amino acid pool in the intestinal tract and prevent its reabsorb back into the body amino acids pool, thereby lowering circulatory tyrosine level.
[0094] Table 4 shows the summary of statistical analysis for tyrosine concentration in two groups. After one week oral administration, there is significant decrease (p<0.005) in tyrosine level in test group compared to that in control group. Continuing this treatment until day 21, the significant decreasing (p<0.0005) in tyrosine level is even greater.
TABLE 4 Compare p-value between Control Group & Test Group C: control group, T: test group Comparing −value C day 0/ NS T day 0 C day 7/ 0.005 T day 7 C day 14/ 0.005 T day 14 C day 21/ 0.0005 T day 21
[0095] Three-dose Experiment
[0096] To decrease tyrosine concentration to a certain level, rats were fed with three oral doses of artificial cells per day. Results showed that the rats in control group and test group continued to get weight during the experiment period (FIG. 18). No abnormal effect or behavior was observed in both groups. From blood sample analysis, there was significant change in tyrosine concentration on day 4 between control group and test group (FIG. 19). The tyrosine concentration in plasma showed constant fluctuations even though the time of feeding and plasma collection was constant. This fluctuation was also found in all experiments, as well as in normal rats. Thus, tyrosine level was taken in control group as 100% original activity, the other data are expressed as percentage of the original activity. On day 4 in test group tyrosine level decreased to 68.8%. On day 18 and day 22, the tyrosine concentration decreased to 56.8% and 52.6% respectively. Results show that 3 doses per day of oral administration can lower tyrosine concentration in rat's plasma from day 4. Table 5 shows the studies of statistical analysis for tyrosine concentration in two groups. At day 4, a significant decrease (P<0.05) in the test group was observed.
TABLE 5 Compare p-value between control group & test group Time (Day) Comparing P-value Day 0 Control group/Test group NS Day 4 Control group/Test group <0.05 Day 8 Control group/Test group <0.05 Day 11 Control group/Test group <0.005 Day 15 Control group/Test group <0.005 Day 18 Control group/Test group <0.005 Day 22 Control group/Test group <0.0005
Combine Intravenous Polyhemoglobin and Oral Encapsulated Tyrosinase in Rats
Combined Animal Studies with Oral Injection and Intravenous Injection
[0097] On day 0, take blood sample at 4:00 pm. No artificial cells were administered on this day. From that day on, and every subsequent day for 4 days, artificial cells were administered orally at 10:00 am, 2:00 pm and 6:00 pm. Take blood samples every day just after the second feeding. On day 1, injected 1 ml of PolyHb sample per 250 g rat's body weight to control group and 1 ml of PolyHb-tyrosinase sample per 250 g rat's body weight to test group. On day 2, injected half volume of PolyHb and PolyHb-Tyrosinase sample to rats respectively.
[0098] Although intravenous (I.V.) injection provides fast decreasing in tyrosine level in rat's blood system, repeated injection is needed to keep low tyrosine concentration. Crosslinking of the enzyme to polyhemoglobin protects the enzyme from causing immunological reactions. However, long term repeated injections is not as convenient and may cause some reactions. To solve this problem, the two methods were combined. Thus intravenous injection of polyhemoglobin-tyrosinase and Oral administration of artificial cells starts from the beginning of the experiment but only oral administration was continued throughout the experiment period. On day 1, give to the rats the first injection. To keep tyrosine in a low level after the first injection, we further investigate if the rats can stand one more dosage on the second day and whether this second injection will be effective to keep or lower tyrosine level. The body weight of rat in this experiment kept at the same level as that on day 0 except that a slightly decrease on day 2 due to the surgery. On day 1, tyrosine level decreased to 54% after the first injection. Then, on day 2, another half volume of injection was given. This time tyrosine level went up slightly to 61%. On day 3, when stop the injection, tyrosine level went up to 70%, which is 9% higher than the level of yesterday. However, on Day 4, tyrosine level started to decrease which indicated the effectiveness of oral administration of encapsulated tyrosinase (FIG. 20). Results show that I.V. injection method rapidly lowered tyrosine level. Then, oral administration of artificial cells containing tyrosinase keeps that low tyrosine level in the body system. Therefore, combined method can lower tyrosine level in a fast and effective way. Table 6 indicates the statistical studies for tyrosine concentration in both control group and test group.
[0099] For control group: feed with artificial cells without enzyme orally three times a day, inject 1 ml per 250 g body weight of PolyHb sample on day 1 and inject half volume of the same sample on Day 2.
[0100] For test group: feed with artificial cells loading with tyrosinase orally three times a day, inject 1 ml per 250 g body weight of PolyHb-tyrosinase sample on day 1 and inject half volume of the same sample on day 2.
TABLE 6 Compare p-value between control group & test group Time (Day) Comparing −value Day 0 Control group/Test S group Day 1 Control group/Test 0.0005 group Day 2 Control group/Test 0.005 group Day 4 Control group/Test 0.005 group Day 5 Control group/Test 0.005 group
Discussion
[0101] In this study, PolyHb-tyrosinase and encapsulated tyrosinase were used to decrease tyrosine level in rat's blood system. Furthermore, since crosslinked hemoglobin is oxygen carrier, it provides additional oxygen supply needed for more effective radiation treatment in melanoma which, like other tumours, is not well perfused by oxygen supplying red blood cells. This is in addition to its ability to quickly lower the tyrosine level from the plasma. However, at 24 h after the intravenous injection, tyrosine level went back to the level before injection. Repeated injections are needed to keep tyrosine at low level, and long term repeated daily intravenous injection is not convenience and may also cause reaction. Encapsulated tyrosinase is effective in lowering tyrosine level through the intestinal amino acids pool. However, this method needs longer time to decrease tyrosine level from the body system. In combining these two methods. I.V. injection rapidly lowered the tyrosine level in the plasma, meanwhile oral administration of encapsulated tyrosinase artificial cells kept tyrosine at that low level. Finally, it is assessed the effect of polyhemoglobin-tyrosinase on the growth of melanoma cells in vitro. Result showed that polyhemoglobin-tyrosinase inhibits the growth of melanoma cells which shows that polyhemoglobin-tyrosinase is effective on melanoma cells.
[0102] While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as follows in the scope of the appended claims.
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The present invention relates to a composition for inhibiting tumor growth, which comprises a tumor growth inhibiting enzymatic moiety in association with at least one protective carrier. The present invention further relates to the methods of inhibiting tumor growth using this composition.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is related to and claims the benefit of U.S. Provisional Application Ser. No. 60/604,945 filed Aug. 27, 2004, the teachings of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to an extended life mineral acid detection tape and, in particular, to a mineral acid detection tape which possesses uniform gas sensitivity and acceptable background color for at least a three-month time period when placed in usage.
DESCRIPTION OF THE PRIOR ART
At present, existing mineral acid detection tapes are available based upon several types of chemistry. One acid detection system utilizes a mineral acid detection tape containing a pH indicator dye. However, the acid based stains on the detector tape are not stable and the pH indicator dyes themselves are toxic. Also in such a system, the relationship between the acid gas concentration and the stain color intensity is non-linear thereby requiring the need of complex optical monitor assemblies. Moreover, a limited number of pH indicating dyes are available for use with such optical monitor assemblies and such detection tapes have a limited useful life of approximately a one-month time period.
Another mineral acid detector tape system relies upon a diazo-coupling reaction in an acid phase to provide an intense red color indicative of the presence of acid gases. Although such a system is sensitive to acid gases, such a system has a limited useful lifetime. Also, the sensitivity and tape background colors of such a system are unstable to chemicals, such as primary amines and coupling reagents in the tape formula which possess temperature and light sensitivities. Over time, the background of such mineral acid gas detection tape darkens, and as the tape background darkens, the sensitivity of the tape decreases. For example, such tapes exhibit significant background drops within a 4-6 week period of use. Also, under room temperature conditions, such tape darkening results in a 30-40% optic reading drop within a 30-day period. Additionally, such detection systems possess unstable tape sensitivities and reduction in sensitivity of between 10-20% within a 30-day period and between 40-60% within a 90-day period. Accordingly, the useful life of such mineral acid detection tape systems are limited to at most a 30-day period of time after they are placed in service. Thus, such tapes must be replaced after a 30-day period of use to provide acceptable monitoring of acid gases.
Also, the reaction rate between the acid gas concentration and the tape color intensity is non-linear at low concentrations of acid/gas detections. The resultant reaction curves are S-shaped, which result in a slow response and a narrow detection range for such mineral acid detection tapes.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a solution to the limited lifetime of existing mineral acid detection tapes. This solution is achieved by utilizing diazo-coupling reagents possessing low toxicity and reduced dependency on temperature and light to thereby provide an improved mineral acid detection tape possessing a useful life of at least 3 months.
It is an object of the present invention to provide a mineral acid detection tape which possesses a uniform tape background stability under room temperature conditions over an extended period of time of at least 90 days.
Still another object of the present invention is to provide a mineral acid detector tape that is sensitive to low acid concentration levels over an extended period of time.
Yet another object of the present invention is to provide diazo-coupling reagents possessing low toxicity resistance and reduced dependency to temperature and light within a stable gas detection tape over an extended period of time.
Still a further object of the present invention is to provide an alkalized mineral acid detection tape which is stable over an extended pH range.
It is another object of the present invention to use a polyalcohol to uniformly impregnate an acid detector tape with diazo coupling reagents to provide a tape possessing moisture and sample gas trapping efficiency for at least 90 days.
In accordance with the present invention, an acid gas detection tape for detecting mineral acid gases, such as hydrochloric acid, hydrobromic acid, hydrofluoric acid, hydriodic acid, nitric acid, sulphuric acid, phosphoric acid, and acetic acid, is provided and which extends the useful life of the mineral acid detecting paper up to at least a three-month period of time when placed in usage.
The extended life mineral acid detection tape is saturated with a formula solution by passing the cellulose paper substrate through a bath containing the formula solution. The formula solution includes a pH buffer of between 8-9% by volume of the total volume of solvent and between about 0.07-0.10% by weight of the total weight of solvent of reagent grade chromotropic acid is added to the composition as a coupling agent. Sodium nitrate, within the composition range of 0.25-0.38% by weight of the total weight of solvent, is added to the formula composition to facilitate the diazotization reaction. A stabilizer of sodium bromide of between 0.3-0.5% by weight of the total weight of the solvent is added to the composition and a diazotization coupling agent, reagent grade sulphanilic acid, of between a weight percent of 0.15-0.35% by the total weight of the solvent is added to the composition. A pH indicator, containing 0.1% ethyl red, of between 4-4.5% by volume of the total volume of solvent is added to the composition, and a humectant comprised of a polyalcohol of between 4-5.5% by volume of the total volume of solvent is added to the composition. Each of the reagents is dissolved in the order shown in an amount of between 3.3 to 3.5 liters of methyl alcohol as the solvent.
When the formula solution is properly mixed, a paper tape substrate is then passed through a bath containing the formula solution. The coated paper substrate is then passed through a oven, one meter in length, that is maintained within a temperature range of 70-80° C. The coated tape paper travels at a speed of between 2.2 to 3.4 meters per minute through the oven. The dried mineral acid detection tape exiting the drying oven possesses a light or faint yellow tinge of color.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph of the background stability of extended life mineral acid detection tapes in accordance with the present invention under room temperature conditions as compared to the background stability of a conventional mineral acid detection tape;
FIG. 2 is graph of the tape sensitivity stability of extended life mineral acid detection tapes in accordance with the present invention under elevated temperature conditions as compared to the background stability of a conventional mineral acid detection tape;
FIG. 3 is a graph of the sensitivity stability of extended life mineral acid detection tapes in accordance with the present invention under room temperature conditions as compared to the sensitivity stability of a conventional mineral acid detection tape;
FIG. 4 is a graph of the sensitivity stability of extended life mineral acid detection tapes in accordance with the present invention under elevated temperature conditions as compared to the sensitivity stability of a conventional mineral acid detection tape; and
FIG. 5 is a graph of the response time at a low end gas concentration of an extended mineral acid detection tapes in accordance with the present invention as compared to the response time of a conventional mineral acid detection tape.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention relates to a extended life mineral acid detection tape for monitoring the presence of mineral acids in the environment. A cellulose tape paper substrate (identified as Chroma-1 from Whatman, Inc.) is saturated with the formula solution in accordance with the present invention to provide a detection tape that possesses an extended life of at least 90 days.
The formula solution is comprised of a pH buffer of 0.26 M sodium hydroxide plus 0.009 M of Borax, which is 8-9% by volume of the total volume of a solvent. In the alternative, the pH buffer may be 0.28 M sodium hydroxide plus 0.15 M of 3-(cyclohexylamino)-1-propanesulfonic acid (hereinafter referred to as CAPS), which is 8-9% by volume of the total volume of the solvent. By reducing the amount of the pH buffer, the tape sensitivity is increased while the background darkening is increased. Increasing the amount of the buffer solution above this range results in the sensitivity of the formula solution being lowered. The pH buffer material and the glycol propoxylate humectant are utilized for stabilization of the detection tape.
A coupling agent of reagent grade chromotropic acid of between 0.07-0.1% by weight of the total weight of the solvent is added to the formula solution. By increasing the amount of this coupling agent to the formula, the background darkening of the tape background is accelerated due to the excess amount of coupling agent, which causes self-coupling of the coupling agent.
The formula solution may optionally contain a reagent grade N-naphthylethylenediamine dihydrochloride (hereinafter referred to as NED) of about 0.05-0.11% by weight of the total weight of the solvent. The NED is used to increase the sensitivity to hydrochloric acid gas. The background darkening is accelerated faster due to the excess amount of coupling agent, which causes self-coupling of the reaction mechanism. The optional coupling agent NED may also be selected from the group of N,N Dimethylaniline, iminodibenzyl, and gentistic acid. The formula solution further includes a sodium nitrite for the diazotization reaction. The amount of sodium nitrite is between 0.25-0.38% by weight of the total weight of solvent.
Also, the formula utilizes a stabilizer comprised of sodium bromide. The amount of stabilizer is between 0.032-0.05% by weight of the total weight of the solvent.
The formula solution further includes reagent grade sulphanilic acid as a diazotization coupling agent. The amount of the coupling agent is between 0.15-0.35% by weight of the total weight of the solvent. The coupling agent may also be selected from the group of metanilic acid, anthranilic acid, m-aminoacetoanilide and p-nitroaniline. The formula solution additionally includes a pH indicator, containing 0.1% ethyl red, of between 4-4.5% by volume of the total volume of the solvent. The pH indicator is red at approximately a pH of 4.5 and is yellow at a pH of 6.5. By increasing the amount of the pH indicator, the linearity at the beginning of detection is enhanced. It is desired that color change occur from colorless/yellow to red or blue when contacted with the acid gas. Additional indicators acceptable for use in the formula solution may be selected from the group of ethyl orange, methyl red and metanil yellow.
Finally, a humectant, which is a polyalcohol comprised of one part ethylene glycol and one part glycerol propoxylate, of between 4-5.5% by volume of the total volume of solvent, is added to the formula solution. By decreasing the amount of glycerol propoxylate in the polyalcohol, the sensitivity of the detection tape is increased upon exposure to the target gas. However, the darkening of the tape background occurs more rapidly. By increasing the amount of this humectant material, the sensitivity is lowered. Other humectants that may be utilized are polyethylene glycol or glycerol.
Each of the reagents, including the pH buffer and the coupling agent, the nitrite for diazotization, the stabilizer, the diazotization coupling agent, the pH indicator and the humectant are dissolved in the order described in 3.3-3.5 liters of methyl alcohol as the solvent. Although ethyl alcohol may be used as the solvent, this solvent results in lower sensitivity and lower gas trapping efficiency.
The nitrite ions present in the formula solution and the aromatic amine react with an acid gas present in a sample gas stream to form an intermediate diazonium salt, as shown by (1). This diazonium salt is characterized by containing diazonium ions, which are electrophiles that seek out species of electrons which can be shared to reach equilibrium.
The diazonium salt couples with the aromatic coupling compound, the chromotropic acid, to form the red-orange colored azo complexes, as shown by (2).
These complexes are evident as a visible color stain on the saturated and extended life mineral acid detection tape. The intensity of the color stain on the tape relates to the amount of the toxic gas present in the sample stream.
The mineral acids that can be detected utilizing this acid detection tape include hydrogen bromide, hydrogen chloride, hydrogen fluoride, hydrogen iodide, nitric acid, sulphuric acid, phosphoric acid, and acetic acid.
The detection tape is comprised of a cellulose paper substrate, which is commercially available as Chroma-1. The paper detection tape is saturated with the formula solution by passing the paper tape through a bath containing the formula solution. The tape is then passed through an oven having a length of approximately one meter and which is maintained between 70-80° C. The saturated tape is advanced through the oven at a speed to provide a residence time within the oven of between about 45 to 75 seconds. Upon exiting the oven, the tape has a light yellow color and is wound onto the cassette.
As shown in FIGS. 1-5 , the paper detection tape is saturated with variations of the formula solution to provide various samples A-C which are compared with a sample detection tape D in accordance with the prior art. In FIGS. 1-5 , Sample A is the standard formula solution utilizing the pH buffer containing borax and the polyalcohol of one part ethylene glycol and one part gylcerol propoxylate, Sample B is the standard formula solution of Sample A wherein the pH buffer contains 10% less glycerol propoxylate, Sample C is the standard formula solution of Sample A wherein the pH buffer includes 3-(cyclohexylamino)-1-propanesulfonic acid (CAPS), and Sample D is a paper detection tape representative of the prior art which contains p-nitroaniline, an aromatic amine, which reacts to provide the diazonium salt which in turn reacts with the coupling compound N-naphthylethylene dihydrocloride.
Specifically, in FIGS. 1 and 2 , the paper detection tapes, Samples A-C, are treated with the formula solution and provide a stable background well in excess of 90 days. Specifically, in FIG. 1 the background changes within 100 optics, a 5% drop within 90 days, under room temperature conditions, and within 100-300 optics reading a 10% drop under high temperature conditions, as shown in FIG. 2 . Also, as shown in FIGS. 3 and 4 , the paper detection tapes, Samples A-C, are treated with the formula solution under room temperature ( FIG. 3 ) and high temperature ( FIG. 4 ) and provide a sensitivity of within ±10% over at least 90 days while the conventional acid detecting tape, represented by Sample D, results in a sensitivity drop of between about 40-60%.
Additionally, as shown in FIG. 5 , the paper detection tapes, Samples A and C, treated with the formula solution provides increased response times for low acid gas concentration levels when compared to an existing acid detection tape, Sample D.
Illustrated and described above is regarded to be the preferred embodiment of the present invention, nevertheless it will be understood that such are merely exemplary and that numerous modifications and rearrangement may be made herein without departing from the spirit of the invention.
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A mineral acid detection tape includes a cellulose paper substrate saturated with a formula solution and provides an extended life detection tape of at least a three-month period of time when place in service.
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OBJECT OF THE INVENTION
[0001] Microwave mixer-dryer-reactor for industrial use, designed for mixing all types of products, solids with solids, solids with liquids and solids with very tacky fluids, also obtaining through product mixing the subsequent drying, as well as the start of a reaction when it is thus required by a massive discharge of microwaves proceeding from a generator especially attached to the spindle of the machine, being possible to use just one of the functions or any combination of them.
BACKGROUND OF THE INVENTION
[0002] In the current industry the machines and process necessary to carry out any of the three processes mentioned are available; thus, there are a great variety of both horizontal and vertical mixers, generally composed of a cylindrically shaped chamber in which the products to be mixed are deposited. In the centre of said chamber a spindle is introduced, which may have blades attached, or which may have the shape of an endless screw, among other different constructive arrangements, depending on the characteristics of the product to be mixed. Said spindle is attached onto a motor, which upon turning makes the spindle mix the product. Said cylindrical chamber often includes two areas or a double sleeve, one in which the products to be mixed are deposited, and another one, outside the first, through which a hot or cold liquid is sent, depending on whether one wishes to warm or cool the products to be mixed.
[0003] As examples of this type of mixers, the following are available:
European Patent Application n o 90107482. Dryer-mixer for producing and elaborating dry, humid, pastes, and fluid products. European Patent Application n o 93120513. Dryer mixer European Patent Application n o 94108192. Mixer-granulator-dryer-container.
[0007] The drying process is based on eliminating water or other liquids carried by the products. In order to eliminate them different mechanical processes have been developed, through warm air, etc. as well as electrical ones, for example be way of microwaves or radio frequency. The following patents are known:
European Patent Application n o 96914119. Crystalline substance drying facility. European Patent Application n o 96923192. Aggressive drying by convection in a tapered screw mixer/dryer. European Patent Application n o 8303667. Microwave treatment mechanism for eliminating dampness from articles.
[0011] The third process, or that of starting the reaction, is obtained by controlling the temperature of the mixture through controlling the power of the microwaves. In the case of a double chamber mixer dryer, it is carried out by sending more or less liquid through the second chamber, thus warming the mixture to the necessary temperature for its reaction. In the case of a microwave dryer the reaction is started by adjusting the power and frequency of the microwaves thus managing to increase the temperature for its reaction and intensifying the interaction of the microwaves in the material; the action of the reactants is influenced by the microwave emission frequency, said frequency being variable within all of the margin of microwaves.
[0012] As can be appreciated in the existing systems, the three processes that are the object of the present invention are effectuated independently, there being no machine that can carry out the mixing, microwave drying and starting of the chemical reactions together in one single continuous or discontinuous process, the unification of the three processes in one being what makes this invention innovative.
DESCRIPTION OF THE INVENTION
[0013] The present invention relates to a machine whose purpose is to unify in a single production process the processes that until now have been carried out separately, which are product mixing, drying by way of a microwave generator and the start of a reaction when the product thus requires, obtaining in this way production cost reduction by decreasing product manipulation, increasing their quality due to improved mixing, avoiding contamination by carrying out the whole process in a single machine, reducing cleaning product costs and labour and also avoiding in this way environmental pollution, enabling the three processes to be carried out continuously or discontinuously.
[0014] A machine has been built that is provided with all of the mechanisms of conventional mixers, adding all of the elements necessary to effectuate drying and starting the reaction due to the incorporation of a microwave generator and to the modifications effectuated in the mixing spindle, on which mixing blades are attached, in order to conduct the microwaves that are generated. In addition, said machine is provided with all of the security systems needed to avoid possible accidents by microwave dispersion.
[0015] The machine of invention has a bed or machine support on which the main motor is arranged, whose power will depend on the mass and physical properties of the product to be mixed; a clutch is coupled onto said motor, and this in turn is coupled to a reducer also designed for the purpose it is to carry out. Between the reducer and the mixing spindle an elastic apparatus is attached, thus composing all of these parts the motor and traction group for the mixing spindle.
[0016] Coupled to said bed and centred with the mixing spindle is the mixing drum, of horizontal cylindrical shape, with double sleeve and made of steel of different qualities depending on the requirements of the process. The products to be mixed are loaded through a loading mouth located on the upper part of the mixing drum, and a liquid can be sent through the double sleeve to cool or warm the mixture. In addition, this mixing drum is provided with a discharge mouth for discharging the product on its lower part, with an inspection door, located adequately on the drum, with a system for adding liquids to the mixture when needed, and with an airing mouth for airing the mixture.
[0017] All of the components coupled to the mixing drum, such as the loading and discharge mouths, are provided with locks or valves with a security system which, in case one of them should be opened during the process, makes the microwave generator stop immediately, automatically interrupting the process and preventing the dispersion of microwaves in every case.
[0018] One of the main components of the machine that is the object of the present invention is the mixing spindle, coupled on one side of the reducer box and on the other rested on the end of the mixing drum. This is the element in which all of the maximum efforts are generated since by way of the mixing blades that are attached to it must mix all of the products within the mixing drum. In order to ensure effective mixing, one or several mixing intensifiers are attached, made up or blades mounted on a spindle that is moved by a motor through an elastic assembly, and which are mounted on the sides of the drum, said blades staying inside said drum and in contact with the product.
[0019] In order for the microwaves to enter into contact with the mixture and to warm it, thus eliminating water or solvents or making the mixture react, the mixing spindle has been designed so that it is hollow inside and includes holes that radially pass through to its outer surface, of different sizes, arranged in a regular distribution along the spindle and with circular or rectangular shapes. This hollow spindle is open at one of its ends in order to allow the entry of the microwaves and closed at the opposite end in order to prevent said microwaves from dispersing unduly.
[0020] A microwave generating apparatus mounted on the open end of the mixing spindle is responsible for sending the microwaves through said spindle, which come out through the holes arranged on it, thus entering into contact with the mixing product.
[0021] The working sequence is identical for both single load machines and for continuous process machines and is always made up of the following steps.
Loading of the material through the different loading mouths, (solids or liquids) in the appropriate proportions or times depending on the products to be mixed. Mixing of the loaded product by way of the mixing blades attached to the mixing spindle; said mixing is carried out by making the mixing spindle turn, the turning speed of the same being adjustable in order to thus obtain a homogeneous mixture. Once the mixed products are dried or are made to react upon the microwaves entering into contact with them; these are produced in a microwave generator situated outside of the mixing drum and are sent to the product through the inside of the mixing spindle and coming out of the mixing drum through the radial holes bored in said mixing spindle. Once all of these processes are completed, the product is discharged through the discharge mouth.
[0026] This procedure can be carried out continuously or discontinuously, the first option being used when the material enters continuously without stopping into the mixer, thus producing the mixture, drying, and chemical reaction during the passage of the material through the machine and discharging the material continuously also at the end of the reaction, through the discharge mouth. In a discontinuous manner, the material is loaded into the machine at once, the drying, chemical reaction, and discharging of all of the material being carried out also in a single process.
DETAILED DESCRIPTION OF THE DRAWINGS
[0027] In order to provide an improved understanding of the present invention, a preferred embodiment is described below of the object of the present invention, based on the attached figures.
[0028] FIG. 1 : General view of the mixer and its components.
[0029] FIG. 2 : View of the locations of the loading mouths and of the intensifiers.
[0030] FIG. 3 : View of the main spindle and microwave outlets.
PREFERRED EMBODIMENT OF THE INVENTION
[0031] The machine that is the object of the present invention unifies the three basic processes of a microwave mixer dryer reactor, which are: mixing several products, warming and drying of the product resulting from the mixture, as well as making it react, and its subsequent discharging, for which a machine has been developed which, although in its basic features it can be considered conventional, includes within it a microwave generator for warming and later drying the product, a completely innovative system in this type of machinery.
[0032] Thus, the machine of the present invention is composed of four main parts: the bed, the mixing drum, the mixing spindle and the microwave generator.
[0033] On the bed ( 1 ), the mixer dryer mechanism is located, serving said support bed and basis of the rest of the machine, and on it the main electrical motor is mounted ( 2 ), which a clutch has been coupled to ( 3 ) and to it, a reducer ( 4 ); between the reducer and the mixing spindle ( 6 ) an elastic assembly ( 5 ) is mounted, thus being defined the motor and traction group of the mixing spindle. All of these components, as the rest of the machine, are sized for the amount of material to be mixed and the physical properties of the product.
[0034] Coupled to said bed ( 1 ) and centred to the mixing spindle ( 6 ), the mixing drum ( 7 ) is located, having a horizontal cylindrical shape and double sleeve, and built of steel; the products to be mixed are loaded in the central part of the mixing drum through a loading mouth ( 8 ) located on its upper part. This mixing drum ( 7 ) is also provided with a product discharge mouth ( 9 ) on its lower part, with an inspection door, with a liquid adding system ( 11 ) for the mixture and with an airing mouth 16 ) for airing the mixture. All of the components coupled onto the mixing drum ( 7 ) such as the mouths for loading ( 8 ) and discharge ( 9 ), are provided with locks or valves with a security system ( 12 ) which, in case of accidental opening of one of the locks, causes an immediate stopping of the microwave generator, thus interrupting the whole process.
[0035] The third component of the machine which is the object of the present invention is the mixing spindle ( 6 ), coupled on one side to the reducer box ( 4 ) by way of a connection ( 5 ) and on the other side, rested on the end of the mixing drum ( 7 ); it is the component in which the maximum efforts are made since by way of the mixing blades ( 14 ) that are attached to it, and the intensifiers ( 17 ), it must mix all of the products inside the mixing drum. It is also the conduct of the microwaves from the generator ( 13 ) to the product, said microwaves entering into contact with the product after having passed through the holes ( 15 ) bored in the mixing spindle ( 6 ). This hollow spindle is open at one of its ends in order to allow microwaves to enter, and closed at the opposite end in order to prevent said microwaves from dispersing unduly.
[0036] At the open end of the mixing spindle ( 6 ) a microwave generator ( 13 ) is assembled. In order for the microwaves to enter into contact with the mixture the mixing spindle ( 6 ) has been designed in such a way that it is hollow inside and on whose outer surface pinholes ( 15 ) have been made passing through it radially, said holes ( 15 ) being of circular shape and said holes ( 15 ) being distributed regularly along said mixing spindle ( 6 ), so that the microwaves generated by the microwave generator ( 13 ) coupled onto one of the ends of said mixing spindle ( 6 ) reach the mixing product, thus also eliminating water or solvents.
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The invention relates to a microwave mixer/dryer/reactor for industrial use. The inventive machine has a three-fold purpose, namely to: a) mix solid products with solids, solids with liquids and solids with very viscous fluids; b) dry aforementioned products; and c) initiate reaction between said products by means of suitable microwave discharge from a generator which is specially connected to the shaft of the machine. Said machine can be used to perform one or two of said functions or all the functions together.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates to a method for manufacturing a complicated fiber grating by probing a diffraction of a phase mask. More particularly, the present invention relates to a method for manufacturing a long-length fiber Bragg grating (FBG) having a complicated structure, and a method for manufacturing a sequentially joined fiber grating longer than a phase mask in order to reduce errors in manufacturing fiber gratings. The present invention further provides a method for sequentially joining a plurality of grating sections into a fiber grating longer than a phase mask.
[0003] 2. Description of Related Art
[0004] In recent years, many methods have been proposed for manufacturing a long-length fiber grating having a complicated structure, including the moving fiber-scanning beam technique and the sequential writing technique. When these two techniques are applied to a UV writing process, a He—Ne laser interferometer is required to track the position of an optical fiber. However, while manufacturing a long-length fiber grating, an accumulative error in the fiber position may occur during exposure due to a drifting of fringes generated by the interferometer and an inaccurate estimation of grating periods. This error has great impact on the manufacturing process and adds to the difficulties in manufacturing fiber Bragg gratings having complicated refractive-index changes and phase shift structures.
[0005] A patent application was filed in Taiwan by the present inventors of a method for manufacturing a fiber Bragg grating (Taiwan Patent Application No. 094115916; filed on May 17, 2005), wherein a phase distribution of a reference fiber grating is probed before each overlapping UV exposure. In this method, a feedback system is employed to probe a phase distribution of the reference grating at each locating point, so that the phase distributions of the reference grating before and after the reference grating is moved can be controlled to be consistent, ensuring that a phase of each written grating section is continuous from a phase of a previous grating section. However, the reference grating has a very small fiber core radius and a low first-order diffraction efficiency, making it difficult to calibrate the accuracy of position monitoring.
[0006] Furthermore, it is known from numerical simulation results that, for a subsequent fiber grating to have a frequency spectrum of a desired quality, a period mismatch between a period of the grating used for position monitoring and a period of UV fringe writing must be smaller than 5%. For ease of contrast, the prior art techniques mentioned in the first paragraph of this section are summarized below in comparison with the present invention to demonstrate their respective pros and cons.
[0007] (1) Taiwan Patent No. 434431
[0008] According to the method of this patent, a light beam is used to directly write a grating into a moving waveguide. Without using a phase mask and the interference technique, the grating is written in a point-by-point manner, whose refractive index is changed along the waveguide solely by controlling a moving speed of the waveguide. This method is suitable only for a long-period fiber grating and not applicable to a short-period fiber Bragg grating.
[0009] (2) U.S. Pat. Nos. 6,834,977 and 6,813,079
[0010] In these two patented methods, a grating is written into an optical fiber through a phase mask, section by section, by exposure to a continuous UV writing beam in an overlapping manner. Besides, an interferometer is used to monitor a position of a translation stage at each locating point. However, using the interferometer to monitor a writing location on the optical fiber leads to an accumulative error and requires accurate calibration of a period of the UV writing beam in advance. In the present invention, a grating is sequentially written in a section-by-section manner by probing a phase of a reference fiber grating, wherein a standard phase distribution is provided as a reference for writing. Therefore, according to the present invention, there are no accumulative error-related problems, and the accuracy of period calibration does not influence the manufacturing process significantly.
[0011] (3) U.S. Pat. No. 5,945,261
[0012] In this patented method, which utilizes the principle that an optical fiber exposed to a UV light will produce a fluorescent light, a grating section is created in advance by UV exposure and, by probing an intensity of the fluorescent light as a feedback system, a position of a translation stage is adjusted according to the fluorescent reaction of this pre-exposed grating section, so that a very long grating can be sequentially formed without phase discontinuity. And yet this method does not allow arbitrary insertion of phase shifts. According to the present invention, however, an arbitrary phase shift can be easily added to any location.
[0013] (4) U.S. Pat. Nos. 6,753,118 and 6,801,689
[0014] In the methods of these two patents, a feedback system is provided to compensate for drawbacks associated with gratings written by section-by-section, overlapping exposures. More particularly, a spectral response of a written grating is used to calculate corrections. However, as it is difficult to perform real-time monitoring with these methods, they are more suitable for regenerating written gratings. In contrast, the present invention allows real-time adjustment of phase distributions at each locating point, so that a grating can be completely created by writing with a UV writing beam only once.
[0015] (5) U.S. Pat. No. 5,830,622
[0016] In this patented method, refractive indices are adjusted by additional UV exposures at predetermined locations to introduce additional phase shifts. Therefore, scanning must be conducted for a second time, which is rather time consuming. In addition, the desired phase shifts to be introduced are hard to obtain in a section-by-section manner. In the present invention, however, an arbitrary phase shift can be easily added to any location without additional UV exposures.
[0017] (6) Paper published in Electronics Letters (1995), p. 1490
[0018] In this paper, grating writing is performed with a moving optical fiber and a phase mask. A fiber grating created by this method is limited in length by a length of the phase mask, while a resolution of a written pattern is affected by a limit on a moving speed of the optical fiber. In contrast, in the present invention, a grating is sequentially written in a section-by-section manner by probing a phase of a reference fiber grating. Therefore, the grating is not limited in length by a phase mask while a resolution of a written pattern is controlled by a writing time.
[0019] (7) Paper published in Journal of Lightwave Technology (1997), p. 1419
[0020] In this paper, a grating is also written by overlapping exposures in a section-by-section manner while an interferometer monitors a position of a translation stage at each locating point. However, a UV pulse is used in this paper as a writing beam, and a pulse laser causes additional noise problems. The present invention causes no such problems because a grating is sequentially created in a section-by-section manner by switching on and off a continuous UV writing beam.
[0021] (8) Paper published in Applied Optics (2002), p. 1051
[0022] In this paper, a grating is also written by overlapping exposures in a section-by-section manner while an interferometer monitors a position of a translation stage at each locating point. Although a continuous UV beam is used as a writing beam, the technique of using the interferometer to monitor a writing location on an optical fiber results in an accumulative error, which requires calibrating a period of the writing beam in advance. In contrast, according to the present invention, a grating is sequentially created in a section-by-section manner by probing a phase of a reference fiber grating, so that there are no accumulative error-related problems.
BRIEF SUMMARY OF THE INVENTION
[0023] In summary, in view of the fact that a phase mask designed for use in writing a fiber grating with a UV writing beam provides such advantages as having a high period accuracy, a high diffraction efficiency, ease of optical calibration and a period which is an integer number of times as long as a period of a written fiber grating thereby, the present invention aims to provide further improvement therein. In order to overcome the shortcomings and defects of prior art techniques, the present invention provides a method for writing a grating, wherein a position of an optical fiber is monitored by probing a reference phase mask whose period is an integer number of times as long as a period of a UV fringe so as to ensure phase continuity. The present invention also achieves a higher calibration accuracy in position monitoring because a phase mask has a much higher first-order diffraction efficiency than those of previously proposed reference fiber Bragg grating elements and allows optical calibration to be conducted more easily.
[0024] Moreover, it is known from numerical simulation results that a grating will achieve a desired quality only when a period mismatch between a period of position monitoring and a period of sequential UV writing is smaller than 5%. Since a phase mask has a very high accuracy when shipped from the factory, the phase mask itself has a minimum error. On the contrary, a conventional reference fiber Bragg grating element is manufactured in a conventional manufacturing system, so it is inevitable for the reference grating itself to have accumulated errors. In contrast, a phase mask having a minimum error of itself can reduce errors in grating manufacture and thereby increase production yield.
[0025] The present invention has two main objectives. A first objective is to provide a method for manufacturing a long-length fiber Bragg grating having a complicated structure, which method comprises steps of:
[0026] (1) Aligning a reference phase mask in parallel with an optical fiber to be exposed, wherein the reference phase mask has a period which is an integer number of times as long as a period of a UV fringe to be written;
[0027] (2) Projecting a probe beam into the reference phase mask along a normal direction thereof each time when a locating point for an overlapping UV exposure is to be determined, so as to generate a first-order Bragg diffraction beam, which interferes with a reference beam to generate a fringe; and using a feedback system to compare phase distributions of the fringe before and after a translation stage is moved, so as to fine-tune a final position of the translation stage for this locating point until the phase distributions are within a given error range, wherein an image recording device, such as a charge-coupled device (CCD), is used to observe the fringe;
[0028] (3) Turning on a UV exposure switch to provide UV exposure and turning off the UV exposure switch after a given time; and
[0029] (4) Translating the translation stage to a next locating point and repeating the steps (1) to (3).
[0030] A second objective of the present invention is to provide a method for manufacturing a sequentially joined fiber grating longer than a phase mask, which method comprises steps of:
[0031] (1) Aligning a reference phase mask in parallel with an optical fiber to be exposed, wherein the reference phase mask has a period which is an integer number of times as long as a period of a UV fringe to be written;
[0032] (2) Projecting a first probe beam and a second probe beam into the reference phase mask along a normal direction thereof at two ends of the reference phase mask, respectively, so as to generate respective first-order diffraction beams, which interfere with a first reference beam and a second reference beam, respectively, to generate fringes on two image recording devices (such as CCDs) (i.e. an image recording device A and an image recording device B), respectively;
[0033] (3) Using the fringe on the image recording device A for phase analysis and real-time position monitoring each time when a locating point for an overlapping UV exposure is to be determined, thereby joining each of a plurality of grating sections sequentially; and
[0034] (4) Calibrating a phase shift between the fringe on the image recording device A and the fringe on the image recording device B and recording the phase shift as Δθ until the first probe beam is relatively translated to the other of the two ends of the reference phase mask; and afterwards using the fringe on the image recording device B for phase analysis and real-time position monitoring, thereby joining each of a plurality of grating sections sequentially, wherein Δθ is added to each said grating section as an additional phase shift.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0035] The invention as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
[0036] FIG. 1(A) is a schematic drawing showing a structure for real-time position monitoring by probing a reference phase mask with an interference technique;
[0037] FIG. 1(B) shows a distribution of modulated refractive indices of a fiber grating experimentally formed by joining grating sections sequentially using the method shown in FIG. 1(A) ; and
[0038] FIG. 2 is a schematic drawing showing a structure for sequentially joining a plurality of grating sections into a fiber grating longer than a phase mask.
DETAILED DESCRIPTION OF THE INVENTION
[0039] Two preferred embodiments of the present invention will be described below with reference to the appended drawings so that a person of ordinary skill in the art can fully appreciate the spirit of the present invention and carry out the present invention. In order to understand a method for manufacturing a long-length fiber Bragg grating having a complicated structure according to a first preferred embodiment of the present invention, please refer to FIG. 1(A) for a schematic drawing showing a structure for real-time position monitoring by probing a reference phase mask 110 with an interference technique. As shown in FIG. 1(A) , the structure comprises a UV writing beam (244 nm) 10 , a He—Ne laser probe beam (632.8 nm) 20 , polarizers 30 , a half-wave plate (HWP) 40 , a polarizing beam splitter (PBS) 50 , reflecting mirrors 60 , a semi-reflecting semi-transmitting beam combiner (BC) 80 , an image recording device (such as a CCD) 90 , a translation stage 100 , a reference phase mask 110 , a UV fringe 120 , an optical fiber 130 , a first probe beam 140 , and a reference beam 160 . FIG. 1(A) mainly illustrates that the reference phase mask 110 for probing and the optical fiber 130 to be exposed are mounted together on the translation stage 100 . According to simulation results of the aforementioned elements, a grating can achieve a desired quality only when a period mismatch between a period of the reference phase mask 110 , which serves a position-monitoring grating, and a period of sequential writing by the UV writing beam 10 is smaller than 5%, wherein the period of the reference phase mask 110 is 1.07 μm, almost exactly twice as long as a period of a grating to be written in the optical fiber 130 by UV exposure. The reference phase mask 110 , which serves as the position-monitoring grating, functions in the following way. When the He—Ne laser probe beam 20 is projected into the reference phase mask 110 , a signal processing technique is used to generate an interferometric phase information regarding a present location of the reference phase mask 110 . This interferometric phase information, in turn, can be used to calculate backwards to obtain a location information having a nanoscale accuracy. The reference phase mask 110 has a first-order diffraction efficiency of 21.2% with respect to the He—Ne laser probe beam (633 nm) 20 . In addition, an optical calibration can be very easily conducted on the reference phase mask 110 , making the reference phase mask 110 highly suitable for use in position monitoring. According to the present invention, the photosensitive optical fiber 130 is exposed to the UV fringe 120 , which has a Gaussian waveform, a wavelength of 244 nm and a 1/e 2 beam width of 6.4 mm, after the optical fiber 130 is pretreated with a UV light to ensure that changes in a refractive index of the optical fiber 130 are in linear proportion to an amount of the UV writing beam 10 . According to the present invention, the UV writing beam (244 nm) 10 is projected onto the photosensitive optical fiber 130 section by section in a partly overlapping manner while the translation stage 100 is moved step by step within a long distance. In addition, the UV writing beam 10 writes at a constant spacing of 0.8 mm, so that an average refractive index remains constant, although a modulated quantity of the refractive index is arbitrary modulated according to the UV fringe profile. In the present invention, a plurality of Gaussian-shaped grating sections are joined in a partly overlapping manner to form a fiber Bragg grating having a length of approximately 2 cm, wherein a structure of the written grating is probed using a lateral diffraction technique.
[0040] Specifically, the method for manufacturing a long-length fiber Bragg grating having a complicated structure according to the first preferred embodiment of the present invention comprises steps of:
[0041] (1) Aligning the reference phase mask 110 in parallel with the optical fiber 130 to be exposed, wherein the period of the reference phase mask 110 is an integer number of times as long as the period of the UV fringe 120 to be written;
[0042] (2) Projecting the Ne—Ne laser probe beam 20 and thereby generating the first probe beam 140 that enters the reference phase mask 110 along a normal direction thereof each time when a locating point for an overlapping exposure by the UV writing beam 10 is to be determined, so as to generate a first-order Bragg diffraction beam, which interferes with the reference beam 160 to generate a fringe on the image recording device 90 ; and using a feedback system (not shown) to compare phase distributions of the fringe before and after the translation stage 100 is moved, so as to fine-tune a final position of the translation stage 100 for this locating point until the phase distributions are within a given error range;
[0043] (3) Turning on a switch of the UV writing beam 10 to provide a UV exposure and turning the switch off after a given time; and
[0044] (4) Translating the translation stage 100 to a next locating point and repeating the steps (1) to (3).
[0045] FIG. 1(B) shows a distribution of modulated refractive indices of a fiber grating experimentally formed by joining grating sections sequentially using the method shown in FIG. 1(A) , wherein measurements from the experiment are compared with design values for the structure of the written grating. More particularly, FIG. 1(B) shows a curve representing changes in refractive indices along a core of the optical fiber 130 measured with the lateral diffraction technique, and the curve is very similar to the desired Gaussian shape. The experiment result has shown that the method according to the first preferred embodiment of the present invention is very practical in manufacturing a fiber grating having a complicated structure, and also proved the feasibility of the method.
[0046] The present invention further provides as a second preferred embodiment thereof a method for manufacturing a sequentially joined fiber grating longer than a phase mask. Refer to FIG. 2 for an experimental structure of the second preferred embodiment of the present invention, wherein the structure comprises a UV writing beam (244 nm) 10 , a He—Ne laser probe beam (632.8 nm) 20 , polarizers 30 , half-wave plates (HWPs) 40 , polarizing beam splitters (PBSs) 50 , reflecting mirrors 60 , a beam splitter (BS) 70 , semi-reflecting semi-transmitting beam combiners (BCs) 80 , an image recording device A (such as a CCD) 92 , an image recording device B 94 , a translation stage 100 , a reference phase mask 110 , a UV fringe 120 , an optical fiber 130 , a first probe beam 140 , a second probe beam 150 , a first reference beam 160 and a second reference beam 170 . In FIG. 2 , the reference phase mask 110 is aligned in parallel with the optical fiber 130 to be exposed, wherein the reference phase mask 110 has a period which is an integer number of times as long as a period of the UV fringe 120 to be written. The first probe beam 140 and the second probe beam 150 are projected into the reference phase mask 110 along a normal direction thereof at two ends of the reference phase mask 110 , respectively, so as to simultaneously generate respective first-order diffraction beams, which interfere with the first reference beam 160 and the second reference beam 170 , respectively, to generate fringes on the image recording device A 92 and the image recording device B 94 , respectively, wherein the image recording device A 92 and the image recording device B 94 as well as the aforementioned image recording device 90 are all charge-coupled devices. Moving the stage until the first probe beam is locate at another end of the phase mask, and the fringe on the image recording device A 92 is used for phase analysis and real-time position monitoring each time when a locating point for an overlapping exposure by the UV writing beam 10 is to be determined, so as to join each of a plurality of grating sections sequentially. A phase shift between the fringe on the image recording device A 92 and the fringe on the image recording device B 94 is calibrated and recorded as Δθ when the first probe beams 140 is relatively translated to the other of the two ends of the reference phase mask 110 . Afterwards, the fringe on the image recording device B 94 resulting from the second probe beam 150 and the second reference beam 170 is used for phase analysis and real-time position monitoring, so as to join each of a plurality of grating sections sequentially, wherein Δθ is added to each said grating section as an additional phase shift. Thus, a sequentially joined fiber grating longer than a phase mask is created.
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A new fiber position monitoring method for sequential FBG UV-writing processes with a reference phase mask as the phase reference is proposed. Also, the new method by probing a reference phase mask can overcome the optical alignment difficulties in using reference fiber as well as provide more signal power for achieving better monitoring accuracy. Moreover, the present invention provides a method for sequentially joining a plurality of grating sections into a fiber grating longer than a phase mask.
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FIELD OF THE INVENTION
The present invention relates generally to optical scanners and more particularly to a scanner which can scan media at different resolutions.
BACKGROUND OF THE INVENTION
An optical scanner is used to generate machine-readable data which is representative of a scanned object such as a document or photograph. This is typically accomplished by employing a controlled light source located within the base of the scanner. The light source is reflected off the surface of a document and back onto an array of photosensitive devices which convert the light intensity into an electronic signal. Other scanner configurations include transmitting the light source through a transparent document, and then onto the array of photosensitive devices The intensity of the light source is controlled, via a closed loop or an open loop, by utilizing calibration circuitry located within the scanner base.
Optical scanners and various components used within such scanners are disclosed in U.S. Pat. No. 4,926,041 for OPTICAL SCANNER of David W. Boyd; U.S. Pat. No. 4,937,682 for METHOD AND APPARATUS FOR PROVIDING CONTRAST/INTENSITY CONTROL IN A DOCUMENT SCANNER of Dan L. Dalton; U.S. Pat. No. 5,019,703 for OPTICAL SCANNER WITH MIRROR MOUNTED OCCLUDING APERTURE OR FILTER of David W. Boyd and John S. Deutschbein; and U.S. Pat. No. 5,038,028 for OPTICAL SCANNER APERTURE AND LIGHT SOURCE ASSEMBLY of David W. Boyd and C. William Eider, Jr.
SUMMARY OF THE INVENTION
The present invention provides a scanner which scans media at different resolutions. The scanner provides more than one light path with each light path having a different lens reduction ratio. In a preferred embodiment, the scanner comprises at least two lenses and a single photodetector array. The present scanner has at least two scanning modes, one for transparencies and another for reflective, or opaque, objects.
An infeed lever moves mechanical components to allow selected media-type to be inserted. This lever prevents media-types other than the selected type from being inserted. Additionally, the proper infeed speed for the selected media-type is determined by the infeed lever.
In a preferred embodiment, the scanner has first and second light paths, the first light path reflects off opaque targets, the second light path passes through transparent targets. The first light path passes through a first focusing lens which has a characteristic first magnification. The second light path passes through a second focusing lens which has a characteristic second magnification. Both light paths are processed by the same photodetector array. In a preferred embodiment the first and second magnifications are different.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGs. 1a and 1b show a block diagram of an exposed side view of an optical scanner according to the present invention.
FIG. 2 shows a block diagram of a front view of the optical scanner.
FIG. 3 shows a block diagram of the control block according to the present invention.
FIG. 4 shows an exploded view of the mechanical components for facilitating the scanning of multiple media.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGs. 1a and 1b illustrate an optical scanner 100 of a type adapted to produce machine readable data representative of a color image of an object which is scanned. The machine readable data produced by the scanner 100 is adapted to be received and used by a digital computer in a conventional manner, for example, the data may be stored on a computer memory device or may be used to produce a color display of the object on a CRT or a color print.
FIGs. 1a and 1b show a block diagram of a side view of the optical scanner according to the present invention. Scanner 100 has a scanner base 105 and a scanner lid 110. The lid 110 is attached to the base 105 via a hinge (not shown) such that the lid 110 can pivot about a center axis of the hinge; this permits easy access to the image area (i.e., that area disposed between the base 105 and the lid 110). The hingeably-attached lid 110 ensures manual access to any target media in the image area. A target medium 115 is disposed between first transparent platen 120 and second transparent platen 121 in the image area.
A lamp 125 projects a narrow line of light off a pivoting illumination mirror 175, through the first platen 120 and onto the surface of the target 115. If the target 115 is opaque, as in the case of a document or photograph, the pivoting illumination mirror 175 pivots into a vertical configuration to allow the light (illustrated by light path 130) to be reflected off the surface of the target 115, onto mirrors 131 and 132. The pivoting illumination mirror 175 is supported by mirror posts as will be discussed below in FIG. 4. The light is then reflected off mirror 132, through apertures 135 and onto mirror 133. These mirrors 131,132,133 reflect the light through a first focusing lens 134 onto mirror 150. The light is then reflected onto photodetector array 155. In a preferred embodiment, the target 115 moves past a stationary lamp 125 via drive roller 172 and idlers 170,171 for detection by the photodetector array 155.
Photodetector array 155 converts light intensity into an electrical signal for an internal controller 160 which, among other things, controls the power to the lamp 125, and adjusts in accordance with the photo-detector electrical signal. In a preferred embodiment, the photodetector array 155 comprises charged-coupled devices (CCDs). In another preferred embodiment, the CCDs are capable of processing 2700 pixels. The internal controller 160 may send image data to a microprocessor-based system, including a computer or a printer, via link 161. In a preferred embodiment, the link 161 is compatible with the SCI bus protocol (akin to RS-232). Other bus protocols, such as SCSI and HPIB could be used without departing from the scope of the present invention. The computer, or other device, can also send commands to the internal controller 160 via link 161.
If the target 115 is transparent, as in the case of a 35 mm slide or negative strip, the light (illustrated by fight path 140) is reflected off the pivoting illumination mirror 175 (configured in an angled configuration as shown), passed through the first platen 120, through the transparent target 115, through the second platen 121 and onto mirror 141. Mirror 141 then reflects the light through a second focusing lens 142 onto mirror 150. This light is then reflected onto the photodetector array 155 for processing. In a preferred embodiment, the magnification of the first focusing lens 134 is different from the magnification of the second lens 142. In another preferred embodiment, the magnification of the first focusing lens is 0.165X and the magnification of the second focusing lens 142 is 0.7559X.
An obstructor 180 is disposed below the mirror 150. Obstructor 180 comprises first and second blocking panels 181,182. Based upon a control signal sent from an infeed lever control (see FIG. 2), one of the focused light paths will be obstructed. If the control signal indicates that a transparent target is to be scanned, obstructor 180 positions blocking panel 181 in the path of the focused opaque light path 130'. If the control signal indicates that an opaque target is to be scanned, obstructor 180 positions blocking panel 182 in the path of the focused transparency light path 140'.
A feature of the present invention is the dual fight paths 130,140. The resolutions provided by these separate fight paths are dependent on the target being scanned. Typically, there is less information present on a photograph than on a slide. In a preferred embodiment, the opaque light path 130 provides a resolution to 300 dots per inch (dpi) while the transparency light path 140 provides a resolution to 2400 dpi.
FIG. 2 shows a block diagram of a front view of the optical scanner according to the present invention. The scanner 100 provides an infeed lever control 210 which determines which selectable media-type can be inserted. An infeed lever (not shown) moves mechanical components based upon the control signal sent by control 210 to allow the selected media-type to be inserted into the scanner 100. At the same time, control 210 prevents other, non-selected, media-types from entering the scanner 100. A feature of the present invention is that scanner 100 is mechanically reconfigurable to permit and/or deny access to the scanning mechanism (i.e., the light paths, mirrors, photodetector array and controller). Once the end-user of scanner 100 selects which media-type is to be scanned, the scanner 100 presents the requisite slot for the end-user to enter that selected media-type.
Additionally, control 210 sets the speed with which the selected media-type is entered and sends a control signal to the obstructor (item 180 in FIG. 1b) to block the light path of the nonselected media-type. Scanner 100 accepts three separate media-types through an input port that has three different configurations 220,230,240. In a preferred embodiment, scanner 100 accepts a print photograph (item 220) up to the dimensions of 5"×7" (127 mm by 177.8 mm), a 35 mm slide (item 230), and a 35 mm negative strip (item 240). In a preferred embodiment, the speed with which a print photograph is entered is faster than with respect to a 35 mm slide or 35 mm negative strip. In another preferred embodiment, a print photograph is scanned at 0.003 inches/second (0.076 mm/sec) while a 35 mm slide or negative strip is scanned at 0.00042 inches/second (0.01058 mm/see).
FIG. 3 shows a block diagram of the control block. The control block 160 is centered around a microcontroller 302. The microcontroller 302 may be, for example, a 68HC05 microcontroller available from Motorola, Inc., Schaumburg, Ill. The microcontroller 302 receives commands from the scanner via the serial communications link 161. Commands sent from the scanner include, among other things, turning on the lamp, change light intensity, and report status.
The microcontroller 302 drives a digital-to-analog converter (DAC) 304 and a lamp driver 306. One output of the DAC 304 is connected to the lamp driver 306, while a second DAC output is connected to a comparator 312. The comparator 312 also receives input from a photodiode which measures the fight intensity of the lamp 308 and converts it to an analog signal. This signal is then supplied to the comparator 312 as feedback to maintain the fight intensity of the lamp 308 at a constant level.
FIG. 4 shows an exploded view of the mechanical assembly for facilitating the scanning of multiple media. The mechanical assembly is located in the scanner base 105 and comprises a negative cap 440, a carriage 420, and a gill 410. The gill 410 comprises a front face 411, a slide base 412, a print ledge 413 and a cam 414. The negative cap 440 comprises an aperture rise 441, at least two posts 442 and a top portion 443. The carriage 420 comprises an aperture 421, first and second negative guide plates 422,423, a plurality of roller apertures 424, negative guide sides 426, a plurality of guides 427 and at least two mirror support posts 431. The plurality of guides 427 support the target media that is placed in the scanner. The at least two mirror support posts 431 support the pivoting illumination mirror (item 175 in FIG. 1a), the mirror pivoting as the mechanical assembly moves upward and downward with respect to the control signal from control 210. In a preferred embodiment, the negative cap 440, the carriage 420 and the gill 440 are all formed of plastic, although other materials could be used without departing from the scope of the present invention.
Depending on which media-type was selected (via control 210), the mechanical assembly moves to permit the selected media-type to enter the scanner and, at the same time, prohibit the nonselected media-types from entering. In a preferred embodiment, there are three media-types: print photograph, 35 mm slide, and 35 mm negative strip.
If the print photograph media-type has been selected, gill 410 is driven by the cam 414 downward in relation to carriage 420 so that the print photograph can be fed along prim ledge 413. The drive roller (item 172 in FIG. 1b), which is positioned in the plurality of roller apertures 424, moves the print photograph along through the scanner 100. After scanning the print photograph, the drive roller reverses direction to send the print photograph back out from the scanner 100. In a preferred embodiment, the drive roller is a single roller having a plurality of large diameter sections, corresponding to the plurality of roller apertures 424, interconnected by a plurality of small diameter sections. Additionally, the drive roller has two internal sections that are positioned on the inside of the negative guide sides 426. In a preferred embodiment, the two internal sections have the same diameter as the large diameter sections and each has a width sufficiently thin enough to ensure that light path 140 (see FIG. 1a) is not hindered as it passes through the transparent media, through aperture 421 and onto the internal mechanisms of the scanner. In another preferred embodiment, the drive roller is comprised of a plurality of separate rollers interconnected via an roller axle.
If the 35 mm slide media-type has been selected, gill 410 is driven by the cam 414 upward relative to the carriage 420 to permit the 35 mm slide to be positioned on the slide base 412 before the internal sections of the drive roller moves the slide into, and then out from, the scanner. If the 35 mm negative strip media-type is selected, gill 410 is driven by the cam 414 further upward relative to the carriage 420 and the negative cap 440. First and second negative guide plates 422, 423, in conjunction with the negative guide sides 426 ensure that proper alignment of the negative strip is achieved across aperture 421. In a preferred embodiment, the negative guide plates 422,423 are at least 35 millimeters apart.
A feature of the present invention is that the same mechanical assembly is used to move different media-types across the scanning aperture. That is, the roller, carriage 420 and gill 410 are designed to transport print photographs up to a size of 5"×7" (127 mm×177.8 mm), 35 mm slides and 35 mm negative strips.
While the present invention has been illustrated and described in connection with the preferred embodiment, it is not to be limited to the particular structure shown. It should be understood by those skilled in the art that various changes and modifications may be made within the purview of the appended claims without departing from the spirit and scope of the invention in its broader aspects. For example, a moveable lens can be provided in place of the first and second focusing lenses (items 134 and 142 in FIG. 1a). In this configuration, the moveable lens can be moved from a first position in light path 130 through to a Nth position in light path 140 using an actuator. N positions throughout the path of the moveable lens can be used to provide a "zoom" for infinitely variable resolutions.
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An apparatus providing the capability to scan media at different resolutions is presented. The apparatus comprises an image area which is disposed between scanner lid and a scanner base, the lid is pivotally attached to the base to provide easy access to the image area. A light source resides within the scanner lid. Two separate light paths are provided, the first fight path is reflected off opaque targets, through the lid before entering the base and onto an array of photosensitive devices. The second light path is passed through transparent media, into the base and onto the array. First and second focusing lenses are provided, each for a light path. The focusing lenses provide two separate magnifications which yield two separate resolutions.
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BACKGROUND OF THE INVENTION
The present invention relates to a method for controlling the assembly cycle of a frame assembling machine and to a machine for carrying out the method.
Frame assembling machines are known in which the manufacturing cycle is controlled by a system in which the necessary information is entered by an operator by means of an appropriately provided keyboard. This information varies according to the profile of the strips that compose the frame.
The information that the operator must enter in the system relate to the height and number of staples to be used for the corner jointing of the strips, to the positions in which the staples are to be inserted, particularly the distance from the outside and inside comers of the frame, and to the position of the means by way of which the frames are fixed to the worktable.
SUMMARY OF THE INVENTION
The aim of the present invention is to provide a method which allows to automatically control an assembling machine on the basis of parameters derived from the cross-section of the strips.
Within the scope of this aim, an object of the present invention is to provide an apparatus whose characteristics are defined in the appended claims.
This aim and this object are achieved with a method for controlling the assembly cycle of strips for forming frames in assembling machines, characterized in that it comprises the steps of:
reading, by means of a scanner, the cross-section of one of the strips that compose the frame in order to obtain a resulting image of said cross-section;
digitizing the resulting image in binary format;
graphically visualizing said cross-section;
calculating dimensions of the cross-section;
identifying points suitable for positioning strip locking means;
determining points of application of stapling elements and the number of said elements to be applied in each point;
activating the assembling machine to perform the stapling of the strips.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of the method according to the present invention will become better apparent hereinafter on the basis of the accompanying drawings, wherein:
FIG. 1 is a schematic and non-limitative exemplifying view of a frame assembling machine which allows to carry out the method according to the present invention;
FIG. 2 is a flowchart of the operating sequence of the method;
FIGS. 3 and 4 are two flowcharts of two further embodiments of the method.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, the apparatus for performing the method comprises a footing 1 provided with a worktable 2 on which means are provided for arranging strips 3 for forming a frame. In the footing 1 , under the worktable 2 , there are fixed guides 4 for the sliding of a carriage 5 which can be positioned along the guides 4 by means of a reversible motor 6 which is fixed to the footing 1 and whose output shaft 7 is threaded so as to engage by screwing in a shoulder 8 of the carriage 5 . The shaft 7 , turned by the motor 6 , allows to move the carriage 5 in both directions A and B.
A conventional stapling head, generally designated by the reference numeral 9 , is rigidly arranged on the carriage 5 . The head 9 comprises a cylinder 10 which has a vertical axis and inside which a piston 12 is movable, said piston having a stem 13 which protrudes upward and ends with a striker punch 14 for expelling the stapling elements, particularly for the corner jointing of two strips that compose the frame.
The striker punch 14 is guided in a channel of a head 15 which protrudes from the worktable 2 through a slot which is parallel to the shaft 7 .
The elements for joining the strips, typically laminar staples, are contained in a magazine 16 and are conveyed into the channel of the head 15 through a lateral opening of the head.
A fluid-actuated actuator 17 is further installed below the worktable 2 and is composed of a cylinder 18 which is fixed below the worktable 2 and in which a piston 19 runs in the direction C. A column-shaped stem 20 is rigidly coupled to the piston 19 , protrudes above the worktable 2 and supports a strip locking device, generally designated by the reference numeral 21 , which is composed of an arm 22 which cantilevers out from the top of the column 20 to which it is fixed and includes guiding means for a pair of sliders 23 and 24 .
Two hydraulic jacks 25 and 26 are fitted on the sliders 23 and 24 and their stems 27 and 28 protrude downward below the arm 22 and support respective pads 29 and 30 at their lower end.
Respective threaded shafts 31 and 32 are engaged by screwing in the sliders 23 and 24 and can be actuated by a pair of motors 33 and 34 so as to allow the movement of the sliders 23 and 24 along the guides independently of each other.
According to the method of the invention, once the profile of the cross-section of the strips 3 has been detected, the motors 33 and 34 are actuated so as to place the pads 29 and 30 in the intended positions for locking the strips 3 . At the same time, the motor 6 is actuated so as to arrange the stapling head 9 on the points where the staples for joining the strips 3 are to be inserted.
According to the flowchart of FIG. 2, the method starts by reading, step 35 , the cross-section of the strips that compose the frame. This can occur by means of a scanner which faces a reference “slice” of the strip used.
The image obtained by the scanner is processed so as to provide the stapling machine with the necessary operating instructions.
This processing comprises the digitizing 36 of the image in binary format (black and white).
By using smoothing methods, the elimination 37 of the background noise from the image and the calculation and graphical visualization 38 on an appropriate display of the contour of the cross-section are performed. Such calculation and visualization can use electronic filters based on differentiation processes (gradient) and linear interpolation functions.
Depending on the resolution of the image and on the distance of the black and white pixels that define the contour, the calculation 39 of the dimensions of the frame is performed and the type of strip is identified. From the detected dimensions and the type (profile) of the identified strip, identification 40 of the points where the locking pads 29 and 30 are to be placed is performed.
The position 41 in which the staples must be driven into the strips and their number is determined depending on the type of stapling provided, i.e., on the characteristics of the staples used, on the sectional dimensions of the strips and on the frame to be provided, and on the engagement positions of the locking pads.
The stapling program thus set is sent to the stapling machine 42 , which performs it by initially placing the pads 29 and 30 and actuating them into the position for locking the strips and by then moving the carriage 5 along the guides 4 so that the stapling head 9 is arranged in a staple insertion point. Then, by means of the motor 6 , the head 9 is moved at the other positions for inserting the staples.
Conveniently, after determination 41 of the position of the staples and before transfer of the stapling program to the stapling machine 42 , it is possible to perform a verification 43 of the mechanical strength of the stapling according to the type of wood and staples used and a graphical visualization 44 on a display of the set stapling, so that the operator can perform optional variations of the stapling parameters.
The described method is susceptible of numerous modifications and variations, all of which are within the scope of the same inventive concept. FIG. 3 illustrates an embodiment in which, after calculation 39 of the dimensions of the frame and identification of the type of strip used, a search is conducted on a database 45 which contains programs for stapling a strip having the same characteristics as the visualized one. If the search leads to a positive decision 46 , the program is loaded 47 and visualized 44 .
On the other hand, if the decision 46 is negative, after identification 40 of the locking points, determination 41 of the stapling points and of the number of staples, verification 43 of mechanical strength is performed, with consequent automatic correction 48 of the stapling parameters or with visualization 44 of the stapling.
At this point it is possible to perform, or not perform, manual modifications 49 of the parameters of the stapling program.
In case of a negative decision regarding modifications, the program 51 is saved as new and transferred 52 to the stapling machine.
FIG. 4 illustrates another embodiment in which, if an operator does not wish to make changes 50 to the stapling program before it is saved and sent to the stapling machine, the newness or existence of applied modifications 53 is checked.
The disclosures in Italian Patent Application No. BO99A000601 from which this application claims priority are incorporated herein by reference.
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A cross-section of one of the strips in a frame is digitized in binary format by means of a scanner and graphically visualized; dimensions of the cross-section and points suitable for positioning a strip locking device are determined, together with points of application of the stapling elements and the number of the elements to be applied in each point. A frame assembling machine is then activate to perform the actual stapling of the strips.
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BACKGROUND OF THE INVENTION
[0001] The invention discloses an arrangement of building elements with connecting means, especially panels capable of separable connection to one another.
[0002] In this context, building elements are understood to mean panel-shaped building elements such as panel boards, floor boards, cladding boards, cladding strips especially for covering walls, ceilings or floors in buildings of every type. Building elements of this kind may comprise single or multiple-layer panels and/or strips made from wooden materials or on a wooden base (laminate), especially chipboard, medium density fibre board (MDF), high density fibre board (HDF), oriented strand board (OSB) and plywood panels, which may optionally be coated on one or both of the exterior surfaces. The coating or so-called useful surface maybe produced with synthetic material sheets, solid wood, veneers made from wood or synthetic material or paper etc. In the case of flooring panels, a decorative paper, for example with a natural wood design, intended to create the impression of a solid wooden panel, is widely known. Since flooring is placed under considerable stresses during normal use, the surface of the decorative paper is sealed with a hard, especially scratch-resistant and abrasion-resistant, overlay made, for example, from resin-soaked alpha-cellulose paper, and is therefore protected from scratches and dents. In particular, therefore, the invention relates to flooring boards or so-called panels, which consist of wooden materials and provide a relatively hard surface made from synthetic-material laminates.
[0003] Arrangements of building elements with separable connecting means are known from the prior art. The invention discloses a special type of design and manufacture for building elements and connecting means, which keeps the building elements in the optimum position relative to one another in the connected condition, but also allows the building elements to be separated from one another if required.
[0004] Known arrangements of building elements in the form of flooring panels provide at their lateral edges tongues and/or grooves, especially tongues which can snap into the grooves. Panels of this kind can be manufactured in a particularly economical manner, because only the generally relatively soft middle layer of the panels consisting particularly of wood needs to be processed specially in order to form the tongues and grooves acting as the locking means. The middle layer can also be described as the carrier layer or core. In the case of laminate flooring with a tongue milled into the middle layer, the middle layer generally consists of chipboard, MDF, HDF, hard-fibre board, solid wood or plywood material. These materials provide the disadvantage that, as described above, the tongues, in particular, are relatively soft and can therefore break either in their entirety or in part. A panel with a partially crushed tongue can only be introduced into the groove of another panel if the crush damage is specially treated prior to laying. This requires additional work when laying, and the strength of the connection between the interconnected panels is reduced.
[0005] The tongue which projects beyond at least one lateral edge of the panel is particularly susceptible to damage, because it can strike obstacles particularly hard in view of its small cross-section and the relatively heavy weight of the panel. This problem is encountered in manufacture and transportation as well as laying. The groove is also susceptible, because in the region of the groove, the panel provides a reduced wall thickness and strength. The exterior walls of the groove may even be thinner than the cross-section of the tongue.
[0006] Damaged tongues or tongues made from material permeable to water or capable of absorbing water also render the tongue and groove connection itself more permeable to water. Water spilled on the area of the connection can therefore penetrate more readily into the generally liquid-absorbing internal material layer (core) of the panel, which therefore swells and becomes visually unattractive. The moisture can also penetrate through the tongue and groove connection settling under the panels for a considerable time. This moisture cannot be observed or removed and, in the long-term, can therefore lead to consequential damage typical of moisture, especially mould, bacteria, efflorescence and staining.
[0007] EP 1 024 234 discloses panels of this kind with tongue and groove connections, wherein locking means for a snap-fastening are provided on the tongues and grooves. Since the tongues and grooves are milled from the core, which consists of HDF or MDF, in one piece with the locking means, the strength properties of the tongues and grooves are determined by the material properties of the core of the panel. In view of the strength of the connecting and locking means required for a secure connection, the core of the panel must therefore be harder, stronger, heavier and more expensive than is necessary, for example, for a floor covering.
[0008] U.S. Pat. No. 5,295,341 discloses panels in which the fastening means are connected to the edges of the panels in the form of strips, so that the materials used for the panels and the connecting means can each be optimised. In order to connect the connecting means to the panels, hook-shaped anchors are formed on the connecting strips, which engage with undercutting provided on the panels. An undercut geometry of this kind can only be manufactured at a considerable expense.
[0009] WO-A-00/20706 and WO-A-00/20705 disclose flooring panels which can be connected to one another via separate connecting profiles by moving the longitudinal edges horizontally towards one another or by lowering the longitudinal edges vertically. Accordingly, the locking means must lock on both sides, that is, with the longitudinal edges of two profiles to be connected. This increases manufacturing costs, because the separate connecting means must be attached to the longitudinal side of a profile in the factory. Otherwise, the work required on-site by the installer is increased, because, immediately before installation, the installer has to connect the connecting means first to one side and then to the other side of the panel to be connected. Accordingly, the connecting means are not firmly connected to the panel on both sides, thereby doubling the risk of accidental separation and rendering the connection less rigid and less strong. Moreover, additional processing stages must be carried out for each connection, namely, for two grooves and two tongues. Normally one groove and one tongue is sufficient for each connection.
[0010] The object of the present invention is therefore to provide an improved arrangement for building elements with connecting means, which removes the disadvantages named above.
SUMMARY OF THE INVENTION
[0011] This object is achieved with an arrangement of building elements according to this invention.
[0012] The invention creates an arrangement of building elements capable of interconnection using connecting means, in particular, snap-fastening connecting means.
[0013] Optimum materials with reference to properties and costs can be selected independently from one another both for the building elements and the connecting means, especially the tongues, because at least one of the two connecting means, especially tongue, consists of a different material from the building element to which the connecting means, especially tongue, is inseparably connected. Manufacturing costs can been reduced because only one tongue and one groove need to be manufactured to provide the separable connection.
[0014] In order to manufacture a non-glued connection between flooring elements and other building elements according to the prior art, the corresponding carrier materials, that is to say, the building elements, had to provide good mechanical strength, because hitherto, the corresponding form-fit or force-fit connections were also made from the carrier materials. Known panels are formed in one piece with the tongue and/or groove, whereas the invention presents a two-piece design. Accordingly, it is now possible to manufacture the middle layer of the panels in a particularly cost-favourable manner or with a very light weight-to-area ratio, for example, by using the materials named above. The connecting means comprising tongues and/or grooves can, however, be manufactured from strong and heavy materials, because the overall weight of the arrangement of panels is only slightly influenced. The connecting means may, for example, consist of PVC, synthetic materials and similar, which are harder than the core of the panels and can be manufactured using a special milling machine (e.g. pencil milling cutter). As a result, this particularly heavy and/or stable material is only processed where it is actually needed, while the core of the panel consists of lighter and more cost-favourable material. The weight of the panels is a substantial economic factor, because it influences transport costs, the price of the products and acceptance by the consumer. Accordingly, a high potential for savings is achieved if only the form-fit or force-fit component is provided with high mechanical strength.
[0015] If at least one of the connecting means is inseparably connected to the building element to which it is allocated, for example, in the form of a tongue or groove consisting of a different material from the corresponding building element, errors in assembly can be avoided. The connecting means cannot, for example, slip or be displaced along the longitudinal side, and liquid spilled onto the joint between two building elements is prevented from penetrating any further into the building element or from entering under the building element where it may cause further damage.
[0016] An inseparable connection of this kind can be achieved, in particular, with a form-fit connection. A connection of this kind is particularly economical to manufacture and very strong, if the connecting means are brought into contact with the relevant building element in a liquid or soft condition. The liquid connecting means penetrates into openings and pores in the building element thereby providing a form-fit connection. A comparable strength cannot be achieved by gluing.
[0017] A form-fit connection is particularly effective if the still liquid or soft connecting means is introduced into groove with or without undercutting of the building element, in particular, along the end face or longitudinal side of a panel-shaped building element. Grooves without undercutting can be produced very simply and rapidly, for example, working from the end face, along the entire length of the end-face. Undercut grooves are more expensive to manufacture but hold the connecting means introduced more firmly in place.
[0018] The interior contour of the grooves may also be formed as desired, for example, by milling, crushing or other less accurate processes. This renders the process simpler, more cost-favourable and faster, and the strength of seating is improved. Accurate processing tools are not required in this context.
[0019] If the grooves provided for the inseparable connection of the connecting means, provide arms of unequal length, that is to say, if they are designed in a projecting manner, the building elements can be assembled more readily. The arm projecting at the lower side of the building element can be used as a guide when moving the building elements together.
[0020] If the grooves provided for the inseparable connection of the connecting means, provide arms of unequal length, that is to say, if they are designed in a projecting manner, a higher loading capacity of the connecting means will be provided in the direction of the projecting arm. A projecting arm of this kind at the underside of the building element can, for example, absorb the forces resulting from walking over the building element.
[0021] This can be achieved in a particularly economical manner if the connecting means is manufactured from extrudate, wherein this extrudate can be brought into contact with the building element after leaving the extruder while still in a soft condition, in order to form a connection with the building element.
[0022] Extrudates are generally formed parts, manufactured by means of an extruder. While formed parts of this kind normally initially harden into the final shape, before they are connected to other building elements, it is advantageous to connect these formed parts to the building elements while they are still in a soft and or liquid condition. In this context, it is not necessary for the extruder to provide a specific profile. On the contrary, it is merely important that the liquid and/or soft extrudate is introduced into the groove of the building element which it fills thereby creating a connection with the building element. If the end face, that is to say, the longitudinal or transverse side of the building element in which the groove has been formed, is disposed in a horizontal orientation, the extrudate can flow downwards into the groove, whereby a surplus of material will accumulates on the end face, without adopting a precisely defined profile. Providing a precisely defined profile is the object of the subsequent processing stage. Accordingly, in the sense of the invention, any device from which a still not completely hardened material can be expelled in a controlled manner may be used as the extruder; there is no need for the extruder to give the material a defined form. However, it is advantageous if the form is adapted to the final form so that less material needs to be removed in final processing.
[0023] In the sense of the invention, a connection is separable if, on the one hand, this connection is sufficiently strong so that it cannot be accidentally separated, but on the other hand, it can be separated again without destruction if required. In the context of flooring panels, this means that during use, that is to say, when walking on the floor and moving loads across the floor, the laid and connected flooring panels cannot accidentally be separated from one another. However, if required, for example, in the case of a laying error, repair or disassembly, the connection should be readily separable, for example, by pulling apart or separating two building elements from one another within the plane which they occupy. By way of additional explanation or as an alternative, a separable connection may also be understood to mean a connection which can be released again, if required, by tilting or twisting the individual building elements.
[0024] A particularly strong and cost-favourable connection can be achieved if the connecting means is capable of foaming and can therefore completely fill the groove in the building element intended for filling (filling groove), thereby enlarging the contact surface between the connecting means and the filling groove.
[0025] The extrudate is therefore introduced into the filling groove in the same operational process as the manufacture of the flooring, thereby achieving cost-savings.
[0026] The connecting means inseparably connected to the building element provides the further advantage that during final processing, for example, during the milling out of the tongue or groove, the connecting means cannot slip and is already located in its final position. As a result, the tongue or groove is formed more accurately and provides a better fit. Accordingly, the building elements can be connected to one another more simply, more strongly and more securely. This cannot be achieved when using ready-formed tongues which are subsequently fixed to the building elements.
[0027] A snap-fastening is provided when a form-fit connection is produced with resilient building elements which give during the connecting process, e.g. by spreading the arms of the groove, or compressing the tongue. So-called snap-fastening connections can be easily and securely implemented by the installer and are also very accurate.
[0028] Provided the maximum thickness of the connecting means is less than the thickness of the panels, the connecting means will not be perceived and cannot therefore impair the visual effect. The connecting means can be produced in a material-saving manner if its maximum thickness is equal to the maximum thickness of the tongues.
[0029] If the end faces of two adjacent panels are butted together in the region of the upper surface, for example, the decorative or overlay surface, dirt and moisture cannot penetrate into the core of the panels.
[0030] The flat under-surface of the panels has a positive visual effect; it is simpler to manufacture than a contoured underside and also provides footfall damping because it avoids hollow cavities.
[0031] Coated upper and lower sides also make the surface less sensitive to scratching, dents and moisture as well as ensuring an attractive visual effect.
[0032] Tongues and grooves with snap-fastening locking elements in the form of recesses or indentations, extending along the entire length of the groove and tongue, allow very simple and economical manufacture. The connecting means formed in this manner can be connected and/or separated rapidly and reliably in a material-saving manner at the same time as ensuring that the panels are held in place relative to one another in an optimum manner in the connected condition.
[0033] If the locking means are glued or connected to the panels in the factory, no changes are required in the laying of panels by comparison with the laying of known tongue and groove panels. Joining together building elements designed according to the invention, achieves a strong and stable but still separable connection, which is appropriate for the stresses arising and which connects the building elements to one another in a stable position.
[0034] The groove is advantageously worked, especially milled directly into the building element, thereby simplifying the manufacture of panels of this kind. This applies especially for building elements which provide groove arms of the same length and can therefore be manufactured in a single operation with a symmetrical milling head. Apart from slight differences in length, resulting from the fact that the building elements may be disposed close to one another in the region close to the surface, but may be arranged at a distance from one another in the region close to the floor thereby providing a small gap, the two arms of the groove are essentially of the same length. This ensures that the two upper sides of panels can be securely butted together even in the presence of certain irregularities in the surface of the under-floor.
[0035] As with conventional floor panels, the installer must then simply push the two elements together; there is no perceptible difference in the product. The installer benefits only from the improved material properties of the connecting means, of which only the tongue projecting beyond the panels and the interior of the groove is visible. Panels manufactured in this manner can also be combined with existing panels with a one-piece tongue and groove milled out of the core; however, a certain downward compatibility of the product according to the invention would apply with reference to known products. As a result, further areas of application are opened up and the system can be used in the more flexible manner.
[0036] The width of the groove, which increases from the inside to the outside and/or the thickness of the tongue, which reduces towards its free end, are matched with one another, so that when the building elements are connected to one another, the surfaces of the groove and tongues are in close contact with one another and create a form-fit connection. Accordingly, the building elements are held in place in a mutually defined position.
[0037] The fact that the surface close to the building element of the projection formed on the tongue, and the surface close to the groove opening of the indentation in the groove provide an oblique and/or inclined course towards the building element and the groove opening respectively, so that the tongue can be withdrawn from the groove, makes a substantial contribution to the formation of a separable connection. Insertion and withdrawal is possible because at least one of the arms of the groove is capable of being widened or moved apart in a resilient manner relative to the other arm; in particular, both arms of the groove are designed with reference to material thickness and strength in such a manner that a resilient bending outwards is possible thereby allowing the tongue to be inserted into the groove; the at least one projection formed on the tongue can overcome the internal edges at the groove opening, precisely because the projection slides over the internal edges thereby pressing apart the arms of the groove.
[0038] The locking elements for connecting the building elements in a stable position, which are formed from mutually matching projections and indentations, are provided on the tongue and on the groove. These locking elements can be provided in separate portions along the tongue and the groove; however, better holding and simpler manufacture are achieved if the locking elements extend over the entire length of the tongues and grooves.
[0039] One embodiment of the arrangement according to the invention, in which corresponding projections are provided on both sides of the tongue and corresponding indentations are formed on both surfaces of the groove is particularly advantageous, because this achieves a double snap-fastening effect thereby ensuring a strong connection between the building elements.
[0040] The width of the building elements can be selected as desired. Building elements of the same width or of a different width can be connected to one another, for example, in order to achieve a given floor design.
[0041] The building elements can be pushed together and/or separated advantageously wherein the connecting means provides greater strength than the material of the building element.
[0042] One preferred embodiment of the invention is characterised that the cross-sectional form of a tongue with at least one projection disposed upon it and at least one correspondingly matching indentation in the groove allows good sliding between the surfaces of the tongue and/or the projection provided on the tongue along the groove surfaces and/or the groove surfaces directly adjacent to the groove opening when the tongue is inserted into the groove.
[0043] A strong snap-fastening between the two building elements to be connected is provided where especially, in order to achieve a strong but separable connection of the building elements, the groove is formed directly in the building element itself and/or is worked into the building element, the width of the groove increases from the inside to the outside, the thickness of the tongue decreases towards its free end, the projection on the tongue provides a front surface enclosing an angle α relative to the surface of the building elements and a shorter rear surface adjoining the latter surface and enclosing an angle β, which exceeds the angle α relative to the surface of the building elements thereby forming a kink, the indentation in the groove provides a contact surface close to the base of the groove, which, in the locked position, is at least partially in contact with the longer front surface, and a shorter, contact surface, remote from the base of the groove, which, in the locked position, is in contact with the shorter, rear surface of the projection, and, at least one of the two, but preferably both, of the arms of the groove can be bent outwards in a resilient manner relative to the other arm of the groove in each case, so that the tongue is held in the resting position by the arms of the groove subject to the clamping effect and/or can be inserted into and/or withdrawn from the groove subject to the resilient deformation of the arms of the groove.
[0044] The tongue of one building element can be inserted into and released from the groove of the other building element in a particularly advantageous manner where the angle α enclosed by the front surface relative to the upper surface of the building elements is greater than the angle γ enclosed by the region of the groove surface close to the base of the groove relative to the upper surface of the building elements. In this context, the release or separation of the tongue from the groove is indeed associated with an increased resistance by comparison with the resistance encountered when the tongue is inserted into the groove; however, the tongue is held firmly in the groove, while the separation of this snap-fastening connection is still readily possible.
[0045] The formation of an elastic, resilient tongue, e.g. a slotted tongue or slotted portions of the tongue, is not necessary, because the arms of the groove are sufficiently resilient to widen accordingly when the tongue is inserted. A solid tongue can therefore be manufactured more readily where in forming the projection only on one side of the tongue and the indentation only on the side of the groove facing towards the latter side, the surfaces of the tongue and groove without projections or indentations are in tight and close contact with one another and enclose the same angle γ relative to the upper surface of the building elements.
[0046] The tongue and groove are simple to manufacture and allow good mutual positioning of the tongue and groove where the tongue surfaces close to the end region of the tongue provide the same angle of inclination relative to the surface of the building elements, as the regions of the groove surfaces close to the base of the groove, with which regions of the tongue surface close to the end of the tongue are in contact in the connected condition of the building elements, an indentation or recess with a triangular form in the cross-section perpendicular to the direction in which the building elements are joined, is provided as a locking element along the course of at least one groove surface, preferably the groove surface close to the upper surface, and especially along both groove surfaces, a projection with a triangular form in the cross-section perpendicular to the direction in which the building elements are joined is provided along the course of at least one tongue surface, preferably the tongue surface close to the upper surface, and especially along both tongue surfaces, and in the connected condition of the building elements, the projection and the indentation are in contact with one another along their contours in a tight, close and play-free manner.
[0047] The insertion of the tongue into the groove is simplified where in the locked condition of the building elements, substantially the entire region of the tongue surface disposed in front of the projection towards the front end of the tongue is in contact with the groove surface.
[0048] The position of the tongue in the groove, because the projection is disposed exactly in the indentation and accordingly, the projection and the indentation and/or the surfaces of the tongue and the surfaces of the groove are in accurate and close contact with one another.
[0049] The formation of the cross-section of the triangular projection and/or of the projection on the tongue accommodated in the indentation in the groove simplifies the insertion of the tongue into the groove and/or holds the tongue securely in the groove while still allowing the tongue to be withdrawn from the groove without material damage.
[0050] The insertion of the tongue into the groove avoids jamming and ensures that the surfaces of the building elements to be connected are in close contact with one another at the end faces and/or are brought closely together by the snap-fastening of the projections on the tongue in the indentations of the groove where the surface region of the groove surface between the groove opening and the beginning of the shorter side of the triangle of the indentation encloses an angle relative to the surface of the building elements which corresponds to the angle of inclination of the longer side of the triangle, wherein this surface region of the groove is designed as a sliding surface for the longer side of the triangle of the protection provided on the tongue.
[0051] It has been shown in practice that where the region close to the free end of the tongue and also the region of the tongue surface close to the end face of the building elements continues in each case into the longer and shorter side of the triangle of the projection, in each case forming a kink, the groove widens smoothly when pushing the building elements together; the panels are automatically fixed by the snap-fastening; and a very firm, play-free seating of the connection is provided in the closed condition. Furthermore, the manufacture of the tongues and grooves is simplified, and forces are transferred in the material-saving manner.
[0052] With reference to floor-laying technology, where the side of the triangle close to the base of the groove or the portion of the tongue surface accommodated in the indentation is approximately four-times to eight-times, preferably five-times to seven-times as long as the side of the triangle remote from the base of the groove or the shorter, rear surface, and that the angle between the two sides of the triangle or between the portion of the tongue surface and the shorter rear surface is 100° to 140°, particularly, 110° to 130°, or the longer side of the triangle and the shorter side of the triangle of the projection or of the indentation continue into the front and/or rear region of the groove surface and tongue surface respectively, thereby forming a kink and at the same time a simple, visually attractive result is ensured. In this context, relatively wide, panel-shaped building elements, which need not necessarily be elongated, but may, for example, also be rectangular or square, are held together with the assistance of narrow, strip-like building elements, thereby providing an attractive pattern as well as a simple laying technique.
[0053] Further advantageous embodiments of the invention are described below with reference to the diagrams and claims.
[0054] By preference, the following procedure is used for the manufacture of the arrangement of building elements according to the invention. Initially, the building element, especially an MDF/HDF panel is milled along the longitudinal and/or transverse sides and then the resulting groove is provided and/or foam-filled with extrudate. Following this, the free ends of the extrudate are milled off to form the profile of the tongue. Alternatively, however, a groove may also be milled into of the extrudate.
[0055] A rapid-hardening extrudate may also be profiled during the extrusion process thereby saving time, materials and costs. The profiling can be carried out, for example, by forming or by cutting. A corresponding one-piece procedure can therefore be realised alongside the one-piece operation already described.
[0056] The use of a synthetic material as the extrudate is preferred because this can be milled most accurately.
[0057] Amongst other factors, the advantage of the invention by comparison with the prior art is that the extrudate can be introduced in the same operational procedure as the manufacture of the building element; the profiles are very firmly bonded to the core material; when synthetic material is used, the profiles can be milled much more precisely and can therefore be milled to achieve better locking; the extrudate represents a cost-favourable material; the tongues or grooves can be provided with resilient properties independently from the material properties of the core material; and the connecting surfaces do not need to be sealed, because the absorption of water and moisture is reduced and/or prevented by the extrudate and/or the synthetic material.
[0058] Potential savings can be achieved with reference to material and transport if the milled material, that is, the material which has been removed from the panel during the milling of the grooves, is mixed with other components and subsequently injected back into the grooves in order to mill the tongue and/or the groove into this material to form a sharp edge. Accordingly, this wooden material need not be procured or transported. Storage and disposal of milling waste are not required.
[0059] Furthermore, according to the invention, the extrudate may extend up to the surface of one or both building elements. In this context, it provides an intermediate component, mechanically and visually, along the edges of the building elements. It therefore fulfils a double function, acting as a connecting means and at the same time fulfilling aesthetic, protective and stabilising functions; in the sense of the invention, it is not compulsory for the extrudate to serve as a connecting means.
[0060] If the extrudate forms the end face of the building elements, this edge can be processed more accurately, thereby achieving a more precise fit. This prevents the accidental separation of the connection and the penetration of contamination into the connection. Furthermore, the connection itself is less visible. The edges of the wooden materials very frequently become splintered i.e. provided with raised fractures in the region of the surface in danger of impact. Splintering also occurs when processing the edges. Especially after the panels have been laid, such splinters are very readily visible along the edges if viewed against back lighting. When the extrudate according to the invention extends up to the surface, it can prevent or conceal these edges.
[0061] If the extrudate is water-resistant, it will protect the building element, which is generally moisture-absorbing, thereby preventing the absorption of water. Moisture is known to cause swelling, leading to an unattractive appearance of the building element. Impregnating the edges of the building element, which would normally be carried out for this reason, is therefore no longer required.
[0062] The extrudate acting as an intermediate component can be produced in various materials, structures and colours. Especially when they are coloured, intermediate components of this kind, provide a decorative feature creating visual effects ranging from the sophisticated to the rustic.
[0063] As a component of the tongues and grooves, the extruded intermediate components may also be milled as desired. Accordingly, the edges of the building elements can be profiled as required. For example, indentations and/or raised portions is can be milled into the connections. Such indentations and/or raised portions can be used to conceal differences in height between the individual surfaces of the building elements and/or raised splinters. For instance, a V-shaped connection manufactured in the above manner creates a particularly rustic look. By contrast, metallic intermediate components provide a sophisticated look, giving the impression of expensively framed wooden boards. Because the extrudate is first connected to the building element and only then is the extrudate processed, the accuracy of fit and strength of the connection are both increased, and water cannot penetrate into the building element because of the excellent edge seal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0064] The invention will be explained below in great detail with reference to the diagrams:
[0065] [0065]FIG. 1 shows an MDF/HDF board in the region of the longitudinal or transverse side in cross-section before the application of the extrudate;
[0066] [0066]FIG. 2 shows the board from FIG. 1 after application of the extrudate;
[0067] [0067]FIG. 3 shows the board from FIG. 2 after the processing of the extrudate connected to the board;
[0068] [0068]FIG. 4 shows an initial embodiment of two building elements connected to one another according to the invention;
[0069] [0069]FIG. 5 shows a detail illustrating the profile of the tongue designed for snap-fastening;
[0070] [0070]FIG. 6 shows the profile of the tongue in an asymmetrical design
[0071] [0071]FIG. 7 shows two building elements connected to one another according to the invention in a second embodiment;
[0072] [0072]FIG. 8 shows an MDF/HDF board in the region of a longitudinal or transverse side in cross-section before application of the extrudate according to another embodiment of the groove.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0073] [0073]FIG. 1 shows a cross-section of the left-side, free end of an MDF/HDF panel in the region of a longitudinal or transverse side. The left, end face 42 of the panel 2 provides a groove 5 b manufactured, for example, by milling. The interior surfaces of the groove 5 b are therefore formed by the two equally long arms 3 and 4 , and by the base of the groove 11 .
[0074] [0074]FIG. 2 shows the panel from FIG. 1 after the extrudate 40 has been introduced into the groove 5 b. The extrudate 40 was introduced into the groove in a liquid and/or soft condition and fills the groove completely, that is, down to the base of groove 11 . The extrudate is firmly connected to the panel via the arms 3 , 4 and the base of groove, because the extrudate has penetrated into the pores of the panel and/or has filled any irregularities in the interior of groove. The extrudate may also provide the property of foaming. If the extrudate is readily pourable, it should be poured from above into the groove 5 b when the groove is in a vertical orientation. This corresponds to FIG. 3 after rotation through 90° in a clockwise direction. An excess of extrudate remains on the end face 42 providing a protuberance 41 .
[0075] In FIG. 3, a tongue 6 , which, for example, comprises the locking means 7 for connecting to a correspondingly formed groove 5 a (not shown), has been formed by an appropriate process such as milling, from the excess of extrudate 40 providing the protuberance 41 .
[0076] The procedure shown in FIGS. 1 to 3 for forming a tongue is merely exemplary. With the same operational stages, it is possible to introduce the extrudate into the groove 5 b and subsequently to form an internal groove in this extrudate for connection with the tongue. The following possibilities are therefore provided by the invention: forming only the tongue from an external material; forming only the groove from an external material; and forming the tongue and the groove from the external material.
[0077] By way of additional information, FIG. 8 shows that the internal contour of groove 5 b can also be formed as desired, for example, by milling, crushing or other less accurate processes than milling. The filling 40 then contacts the interior contour of the groove 5 b in a very positive manner, which increases the strength of the connection.
[0078] [0078]FIG. 4 shows two building elements 1 , 2 , for example, panels, connected to one another, wherein grooves 5 a and 5 b are formed in each of the building elements. The groove 5 b in the right-hand building element 2 is firmly connected to the extrudate 40 processed to form the tongue 6 , wherein the extrudate 40 completely fills the groove 5 b. In the exemplary embodiment shown in FIG. 4, the extrudate 40 is connected by form-fit fit connection to the interior of the groove 5 b in the right-hand panel 2 , for instance, by gluing or filling with the still-soft extrudate. In the exemplary embodiment, the free end 6 of the extrudate 40 has been processed by milling so that it creates a form-fit connection with the correspondingly formed groove 5 a of the adjacent, left-hand panel 1 . However, according to the invention, a force-fit, separable connection, not shown here, of the end of the extrudate forming the tongue 6 to the panel 1 can also be provided. The building elements 1 , 2 are disposed with their end faces in contact with one another in the region close to the useful surface (e.g. the floor surface), but they provide a gap 16 in the region close to the base.
[0079] [0079]FIG. 4 shows an embodiment of the invention in which each of the individual building elements 1 , 2 has been provided with grooves 5 a and 5 b on both of its opposing end faces or on all four of its end faces. The building elements 1 , 2 are therefore designed in a symmetrical manner relative to their middle plane shown in the diagram as M.
[0080] The design of the grooves 5 a and 5 b and of the tongue 6 of the connecting means 40 is implemented in the same manner as described in the context of FIGS. 5 and 6 and the subsequent description. As shown in FIG. 4, the mutually-engaging projections 7 and indentations 8 , which act as locking elements, are matched with one another and correspond, with reference to their cross-sectional form, to the projections 7 and indentations 8 shown in FIGS. 5 and 6. However, in principle, it is also possible to select other, similar cross-sectional forms for the locking elements 7 , 8 and/or to provide different angles of inclination for the tongue and groove surfaces relative to the surface 13 of the building elements 1 , 2 shown here. The essential feature is the resilience of the arms 3 , 4 , in order to ensure the interlocking of the locking elements 7 , 8 , in other words to guarantee the desired snap-fastening.
[0081] If necessary or desirable for technical reasons, the locking elements 7 , 8 can also interlock, if the arms 3 , 4 of the left-hand panel 1 are not designed to be resilient. For example, the groove 5 a of the left-hand panel 1 may also be made from extrudate or similar, like the tongue 6 ; this could be achieved by filling and/or foaming of a groove with an appropriate, preferably resilient material and subsequently milling the groove geometry into the material introduced into the original groove 5 a. In this case, it is not necessary for the arms 3 , 4 of the panel, that is, of the core material, to give in a resilient manner. In this context, the connection itself has a better appearance, and contamination and water can penetrate less easily into the connection.
[0082] It is also conceivable for the free end, i.e., the tongue 6 made from the extrudate 40 to be provided with a gap, in such a manner that the upper side and the lower side of the tongue 6 can be pushed together by pressure from the outside, so that a snap-fastening can be achieved with the groove 5 a; in other words, the locking means 7 and 8 are engaged with one another.
[0083] The relatively wide building elements 1 , 2 , which are, however, shown in FIG. 4 with a compressed width, provide dovetail grooves 5 a on one of their opposing end faces, but especially on two end faces disposed at right angles to one another.
[0084] [0084]FIGS. 5 and 6 serve to illustrate the profile of the tongue 6 . They should be understood as a detail from FIG. 4; only the free end of the tongue 6 is shown in FIG. 6.
[0085] As can be seen in FIG. 5, the building elements 1 , 2 consisting especially of wooden or synthetic material, can be provided with coatings 23 , 24 , in order to achieve appropriate surface qualities and/or an appropriate appearance.
[0086] Mutually matching locking elements 7 , 8 are provided on the tongue 6 and/or the tongue surfaces 10 and in the groove 5 a and/or on the groove surfaces and/or the lateral surfaces 9 of the groove 5 a. These locking elements are formed by projections 7 and indentations 8 , which co-operate with one another or can be snap-fastened together. The cross-sectional forms of the indentations 8 and the associated projections 7 correspond to one another, so that the locking elements enter into close contact with one another, that is to say, they form a form-fit snap-fastening.
[0087] In the connected condition of the building elements 1 , 2 , the locking elements 7 , 8 are engaged with one another. In particular, the locking elements 7 , 8 are designed along the entire length of the longitudinal and/or narrow sides of the building elements 1 , 2 .
[0088] In FIG. 6, a projection 7 is provided only on the lower tongue surface 10 ; this is accommodated in an indentation 8 in the groove surface 9 which is in contact with this tongue surface 10 . When the tongue 6 is introduced into the groove 5 , the two arms 3 , 4 of the groove 5 are pressed apart in a resilient manner; when the tongue 6 is withdrawn from the groove 5 , a resilient spreading of the arms 3 , 4 of the groove takes place.
[0089] In the case of the embodiment of the invention shown in FIG. 6, a projection 7 is formed only on one side of the tongue 6 . The projection 7 is designed in such a manner that the tongue surface 10 runs level from the front, free end-region of the tongue 6 up to a kink, which is disposed at the thickest position of the tongue and continues into a rear, short surface 17 , which in its turn continues into a surface 31 leading to the building element 2 . Only a partial region 30 of the tongue surface 10 is accommodated in the indentation 8 in the groove surface 9 ; this partial region of the tongue surface, however, is disposed in close contact with the surface 18 ′ of the indentation; also, the rear, shorter surface 17 is in close contact with the surface 17 ′ of the indentation 8 disposed towards the opening of the groove.
[0090] The groove surface 10 and/or its partial region 30 is inclined at an angle α to the surface 13 of the two building elements 1 , 2 ; the rear, shorter surface portion 17 is inclined at an angle β to the surface 13 of the two building elements 1 , 2 . The same applies for the two surfaces 17 ′ and 18 ′ of the indentation 8 in the arm 3 of the groove. The region of the groove surface 9 disposed outside the indentation 8 of the groove arm 3 and/or the region of the groove surface 9 close to the base of the groove, is inclined at an angle γ to the surface 13 of the two building elements. The surface 10 of the tongue 6 , which does not provide a projection and which is in close contact with the facing groove surface 9 , is inclined at the same angle γ.
[0091] In order to achieve a defined mutual position of the connected building elements 1 , 2 , it may be expedient, if the angle α relative to the useful surface and/or upper surface 13 of the longer side 18 of the triangle of the projection 7 on the tongue 6 corresponds to the angle and/or the inclination, especially of the front region, of the tongue surface 10 , which runs, in its front region, at a distance from the groove surface 9 . The majority of the length of the tongue surface 10 which is free from locking elements is in contact with the inner surface 9 of the groove, and both surfaces approach the upper surface or useful surface 13 of the two building elements 1 , 2 at the angle γ, viewed from the base of the groove 11 .
[0092] In practice, it is advantageous if the indentation and/or the groove are provided in the groove surfaces and tongue surfaces which are closer to the upper surface. It is particularly advantageous, if corresponding locking elements are provided in both tongue surfaces and both groove surfaces. The connection is then formed in a self-centring manner, which simplifies assembly and is self-locking in the final position.
[0093] [0093]FIG. 6 shows that when the tongue 6 is inserted into the groove 5 , the groove arms 3 , 4 are spread or pushed away from one another. In particular, the groove surface 25 ′ close to the opening of the groove and the tongue surface 10 , especially its region 30 , slide over one another, so that the groove arms 3 , 4 are moved apart without damage. When the tongue 6 is removed from the groove 5 , the groove arms 3 , 4 are widened as a result of the sliding of the surfaces 17 and 17 ′ against one another.
[0094] [0094]FIG. 5 shows a particularly advantageous embodiment of the invention, wherein the groove 5 and the tongue 6 are advantageously designed to be symmetrical to a middle plane M′ through the building elements 1 , 2 perpendicular to the plane of the drawing.
[0095] The cross-section of the projection 7 and/or of the indentation 8 according to FIG. 5 is triangular, wherein the sides 17 , 17 ′ disposed closer to the opening of the groove are shorter and more steeply inclined than the sides 18 , 18 ′ of triangle disposed closer to the base 11 of the groove. When the tongue 6 is introduced into the groove 5 a, the longer side 18 of the projection 7 slides over the inner edge and/or over a chamfer 25 ′ formed in this region of the arm 3 of the groove until the projection 7 has overcome this interior edge surface 25 ′ and is then accommodated in the indentation 8 . Accordingly, a locking of the building elements is achieved by snap-fastening.
[0096] In the case of the advantageous embodiment according to FIG. 5, especially symmetrically disposed projections 7 or indentations 8 are formed on the two opposing tongue surfaces 10 , and indentations and projections are formed on the two contacting groove surfaces 9 , matching these projections 7 and indentations 8 respectively, and/or the groove 5 a and the tongue 6 are formed in a mutually matching dovetail design. This embodiment allows a double locking of the two building elements 1 , 2 , wherein this kind of locking is also readily separable, by detaching and/or pulling apart the two building elements 1 , 2 from one another within the plane which they occupy. The widening of the arms 3 , 4 can be supported by twisting the building elements relative to one another.
[0097] In this embodiment, the longer side 18 of the triangle and/or the surface of the projection 7 formed by this side continues to the front region of the tongue surface 10 forming a kink 19 ; the region of the groove surface 9 close to the base of the groove and this front region of the tongue surface 10 are disposed, like the projection 7 and the indentation 8 , in close contact with one another; in this manner, a very accurate connection of the building elements 1 , 2 can be achieved and, at the same time, it can be guaranteed that the end faces of the building elements 1 , 2 contact one another under pressure and/or are drawn together so that any gap between the building elements 1 , 2 at the useful surface 13 , as well as any separation of the building elements 1 , 2 during their use, can be avoided.
[0098] The region of the groove surfaces 9 closer to the base of the groove and the region of the tongue surfaces 10 close to the free end of the tongue 6 provide the same angle of inclination γ. The angle α, enclosed by the surfaces 18 of the projection and/or the surfaces 18 ′ of the indentation relative to the surface 13 of the building elements 1 , 2 , is greater than the angle γ. The region of the interior edge surface 25 ′ is also inclined at this angle α relative to the surface 13 of the two building elements 1 , 2 .
[0099] The angle β, at which the shorter sides 17 , 17 ′ of the triangle are inclined, is greater than the angle α and advantageously encloses an angle between 25° and 65° relative to the surface 13 of the building elements 1 , 2 .
[0100] With reference to the connection and separation of the building elements, it is advantageous if the sides 18 , 18 ′ of the triangle close to the base of the groove are approximately four-times to eight-times, preferably five-times to seven-times, as long as the sides 17 , 17 ′ of the triangle remote from the base of the groove, and if the angle between the two sides 17 , 18 and/or 17 ′, 18 ′ of the triangle is 100° to 140°, and in particular, 110° to 130°.
[0101] To simplify insertion, it is advantageous if the internal end edges of the tongue 6 are provided with chamfers 12 and/or the internal end edge of the arm 4 of the groove without a snap-fastening and/or locking element are provided with a chamfer 29 .
[0102] Using the method of connection according to the invention, it is possible and it is intended that the building elements 1 , 2 to be interconnected are disposed with the lower surfaces 15 in one plane.
[0103] In principle, several projections and/or indentations can be provided on one groove and/or tongue surface, which would further improve the self-locking of the connection in the final position.
[0104] [0104]FIG. 7 illustrates building elements 1 , 2 , wherein, according to the invention, the extrudate 40 , 43 also extends as far as the surfaces 13 . Mechanically and visually, it therefore provides a V-shaped joint 43 , 44 between the two end faces 42 of the building elements and along the edges of the building elements. The intermediate components 43 , 44 serve as a connecting means and also provides protection and decoration. The right-hand intermediate component is inserted in an inseparable manner in the groove 5 b, and at the same time, forms the tongue 6 , while the left-hand intermediate component is applied only to the edge 42 of the left-hand building element and only partially forms the groove 5 a, and therefore acts only partially as a connecting means 17 ′, 18 .
[0105] Since the extrudate forms the end face of the building elements 1 , 2 , this edge can be processed more accurately.
[0106] The production of a building element according to the invention will be described below with reference to the example of a floor covering. A wooden material, plywood/MDF/HDF or OSB board of standard format, for example, 1.040 mm×2.825 mm is coated with decorative paper on the upper side and counteracting paper on the other side using a short-cycle press or throughpress process. After coating, the large format is cut to the size required for the elements, for example, 195 mm×1.250 mm.
[0107] The elements obtained in this manner are now processed in milling machines to provide milled grooves in the longitudinal and transverse sides. Following this, the pre-milled elements are conveyed to an extrusion plant, where the extrudate is introduced into the milled grooves. The extrusion plant may also operate directly behind the milling machine, so that the extrudate is introduced into the form immediately behind the milling head.
[0108] In the final stage, the panels, processed according to the invention along the end faces of the longitudinal and transverse sides, are again conveyed to the milling machine for the formation of the required tongue and groove. As an alternative, this processing stage can also be implemented immediately behind the milling head and/or the extruder.
[0109] The extrudate can also be applied to normal end faces without a groove, thereby dispensing with one operational stage in this end-face region.
[0110] It is particularly economical if all of the end faces are initially provided with a groove, which is suitable for engagement with the tongue. Only one machine tool is required for this process, and it is not possible for a wrong side to be processed. The grooves, which are subsequently to be provided with tongues, are now filled with the extrudate. Following this, the extrudate is processed to form the tongues.
[0111] The invention is not restricted to connecting means in the form of tongues and grooves. On the contrary, the tongue and groove connection serves merely as an example for a type of connection, which may optionally be realised as a force-fit or form-fit connection.
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An arrangement of building elements capable of a snap-fastening interconnection comprises an element, especially the tongue, consisting of a different material from the other building elements. An MDF/HDF panel, is initially milled along the longitudinal and/or transverse sides, and the resulting groove is then provided and/or foam-filled with extrudates. Finally, the free ends of the extrudates are milled to form the profile of the tongue. Alternatively, or additionally, a groove may also be milled into the extrudates.
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[0001] The present invention relates to a method, notably to a method for treating fluid waste materials, especially for digesting sewage waste, and to apparatus for use in that method.
BACKGROUND TO THE INVENTION
[0002] Many processes and operations in current use result in fluid waste products which must be treated before they can be recycled for re-use in the process or operation from which they have been derived, or to meet ever increasingly severe requirements before they can be discharged into the environment. Sources of such waste materials include the chemical, pharmaceutical, food processing and brewing industries; agricultural sources, such as animal husbandry, notably intense rearing of poultry, cattle and pigs, and abattoirs; and municipal and other sewage systems. Many of such waste materials are water based and it is desirable to reclaim that water for re-use and/or to purify it to sufficient extent to be able to recycle the treated water into the water usage system, for example by discharge of the treated water into rivers, lakes or reservoirs.
[0003] The term fluid waste material will be used hereinafter to denote in general a waste material from any source which has a fluid, notably water, as a major component. For convenience, the invention will be described hereinafter in terms of the treatment of municipal sewage, that is the discharge from foul water drainage systems, as the fluid waste material.
[0004] A typical method for the treatment of such waste material is to subject the material to aerobic boilogical digestion in the fluid phase so as to reduce the biological oxygen demand of the treated water to within mandatory limits so that it may be discharged to the environment. Such treatment can take place in the fluid phase in an aerated or agitated vessel containing the waste to be treated. A preferred form of such a fluid phase digestion treatment is known as the activated sludge treatment. In such a process, aeration keeps the solid particles of waste suspended in the fluid phase and enables bacteria, fungi, protozoa, metazoa and other boilogical organisms to utilise the suspended and soluble components of the sewage for the digestion process during which a biomass is built up. For convenience, the invention will be described hereinafter in terms of such an activated sludge process.
[0005] During an activated sludge process, a biomass is produced as a result of the bacterial digestion of components within the fluid waste. The term biomass is used herein to denote the live and dead bacteria and other organic materials dissolved in or suspended in the fluid phase of the digestion mixture. Part of this biomass accumulates as flocs or particles which are suspended in the aqueous phase and settle out in a subsequent settling tank or other sedimentation operation. The biomass and settled solids must be removed from the system to prevent their accumulation to excessive extents. It is also required by legislation that the effluent water contain less than stated levels of various materials and suspended solids before it can be discharged to the environment. The removed biomass and other solids are disposed of as a waste product from the system, although part of the biomass may be recycled for admixture with incoming sewage to provide and maintain the necessary bacterial population for the digestion stage. The treated water can then be discharged as the effluent from the system or may be subjected to further treatments.
[0006] The regulations and legislation governing the nature and quality of the effluent and the disposal of the biomass are becoming increasingly stringent. These, and awareness of the environmental effects of disposal of the biomass, are making conventional disposal techniques unacceptable. For example, the use of the biomass, or sewage sludge as it is also known, as a fertiliser on the land, or disposal in the sea are no longer acceptable. The cost of disposal of the biomass now represents about 60% of the cost of operating an activated sludge process and the need for an economic yet environmentally acceptable method for reducing the problem of biomass disposal still exists.
[0007] One proposal for reducing the problem has been to reduce the amount of biomass produced by the activated sludge process by the use of predator organisms which graze upon the bacteria causing digestion of the waste material. Ciliated protozoa and other metazoa, such as rotifers and oligochaete worms, are stated to be predators for the types of bacteria normally present in an activated sludge process. However, they are normally present in only a few tens or hundreds of organisms per litre in a conventional activated sludge process and do not normally have any significant effect on the digestion process and the production of biomass. It has been proposed that such predators could be held on a filter trap so that they are not swept through the system by the volumes of water being treated and can accumulate and thus have an effect on reducing the amount of biomass produced. However, this was a laboratory proposal using synthetically cultivated bacteria and ciliate predators using a synthetic nutrient composition. In a practical process, the population of such predator organisms which could be maintained is restricted by the available nutrient level in the waste material. As stated above, in a conventional activated sludge process, this population is too small to have any significant effect on the amount of biomass produced.
[0008] We have now found that if the median primary particle size of the biomass and other solids in the digestion stage of an aqueous waste material aerobic bacterial treatment process, notably an activated sludge process for the treatment of municipal sewage, is reduced to less than 10, preferably from 1 to 6, notably from 1 to 3, micrometres, then the quality, notably the suspended biomass solids content, of the treated water is enhanced. We have found that this particle size range corresponds to that at which ingestion of solid particles by rotifers and other predator organisms, such as ciliate filter feeders, is optimised and that the organisms obtain the nutrients from the ingested solids without the need to rupture the cell walls. As a result, the ingestion of biomass and other solids by the predator organisms in the waste water is increased as compared to where the biomass particle size range contains significant proportions of particles outside this range. The optimisation of the particle size for ingestion by the predator organisms enables a higher population of the predator organisms in the waste digestion stage to be supported than where no comminution has taken place. As a result, a useful reduction in biomass production in the digestion stage can be achieved without the need for additional nutrients or the expenditure of uneconomically large amounts of energy.
SUMMARY OF THE INVENTION
[0009] Accordingly, the present invention provides a method for the aerobic biological, notably bacterial, digestion of a fluid waste material, notably an aqueous waste containing particulate solids, characterised in that at least part of the solids in or produced from the fluid during the digestion stage are subjected to a particle comminution step so as to reduce the median particle size of those particulate solids to less than 10 micrometres, preferably to within the size range 0.2 to 10, preferably 1 to 6, micrometres, without causing significant rupture of cell walls of cellular material within the solids.
[0010] It has been proposed in a laboratory simulation of an activated sludge process to subject solid biomass particles to ultrasonic disintegration, shear working and other high energy disintegration techniques. However, the objective of such a proposal was to rupture the cell walls of cellular material in the biomass so as to release proteins and other intra-cellular nutrients for consumption by the bacteria used in the waste material digestion stage. The size reduction processes were therefore deliberately operated at sufficiently high energy levels to cause rupture of cell walls of a high proportion of the solid particles. This is both energy intensive and expensive and is not feasible for use on a large scale, low cost process, such as an activated sludge process for the treatment of municipal sewage. In the present invention, the comminution, or size reduction, process is carried out at a significantly lower energy level so that substantially no cell wall rupture takes place, that is only a minor proportion of, preferably less than 20%, of the cells are ruptured. Typically, less than 10% of the cells are ruptured in the present invention. As a result, the process of the invention can be applied economically to part or all of the fluid fed to and/or circulating in an activated sludge process to achieve a significant reduction in biomass production from such a process.
[0011] It has also been proposed to apply low energy ultra sonic disintegration techniques to the solid flocs in a laboratory scale simulation of an activated sludge process. The objective in such a proposal was to break up large sized flocs to investigate the nature and behaviour of the primary particle size solid particles in the digestion stage. However, is was stated that this process resulted in the presence of large amounts of fine particles suspended in the aqueous phase and that this deleteriously affected the filtration properties of the resultant suspension, which would be detrimental on a commercial scale activated sludge process. However, in an activated sludge process where predator organisms are present, we have found that the predator organisms graze preferentially upon such fine particles and thus reduce the overall solids content of the effluent water. Thus, this apparently adverse property of low energy working of the biomass is turned to a benefit.
[0012] We have found that particles within the size range 0.2 to 10 micrometres are preferentially ingested by predators, notably rotifers. As a result, if the median particle size of at least part of the suspended biomass particles is reduced to less than 10 micrometres, the organisms can be used to reduce the biomass both by grazing on the bacteria which form the biomass and on the fine particle size biomass produced by the comminution step. By grazing on the suspended solids, the predators reduce the suspended solids in the water effluent, which is thus clarified and more suitable for discharge into the environment.
[0013] Accordingly, from a preferred aspect, the present invention provides a method for the treatment of a fluid waste material, notably a municipal sewage, in which the waste material is subjected to fluid phase aerobic bacterial digestion in a digestion stage to produce biomass particles and a water effluent, preferably in an activated sludge process, characterised in that:
a. at least part of the digestion of the waste material is carried out in the presence of a population of predator organisms which graze upon at least some of the bacteria used to digest the waste material, which population is maintained at a level of at least 10,000 of such organisms per litre of the fluid phase in the digestion stage; and b. at least part of the waste material and/or the biomass and other solids present in the digestion stage are subjected to a comminution process so as to reduce the median particle size of the comminuted solids to less than 10 micrometres, without causing significant cell rupture of cellular components of the waste material or biomass, so as to enhance ingestion, or grazing, of the solids particles by the predator organisms.
[0016] In the present invention the comminution of the solids is carried out at a sufficiently low energy level for no significant rupture of the cell walls to be performed, since we have found that the predators graze on the bacteria and fine particle size solids and obtain the benefit of nutrients within the bacteria and other cellular materials without the need to rupture the cell walls. Typically, less than 20% of the cellular material in the waste or biomass has its cell walls ruptured. This is achieved by the use of suitably short comminution times and/or low comminution energies. A particularly preferred comminution process is one in which cavitation is caused within the fluid phase.
[0017] The invention can be applied to a conventional activated sludge process or to other treatment processes where bacteria are used to digest aerobically at least part of a fluid waste material. Thus, the invention can be applied to trickle filter processes, Kaldnes suspended carrier process or agitated tank processes as well as to activated sludge processes. The invention can be applied to waste materials from a wide range of sources which are to be subjected to aerobic bacterial digestion in a fluid phase. However, for convenience, the invention will be described in terms of the activated sludge treatment of a municipal sewage waste material.
[0018] It is customary to subject the fluid waste material to an initial solids separation step, for example a coarse screening, so as to remove large solids before the digestion stage. Such initial solids separation can be carried out using any suitable technique and the fluid/solids phase from such initial solids separation stage forms the fluid waste material for the digestion stage of the present invention.
[0019] In the method of the invention, at least part of the mixture of waste material solids, bacteria, biomass and water in the digestion stage of the treatment process is subjected to comminution so as to disintegrate larger particles and of aggregates of smaller particles so as achieve the desired optimum particle size in the suspended solids for predator grazing. Such comminution can be achieved at any suitable stage before or during the digestion stage and by any suitable technique. Thus, part or all of the fluid waste material fed to the digestion stage can be subjected to the comminution process, and/or part or all of the digestion mixture can be comminuted at some stage during the digestion stage. Suitable comminution techniques include, for example, shear working by inducing turbulence in the mixture of solids, biomass and water, for example by a high speed stirrer, contra-flow spiral baffles or vanes, contra-rotating paddles; or by using a ball mill. A particularly preferred form of disintegration uses destructive cavitation of the solid particles in the fluid waste material and/or the digestion mixture. Such destructive cavitation can readily be achieved by high pressure homogenisers or other techniques. However, a particularly preferred process uses hydrodynamic cavitation. As indicated above, the use of too high an energy level during such disintegration results in rupture of the cell walls of cellular components of the mixture, which is not necessary and is wasteful of energy for present purposes. In order to reduce cell wall rupture to less than about 20%, we prefer to apply a hydrodynamic cavitation technique in which a pressure drop is induced as the material flows through one or more nozzle orifices or apertures, thus inducing cavitation turbulence within the fluid phase downstream of the nozzle orifice or the aperture. This results in a transfer of disruptive energy to the solid particles as the cavitation collapses. It will usually be preferred to cause a pressure drop of at least 2 Bar within the fluid phase of the digestion mixture to cause the formation of cavitation bubbles within the fluid phase. Typically, at a pressure drop of 5 to 6 Bar, approximately 4 to 20 Joules per ml of fluid being treated are transferred to the solid particles. This achieves satisfactory disintegration of the solid particles or flocs without significant cell wall rupture, as would be evidenced by an increase in the protein content of the comminuted material. Typically, such a comminution technique releases less than 10 mg/litre of intra-cellular protein from the material being comminuted, whereas high energy sonification releases more than 40 mg/litre of intra-cellular protein.
[0020] In a particularly preferred form of the hydrodynamic cavitation process, the fluid/solids digestion mixture or waste material is forced through an aperture, for example a nozzle orifice, whose dimensions and fluid flow therethrough are selected to achieve the desired pressure drop. Typically, the pressure drop required to achieve satisfactory comminution will be in the range 2 to 7.5 Bar, notably from 4 to 6 Bar. It will also be necessary to select the diameter of the aperture and of the conduit carrying the digestion mixture to the aperture so as to achieve the flow rate desired for the operation of the waste treatment process. We have found that a ratio of the cross-sectional area of the flow path of the conduit upstream of the aperture to the effective cross-sectional area of the aperture is preferably within the range 20:1 to 350:1. Preferably, the ratio is greater than 30:1, notably about 50:1 to 150:1. Surprisingly, we have found that cavitation apparatus having such a ratio of conduit to aperture areas can be scaled up successfully, for example to achieve greater flow rates through the apparatus, without the need for significant changes to the value of the ratio.
[0021] The aperture can be provided by a single hole in a transverse plate in a conduit or a single nozzle outlet to the conduit. The aperture can be of any suitable shape, for example circular, square or polygonal. However, a circular aperture is preferred. If desired, a plurality of nozzles or apertures can be used so as to achieve a larger flow across the plane of the plate. It is the sum of the cross sectional areas of the apertures or nozzle orifices which gives the effective area of the apertures for calculating the value of the ratio of areas. For convenience, the invention will be described hereinafter in terms of passing a digestion mixture through a single circular aperture or nozzle orifice submerged within a tank or vessel operated at atmospheric pressure.
[0022] The flow of the digestion mixture through the aperture conveniently achieved by pumping at least part of the digestion mixture through the aperture using any suitable pump mechanism. Typically, the pump will be a conventional axial flow, centrifugal, gear, peristaltic or other pump. Such a pump may cause some comminution of solids within the pump itself, but this will usually not achieve adequate comminution for the purposes of the present invention.
[0023] If desired, air bubbles can be introduced into the fluid phase during the comminution step to assist transfer of energy to the solid particles. For example the digestion mixture may be passed through the throat of a venturi type apparatus and an air stream fed to the throat of the venturi to form bubbles within the digestion mixture.
[0024] If desired two or more comminution apparatus may be used in parallel to achieve the desired flow rate of comminuted material into or through the digestion stage. For convenience, the present invention will be described in terms of passing the digestion mixture through a single apertured plate.
[0025] Accordingly, the present invention also provides apparatus for the aerobic bacterial digestion of a fluid waste material, characterised in that it comprises:
a. a digestion vessel within which the waste material is to be digested; and b. means by which at least part of the waste material and/or the fluid/solids mixture in the digestion vessel is subjected to comminution so as to reduce its median primary particle size to less than 10 micrometres, said means being characterised in that it is operated at sufficiently low energy input to the waste material that it is adapted to cause no significant rupture of the cells walls of cellular material in the waste material or biomass produced therefrom during the digestion stage.
[0028] Preferably, the comminution means imparts less than 20 J/ml energy to the waste material and/or the digestion mixture being comminuted. Preferably, the comminution means comprises a pump means for ejecting waste material and/or digestion mixture through an aperture, for example one or more nozzles, so as to achieve a pressure drop of from 2 to 7.5 Bar across the plane of the aperture.
[0029] The comminution process may be carried out at any point during the treatment of the fluid waste material, for example as or before it is fed to the digestion stage. However, the comminution process is preferably carried out on at least part of the fluid waste material during the digestion stage. For example, part of the digestion mixture may be removed from the digestion stage and subjected to the comminution process to disintegrate the biomass flocs and particles and other solids in that mixture. The comminuted mixture can then be recycled to the digestion stage. Since the comminution is designed to enhance the grazing of the predator organisms on the suspended solids or biomass particles, it will be appreciated that such comminution is preferably carried out prior to the establishment of the predator organism population in the digestion mixture.
[0030] In a particularly preferred embodiment, the comminution is carried out on a portion of the digestion mixture which has been removed or isolated from the bulk of the material in the digestion stage prior to the establishment of the desired population of predator organisms in that portion. That portion is then returned to the main body of the digestion mixture to supply the desired fine particles for grazing by the predator organisms. Typically, the recycle ratio of the total volume of the digestion mixture to that in the comminution process (the recycle ratio) is from 5:1 to 25:1, preferably about 10:1.
[0031] The optimum pressure drop, form and dimensions of the aperture and pump and the recycle ratio can readily be determined by simple trial and error tests within the parameters given above and will vary from waste material to waste material. Usually, variation of the recycle ratio and/or the pump operating pressure can be used to accommodate variations in the waste material, which provides a plant operator with a simple means for ensuring that the comminution is optimised.
[0032] The comminution process is carried out to increase the proportion of particles within the digestion stage which are of the optimum size for grazing on by the predator organisms. Typically, the comminution process is carried out to reduce the median particle size of the biomass and other solids to less than 6, preferably from 1 to 3, micrometres, as determined by microscopic examination.
[0033] The desired predators for present use are preferably filter feeding helminths, protozoa or metazoa of the rotifer type, notably the bdelloid rotifers Philodina spp, Habrotrocha spp, Notommata spp and Adineta spp, and monogonont rotifers, eg Lecane spp. Surprisingly, we have found that such rotifers have the unexpected secondary effect of causing some additional flocculation of fine solids within the digestion mixture, thus aiding clarification of the effluent water from the digestion stage. For convenience, the present invention will be described hereinafter in terms of the use of such bdelloid rotifers.
[0034] Such rotifers can be cultivated using any suitable technique to provide a source of the organisms of known population density. This can then be used to establish and maintain the desired population of predator organisms within the digestion mixture. We prefer to generate and maintain populations of at least 10,000, preferably more than 50,000, notably more than 100,000, organisms per litre in the portion of the digestion mixture in which grazing on the biomass and suspended solids is to take place. Preferably, the organisms are cultivated within a portion of the digestion mixture so that the organisms can act directly upon the bacteria and biomass.
[0035] In an activated sludge process, the throughput of fluid through the digestion stage may be sufficiently great that any predator organisms are swept through the digestion stage and discharged with the water effluent so that they are not available to treat incoming fluid waste materials. In such cases, it is preferred to provide a separate zone or vessel within which the predator population can be generated and maintained. For example, the main digestion vessel can be sub-divided to provide a zone having a lower flow rate of fluid therethrough. Alternatively, as indicated above, a portion of the digestion mixture may be separated off from the main body of the digestion mixture for comminution in a separate vessel. The predator organism culture can be added to this vessel to achieve the desired population level and the populated/comminuted portion then returned to the main digestion vessel to achieve the desired predator population therein. The amount of predator culture added is sufficient to maintain the desired population in the digestion stage and also to make up for any loss of predator organisms from the process, for example for that swept out of the digestion stage in the effluent water discharged from the digestion stage.
[0036] In a particularly preferred embodiment, the predator organisms are fed to a filter trap which retains the organisms in the biomass adhering to the surface of the solid members within the trap. Such a filter trap can be provided in a zone within the main digestion vessel or within an external vessel. A particularly preferred form of filter trap is one in which the fluid phase in a vessel flows over or through particles or other solid support materials. These provide a large surface area to which the predator organisms can attach themselves. The attachment and localised reduction of flow rate through and/or over the support material will reduce the washing out of the predator organisms. The support material may be made from plastic particles, notably those available from the Kaldnes company; or may be solid or porous pebbles or lava as used in trickle filters; or may be a metal or plastic mesh material, a mineral wool or glass fibre mat, or tubing or corrugated support members through or over which the fluid to be treated flows. The support material can be retained in position by a grille or other arrangement across the flow path through the filter trap.
[0037] As stated above, the predator organisms graze upon the bacteria and solid particles, at least part of which is comminuted biomass, present in the digestion stage and thus reduce the overall amount of biomass produced in the digestion stage. The extent of reduction of the biomass will depend, inter alia, upon the time for which grazing is to take place. This grazing period may by varied by varying the rate and volume of digestion mixture cycled through the separate vessel to which the predator organisms are added as described above. The reduction in biomass will also be affected by the species and level of the population of predators which is maintained in the digestion or other zone in which grazing on the bacteria and biomass takes place; on the temperature maintained within such a zone; and the nature of the waste material being treated. The optimum predator population and grazing time for any given case can readily be determined by simple trial and error. Once an optimum set of operating conditions has been established, the operator can vary the population of predators within the system to ensure that the optimum reduction in biomass is achieved if other operating conditions vary. Alternatively, the recycle ratio of the portion of the digestion mixture removed for comminution and predator population, to the whole digestion mixture, can be varied to alter the residence time of the predators within the main digestion zone and thus vary the extent of grazing achieved.
[0038] The grazing of the predator organisms on the solid particles reduces the loading of fine suspended solids in the effluent water. Typically, the presence of predator organisms in the digestion stage will reduce the amount of suspended solids having particle sizes in the range 0.2 to 6 micrometres in the effluent water by up to 95%. Since some of the predator organisms will be carried out of the digestion stage in the effluent water, grazing on the suspended solids by the predator organisms may continue after the effluent water leaves the digestion stage. It may be desirable to provide a settling tank or the like in which the effluent water is held prior to discharge to the environment or re-use. Such a settling tank not only provides a zone in which suspended solids can agglomerate and precipitate, but also provides a zone in which grazing of the suspended particle can continue. As stated above, we have found that the use of bdelloid rotifers has the surprising effect of enhancing the flocculation of fine solids during the digestion stage and/or during the settlement stage. Alternatively, this settlement zone may be provided by a vessel having a tortuous flow path for the effluent water therethrough so as to provide a prolonged residence time therein to enable grazing of the fine solid particles to take place. If desired, some or all of the predator organisms required for the digestion stage may be added to such a settling tank or vessel and part of the effluent water containing such organisms recycled to the digestion stage to provide the predator organisms required in the digestion stage.
[0039] As a result, the method of the invention not only reduces the biomass production in an activated sludge process, typically by at least 10 to 30%, but also clarifies the effluent water. Typically, we have found that the effluent water from the method of the invention contains less than 10% of the suspended solids found in effluent water from a process where no predator grazing has taken place, notably where a settling tank is used after the digestion stage, so that the effluent water can be discharged directly to the environment without further filtration or other treatment. The presence of predator organisms in the discharged water is usually not environmentally detrimental. Indeed, some of the predator organisms are used as foodstuffs for farmed fish and may thus be beneficial where the effluent water is discharged into rivers or lakes.
DESCRIPTION OF THE DRAWINGS
[0040] The invention will now be described with reference to a preferred embodiment as shown in the accompanying drawings in which:
[0041] FIG. 1 is a schematic representation of a small scale plant for testing the grazing of rotifers on solids in a fluid waste;
[0042] FIG. 2 is a schematic representation of a cavitation apparatus for the treatment of the digestion mixture in a sewage treatment process; and
[0043] FIG. 3 is a schematic representation of a small scale plant for the evaluation of the effect of the presence of rotifer populations on the clarification of effluent which has been subjected to particle size disintegration using a cavitation treatment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0044] Samples of the effluent from a Kaldnes (K1) “Monster” moving bed reactor plant were taken before the clarification stage. Small activated sludge samples were taken from the aerobic zone of an activated sludge sewage treatment plant, large samples (>20 litre) were taken from the outlet of the plant. The samples were autoclaved immediately after sampling and were determined to have a median particle size in the range 1 to 3 micrometres.
[0045] The samples were introduced into reactors as shown in FIG. 1 . These comprised Duran bottles 1 , which were sealed with special bottle cap assemblies 2 (Anachem, A-610). The samples were aerated using an aquarium air pump 3 dispersing the air through a solvent inlet filter 4 (Anachem, A-310). The air was sterile-filtered using Hepa-Vent 0.3 μm glass microfibre filters 5 and 6 at the air inlet and outlet points. The reactors were operated with sample volumes of either 400 ml or 900 ml and with light aeration.
[0046] In reactors operated with activated sludge samples, the antibiotics ampicillin and kanamycin were added at 100 ug/ml to prevent growth of E. coli , on which rotifers are known to graze. Prevention of bacterial growth was confirmed after plating reactor samples on plan LB agar and incubation at 37° C. overnight. The addition of antibiotics was not necessary in samples from the Kaldnes plant effluent, as bacterial growth was extremely limited in these samples.
[0047] Rotifers of the genus Philodina were added to each of the bottles 1 from tissue culture flasks containing a known number of organisms which had been grown under sterile conditions. The reduction in solids content in each sample was observed using microscopic examination.
[0048] In those cases where rotifers had been added, a reduction in the optical density, the turbidity, of the reaction mixture was noted, indicating that at least some of the solids had been ingested by the rotifers and removed from the aqueous phase.
[0049] Individuals of the rotifer clone Philodina roseola P1 were sampled and fed for three days on suspensions of fluorescent polystyrene particles (micromer blueF plain, Micromod) of the sizes 0.2 μm, 1 μm, 3 μm, 5 μm, 7 μm and 10 μm in a multi-well culture plate. The rotifers were observed and photographed with the Ortholux microscope (filter A, excitation: 340-380 nm, band pass >430 nm). Where particles of a particular size were successfully ingested, fluorescence was clearly visible in the gut of the rotifer. These test showed that the rotifers ingested particles in the size range 0.2 to 3 micrometres. Some of the larger particles, up to 10 micrometre size, were ingested by mature organisms.
[0050] These tests show that rotifer organisms feed on solid particles in effluent waste and that the particles ingested by rotifers are of the size range 0.2 to 10 micrometres.
[0051] Samples of the effluent were subjected to cavitation in a cavitation apparatus shown in FIG. 2 . This comprises a main holding tank 10 with a capacity of 50 litre and a side tank 11 of capacity 25 litre. A centrifugal pump 12 (EVM, model EVM2 7N/0.75) was used to circulate effluent through the apparatus. The piping used to connect components of the apparatus was PVC tubing with an inner diameter of 37 mm and the valves used were full bore valves. Two Bourdan-type pressure gauges 13 , 14 were used, measuring upstream and downstream pressure, before and after the orifice plate 15 . A clear piece of Perspex tubing 16 was installed after the orifice plate 15 so that the cavitation zone could be observed visually. The orifice plate 15 was made of 2 mm metal plate and was interchangeable with plates having different diameter orifices or could be removed altogether. Two metres of straight piping 17 were located immediately upstream of the orifice plate 15 .
[0052] Sludge was sampled from the outlet of an activated sludge plant and the main tank 10 was filled with some 23 litre of this sludge. With the pump 12 on and valve V 2 fully open, valve V 1 was slowly closed until completely closed. The sludge was pumped through the orifice plate 15 and the pressure drop across the orifice measured by pressure gauges P 1 and P 2 . Valve V 3 was initially closed and V 4 open and the flow rate of the sludge was determined and the sludge recycled to the main tank.
[0053] Three identical apparatus were operated in parallel. Feed was taken from the main feed pipe of the sewage works and mixed in equal amounts (5 litre/min) in the mixing tank.
[0054] Through an overflow pipe, the liquid was transferred into a main aeration tank, with a volume of 1.2 m 3 aerated with 2 ppm oxygen. The activated sludge was then transferred via an overflow pipe to the settling tank (“clarifier”, volume of ca. 1 m 3 ). Recycled activated sludge (RAS) was recycled to the mixing tank and the clarified water was sent to the main treatment works inlet. Waste activated sludge was removed directly from the main aeration zone (150 ml/min), using peristaltic pumps.
[0055] Return activated sludge (RAS) was pumped from the inlet from the activated sludge plant directly into the main tank 10 , using a peristaltic pump. The centrifugal pump 12 of the cavitation unit was switched on when the main tank 10 was filled with ca. 35 litre of sludge and switched off, when the level fell below ca. 5 litre. Valve V 4 was minimally closed to allow for some back-pressure to build up and cavitation to form. Cavitated RAS was immediately recycled into the main aeration tank of the pilot plant.
[0056] The hydrodynamic cavitation apparatus shown in FIG. 2 was installed above the pilot scale apparatus shown in FIG. 3 and connected to the duplicate lanes of the pilot scale apparatus using flexible tubing. RAS was pumped into the main tank of the cavitation apparatus with a speed of half the WAS speed at the time, usually 75 ml/min. With RAS twice the particle concentration of the WAS, this meant that each particle was on average treated once per sludge passage.
[0057] The particle size of the comminuted material from the cavitation apparatus was evaluated by microscopic examination. Pictures of the material were taken using a Leitz Ortholux II fluorescent microscope, a JVC TK-C1381 video camera and a Sony DSR-20P digital video recorder connected to an Apple Mackintosh G4 computer. Pictures were captured using Adobe Premiere 5.1 and were exported to NIH Image 1.61. Particle size was calibrated using 1 μm fluorescent polystyrene beads (micromer blueF plain, Micromod GmbH). The size of particles from turbid supernatants of autoclaved sludge was analysed using the calibrated system.
[0058] A HIAC VersaCount particle analyser was also used to analyse particle size range distribution of cavitated sludge particles. The machine was calibrated, using 10 ml samples containing mono-sized beads of known concentration. The machine displayed results at given particle sizes of 2, 3, 5, 10, 15, 20, 25 and 50 μm. As the optimum particle concentration was in the order of ca. 10,000 particles per ml, samples were diluted using distilled water. Typically, 1 ml of sludge sample was diluted to a total volume of 50 ml and two samples were measured for each data-point.
[0059] Cavitation tests were carried out using orifices of diameters of 3, 5 and 8 mms, which gave ratios of the pipe diameter to orifice diameter of 20:1, 50:1 and 150:1. The pressure drop across the orifice was measured at from 2 to 6 Bar. Below about 2 Bar no cavitation was detected. At a pressure drop in excess of about 7 Bar significant cell rupture as exhibited by a rise in the protein content of the cavitated material. At an orifice diameter of 8 mms cavitation was not achieved, whereas satisfactory cavitation was achieved with the 5 and 3 mms diameter orifices at pressure drops of between 2.5 and 6, preferably at about 4.8, Bar and the particle size range in the cavitated samples was predominantly in the range 1 to 5 micrometres.
[0060] Optical density at 600 nm (OD 600 ), measured in a Jasco 7800 Spectrophotometer, was used to determine wastewater turbidity. Five 1 ml samples were measured and the standard deviation calculated.
[0061] Wastewater from a Kaldnes wastewater treatment plant was collected prior to the clarifier and autoclaved. Autoclaving sterilised the samples and produced a suspension of many small sludge particles similar to pin flocs. The effluent was subjected to cavitation using a 5 mms orifice at a pressure drop of 4 Bar using the apparatus of FIGS. 2 and 3 operated in parallel in two lightly aerated batch mini-reactors. One reactor was used as a control, the other was inoculated with ˜50,000 rotifer/l of the genus Philodina . The optical density of the suspension was measured at 600 nm (OD 600 ) periodically and the experiment run for 67.5 hours. In the control reactor without rotifers, OD 600 dropped from 0.158 to 0.099, indicating a degree of clarification of ˜37%, due to particle settling. In comparison, the reactor with 50,000 rotifers/1 showed an improved clarification to a value of 0.006, representing particle removal of 96%.
[0062] Four identical reactors containing Kaldnes wastewater were run in parallel with rotifers at densities of 0, 2,000, 10,000 and 50,000 rotifers/1 respectively, over a period of 88.5 hours. Initial OD 600 values were in the range of 0.150 to 0.183. The clarity of the suspension in all four reactors dropped significantly with time, but for the reactor with the highest rotifer density (50,000 rotifers/1), almost all particles were removed from suspension within 48 h. In comparison, OD 600 in the control reactor without rotifers dropped by 39% in 48 h, compared to the starting value, demonstrating that comminution of the solids in the waste water had a beneficial effect. The OD 600 in the reactors with 2,000 rotifers/litre and 10,000 rotifers/litre dropped to 0.068 and 0.048 respectively, within 48 h, thus showing that rotifers were involved in particle removal.
[0063] To exclude the possibility that rotifers simply function passively as flocculants, without a requirement for an active process, rotifers were exposed to a brief burst of microwave radiation (10 second, 800W), resulting in a killing rate of 100%, but without apparent structural damage. Three mini-reactors containing Kaldnes wastewater were set up, one with 50,000 live rotifers/l, one with 50,000 dead rotifers/1 and one without rotifers. OD 600 was measured over a period of 44 hours. Initial OD 600 in all three reactors was determined to be in the range of 0.145 to 0.157. After 44 hours, only the reactor containing live rotifers showed a significantly reduced optical density when compared to the control reactor without rotifers. The absorption was reduced to 0.006 compared to 0.078 in the control and to 0.106 in the dead rotifer. This demonstrates a 96% clarification of particles in suspension in the live rotifer reactor, whereas the control and the dead rotifer reactors only showed clarification of 50% and 27% respectively, compared to their starting values. This experiment shows that live rotifers are required for effective particle removal.
[0064] Experiments were performed which measured changes in the amount of biomass in the system. The biomass present in waste waters is usually expressed as total suspended solids (TSS). For this work, wastewater from a conventional activated sludge plant was used. If rotifers feed on particles in waste water, a reduction in biomass of the system, due to partial mineralisations, should be observed. However, the amount of solids in suspension will depend on the degree of agitation of the wastewater sample. In the following experiments, therefore, TSS was measured either with or without stirring at sampling times. This also allowed information to be obtained on whether rotifers influence settling of particles in suspension.
[0065] Activated sludge was sampled, autoclaved and the supernatant transferred into four mini-reactors. Two of these mini-reactors, one seeded with 100,000 rotifers/l, the other without rotifers, were not disturbed prior to sampling for TSS and OD 600 analysis. The two other mini-reactors, again with or without rotifers at 100,000/1, were mixed vigorously prior to sampling, using a magnetic stirrer. In the latter two reactors, total biomass was measured, including that which had settled out. The experiment was operated for 48 hours. At the start of the experiment, all reactors had an OD 600 within the range of 0.286 to 0.301 and TSS ranged from 128 mg/l to 146 mg/l. During the course of the experiment, OD 600 of the control reactors decreased by 13% for the undisturbed and by 5% for the stirred reactor. In comparison, the reactors containing 100,000 rotifers/l showed a reduction in OD 600 of 33% for the undisturbed reactor and of 20% for the stirred reactor. A similar result was observed for solids in suspension. The controls showed a decrease in TSS of 18% for the undisturbed reactor and no change in the stirred reactor. In contrast, TSS in the rotifer reactor decreased by 38% in the undisturbed and by 11% in the stirred reactor. As measurements of stirred reactor samples indicate the total biomass in the system, it can be concluded that the total biomass in the reactor containing rotifers was reduced by ˜11%. The settling effect of rotifers in addition to the natural settling process decreased suspended biomass by ˜10%. In a second experiment, 200,000 rotifers/l were added to activated sludge and incubated for 24 hours. TSS was decreased by 9% in the stirred reactor containing rotifers, compared to no significant change of TSS in the stirred control reactor. In the unstirred control reactor, TSS was decreased only insignificantly, but was decreased by 34% in the reactor containing rotifers. This results in a total loss of biomass of ˜9% and an additional settling effect of ˜25% due to the presence of rotifers.
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The present invention relates to a method for the aerobic digestion of a fluid waste material, notably an aqueous sewage, in which at least part of the waste material and/or of the digestion mixture is comminuted to reduce the median particle size of biomass and other solid particles in the digestion mixture to less than 10 micrometres, for example using destructive cavitation with a pressure drop of from 2 to 7.5 Bar. The comminution produces particles which are preferentially ingested by predator organisms in the digestion stage so that they graze on the bacteria and biomass particles and thus reduce the amount of biomass and suspended solids produced in the digestion stage. The invention also relates to apparatus for use in the method of the invention.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims a priority from prior Japanese Patent Application No. 2007-153515 filed on Jun. 11, 2007, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
An aspect of the present invention relates to a centrifuge which includes a single motor as a drive source and a lock mechanism for locking a cover in the two portions thereof.
2. Description of the Related Art
A centrifuge is a machine in which a rotor with a sample stored therein is driven and rotated in a rotor rotation chamber to thereby centrifuge the sample. In the centrifuge, the opening of the rotor ration chamber can be opened and closed with a cover; during the centrifuging operation of the centrifuge while the rotor is rotating, the opening of the rotor rotation chamber is closed by the cover; and, before and after the centrifuging operation, in order to charge and discharge the sample, the cover is opened.
Generally, in a centrifuge which is used in a laboratory or the like, in order to prevent the rotating rotor from being exposed, the cover, which has closed the opening of the rotor rotation chamber, is locked automatically. As a method for locking the cover, there are known two types of methods: that is, in one type, the cover is simply caught by a latch; and, in the other type, the closed state of the cover is detected and, based on this detection, a lock mechanism is operated automatically, whereby the cover cannot be opened manually.
As a drive method for driving the lock mechanism, there are known two types of drive methods: that is, in one type, the cover is latched by reciprocating it using an electromagnetic solenoid; and, in the other type, the cover is pulled in using a motor (for example, see JP-2001-300350-A).
Recently, there has been increasing the need for consideration for safety in order that, even when the rotor is broken during rotation, the broken pieces thereof can be prevented from flying externally of the centrifuge. In this respect, a lock mechanism of a motor drive type, which can provide a relatively large sealing power, is advantageous. A lock mechanism plays an important role as a portion concerned with the safety of the centrifuge, and the reliability of the lock mechanism provides an important element.
Conventionally, several kinds of lock mechanisms using a motor are put into practical use and, in many cases, depending on the intensity of the energy of the rotor and the complexity of the breaking mode of the rotor, the cover is locked in a plurality of positions thereof. In a structure where independent motors are disposed in the individual lock mechanisms according to the relationship between the lock positions of the cover, the cost of the structure is large.
In view of this, there is also proposed a lock mechanism which includes a drive side hook to be driven and rotated by a single motor and a driven side hook connected by a connecting member to the drive side hook to be rotated integrally with the drive side hook, wherein the drive side hook and driven side hook are engaged with the securing members of the cover to thereby lock the cover at two positions thereof.
In the above lock mechanism, when there is employed a structure where both of the drive side hook and driven side hook are engaged with the securing member of the cover and securing member is pulled in to thereby bring the cover into close contact with the opening of the rotor rotation chamber, the two hooks must have a large force to pull in the securing member. In this case, a drive force from the motor is transmitted from the drive side hook through the connecting member to the driven side hook, so that a large torsion torque is applied to the connecting member. Owing to this, high strength and rigidity are required of the connecting member, resulting in the increased dimension (thickness) and weight of the connecting member.
SUMMARY OF THE INVENTION
The present invention aims to solve the above problem and to provide a centrifuge which, when closing a cover, pulls in the securing member of a cover only by a drive side hook to reduce the transmission torque of a connecting member to thereby be able to reduce the size and weight of the connecting member, and also which, after the securing member is pulled in, positively locks the two portions of the cover by both the drive side hook and driven side hook to thereby be able to secure high level of safety.
According to an aspect of the present invention, there is provided a centrifuge including: a rotor that holds a sample therein; a drive device that drives the rotor to rotate; a chamber that houses the rotor therein; a cover that is opened and closed with respect to the chamber; and a lock mechanism that locks the cover in a closed state, wherein the lock mechanism includes: a motor; a first hook that is rotated by the motor; and a second hook that is connected to the first hook through a connecting member and is rotated according to a rotation of the first hook, wherein the cover includes a securing portion on which the first hook and the second hook are respectively secured when the cover is locked, and wherein, during a locking operation of the cover, primary the first hook is engaged with the securing portion to pull the cover toward the chamber, and the second hook is engaged with the securing portion when the cover have been pulled.
The first hook may include an engagement surface that is engaged with the securing portion during the locking operation. The engagement surface may include: a first portion that is formed in an arc shape; and a second portion that is continuously formed with the first portion and is formed in a linear shape. A distance between a rotating center of the first hook and a point on the engagement surface where the engagement surface firstly contacts the securing portion during the locking operation may be set to L 2 . A distance between the rotating center and a point on the engagement surface where the engagement surface contacts the securing portion when the cover is locked may be set to L 1 .
L 2 may be set larger than L 1 . The engagement surface may be continuously formed so that a distance between the rotating center and the engagement surface gradually decreases from L 2 to L 1 .
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will be described in detail based on the following figures, wherein:
FIG. 1 is a broken side view of a centrifuge according to an embodiment;
FIG. 2 is a broken plan view of the lock mechanism portion of the centrifuge according to the embodiment;
FIG. 3 is a perspective view of a lock mechanism provide in the centrifuge according to the embodiment;
FIG. 4 is a side view of the drive side hook of the lock mechanism provided in the centrifuge according to the embodiment;
FIG. 5 is a side view of the drive side hook of the lock mechanism provided in the centrifuge according to the embodiment, explaining the operation of the drive side hook; and
FIG. 6 is a side view of the driven side hook of the lock mechanism provided in the centrifuge according to the embodiment, explaining the operation of the driven side hook.
DETAILED DESCRIPTION OF THE INVENTION
Description will be given below of a centrifuge according to an embodiment of the invention.
FIG. 1 is a broken side view of a centrifuge according to the embodiment, FIG. 2 is a broken plan view of a lock mechanism portion included in the centrifuge, and FIG. 3 is a perspective view of a lock mechanism.
As shown in FIG. 1 , in a main body 1 of a centrifuge, there is formed a rotor rotation chamber 3 for storing a rotor 2 therein and, downwardly of the rotor rotation chamber 3 , there is disposed a drive device 4 which is used to drive and rotate the rotor 2 . Upwardly of the rotor rotation chamber 3 , there is disposed an openable/closable cover 5 which, when charging and discharging a sample to be centrifuged, is used to gain access to the rotor rotation chamber 3 . One end of the cover 5 is rotatably supported by a hinge 6 . The cover 5 is rotated with the hinge 6 as a center to open and close the upper surface opening of the rotor rotation chamber 3 .
On the lower portion two sides (on the two sides in the vertical direction of the sheet surface of FIG. 1 ) that exist on the opening and closing side of the cover 5 , there are vertically mounted a pair of hook catches 7 serving as a securing member for locking the cover 5 . When the hook catches 7 are caught by a pair of hooks 11 a , 11 b of a lock mechanism 10 disposed in the main body 1 , the opening/closing of the cover 5 can be locked.
As shown in FIG. 1 , on the centrifuge main body 1 , there are provided a control device 8 and an operation panel 9 , while these two parts are electrically connected to each other.
Here, description will be given below of the structure of the lock mechanism 10 .
As shown in FIG. 2 , the pair of hooks 11 a and 11 b are respectively disposed at the positions that correspond to the pair of hook catches 7 on the outer peripheral side of the rotor rotation chamber 3 , while the two hooks 11 a and 11 b are spaced from each other; and, the drive side hook 11 a can be driven by a single motor 12 shown in FIG. 3 . The pair of hooks 11 a and 11 b , as shown in FIG. 2 , are rotatably supported on their associated frames 13 a and 13 b respectively mounted on the main body 1 by their associated shafts 14 a and 14 b.
As shown in FIG. 3 , the motor 12 is provided horizontally on one drive side end and, to the output shaft (motor shaft) 15 of the motor 12 , there are connected a link shaft 16 and a disk-shaped disk plate 17 . And, to the end portion of the link shaft 16 that is set eccentric to the axis of the motor shaft 15 , there is connected one end of a link 18 by a pin 19 , while the other end of the link 18 is connected by a pin 20 to such position of the drive side hook 11 a that is set eccentric to the shaft 14 a . The drive side hook 11 a and driven side hook 11 b are connected to each other by a stay 21 serving as a connecting member. The two ends of the stay 21 are respectively mounted on the drive side hook 11 a and driven side hook 11 b at such positions thereof that are offset on the opposite side (in FIG. 3 , on this side) to the rotor rotation chamber 3 with respect to the two hooks 11 a and 11 b.
As shown in FIG. 1 , in the outer periphery of the disk plate 17 , there are formed two notches 17 a ; and, on the periphery of the disk plate 17 , there are disposed two photosensors 23 and 24 which are used to optically detect the rotation position of the disk plate 17 , that is, the rotation position of the motor output shaft 15 . The two photosensors 23 and 24 , as shown in FIG. 1 , are electrically connected to the control device 8 .
As shown in FIG. 2 , the shafts 14 a and 14 b of the drive side hook 11 a and driven side hook 11 b are respectively disposed coaxially with each other on a straight line which is substantially in contact with the outer periphery of the rotor rotation chamber 3 . The stay 21 for connecting together the drive side hook 11 a and driven side hook 11 b , in order to avoid its interference with the outer periphery of the rotor rotation chamber 3 , is mounted at such position that is offset on the opposite side (in FIG. 2 , downwardly) to the rotor rotation chamber 3 with respect to the shafts (centers of rotation) of the hooks 11 a and 11 b . Owing to this structure, between the stay 21 and the outer peripheral surface of the rotor rotation chamber 3 , there is secured at least a clearance 6 (shown in FIG. 2 ), which prevents the stay 21 from interfering with the outer periphery of the rotor rotation chamber 3 in an angle range where the stay 21 rotates together with the drive side hook 11 a.
As shown in FIGS. 1 and 2 , on the two portions of the main body 1 that correspond to the hook catches 7 mounted on the cover 5 , there are provided two lid sensors 25 a and 25 b which are used to detect the hook catches 7 to thereby detect the opening and closing states of the cover 5 , while the two lid sensors 25 a and 25 b are electrically connected to the control device 8 (see FIG. 1 ).
Next, description will be given below of the shapes and operations of the drive side hook 11 a and driven side hook 11 b with reference to FIGS. 4˜6 .
FIG. 4 is a side view of the shape of the drive side hook, FIG. 5 is a side view of the drive side hook, explaining the operation thereof, and FIG. 6 is a side view of the driven side hook, explaining the operation thereof.
As shown in FIG. 4 , the drive side hook 11 a includes an engaging pawl 11 a - 1 . The engaging pawl 11 a -includes a linear-shaped securing portion 11 a - 11 formed in the inside diameter portion thereof (in the contact portion thereof with the engaging hole 7 a of the hook catch 7 ), and an arc-shaped guide portion 11 a - 12 formed in the portion thereof that exists forwardly of the inside diameter portion. The securing portion 11 a - 11 and guide portion 11 a - 12 are smoothly connected together. A distance from the shaft 14 a (the center of rotation of the drive side hook 11 a ) to the securing portion 11 a - 11 and a distance L from the shaft 14 a to the guide portion 11 a - 12 are respectively set for L 1 and L 2 which are respectively shown in FIG. 4 .
A distance L 2 from the shaft (center of rotation) 14 a of the drive side hook 11 a to the engagement start point of the guide portion 11 a - 12 is set larger than the distance L 1 (a constant value) from the shaft (center of rotation) 14 a to the securing portion 11 a - 11 (L 2 >L 1 ). The distance L from the shaft (center of rotation) 14 a of the drive side hook 11 a to the guide portion 11 a - 12 gradually decreases toward the securing portion 11 a - 11 from the maximum value L 2 to the minimum value L 1 . L 1 expresses a distance when the cover 5 is locked, while L 2 expresses a distance when the pulling-in operation of the hook catch 7 is started.
On the other hand, as shown in FIG. 6 , on the driven side hook 11 b as well, there is formed an engaging pawl 11 b - 1 . However, in the inside diameter portion (the contact portion with the engaging hole 7 a of the hook catch 7 ) of the engaging pawl 11 b - 1 , there is formed only a linear-shaped securing portion 11 b - 11 , but there is not formed a guide portion similar to the guide portion 11 a - 12 that is formed in the engaging pawl 11 a - 1 of the drive side hook 11 a . Therefore, the length of the engaging pawl 11 b - 1 of the driven side hook 11 b is smaller than that of the engaging pawl 11 a - 1 of the drive side hook 11 a.
Thus, when, in order to close the cover 5 which is opened, the cover 5 is rotated downwardly about the hinge 6 and the upper surface opening of the rotor rotation chamber 3 is thereby closed by the cover 5 , the pair of hook catches 7 mounted on the cover 5 are detected by the lid sensors 25 a and 25 b , and the detect signal is transmitted to the control device 8 . On receiving this signal, the control device 8 drives and controls the motor 12 , whereby the lock mechanism 10 is allowed to start the locking operation of the cover 5 .
That is, in the lock mechanism 10 , when the motor 12 is driven and the motor shaft 15 is driven and rotated, the link shaft 16 and disk plate 17 connected to the motor shaft 15 are integrally rotated; and, the rotation of the motor shaft 15 is transmitted through the link shaft 16 and link 18 to the drive side hook 11 a , thereby rotating the drive side hook 11 a in the same direction (in FIG. 5 , in the arrow a direction). Since the rotation of the drive side hook 11 a is transmitted through the stay 21 to the driven side hook 11 b , the driven side hook 11 b is also rotated in the same direction (in FIG. 6 , in the arrow a direction).
As a result of this, the engaging pawl 11 a - 1 of the drive side hook 11 a is engaged with the engaging hole 7 a of the hook catch 7 and, as shown by a solid line in FIG. 5 , firstly, the guide portion 11 a - 12 of the engaging pawl 11 a - 1 starts to be engaged with the engaging hole 7 a of the hook catch 7 . At the then time, the engaging pawl 11 b - 1 of the driven side hook 11 b , as shown by a solid line in FIG. 6 , is not yet engaged with the engaging hole 7 a of the hook catch 7 .
When the drive side hook 11 a is rotated further from the above state, as described above, since the distance L from the shaft 14 a to the guide portion 11 a - 11 of the engaging pawl 11 a - 1 decreases gradually from the maximum L 2 to the minimum value L 1 , the hook catch 7 having the engaging hole 7 a to be engaged with the guide portion 11 a - 11 is pulled in downwardly (in FIG. 5 , in the arrow b direction) by the engaging pawl 11 a - 1 ; and, at the time when the engagement of the engaging pawl 11 a - 1 with the engaging hole 7 a of the hook catch 7 reaches the securing portion 11 a - 12 from the guide portion 11 a - 11 , the downward pulling-in operation of the hook catch 7 is ended and, at the then time, the pulling-in amount of the hook catch 7 provides (L 2 -L 1 ).
Owing to the downward pulling-in operation of the catch hook 7 , the cover 5 is closely contacted with the peripheral edge of the upper surface opening of the rotor rotation chamber 3 . However, since, on the cover 5 , there is also mounted another catch 7 disposed on the driven side, the driven side hook catch 7 is also pulled in downwardly (in FIG. 6 , in the arrow b direction) similarly.
When the drive side hook 11 a and driven side hook 11 b are rotated further and, as shown by broken lines in FIGS. 5 and 6 , the engaging pawls 11 a - 1 and 11 b - 1 of the two hooks 11 a and 11 b are completely inserted into the engaging holes 7 a of the hook catches 7 , and the securing portions 11 a - 1 and 11 b - 1 of the engaging pawls 11 a - 1 and 11 b - 1 are secured to the engaging holes 7 a of the hook catches 7 , the locking of the cover 5 is completed and, at the same time, the cover 5 is closely contacted with a door packing 26 which is provided on the peripheral edge of the upper surface opening of the rotor rotation chamber 3 .
The rotation position of the motor shaft 15 can be detected by optically detecting the position of the disk plate 17 by the photosensors 23 and 24 , and the detect signal is input to the control device 8 . On receiving the detect signal, the control device 8 determines the position of the drive side hook 11 a based on the rotation position of the motor shaft 15 and drives and rotates the motor 12 . The locked state of the cover 5 by the lock mechanism 10 can be released through an operation to be carried out on the operation panel 7 .
As described above, in the centrifuge 100 according to the embodiment, the guide portion 11 a - 12 of the engaging pawl 11 a - 1 of the drive side hook 11 a to be driven directly by the motor 12 is engaged with the engaging hole 7 a of the hook catch 7 , and the hook catch 7 is pulled in downwardly to thereby bring the cover 5 into close contact with the door packing 26 provided on the upper surface opening peripheral edge of the rotor rotation chamber 3 , while the pulling-in operation of the hook catch 7 is carried out only by one hook, that is, by the drive side hook 11 a but is not carried out by the other hook, that is, by the driven side hook 11 b . This eliminates the need to transmit a large drive force for pulling in the hook catch 7 to the driven side hook 11 b through the stay 21 , thereby being able to reduce the torsion torque that is applied to the stay 21 . Thus, there is eliminated the need for the stay 21 to have high strength and rigidity, which can reduce the size and weight of the stay 21 .
After the hook catch 7 is pulled in using the drive side hook 11 a and the cover 5 is thereby closely contacted with the door packing 26 provided on the upper surface opening of the rotor rotation chamber 3 , the engaging pawl 11 b - 11 of the driven side hook 11 b is also engaged with the engaging hole 7 a of the hook catch 7 and the cover 5 is thereby locked by both of the drive side hook 11 a and driven side hook 11 b . Owing to this, the cover 5 can be locked positively at the two positions thereof, which makes it possible to secure an enhanced level of safety.
Further, according to the present embodiment, the stay 21 for connecting together the drive side hook 11 a and driven side hook 11 b of the lock mechanism 10 is mounted at a position offset on the opposite side (in FIG. 2 , downwardly) to the rotor rotation chamber 3 with respect to the shafts (centers of rotation) 14 a and 14 b of the hooks 11 a and 11 b in order to avoid its interference with the outer periphery of the rotor rotation chamber 3 . Therefore, even when the shafts 14 a and 14 b of the drive side hook 11 a and driven side hook 11 b are respectively disposed on a straight line which is substantially in contact with the outer periphery of the rotor rotation chamber 3 , there is secured at least such a clearance δ as shown in FIG. 2 between the stay 21 and the outer peripheral surface of the rotor rotation chamber 3 and thus, in the angle range where the stay 21 rotates, there is no possibility that the stay 21 can interfere with the outer periphery of the rotor rotation chamber 3 . Therefore, the drive side hook 11 a and driven side hook 11 b can be disposed in such a manner that they exist close to the rotor rotation chamber 3 . This can reduce the installation space of the lock mechanism 10 , thereby being able to reduce the size and weight of the centrifuge.
According to an aspect of the present invention, when closing the cover, the pulling-in operation of the securing member of the cover is carried out only by one hook, that is, by the drive side hook to be driven directly by the motor, not by the other hook, that is, by the driven side hook. This avoids the need to transmit a large torsion torque for pulling in the securing member to the driven side hook through the connecting member, thereby being able to reduce the torsion torque applied to the connecting member. Therefore, the connecting member need not have high strength and rigidity, which makes it possible to reduce the size and weight of the connecting member.
Also, after the securing member of the cover is pulled in by the drive side hook and the cover is closely contacted with the rotor rotation chamber, the driven side hook is also engaged with the securing member to thereby lock the cover by both of the drive side and driven side hooks. This can positively lock the cover at the two positions thereof to thereby be able to secure high level of safety.
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According to an aspect of the present invention, there is provided a centrifuge including: a rotor rotated by a driver; a chamber housing the rotor therein; a cover openable and closable with respect to the chamber; and a lock mechanism that locks the cover in a closed state, wherein the lock mechanism includes: a motor; a first hook rotated by the motor; and a second hook connected to the first hook through a connecting member, wherein the cover includes a securing portion on which the first hook and the second hook are respectively secured when the cover is locked, and wherein, during a locking operation of the cover, primary the first hook is engaged with the securing portion and pulls the cover toward the chamber, and then the second hook is engaged with the securing portion.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is the national stage of Application No. PCT/EP02/13561, filed Dec. 2, 2002, which application claims priority from EP 01204962.3 filed Dec. 7, 2001.
The present invention concerns processes for the preparation of each of the 4 diastereomers of cis-fused 3,3a,8,12b-tetrahydro-2H-dibenzo[3,4:6,7]cyclohepta[1,2-b]furan derivatives in stereochemically pure form from a single enantiomerically pure precursor. The tetracyclic ring system having cis-fused five and seven membered rings is formed in a base-catalysed cyclization reaction. The invention further relates to the thus obtained cis-fused tetracyclic alcohol intermediates, the methanamine end-products, the methanamine end-products for use as a medicine, in particular as CNS active medicines.
An article by Monkovic et al. (J. Med. Chem. (1973), 16(4), p. 403–407) describes the synthesis of (±)-3,3a,8,12b-tetrahydro-N-methyl-2H-dibenzo[3,4:6,7]-cyclohepta-[1,2-b]furan-2-methanamine oxalic acid. Said compound was synthesized as a potential antidepressant; however, it was found that this particular tetrahydrofurfuryl-amine derivative was inactive as an antidepressant at a dose of 300 mg/kg.
WO 97/38991, published on 23 Oct. 1997, discloses tetracyclic tetrahydrofuran derivatives of formula
wherein the hydrogen atoms on carbon atoms 3a and 12b have the trans configuration. The 4 possible trans products are obtained from a racemic intermediate in a non-selective cyclization reaction and can be separated from one another using HPLC techniques.
WO 99/19317, published on 22 Apr. 1999, concerns halogen substituted tetracyclic tetrahydrofuran derivatives of formula
wherein the hydrogen atoms on carbon atoms 3a and 12b have the trans configuration. The 4 possible trans products are obtained from a racemic intermediate in a non-selective cyclization reaction and can be separated from one another using HPLC techniques.
As the method for preparing the trans-fused compounds proved ill-suited for upscaling, alternative routes for synthesis of these trans-fused compounds were explored, one of which opened a pathway to each of the 4 diastereomers of the previously unknown cis-fused 3,3a,8,12b-tetrahydro-2H-dibenzo[3,4:6,7]cyclohepta[1,2-b]furan derivatives.
SUMMARY OF THE INVENTION
The present invention concerns a process for preparing each of the 4 individual diastereomers of formula (I)
wherein the substituents on carbon atoms 3a and 12b have the cis configuration and the substituent on carbon atom 2 may have the R or the S configuration, comprising the step of cyclizing a compound of formula
wherein R represents C 1-3 alkylcarbonyl;
R 1 is hydrogen and OR 2 is a leaving group, or OR 1 is a leaving group and R 2 is hydrogen; and the substituents R and CH 2 —CHOR 1 —CH 2 OR 2 have the cis configuration,
in a reaction inert solvent in the presence of a base, whereby
alternatively cyclizing a compound of formula
wherein R represents C 1-3 alkylcarbonyl;
R 1 is hydrogen and OR 2 is a leaving group, or OR 1 is a leaving group and R 2 is hydrogen; and the substituents —OR and —CH 2 —CHOR 1 —CH 2 OR 2 have the cis configuration,
in a reaction inert solvent in the presence of a base, whereby
(ent-II-a) yields (I-d), (ent-II-b) yields (I-c), (ent-II-c) yields (I-b), and (ent-II-d) yields (I-a).
DETAILED DESCRIPTION OF THE INVENTION
C 1-3 alkylcarbonyl represents methylcarbonyl, ethylcarbonyl and propylcarbonyl; the term ‘a leaving group’ represents sulfonyloxy groups such as methanesulfonyloxy, trifluoromethanesulfonyloxy, benzenesulfonyloxy, 4-methylbenzenesulfonyloxy, 4-nitrobenzenesulfonyloxy and 4-bromobenzenesulfonyloxy. The prefix ‘ent’ designates the mirror image of the enantiomers of formula (II) shown hereinbefore.
Suitable solvents are, for example, alkanols, e.g. methanol or ethanol. Suitable bases are, for example, inorganic bases, e.g. potassium carbonate, particularly anhydrous potassium carbonate. The reaction can conveniently, be conducted by stirring the reagent, substrate and solvent at ambient temperature.
Under the reaction conditions, the acyl group (OR) is saponified, the hydroxyl group on the C 3 side chain engages in a nucleophilic substitution reaction of the vicinal carbon atom bearing the leaving group forming an intermediate epoxide, and the hydroxyl on the seven membered ring group engages in a nucleophilic substitution reaction of the nearest carbon atom of the intermediate epoxide forming a cis-fused tetrahydrofuran ring.
The numbering of the tetracyclic ring-system present in the compounds of formula (I), as defined by Chemical Abstracts nomenclature is shown in formula (I′).
The compounds of formula (I) have at least three asymmetric centers, namely carbon atom 2, carbon atom 3a and carbon atom 12b. Carbon atoms 3a and 12b are part of an annelated ring system. In this case, where more than 2 asymmetric carbon atoms are present on a ring system, the substituent highest in priority (according to the Cahn-Ingold-Prelog sequence rules) on the reference carbon atom, which is defined as the asymmetric carbon atom having the lowest ring number, is arbitrarily always in the “α” position of the mean plane determined by the ring system. The position of the highest priority substituent on the other asymmetric carbon atoms relative to the position of the highest priority substituent on the reference atom is denominated by “α” or “β”. “α” means that the highest priority substituent is on the same side of the mean plane determined by the ring system, and “β3” means that the highest priority substituent is on the other side of the mean plane determined by the ring system.
The following table summarizes the nomenclatures using absolute and relative stereodescriptors of each of the four cis-stereoisomers of the compound of formula (I).
Absolute configuration
Relative configuration
2
3a
12b
2
3a
12b
R
R
R
α
α
α
R
S
S
α
β
β
S
R
R
α
β
β
S
S
S
α
α
α
The tetracyclic alcohols of formula (I) can be converted further into target compounds of pharmaceutical interest by
(a) converting the primary hydroxyl group into a leaving group, and (b) reacting the thus obtained intermediate compound of formula (IV)
wherein R 3 represents a sulfonyl group, with aqueous or gaseous methanamine in an organic solvent at an elevated temperature, thus yielding
A suitable organic solvent is for example tetrahydrofuran. The reaction is preferably conducted in a pressure vessel at a temperature in the range of 120° C. to 150° C.
Each of the intermediate compounds of formula
is prepared from a diol of formula
using one or more chemoselective reactions.
The intermediates of formula (II) wherein
(i) R 1 is hydrogen and OR 2 is a leaving group as defined hereinbefore, are prepared from the diol of formula (V) by chemoselective conversion of the primary hydroxyl group into a leaving group. One such method comprises stirring the diol of formula (V) in a reaction inert solvent such as a halogenated hydrocarbon, e.g. dichloromethane, in the presence of an excess of a base such as triethylamine, an equivalent of dimethylaminopyridine and half an equivalent of dibutyl(oxo)stannane, and two equivalents of tosylchloride or a similar sulfonylchloride. The reaction may also be conducted in the absence of dibutyl(oxo)stannane and dimethylaminopyridine, but then typically will yield a mixture of substrate, mono- and disubstituted product from which the desired mono-substituted compound needs to be separated.
Or, the intermediates of formula (II) wherein
(ii) OR 1 is a leaving group and R 2 is hydrogen, are prepared from the diol of formula (V) by
(1) chemoselective protection of the primary hydroxyl group with an acid labile protecting group such as a trityl group; (2) converting the secondary hydroxyl group into a leaving group by reaction with a sulfonylchloride in a solution of dichloromethane in the presence of triethylamine and diethylaminopyridine; (3) deprotecting the primary hydroxyl group in the thus obtained intermediate of formula (VI)
wherein Tr represents trityl, in the presence of an acid such as an acidic ion exchange resin, e.g. Amberlyst-15, in a reaction inert solvent such as an alkanol e.g. methanol, at a temperature ranging from 40° C. to 60° C.
The overall reaction scheme for converting diol (V) into intermediate II-b thus is as follows
The intermediate diol of formula (V) can be prepared from a ketone of formula
by the following series of reaction steps:
(a) reducing the ketone of formula (VII) to the cis-oriented hydroxyl group by reaction with lithium or sodium borohydride in a mixture of an organic solvent and an aqueous buffer having a pH of about 7 at a temperature below ambient temperature; (b) acylating the hydroxyl group with an acylchloride or acyl anhydride following art-known procedures, and (c) unmasking the diol by a deacetalisation reaction in an organic solvent in the presence of an acid, whereby
The intermediate ketones of formula (VII) are prepared from the α,β-unsaturated ketone (VIII)
by either Pd/C catalyzed hydrogenation or a reduction procedure using sodiumcyanoborohydride, yielding a mixture of epimeric ketones (VII-a) and (VII-b) in a rather invariant ratio of about 3:2.
The hydrogenation reaction may conveniently be conducted in a variety of solvents such as alcohols, e.g. methanol, ethanol, isopropanol; esters, e.g. ethyl acetate; ethers, e.g. tetrahydrofuran; aromatic hydrocarbons, e.g. toluene; optionally in the presence of a tertiary amine such as triethylamine or quinine.
Reduction of (VIII) can be accomplished with sodium cyanoborohydride under slightly acidic conditions.
The epimeric ketones (VII-a) and (VII-b) can be obtained separately by chromatographic separation (diethylether/hexane 60/40). Separation can also be effected on the epimeric alcohols obtained following reduction of (VII) according to step (a).
To prepare intermediate (VIII), (4S)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde (IX) and pro-chiral ketone (X) can be dissolved in a suitable solvent such as tetrahydrofuran and treated with a base such as tert.butyloxypotassium salt and a co-reagent such as magnesium chloride or bromide (aldol condensation).
The pro-chiral ketone (X) can be prepared by adaption of an art-known sequence (Can. J. Chem., 1971, 49, 746–754) starting with a Friedel-Crafts acylation reaction using fluorobenzene and phthalic anhydride to form keto-acid (XI), followed by reductive removal of the ketone group and homologation of the carboxylic acid function.
Cyclization of the homologous acid (XII) in another Friedel-Crafts acylation affords ketone (X).
The process according to the present invention provides an enantioselective approach to the target molecule (III) in enantiopure form via the enantiopure alcohols of formula (I). Both target and intermediate molecules of formulae (III) and (I) are novel.
The pharmaceutically active compounds of formula (III) may occur in their free form as a base or in a pharmaceutically acceptable salt form obtained by treatment of the free base with an appropriate non-toxic acid such as an inorganic acid, for example, hydrohalic acid, e.g. hydrochloric or hydrobromic, sulfuric, nitric, phosphoric and the like acids; or an organic acid, such as, for example, acetic, hydroxyacetic, propanoic, lactic, pyruvic, oxalic, malonic, succinic, maleic, fumaric, malic, tartaric, citric, methanesulfonic, ethanesulfonic, benzenesulfonic, p-toluenesulfonic, cyclamic, salicylic, p-aminosalicylic, pamoic and the like acids.
The term addition salt as used hereinabove also comprises the solvates which the compounds of formula (I) as well as the salts thereof, are able to form. Such solvates are for example hydrates, alcoholates and the like.
The term ‘enantiopure form’ designates compounds and intermediates having a stereoisomeric excess of at least 80% (i.e. minimum 90% of one isomer and maximum 10% of the other possible isomers) up to a stereoisomeric excess of 100% (i.e. 100% of one isomer and none of the other), more in particular, compounds or intermediates having a stereoisomeric excess of 90% up to 100%, even more in particular having a stereoisomeric excess of 94% up to 100% and most in particular having a stereoisomeric excess of 97% up to 100%.
The compounds of the present invention show affinity for 5-HT receptors, particularly for 5-HT 2A , 5-HT 2C and 5-HT 7 receptors (nomenclature as described by D. Hoyer in “Serotonin (5-HT) in neurologic and psychiatric disorders” edited by M. D. Ferrari and published in 1994 by the Boerhaave Commission of the University of Leiden). The serotonin antagonistic properties of the present compounds may be demonstrated by their inhibitory effect in the “S-hydroxytryptophan Test on Rats” which is described in Drug Dev. Res., 13, 237–244 (1988). Furthermore, the compounds of the present invention show interesting affinity for H 1 -receptors (pIC 50 : 7.15–7.89), D2 and/or D3 receptors, and surprisingly for norepinephrine reuptake transporters (pIC 50 : 6.03–7.34).
In view of these pharmacological and physicochemical properties, the compounds of formula (III are useful as therapeutic agents in the treatment or the prevention of central nervous system disorders like anxiety, depression and mild depression, bipolar disorders, sleep- and sexual disorders, psychosis, borderline psychosis, schizophrenia, migraine, personality disorders or obsessive-compulsive disorders, social phobias or panic attacks, organic mental disorders, mental disorders in children, aggression, memory disorders and attitude disorders in older people, addiction, obesity, bulimia and similar disorders. In particular, the present compounds may be used as anxiolytics, antipsychotics, antidepressants, anti-migraine agents and as agents having the potential to overrule the addictive properties of drugs of abuse.
The compounds of formula (III) may also be used as therapeutic agents in the treatment of motoric disorders. It may be advantageous to use the present compounds in combination with classical therapeutic agents for such disorders.
The compounds of formula (III) may also serve in the treatment or the prevention of damage to the nervous system caused by trauma, stroke, neurodegenerative illnesses and the like; cardiovascular disorders like high blood pressure, thrombosis, stroke, and the like; and gastrointestinal disorders like dysfunction of the motility of the gastrointestinal system and the like.
In view of the above uses of the compounds of formula (III), it follows that the present invention also provides a method of treating warm-blooded animals suffering from such diseases, said method comprising the systemic administration of a therapeutic amount of a compound of formula (III) effective in treating the above described disorders, in particular, in treating anxiety, psychosis, schizophrenia, depression, migraine, sleep disorders and addictive properties of drugs of abuse.
The present invention thus also relates to compounds of formula (III) as defined hereinabove for use as a medicine, in particular, the compounds of formula (III) may be used for the manufacture of a medicament for treating anxiety, psychosis, schizophrenia, depression, migraine, sleep disorders and addictive properties of drugs of abuse.
Those of skill in the treatment of such diseases could determine the effective therapeutic daily amount from the test results presented hereinafter. An effective therapeutic daily amount would be from about 0.01 mg/kg to about 10 mg/kg body weight, more preferably from about 0.05 mg/kg to about 1 mg/kg body weight.
For ease of administration, the subject compounds may be formulated into various pharmaceutical forms for administration purposes. To prepare the pharmaceutical compositions of this invention, a therapeutically effective amount of the particular compound, optionally in addition salt form, as the active ingredient is combined in intimate admixture with a pharmaceutically acceptable carrier, which may take a wide variety of forms depending on the form of preparation desired for administration. These pharmaceutical compositions are desirably in unitary dosage form suitable, preferably, for administration orally, rectally, percutaneously, or by parenteral injection. For example, in preparing the compositions in oral dosage form, any of the usual pharmaceutical media may be employed, such as, for example, water, glycols, oils, alcohols and the like in the case of oral liquid preparations such as suspensions, syrups, elixirs and solutions; or solid carriers such as starches, sugars, kaolin, lubricants, binders, disintegrating agents and the like in the case of powders, pills, capsules and tablets. Because of their ease in administration, tablets and capsules represent the most advantageous oral dosage unit form, in which case solid pharmaceutical carriers are obviously employed. For parenteral compositions, the carrier will usually comprise sterile water, at least in large part, though other ingredients, for example, to aid solubility, may be included. Injectable solutions, for example, may be prepared in which the carrier comprises saline solution, glucose solution or a mixture of saline and glucose solution. Injectable solutions containing compounds of formula (III) may be formulated in an oil for prolonged action. Appropriate oils for this purpose are, for example, peanut oil, sesame oil, cottonseed oil, corn oil, soy bean oil, synthetic glycerol esters of long chain fatty acids and mixtures of these and other oils. Injectable suspensions may also be prepared in which case appropriate liquid carriers, suspending agents and the like may be employed. In the compositions suitable for percutaneous administration, the carrier optionally comprises a penetration enhancing agent and/or a suitable wettable agent, optionally combined with suitable additives of any nature in minor proportions, which additives do not cause any significant deleterious effects on the skin. Said additives may facilitate the administration to the skin and/or may be helpful for preparing the desired compositions. These compositions may be administered in various ways, e.g., as a transdermal patch, as a spot-on or as an ointment. Acid or base addition salts of compounds of formula (III) due to their increased water solubility over the corresponding base or acid form, are more suitable in the preparation of aqueous compositions.
In order to enhance the solubility and/or the stability of the compounds of formula (III) in pharmaceutical compositions, it can be advantageous to employ α-, β- or γ-cyclodextrins or their derivatives, in particular hydroxyalkyl substituted cyclodextrins, e.g. 2-hydroxypropyl-β-cyclodextrin. Also co-solvents such as alcohols may improve the solubility and/or the stability of the compounds of formula (III) in pharmaceutical compositions.
Other convenient ways to enhance the solubility of the compounds of the present invention in pharmaceutical compositions are described in WO 97/44014.
More in particular, the present compounds may be formulated in a pharmaceutical composition comprising a therapeutically effective amount of particles consisting of a solid dispersion comprising a compound of formula (III), and one or more pharmaceutically acceptable water-soluble polymers.
The term “a solid dispersion” defines a system in a solid state (as opposed to a liquid or gaseous state) comprising at least two components, wherein one component is dispersed more or less evenly throughout the other component or components. When said dispersion of the components is such that the system is chemically and physically uniform or homogenous throughout or consists of one phase as defined in thermodynamics, such a solid dispersion is referred to as “a solid solution”. Solid solutions are preferred physical systems because the components therein are usually readily bioavailable to the organisms to which they are administered.
The term “a solid dispersion” also comprises dispersions which are less homogenous throughout than solid solutions. Such dispersions are not chemically and physically uniform throughout or comprise more than one phase.
The water-soluble polymer in the particles is a polymer that has an apparent viscosity of 1 to 100 mPa.s when dissolved in a 2% aqueous solution at 20° C. solution.
Preferred water-soluble polymers are hydroxypropyl methylcelluloses or HPMC. HPMC having a methoxy degree of substitution from about 0.8 to about 2.5 and a hydroxypropyl molar substitution from about 0.05 to about 3.0 are generally water-soluble. Methoxy degree of substitution refers to the average number of methyl ether groups present per anhydroglucose unit of the cellulose molecule. Hydroxy-propyl molar substitution refers to the average number of moles of propylene oxide which have reacted with each anhydroglucose unit of the cellulose molecule.
The particles as defined hereinabove can be prepared by first preparing a solid dispersion of the components, and then optionally grinding or milling that dispersion. Various techniques exist for preparing solid dispersions including melt-extrusion, spray-drying and solution-evaporation, melt-extrusion being preferred.
It is especially advantageous to formulate the aforementioned pharmaceutical compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form as used in the specification and claims herein refers to physically discrete units suitable as unitary dosages, each unit containing a predetermined quantity of active ingredient calculated to produce the desired therapeutic effect, in association with the required pharmaceutical carrier. Examples of such dosage unit forms are tablets (including scored or coated tablets), capsules, pills, powder packets, wafers, injectable solutions or suspensions, teaspoonfuls, tablespoonfuls and the like, and segregated multiples thereof.
Experimental Part
Hereinafter, “DMF” is defined as N,N-dimethylformamide, “THF” is defined as tetrahydrofuran, “DIPE” is defined as diisopropyl ether, “HCl cp ” is defined as chemically pure hydrochloric acid (34.5% w/w).
A. Preparation of the Intermediate Compounds
EXAMPLE A1a
Intermediate 1: 2-(4-fluorobenzoyl)benzoic acid —CAS RN [7649–29–5]
(i) A solution of p-fluorobenzenemagnesium bromide (1.2M solution in THF, 1 eq.) was added to a 0.4M solution of phthalic anhydride in THF, so that the temperature remained under 30° C. After 1 h, half of the solvent was distilled off and the reaction mixture was stirred overnight at room temperature. The obtained precipitate was filtered off and taken up in water (0.3 L/mol). Toluene (1 L/mol) and HCl cp were added so that the temperature remained under 35° C. After stirring 1 h, the organic layer was evaporated (50° C., vac.) and the obtained solid was dried at 50° C. under vacuum.
Physical yield: 74% Purity: 93% (LC abs %) Active yield: 69% of intermediate 1
(ii) Alternatively, a Friedel-Crafts reaction can be performed:
Phthalic anhydride, fluorobenzene (1.2 eq.) and CH 2 Cl 2 (0.5 L/mol) were mixed at room temperature. AlCl 3 (0.8 eq.) was added over 60 min. (at 1 mol scale). After 5 h at room temperature, the mixture was heated up to reflux during 18 h, then cooled down to room temperature and poured very slowly in ice/water and stirred during 1 h. The organic layer was separated and the water layer was extracted with CH 2 Cl 2 (0.25 L/mol)
The combined organic layers were washed with water (0.3 L/mol), then extracted with 320 ml water (0.7 L/mol)/NaOH 50% (0.07 L/mol). The water layer was separated and washed with 60 ml CH 2 Cl 2 (0.15 L/mol) Norit-A-Supra (active charcoal) (10 g/mol) was added and the mixture was stirred and filtered.
Water (0.7 L/mol)/HCl cp (2.5 eq.) solution was added dropwise, the mixture was stirred during 30 min., the precipitate filtered off, washed with water (2×0.2 L/mol) and dried.
Yield: 92% of intermediate 1.
EXAMPLE A1b
Intermediate 2: 2-[(4-fluorophenyl)methyl]benzoic acid—CAS RN [346474]
Intermediate 1 was dissolved in isopropanol (2 L/mot) and Pd/C (10% dry) was added. The reaction mixture was heated up to 45° C. and hydrogenated overnight at atmospheric pressure. After cooling the flask to room temperature, the catalyst was filtered off over diatomaceous earth and rinsed with 30 ml isopropanol. The filtrate was evaporated at 45° C. under vacuum.
Physical yield: 98% Purity: 96.4% (LC abs %) Active yield: 94% of intermediate 2
EXAMPLE A1c
Preparation of Intermediate 3
Intermediate 2 was dissolved in toluene (1.5 L/mol) and DMF (1 ml/mol) was added. The reaction mixture was heated up to 40° C. and thionyl chloride (1.1 eq.) was added. During the addition the reaction mixture was further heated up to 50° C. The reaction mixture was stirred at 50° C. during 2 h 30, then evaporated at 50° C. under vacuum. THF (0.3 L/mol) was added and that solution was dropped into a 2M NaBH 4 solution in THF (1.5 eq.). The temperature rose to reflux (67° C.) and the reaction mixture was stirred at reflux during 2 h. The reaction mixture was cooled down to room temperature. Aceton (350 ml/mol) was added (temperature rose to 40° C.), the reaction mixture was stirred during 30 minutes, followed by toluene (1 L/mol) and water (1.5 L/mol). The reaction mixture was heated up to 50° C. and the organic layer evaporated at 50° C. under vacuum. CH 2 Cl 2 (3 L/mol) was added, followed by triethylamine (1.1 eq.). SOCl 2 (1.1 eq.) was added dropwise, the temperature rose to reflux. The reaction mixture was stirred during 45 min to room temperature. Water (1 L/mol) was added and the reaction mixture was stirred vigorously during 15 min. The organic layer was washed a second time with water (1 L/mol) and evaporated (40° C., vac.). The product was dissolved in toluene (2.5 L/mol), tetrabutylammonium hydrogenosulfate (phase-transfer reagent) (0.1 eq.) was added at 70° C. NaCN 6M (1.6 eq.) was added at 70° C. under vigorous stirring. The reaction mixture was then heated up to reflux and stirred 3 h. After cooling down to room temperature, water (0.5 L/mol) was added, the reaction mixture was stirred during 30 minutes. After washing a second time with water (0.5 L/mol), drying on MgSO 4 and evaporating the solvent, intermediate 3 was obtained.
Physical yield: 98% Purity: 96.4% (LC abs %) Active yield: 94% of intermediate 3
EXAMPLE A1d
Preparation of Intermediate 4
Intermediate 3 was suspended in acetic acid (0.5 L/mol), water (0.3 L/mol) and sulfuric acid (0.35 L/mol). After 5 h at reflux, the mixture was cooled down, water (1.2 L/mol) and dichloromethane (0.3 L/mol) were added. The organic extract was washed with water (1.3 L/mol) and NaOH 50% (0.15 L/mol). After stirring 20 min., the aqueous layer was separated and washed with CH 2 Cl 2 (0.1 L/mol), which was discarded. The aqueous layer was acidified with HCl cp (2 eq.). The mixture was stirred during 3 h, the precipitate was then filtered off and washed with water (0.1 L/mol).
Yield: 74% of intermediate 4
EXAMPLE A1e
Preparation of Intermediate 5
Intermediate 4 was dissolved in dichloromethane (0.6 L/mol) and N,N-dimethyl acetamide, 15 ml/mol). Thionyl chloride (1 eq.) was added dropwise and the reaction mixture was refluxed during 1 h30. After cooling down to 0° C., AlCl 3 (1 eq.) was added and the mixture was stirred during 2 h. HCl, (2 eq.) and water (0.3 L/mol) were added. The layers were separated, the organic layer was washed with 5% NaHCO 3 solution (0.6 L/mol), then with water. The organic layer was evaporated, isopropanol (0.25 L/mol) was added. The mixture was heated up to reflux (30 min.) and cooled down. Seeding occured at 65° C. After cooling down further and stirring 2 h at rt, the precipitate was filtered off, washed with isopropanol (0.05 L/mol) and dried at 50° C. under vacuum.
Yield: 40–80% of intermediate 5. Typical purity between 77% and 93%
EXAMPLE A1f
Preparation of Intermediate 6
Intermediate 5 was dissolved in toluene (2 L/mol). MgCl 2 anhydrous (1.2 eq.) was added and the reaction mixture was stirred at room temperature during 30 min. (S)-solketal aldehyde (from DSM, 1.7 eq., 20% solution in THF) was added and in one time 0.2 eq. potassium tert-butoxide. Slight exothermicity was observed. The reaction mixture was stirred during 68 h at room temperature. Water (0.5 L/mol) was added, followed by 0.2 eq. HCl cp . The reaction mixture was stirred vigorously during 5 min. The organic layer was washed again with 0.5 L/mol water, then again with 1 L/mol water. After adding Na 2 SO 4 (125 g/mol), active carbon (40 g/mol), the mixture was filtered, the remaining solid was rinsed with toluene (0.2 L/mol) and the filtrate was evaporated. Isopropanol (1.5 L/mol) was added, the reaction mixture was stirred at least 8 h at 20–25° C., then cooled down to 0–5° C. and stirred at that temperature for at least 2 h. The precipitate was filtered off, washed with cold isopropanol (0.07 L/mol) and air-dried at 40° C.
Physical yield: 58% Purity: 93.1% (LC abs %) Active yield: 54% of intermediate 6.
The product could be recrystallized from iPrOH.
EXAMPLE A1g
Preparation of Intermediate 7
Intermediate 6 was dissolved in acetone (2 L/mol), triethylamine (1 eq.) and thiophene (4% solution in EtOH, 0.007 L/mol.) were added. After suspending Pd/C (60 g/mol, 10% wet), the hydrogenation was performed. In case the conversion was low, another 60 g/mol Pd/C was added and the hydrogenation was continued till complete conversion. Some exothermicity was observed (temperature rises to 35° C.). When the reaction was completed, the catalyst was filtered off over diatomaceous earth and the solid was rinsed with acetone (0.07 L/mol). The filtrate was evaporated (atm.) at 75–80° C. The residue was cooled down to 70–75° C. Isopropanol was added (0.84 L/mol), then evaporated again. The reaction mixture was cooled down. At 45–50° C., triethylamine (1 eq.) was added to the heterogeneous mixture. After stirring at least 8 h at 45–50° C., the mixture was cooled down to 20–25° C., stirred 2–16 h at 20–25° C., cooled down to 0–5° C. and stirred at that temperature during 2–16 h. The precipitate was filtered off, washed with cold isopropanol (0.07 L/mol) and dried during 16 h at 50° C. under vacuum. A light rose solid was obtained.
Physical yield: 83% of intermediate 7.
EXAMPLE A2a
Preparation of Intermediate 8
In THF (1.4 L/mol), a buffer solution of pH 7 containing potassium dihydrogenphosphate and disodium hydrogenphosphate, 0.3 L/mol was added. The mixture was cooled down to 0–5° C. and intermediate 7 was added. Lithium borohydride 2N in THF (0.48 eq.) was added and the temperature was maintained under 10° C. After the addition, the reaction mixture was stirred during 2 h at 0–5° C. Acetone (1.7 eq.) was is cautiously added and the reaction mixture was stirred to room temperature. Water (0.7 L/mol) was added at 10–25° C. and the reaction mixture was stirred 30 min. at room temperature. Acetic acid (2.2 eq.) and 200 ml toluene were added. After stirring during 10 min., the organic layer was washed with water (0.36 L/mol) and NaOH 50% (2.2 eq.), then washed again twice with water (0.45 L/mol). The solution was evaporated (a viscous oil was obtained) and dichloromethane (1 L/mol) was added. The solution was used further in the next step, assuming that 100% intermediate 8 had been obtained.
EXAMPLE A2b
Preparation of Intermediate 9
Dimethylaminopyridine (0.05 eq.) and triethylamine (1.1 eq.) were added to intermediate 8 (solution in CH 2 Cl 2 ). Acetic anhydride (1.1 eq.) was added dropwise. The temperature was allowed to rise to 40° C. The reaction mixture was stirred during 2 h and NH 4 Cl 1N (0.5 eq.). About 90% of the solvent was distilled off (atmospheric pressure) and isopropanol (1 L/mol) was added. About one fifth of the solvent was evaporated (atmospheric pressure) and the reaction mixture was slowly cooled down to room temperature and stirred overnight. After cooling down further to 0–5° C. and stirring at that temperature during 8–16 h, the precipitate was filtered off and washed with isopropanol (0.2 L/mol). The product was dried for 16 h at 50° C. under vacuum.
Active yield: 80% of intermediate 9.
EXAMPLE A2c
Preparation of Intermediate 10
Intermediate 9 was suspended in water (0.3 L/mol) and glacial acetic acid (0.45 L/mol) was added. This mixture was stirred at 55° C. for 8 hours. The reaction proceeded to 93% conversion. The reaction mixture was cooled to ambient temperature. Water (1.5 L/mol) and methylene chloride (0.8 L/mol) were charged and the mixture was stirred for 15 minutes. The water phase was separated and extracted three times with methylene chloride (each time with 0.6 L/mol). The combined organic phases were washed with water (1 L/mol) and dried over sodium sulfate. The solvent was evaporated, yielding a fluffy white solid.
Active yield: 94% of intermediate 10.
EXAMPLE A2d
Preparation of intermediate 11
Intermediate 10 was dissolved in toluene (3.5 L/mol) and p-toluenesulfonyl chloride (1.5 eq.) was added in one portion. To this mixture, pyridine (10 eq.) was added dropwise. The reaction mixture was stirred 4 h at 40° C. Water (1.5 L/mol) was added, followed by 1 M ammonium chloride (1.3 eq.). After drying the organic phase over sodium sulfate, the organic solvent was evaporated yielding crude product, which was a mixture of starting material (8%), mono-tosylate (76%) and di-tosylate (16%) (LC area %).
Yield: 61% of intermediate 11.
EXAMPLE A2e
Preparation of intermediate 12
To a solution of intermediate 11 (0.62 g, 1.23 mmol) in MeOH (30 mL) was added K 2 CO 3 (0.34 g, 2.46 mmol) and the mixture was stirred at room temperature for 1 day. 25 mL NH 4 Cl (sat. aq. solution) was added, extracted 3 times with CH 2 Cl 2 (3×20 mL) and then dried on MgSO 4 . Column purification on silica gel using ether/hexane (70:30) gave intermediate 12 as a white crystalline product (0.32 g, 90%) (mp. 157–158° C.).
EXAMPLE A2f
Preparation of intermediate 13
Intermediate 12 (0.31 g, 1.09 mmol) in CH 2 Cl 2 was dissolved. Et 3 N (0.46 ml, 3.28 mmol), DMAP (64 mg, 0.55 mmol) and TsCl (0.32 g, 1.64 mmol) were added. The solution was stirred at room temperature for 3 hr. NH 4 Cl (sat. aq. sol.) was added and the aqueous layer was extracted 3 times with CH 2 Cl 2 and dried with magnesium sulfate. Column purification on silica gel with Ether/Hexane (60/40) gave an yellowish oil. Yield: 0.46 g of intermediate 13 [(2S, 3aR, 12bR)-11-fluoro-3,3a,8–12b-tetrahydro-2H-dibenzo[3,4:6,7]cyclohepta[1,2-b]furan-2-yl]methyl 4-methylbenzenesulfonate (96%).
EXAMPLE A3
Preparation of Intermediate 14
Acetate diol (intermediate 10) (826 mg, 2.39 mmol) was dissolved in CH 2 Cl 2 (12 ml). Et 3 N (4 ml) and Ph 3 CCl (1.50 g, 5.38 mmol) were added and stirred at room temperature for 6 hr. NH 4 Cl (sat. aq. sol.) was added. The mixture was extracted 3 times with CH 2 Cl 2 and dried with MgSO 4 . The solution was evaporated. Column purification on silica gel using ether/hexane (40/60) gave an oil (0.95 g, 68%). The above oil was dissolved in CH 2 Cl 2 , Et 3 N (2.2 ml, 1.58 mmol), DMAP (190 mg, 1.56-mmol) and MsCl (190 μl 2.45 mmol) were added. The reaction mixture was stirred at room temperature for 2 hr. NH 4 Cl (sat. aq. sol.) was added, the mixture was extracted 3 times with CH 2 Cl 2 and dried with MgSO 4 . Column purification on silica gel by using ether/hexane (40/60) gave an oil (900 mg, 84%). This oil (840 mg, 1.26 mmol) was dissolved in MeOH (25 ml), Amberlyst (4.5 g) was added and heated at 50° C. for 3 hr. The Amberlyst was filtered off and evaporated. The remaining oil was dissolved in MeOH (15 ml) and K 2 CO 3 (1.68 g, 10.0 mmol) was added. The reaction mixture was stirred at room temperature for 18 hr. NH 4 Cl was added and extracted 3 times with CH 2 Cl 2 and dried with MgSO 4 . Column purification on silica gel by using ether gave a white crystalline compound (Yielding: 330 mg of intermediate 14 [(2R, 3aR, 12bR)-11-fluoro-3,3a,8,12b-tetrahydro-2H-dibenzo[3,4:6,7]cyclohepta[1,2-b]furan-2-yl]methanol, 92%).
Table 1 lists the intermediates that were prepared according to one of the above Examples.
TABLE 1 Int. Ex. No. No. Structure Physical data 1 A2f 2S, 3aR, 12bR;mp.: 157–158° C. 2 A3 2R, 3aR, 12bR;mp. 99–101° C. 3 A3 2R, 3aS, 12bS; 1 H NMR: 1.90(br s, 1H, OH), 2.05(ddd, 1H, J = 12.6, 9.6, 8.4 Hz, CH 2 -3), 2.48(ddd, 1H, J = 12.6, 8.4, 3.6Hz, C H 2 ′-3), 3.70–3.80(m, 2H,CH 2 OH), 3.81(d, 1H, J = 14.2 Hz,CH 2 -8), 3.94(q, 1H, J ≅ 8.1 Hz, CH-3a), 4.04(d, 1H, J = 14.4 Hz, CH 2 ′-8), 4.48(m, 1H, CH-2), 5.62(d, 1H,J = 8.1 Hz, CH-12b), 6.84(dt, 1H, J = 2.6, 8.2 Hz, Ar—H-10), 6.87(dd, 1H, J = 8.1, 2.7 Hz, Ar—H-4), 7.07–7.20(m,5H, Ar—H). 4 A2f 2S, 3aS, 12bS; 1 H NMR: 2.02(br s, 1H, OH), 2.02–2.12(m, 1H, CH 2 -3), 2.49(ddd, 1H,J = 12.9, 8.0, 3.9 Hz, CH 2 ′-3), 3.67–3.76(m, 1H, C H 2 —OH), 3.78–3.86(m,1H, C H 2 ′—OH), 3.83(d, 1H, J = 14.1Hz, CH 2 -8), 3.94(q, 1H J ≅ 8.8 Hz,CH-3a), 4.05(d, 1H, J = 14.1 Hz,CH 2 ′-8), 4.45–4.54(m, 1H, CH-2),5.63(d, 1H, J = 7.3 Hz, CH-12b),6.84(dt, 1H, J = 2.9, 8.4 Hz, Ar—H-10), 7.08–7.20(m, 6H, Ar—H).
B. Preparation of the Final Compounds
EXAMPLE B1
Preparation of Compound 1
The tosylated compound (intermediate 13) (0.46 g, 1.05 mmol) was dissolved in THF (15 ml) and 40% CH 3 NH 2 solution (15 ml) was added. The reaction mixture was brought into a tightly sealed steel vessel and heated at 130° C. for 12 hr. The mixture was cooled down to room temperature and NH 4 Cl (sat. aq. sol.) was added. The solution was extracted 3 times with CH 2 Cl 2 and dried with MgSO 4 . After evaporation, the residue was purified on silica gel column with MeOH/CHCl 3 (15/85) to give an yellowish oil (Yield: 0.30 g, 97% of compound 1 [(2S,3aR,12bR)-11-fluoro-3,3a,8,12b-tetrahydro-2H-dibenzo[3,4:6,7]cyclohepta[1,2-b]furan-2-yl]-N-methylmethanamine).
EXAMPLE B2
Preparation of Compound 2
To a solution of alcohol (intermediate 14) (172 mg, 0.605 mmol) in CH 2 Cl 2 (15 mL) was added TsCl (0.20 g, 1.05 mmol), Et 3 N (0.25 mL, 1.80 mmol), DMAP (37 mg, 0.303 mmol). The reaction mixture was stirred at room temperature for 2 hr. 15 mL NH 4 Cl (sat. aq. solution) was added. The mixture was extracted 3 times with CH 2 Cl 2 (3×15 mL) and dried with MgSO 4 . Column purification on silica gel by using ether/Hexane (60:40) gave an oil (0.26 g, 95%). To this oil (0.26 g, 0.571 mmol) in THF (15 mL) was added 40% MeNH 2 aqueous solution (15 mL). This solution was put into a tightly sealed steel vessel and heated at 130° C. for 12 hr. After cooling down to room temperature 15 mL NH 4 Cl (sat. aq. solution) was added. The solution was extracted 3 times with CH 2 Cl 2 (3×15 mL) and dried with MgSO 4 . Column purification on silica gel using MeOH/CHCl 3 (15:85) yielded a yellow solid (Yielding: 0.16 g, 94% of compound 2 [(2R,3aR,12bR)-11-fluoro-3,3a,8,12b-tetrahydro-2H-dibenzo[3,4:6,7]cyclohepta[1,2-b]furan-2-yl]-N-methylmethanamine).
Table 2 lists the compounds that were prepared according to one of the above Examples.
TABLE 2
Comp
Ex.
No.
No.
Structure
Physical data
1
B1
2S, 3aR, 12bR: Mass spectrum:CI m/z(assignment, relative intensity)298 (MH + , 100%)EI: m/z(assignment, relative intensity)297(M + , 12%), 209(100%)High resolution EICalculated C 19 H 20 FNO(M + ): 297.1529Found: 297.1526 (56%)
2
B2
2R, 3aR, 12bR; mp. 214–215° C.
3
B2
2R, 3aS, 12bS; 1 HNMR: 2.11(ddd, 1H, J = 12.5, 10.0, 8.7Hz, CH 2 -3), 2.41(ddd, 1H, J = 12.5, 8.7, 3.8Hz, CH 2 ′-3), 2.50(br s, 1H, NH), 2.58(s, 3H,CH 3 ) 2.78–2.96(m, 2H, C H 2 NHMe), 3.79(d,1H, J=14.6 Hz, CH 2 -8), 3.90(q, 1H, J ≅ 8.6Hz, CH-3a), 3.99(d, 1H, J=14.6 Hz, CH 2 ′-8), 4.41–4.51(m, 1H, CH-2), 5.57(d, 1H, J = 7.5 Hz, CH-12b), 6.80(dt, 1H, J = 2.5, 8.4Hz, Ar—H-b), 7.06
4
B1
2S, 3aS, 12bS; 1 H NMR: 2.06–2.16(m, 1H, CH 2 -3), 2.29(s,1H, NH), 2.40(ddd, 1H, J=12.6, 7.9, 3.6 Hz,CH 2 ′-3), 2.54(s, 3H, CH 3 ), 2.72–2.90(m, 2H,C H 2 NHMe), 3.82(d, 1H, J = 14.3 Hz, CH 2 -8), 3.91(q, 1H, J ≅ 8.3 Hz, CH-3a), 4.02(d,1H, J=14.3 Hz, CH 2 ′-8), 4.48– 4.58(m, 1H,CH-2), 5.57(d, 1H, J = 7.3 Hz, CH-12b),6.82(dt, 1H, J = 2.8, 8.3 Hz, Ar—H-10), 7.06–7.20 (m, 6H, Ar—H)
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The present invention concerns a process for preparing each of the 4 individual diastereomers of formula (I) in stereochemically pure form from a single enantiomerically pure precursor. The tetracyclic ringsystem having cis-fused five and seven membered rings is formed in a base-catalysed cyclization reaction. The invention further relates to the thus obtained cis-fused tetracyclic alcohol intermediates and methanamine end-products, and the methanamine end-products for use as a medicine, in particular as CNS active medicines
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PRIORITY CLAIM
[0001] This application claims priority to and the benefit as a continuation application of U.S. patent application Ser. No. 11/773,523, filed Jul. 5, 2007, entitled, “Fluid Delivery System With Autoconnect Features”, the entire contents of which are incorporated herein by reference and relied upon.
BACKGROUND
[0002] In general, the present disclosure relates to medical fluid delivery systems that employ a disposable cassette. In particular, the present disclosure provides systems and methods for cassette-based dialysis medical fluid therapies, including but not limited to those using peristaltic pumps and diaphragm pumps.
[0003] Due to various causes, a person's renal system can fail. Renal failure produces several physiological derangements. The balance of water, minerals and the excretion of daily metabolic load is no longer possible and toxic end products of nitrogen metabolism (urea, creatinine, uric acid, and others) can accumulate in blood and tissue. Kidney failure and reduced kidney function have been treated with dialysis. Dialysis removes waste, toxins and excess water from the body that would otherwise have been removed by normal functioning kidneys. Dialysis treatment for replacement of kidney functions is critical to many people because the treatment is life saving.
[0004] Hemodialysis and peritoneal dialysis are two types of dialysis therapies used commonly to treat loss of kidney function. Hemodialysis treatment utilizes the patient's blood to remove waste, toxins and excess water from the patient. The patient is connected to a hemodialysis machine and the patient's blood is pumped through the machine. Catheters are inserted into the patient's veins and arteries so that blood can flow to and from the hemodialysis machine. The blood passes through a dialyzer of the machine, which removes waste, toxins and excess water from the blood. The cleaned blood is returned to the patient. A large amount of dialysate, for example about 120 liters, is consumed to dialyze the blood during a single hemodialysis therapy. Hemodialysis treatment lasts several hours and is generally performed in a treatment center about three or four times per week.
[0005] Peritoneal dialysis uses a dialysis solution, or “dialysate,” which is infused into a patient's peritoneal cavity via a catheter. The dialysate contacts the peritoneal membrane of the peritoneal cavity. Waste, toxins and excess water pass from the patient's bloodstream, through the peritoneal membrane and into the dialysate due to diffusion and osmosis, i.e., an osmotic gradient occurs across the membrane. The spent dialysate is drained from the patient, removing waste, toxins and excess water from the patient. This cycle is repeated.
[0006] There are various types of peritoneal dialysis therapies, including continuous ambulatory peritoneal dialysis (“CAPD”), automated peritoneal dialysis (“APD”), tidal flow APD and continuous flow peritoneal dialysis (“CFPD”). CAPD is a manual dialysis treatment. The patient manually connects an implanted catheter to a drain, allowing spent dialysate fluid to drain from the peritoneal cavity. The patient then connects the catheter to a bag of fresh dialysate, infusing fresh dialysate through the catheter and into the patient. The patient disconnects the catheter from the fresh dialysate bag and allows the dialysate to dwell within the peritoneal cavity, wherein the transfer of waste, toxins and excess water takes place. After a dwell period, the patient repeats the manual dialysis procedure, for example, four times per day, each treatment lasting about an hour. Manual peritoneal dialysis requires a significant amount of time and effort from the patient, leaving ample room for improvement.
[0007] Automated peritoneal dialysis (“APD”) is similar to CAPD in that the dialysis treatment includes drain, fill, and dwell cycles. APD machines, however, perform the cycles automatically, typically while the patient sleeps. APD machines free patients from having to manually perform the treatment cycles and from having to transport supplies during the day. APD machines connect fluidly to an implanted catheter, to a source or bag of fresh dialysate and to a fluid drain. APD machines pump fresh dialysate from a dialysate source, through the catheter, into the patient's peritoneal cavity, and allow the dialysate to dwell within the cavity, and allow the transfer of waste, toxins and excess water to take place. The source can be multiple sterile dialysate solution bags.
[0008] APD machines pump spent dialysate from the peritoneal cavity, though the catheter, to the drain. As with the manual process, several drain, fill and dwell cycles occur during APD. A “last fill” occurs at the end of CAPD and APD, which remains in the peritoneal cavity of the patient until the next treatment. Both CAPD and APD are batch type systems that send spent dialysis fluid to a drain. Tidal flow systems are modified batch systems. With tidal flow, instead of removing all of the fluid from the patient over a longer period of time, a portion of the fluid is removed and replaced after smaller increments of time.
[0009] Continuous flow, or CFPD, systems clean or regenerate spent dialysate instead of discarding it. The systems pump fluid into and out of the patient, through a loop. Dialysate flows into the peritoneal cavity through one catheter lumen and out another catheter lumen. The fluid exiting the patient passes through a reconstitution device that removes waste from the dialysate, e.g., via a urea removal column that employs urease to enzymatically convert urea into ammonia. The ammonia is then removed from the dialysate by adsorption prior to reintroduction of the dialysate into the peritoneal cavity. Additional sensors are employed to monitor the removal of ammonia. CFPD systems are typically more complicated than batch systems.
[0010] Hemodialysis, APD (including tidal flow) and CFPD systems can employ a pumping cassette. The pumping cassette typically includes a flexible membrane that is moved mechanically to push and pull dialysis fluid out of and into, respectively, the cassette. Certain known systems include flexible sheeting on one side of the cassette, while others include sheeting on both sides of the cassette. Positive and/or negative pressure can be used to operate the pumping cassettes. Cassettes with other pumps or fluid transfer mechanisms may be used.
[0011] There are two concerns for patient using dialysis treatments, especially for home-use peritoneal dialysis. Dialysis patients tend to be elderly, with many aged 50 or 60 years, and older. Connecting bags of dialysis fluid to a treatment machine may be difficult because of the force required to push a connecting spike through a sealing membrane. This force can be as much as 20 lbs or more, and may be required to connect each of four bags every night. The force and physical dexterity required make it difficult for significant numbers of patients to make the connections properly, e.g., without spiking through a connecting line, rather than a sealing membrane. The difficulty encountered in making connections may lead to improper touching and contamination of one or more of the lines, if the patient inadvertently grasps or touches a connector or an portion which is sterile and is intended to remain sterile. Inadvertent touches can lead to infections and peritonitis, and may require hospitalization or other stressful procedures.
[0012] Accordingly, what is needed is a better way to connect containers of dialysis solutions to a dialysis machine, such as a peritoneal dialysis machine. The present disclosure addresses the above-described needs and concerns.
SUMMARY
[0013] A first embodiment is a system for automatically connecting tubing while maintaining sterility. The system includes a frame for mounting adjacent a cassette in a dialysis machine, a shuttle mounted within the frame, the shuttle configured for receiving tubing from at least two containers, the tubing including a cap, a shuttle driving system for translating the shuttle within the frame, and at least two rotating fingers configured for receiving and removing the caps, the fingers mounted to the frame and operably adjacent the shuttle. The system also includes a finger rotating system configured for rotating the fingers in a plane parallel to a direction of travel of the shuttle, and a control system for operating the system for automatically connecting tubing, wherein the system for automatically connecting tubing is configured for receiving sterile tubing from at least two containers, the fingers are configured for receiving caps from the tubing, the shuttle is configured for advancing the ends of the tubing, the control system is configured to rotate the fingers to remove the caps, and the cassette comprises at least two spikes for piercing sterile sealing membranes of the tubing and making a sterile connection.
[0014] Another embodiment is a system for automatically connecting sterile tubing. The system includes a frame for mounting adjacent a cassette in a dialysis machine, a shuttle mounted within the frame, the shuttle including a tubing side and a cassette side, the shuttle configured for receiving tubing from a plurality of sterile containers of dialysis fluid, each container including a length of tubing and a cap, a shuttle driving system for translating the shuttle within the frame, and a plurality of rotating fingers, each rotating finger configured for receiving and removing the cap from the length of tubing and configured for receiving and removing a cassette port cap, the rotating fingers mounted to the frame and adjacent the shuttle. The system also includes a finger rotating system including a shaft configured for rotating the fingers in a plane parallel to a direction of travel of the shuttle, and a control system for operating the system for automatically connecting tubing, wherein the system for automatically connecting tubing is configured for receiving tubing of a plurality of containers of dialysis fluid, the fingers configured for receiving caps from the tubing and cassette port caps, and the control system configured to translate the shuttle, to rotate the fingers, and to advance ends of the tubing into an adjacent cassette, the cassette including at least two spikes for piercing sealing membranes of the tubing and making a sterile connection.
[0015] Another embodiment is a system for automatically connecting tubing. The system includes a frame for mounting adjacent a dispensing machine, a shuttle mounted within the frame, the shuttle including a tubing side and a dispensing side, the shuttle configured for receiving tubing from a plurality of containers, and a shuttle driving system for translating the shuttle within the frame. The system also includes a plurality of rotating fingers, each rotating finger configured for receiving and removing a tubing cap and also configured for receiving and removing a dispensing machine port cap, the rotating fingers mounted to the frame and adjacent the shuttle, a finger rotating system including a shaft configured for rotating the fingers in a plane parallel to a direction of travel of the shuttle, and a control system for operating the system for automatically connecting tubing, wherein the system for automatically connecting tubing is configured for receiving tubing of a plurality of containers of liquid, the fingers configured for receiving tubing caps and dispensing machine port caps, and the control system is configured to translate the shuttle, to rotate the fingers, and to advance ends of the tubing into an adjacent dispensing machine, the dispensing machine including at least two spikes for piercing sealing membranes of the tubing.
[0016] Another embodiment is a system for automatically connecting tubing. The system includes a frame for mounting adjacent a dispensing machine, a platform mounted within the frame, the platform including a tubing side and a dispensing side, the platform configured for receiving tubing from a plurality of containers, and a plurality of moving mounts on the platform, each mount further including a driving system for advancing and retracting the mount. The system also includes a plurality of rotating fingers, each rotating finger configured for receiving and removing a tubing cap and also configured for receiving and removing a dispensing machine port cap, the rotating fingers mounted to the frame and adjacent the platform, a finger rotating system including a shaft configured for rotating the fingers in a plane parallel to a direction of travel of the mounts, and a control system for operating the system for automatically connecting tubing, wherein the system for automatically connecting tubing is configured for receiving tubing from a plurality of containers of liquid, the fingers are configured for receiving tubing caps and dispensing machine port caps, and the control system is configured to translate the mounts individually, to rotate the fingers, and to advance ends of the tubing into an adjacent dispensing machine, the dispensing machine including at least two spikes for piercing sealing membranes of the tubing.
[0017] Another embodiment is a method for connecting dialysis bags to a dialysis cassette. The method includes placing tubing from a dialysis bag into a shuttle of an autoconnect machine, the autoconnect machine including a frame, a shuttle and shuttle driving system mounted on the frame, a plurality of rotating fingers, each finger configured for receiving a cap from dialysis bag tubing, and a finger rotating system for rotating the fingers, and wherein the tubing fits into tubing runs atop the shuttle, placing the tubing cap into a first pocket of one of the rotating fingers of the autoconnect machine, causing the rotating finger with the tubing cap to rotate in a direction away from the shuttle and toward a disposable cassette on an opposite side of the rotating fingers. The method also includes steps of translating the shuttle a distance in a direction toward the disposable cassette, wherein translating the shuttle rotates or translates the rotating finger with the tubing cap, and causes only the rotating finger into which the tubing cap was placed to capture a port cap from a port of the disposable cassette in a second pocket of the rotating finger, translating the shuttle in a direction away from the cassette, removing the tubing cap from the dialysis bag and leaving the tubing cap in the first pocket, rotating the rotating fingers in a direction toward the shuttle, removing the port cap from the port of the dialysis cassette and leaving the port cap in the second pocket, and translating the shuttle toward the dialysis cassette and causing a spike in the port of the disposable cassette to pierce a sealing membrane in the tubing, and translating the occluder to allow dialysis fluid to flow in the tubing.
[0018] Another embodiment is a method for connecting fluid containers. The method includes placing a connector from a fluid container into an autoconnect machine, placing a tubing cap from one of the fluid containers into a pocket of one of a plurality of fingers of the autoconnect machine, causing the finger to move or rotate in a direction toward a dispensing machine on a different side of the fingers. The method also includes steps of translating the tubing and the tubing cap a distance in a direction toward the dispensing machine, wherein translating rotates the plurality of fingers, and causes only the finger into which the tubing cap was placed to capture a port cap from a port of the dispensing machine, translating the tubing in a direction away from the dispensing machine, removing the tubing cap from the tubing and leaving the tubing cap from the tubing in the pocket, rotating the fingers away from the dispensing machine and in a direction to remove the port cap from the port of the dispensing machine, and translating the tubing toward the dispensing machine and causing a spike in the port of the dispensing machine to pierce a sealing membrane in the tubing.
[0019] As will be clear from the disclosure below, an autoconnect device may be used for both peritoneal dialysis and hemodialysis. In addition, embodiments of an autoconnect device may be used for dispensation or administration of other fluids with devices other than dialysis or hemodialysis machines, such as for blood or blood-substitute transfusions. Additional features and advantages of the present disclosure are described in, and will be apparent from, the following Detailed Description of the Disclosure and the figures.
BRIEF DESCRIPTION OF THE FIGURES
[0020] FIG. 1 is an exploded view of a first embodiment of an autoconnect mechanism used with a disposable cassette and a dialysis machine;
[0021] FIG. 2 is an isometric view of a second embodiment of an autoconnect mechanism for use with a dispensing machine;
[0022] FIGS. 3A and 3B are isometric views of alternate embodiments of disposable cassettes for use with an autoconnect mechanism and a dialysis machine;
[0023] FIG. 4A is an exploded view of a container of dialysis fluid, tubing for use with the container, and a cap for maintaining a sterile end of the tubing;
[0024] FIGS. 4B and 4C are alternate embodiments of a cap with an RFID chip or other direct part marking feature;
[0025] FIGS. 5A , 5 B and 6 depict the occluder and the occluding mechanism;
[0026] FIG. 7 graphs experimental results for the force needed for connecting containers of fluid;
[0027] FIGS. 8A , 8 B and 8 C are a cross-sectional views of engagement between a containers of fluid and spikes, such as those from a pumping cassette;
[0028] FIGS. 9 and 10 are rear and front perspective views of details of a first embodiment of rotating fingers for use in an autoconnect machine;
[0029] FIG. 11 is an exploded view of the embodiment of FIGS. 9 and 10 ;
[0030] FIG. 12 is a side view of the embodiment of FIG. 9 ;
[0031] FIGS. 13-14 are additional views showing the functioning of the rotating fingers;
[0032] FIGS. 15A , 15 B, 16 A, 16 B, 17 A and 17 B depict operation of an autoconnect machine;
[0033] FIG. 18 is a flowchart for a method of operating an autoconnect machine;
[0034] FIGS. 19-21 disclose alternative mechanical equipment for operating an autoconnect device;
[0035] FIGS. 22-23 are schematic diagrams for a control system for operating an autoconnect machine, a pumping cassette, and a dialysis machine; and
[0036] FIGS. 24-25 are flowcharts for methods of operating autoconnect devices.
DETAILED DESCRIPTION
[0037] The present disclosure relates to medical fluid delivery systems that employ a pump, such as a diaphragm pump or a peristaltic pump. In particular, the present disclosure provides systems, methods and apparatuses for cassette-based dialysis therapies including but not limited to hemodialysis, hemofiltration, hemodiafiltration, any type of continuous renal replacement therapy (“CRRT”), congestive heart failure treatment, CAPD, APD (including tidal modalities) and CFPD. The cassette is disposable and typically discarded after a single use or therapy, reducing risks associated with contamination. The autoconnect device is intended for reuse as a part of the dialysis machine.
Patient Care
[0038] An autoconnect device, as discussed below, is intended to ease the burden on dialysis patients, who may be elderly and in poor health, and those who care for them, who may also be elderly, and who may also be in poor health. The daily task of hooking up dialysis fluid bags is indeed difficult for those with limited strength. In addition, it is easy to inadvertently break sterility or to contaminate the instrument or the container of fluid. In general terms, and for which a detailed explanation is given below, the autoconnect device works in the following manner.
[0039] After the cassette is loaded into the dialysis machine, the user attaches tubing from one or more dialysis bags by laying tubing in the top portion of the device and by placing caps from the tubing in the tops of special fingers on the top of the device. The autoconnect machine is then activated. A series of pinchers or occluders grasps the tubing and a shuttle then moves the tubing forward with the shuttle. The forward movement also causes the fingers to rotate forward, in the direction of the shuttle motion and toward the dialysis disposable cassette. Only those fingers with a tubing cap will rotate sufficiently to contact a shielding cap from a port of the dialysis disposable cassette. These fingers are rotated into the shielding cap or caps and grasp the cap or caps. After this forward rotation, the shuttle reverses direction, and the cap from the tubing, held in place by a restraining orifice atop the finger, is removed by remaining stationary while the shuttle and the tubing moves backward. The finger is now rotated in the opposite direction, while grasping the cap from the disposable cassette port, the rotation causing the cassette port cap to remain in the top of the rotating finger, thus removing the port cap. Both caps have now been removed without the user touching the caps.
[0040] The top of the finger (or fingers) now contains a cap from the tubing and a cap from the cassette port. The fingers are then rotated downward, causing the caps to fall from the tops of the fingers into a chute, drawer, or other area. The fingers remain in the downward position while therapy is in progress. Once the caps are disposed of, the shuttle again reverses direction. At this point, the caps have been removed and all that remains before dialysis is to connect the end of the tubing, with its sterile seal, to the cassette port, which is also sterile. The shuttle now translates forward pushing on the connector while the tubing is held in place by the occluder, and extends the tubing into a piercing needle contained within the cassette port. The piercing needle is preferably somewhat recessed from the outer lip of the port for ease of maintaining the sterile environment and a sterile connection. Once the needle pierces the membrane seal of the dialysis tubing, the connection is made and will remain secure. With the dialysis containers now attached via a sterile connection, an after the occluder is released, dialysis may now begin. In the embodiments discussed below, the autoconnect device may be used to connect from one to five containers of dialysis fluid. Other embodiments may be used to connect less than five or more than five containers. Still other embodiments may be used for one or more fluid containers other than dialysis fluid, such as blood, blood substitutes, saline solution, nutritional fluids, medications, and others. For example, one of the containers may include a neutral fluid, such as saline, and a medication needed by the patient, such as heparin, insulin, or an antibiotic. These medication fluids may just as easily be used with the autoconnect device and a device for downstream infusion or dispensing.
The Autoconnect Device
[0041] Referring now to the drawings and in particular to FIG. 1 , a dialysis machine 1 is intended for use with a disposable dialysis cassette 3 and an autoconnect machine 5 . Autoconnect machine 5 in this embodiment includes a frame or base 7 , a central area 9 for disposal of caps from the dialysis cassette and from bags of dialysis fluid. In this embodiment, frame 7 includes sides 12 a and back portions 12 b , joined by hinges 12 c . Main chassis 10 includes a central area 11 includes discrete portions of channels 14 for tubing from the dialysis bags. Autoconnect 5 also includes top covers 13 on either side to shield and protect the inner workings. Also included in top working area 19 is a shuttle 15 for advancing the tubing, an occluder 16 , and fingers 17 for removing caps from the dialysate bags and from the dialysis cassette.
[0042] In using the autoconnect device, a plurality of containers of dialysis fluid may be positioned in the vicinity of the dialysis machine or near the autoconnect device. Since dialysis bags typically include tubing about 2 feet long, either position is possible and may be suitable. If the dialysis machine includes one or more facilities for heating, the containers of dialysis fluid are desirable heated to a temperature close to body temperature before use. Alternatively, the disposable dialysis cassette may include provisions for heating dialysis fluid as it is being pumped. For example, the dialysis cassette 30 depicted in FIG. 3A may be used to warm the dialysis fluid.
[0043] The embodiment of FIG. 1 may be used as presented for automatically connecting containers of dialysis fluid to the pumping cassette while preserving a sterile connection. Alternatively, the main chassis portion may be used separately, as shown in FIG. 2 , as an autoconnect device 20 . Autoconnect 20 includes a frame 21 , frame back wall 21 a , and also includes a drive motor 22 and a drive system 23 for positioning shuttle 24 . Drive system 23 includes left and right lead screws 23 a , 23 b , and a power transmission system as shown, including a timing belt, and belt tensioners as needed, to distribute power from motor 22 to the two lead screws. The system could use gears rather than a timing belt. Drive system 23 includes at least mounts 23 c and bearings 23 d as shown, and also preferably includes a drive train and any necessary gear reduction for matching motor 22 to the desired speed for advancing and retracting shuttle 24 . A brushed 24 VDC planetary gear motor, with a suitable controller, has been found satisfactory for the motor for this application. Other suitable motors may be used.
[0044] Autoconnect 20 includes a central area 26 with discrete channels for tubing from dialysis containers, and also includes front occluder 25 a and a rear occluder 25 b for occluding or pinching tubing from the dialysis containers. In this embodiment, central area 26 includes five channels for placement of tubing from five dialysis containers. Occluders 25 a , 25 b each include openings for the tubing, in this case five openings 25 c . In one embodiment, occluders 25 a , 25 b are both part of a single, U-shaped piece of sheet metal, in which occluder 25 a performs the occlusion function, i.e., pinching the tubing so no flow is possible, while occluder 25 b acts only to secure the membrane port into shuttle 24 . When the occluder is actuated and no flow is possible in the tubing, there will be no premature flow of fluid during spiking, and the machine may, with confidence, perform an integrity test. There are also five fingers 27 for grasping and removing caps from the ends of the dialysis tubing, and also for grasping and removing caps from the ports of a dialysis cassette used with the autoconnect and a dialysis machine. Visible also in FIG. 2 is a motor 28 for rotating fingers 27 . A brushed 24 VDC planetary gear motor, with a suitable controller, has also been found satisfactory for this application. Other suitable motors may be used.
[0045] Autoconnect device 20 preferably is enclosed in a housing 18 , to protect the device. The housing preferably also includes ducting 19 a connected to a blower 19 b and HEPA or other filter 19 c . The filter provides clean air to the blower which can keep the housing under a slight positive pressure during use, thus preventing dust, mold, and the like from entering the atmosphere of the device. This embodiment of an autoconnect device works in the following manner. A user furnishes one or more containers of dialysis fluid and tubing for the containers, the tubing including a special cap for connecting via the autoconnect device. The tubing connects to the containers and the tubing is then connected to the dialysis machine via a disposable cassette. The special cap is placed into the near side of the rotating finger and the tubing is laid into the channel atop the autoconnect device. The autoconnect device then begins its automatic sequence for connecting one or more containers of dialysis fluid to the dialysis machine.
[0046] The occluder translates to the left, thus grasping the tubing and holding it immobile within the shuttle. The shuttle translates forward, and each finger with a cap causes that finger to rotate forward, in the direction of the shuttle movement. The movement of the finger causes the finger to grasp the cap from a port on the disposable cassette. The shuttle is now translated backward, away from the disposable. The finger, with the tubing cap atop, is captured by the port cap. When the shuttle translates backward, the tubing cap is removed because it is restrained within the finger. After the shuttle translates backward, the fingers rotate in a backward direction. Since the cap or caps from the disposable ports are captured by one or more fingers, this rotation removes the cap or caps. Further rotation below horizontal causes the caps to fall from the finger or fingers into a bin or open area below the fingers.
[0047] Movement of the shuttle, the occluder, and the fingers is controlled by a controller or microcontroller of the autoconnect device. As part of the controls, the shuttle is equipped with an optical sensor 24 a , mounted on the bottom portion of the shuttle. The optical sensor 24 a is guided by a stationary sensor track 21 b , mounted in parallel with the lead screws. Sensor track 21 b includes a series of notches as shown. The notches allow the optical sensor to keep the controller informed of the position of the shuttle. As will be obvious to those with skill in the art, other sensors or techniques may be used, such as an encoder on shuttle motor 22 , a proximity sensor mounted on the shuttle and targets placed at appropriate locations along the shuttle path, and so forth. For example, a hall effect sensor mounted on the shuttle may be used to detect its position by placement of magnets or other targets along the shuttle path. Alternatively, a position sensor for detecting a position of the shuttle may be placed on the frame with notches, magnets, or the like placed on the shuttle.
Fluid Containers and Disposable Cassettes
[0048] The autoconnect device is not limited to the embodiments above. For instance, other dialysis disposable cassettes may include the model depicted in FIG. 3A . Disposable cassette 30 includes a front portion 31 , heating tube 32 and five ports 33 for connecting to dialysis fluid connectors. Each port includes a cap 34 with a protruding, stepped central portion 34 a . This protruding portion makes it easier for the autoconnect rotating fingers (discussed below) to grasp the cap. Port 35 a is used for input/output lines to and from the patient, and port 35 b is used for a drain. This particular model of a disposable cassette may require an autoconnect device in which the tubing on the shuttle is oriented in a vertical direction, rather than in a horizontal direction. The shuttle will still translate back and forth toward and away from the cassette, and the occluders will translate in a direction perpendicular to the movement of the shuttle. The fingers will be oriented for rotation in a horizontal plane, rather than vertical. When the caps are removed, they will fall away from and to the right of the autoconnect device. The ports have spikes, visible in FIG. 3B below.
[0049] The port caps 34 have symmetry, preferably radial symmetry. The caps are also preferably radiation-sterilizable and steam-permeable, and are made from low density polyethylene (LDPE). LDPE is able to form a tight seal against the cassette port, protecting the sterility of the port. Other relatively soft materials may be used, but the stepped tips or nipples should be able insert themselves within the jaws of the rotating fingers. Other embodiments may use non-stepped nipples or central portions. The wider next portion of the nipple causes a slight interference with the jaws, and allows the caps to be pulled off the ports when the fingers rotate downward. Besides LDPE, other materials may be used, such as PVC, (poly-vinyl chloride), polyisoprene, silicone and other suitable sterilizable materials.
[0050] FIG. 3B is an alternate embodiment of a cassette suitable for use with an autoconnect device. Cassette 30 a is similar to cassette 30 , in that it includes a front portion 31 a (shown), a back portion (not shown), a heating tube 32 a , and four ports 33 with spikes 33 a for containers. In addition, port 35 c is provided for connection to the patient, and port 35 d for the drain, and port 35 e is used return from the patient. The other ports also have spikes 33 a for making tubing connections. Rather than using the same port and line for to and from the patient, separate lines are used to help preserve the purity of the dialysate or other fluid. For example, pediatric patients may use much smaller volumes of dialysate, and much smaller volumes for recirculation. With very small babies, volume could be as low as 50 ml, while the spent dialysate in the tubing to/from the patient and the cassette could be as much as 15 ml. Separate lines to and from the patient avoid reuse of spent dialysate to the maximum extent possible.
[0051] A closer view of a typical dialysis fluid container is depicted in the exploded view of FIG. 4A . Dialysis bag 40 includes an outlet connection 41 and is used with tubing 43 and a tubing connector 42 for connecting to dialysis bag 40 . Tubing 43 includes a housing 46 for a radio-frequency identification (RFID) tag 47 . RFID tag 47 is used to identify this particular container and lot of dialysis fluid when the tubing is placed into the autoconnect device and the tag is read. The tubing also includes a flanged handle 45 and a membrane port 45 a (internal to the tubing) or internal seal. Tubing 43 is terminated with a cap 44 , the cap including a groove 44 a , a fold-down handle 44 b , and a core pin 44 c . Groove 44 a is preferably about 2.5 mm wide and about 2.0 mm deep. The handle is useful for removing the cap manually if an autoconnect device is not available. The core pin 44 c is used for interfacing and with the internal portions of tubing 43 , to preserve the dimensional stability of the tubing up to internal membrane 45 a.
[0052] The tubing 43 and membrane port 45 a may be made from PVC, and the tube cap 44 is preferably a relatively soft material, both the tubing and the tube cap steam are preferably steam sterilizable and steam permeable materials. Very soft silicone, with a Shore A durometer reading of about 35 is preferred, although other materials, with a durometer from 50-100 may also be used. Polyisoprene may be used, as may many styrenic block copolymers, such as those produced by Kraton Polymers, LLC, Houston, Tex., USA. Any of the softer, steam permeable grades will work well in the application. In one embodiment, tube cap 44 may also serve as the RFID housing.
[0053] RFID housing 46 is easier to handle and install in the translating shuttle if the housing is a little stiffer. For example, the housings may be made of HDPE, polycarbonate, harder PVC, or other material with a higher Young's modulus. If housing 46 is more rigid, it is easier to insert into the channels of the autoconnect shuttle. The RFID housing need not take the shape disclosed herein, which is configured for ease of placement onto the shuttle. The housing may be any convenient and useful shape that will reliably adhere to the tubing or even to the bag of fluid. In some embodiments, the RFID chip is placed into the housing in a secure manner, such as with a snap-fit. In other embodiments, the RFID chip is insert or over-molded into the housing. In the embodiments disclosed below, the RFID housing is configured for placement over the tubing, for ease of installation onto the shuttle. In other embodiments, the RFID housing may be placed or adhered onto the bag or container of fluid, and is read by a single RFID reader on board the frame or the shuttle. The autoconnect system then directs the user to connect the tubing to a particular channel on the shuttle. Thus, the controller knows the location of each connector and how to utilize each container.
[0054] In some embodiments, as shown in FIG. 4B , the RFID chip may be assembled or otherwise installed into the cap itself, without a separate housing for the RFID chip. Using this technique, each rotating finger 27 , as shown in FIG. 2 , will include an RFID reader, to read the chip and report back to the autoconnect controller. Thus, tubing cap 49 will include RFID chip 47 and will be read by an IR reader in the finger 27 in which the cap is placed. In other embodiments, the cap of the tubing, or even the tubing itself, may include a mark as shown in FIG. 4C . In versions using direct parts marking, appropriate information about the solution to be administered, such as the solution, the lot number, and so forth, may be marked onto the cap or the tubing directly. Marks may be made by imprinting, for example, by stamping or ink-jet or other printing method, as shown by imprinted mark 61 a . Marks may also be made by placing a bar code indicia, 61 b , or by etching a mark 61 c . Etching may be accomplished by laser marking, for example. The marked cap or tubing may be detected by a camera 61 mounted on the autoconnect frame and operably connected to the autoconnect controller or the dialysis machine controller.
Placement and Identification of Tubing and Operation of the Occluders
[0055] The placement of tubing from the dialysis containers, or tubing from other containers, is depicted in FIGS. 5A , 5 B and 6 . FIG. 5A depicts a view of shuttle 24 from the tubing side, while FIG. 6 depicts the view from the opposite or disposable side. FIG. 5B shows a close-up of the occluder drive mechanism. Autoconnect device central area 26 includes one or more channels 26 a for tubing. Each channel 26 a includes side walls 26 b with shroud 26 c , back end wall 26 d , front end wall 26 e , and an RFID reader 26 f . End walls 26 d , 26 e include rounded orifices to accommodate the tubing. In one embodiment, the channels 26 a and the RFID housing 46 are designed so that the RFID housing is retained in a releasable snap fit once it is inserted into the channel. The RFID reader is intended to read the RFID tag 47 placed in each RFID housing 46 as discussed above.
[0056] Occluder 25 a has been translated to the left in the direction of arrow A, capturing tubing 43 between occluder 25 a and shroud 26 c . Occluder 25 a is translated using a 6 VDC gear motor 36 mounted on the shuttle, with a suitable speed reduction gearbox 37 and a lead screw 38 mounted to the occluder. Both occluders move at the same time. In some embodiments, spring 39 may used to bias the occluder to a closed position. In other embodiments, the spring may be placed, for instance on the opposite end of the occluder, to bias the occluder open. In yet other embodiments, the control circuitry may include a large capacitor to assure sufficient energy to drive the occluder to a safe closed position as a fail-safe mechanism. At this point, the seals upstream of the tubing may not have been broken, and there may be no fluid in the tubing. The purpose of the occluder, or grasping mechanisms, is to occlude the tubing lumen and also to grasp the tubing to advance the tubing or, as will be seen, to retract the tubing and automatically remove the tubing cap. It will be understood that a solenoid or an air cylinder, or other mechanism, may be used to slide the occluder back and forth on its mounts or mounting pins rather than a lead screw.
[0057] Some embodiments may not use occluders. As discussed below, the tubing from the container fits tightly into a housing for an RFID chip. With only a small amount of friction, the tubing will adhere to the RFID housing and will follow along when the RFID housing is placed onto the shuttle. The tubing will also remain in place in the housing when the shuttle is advanced a short distance back and forth within the frame to remove the tubing cap and to pierce the tubing membrane. Some embodiments may thus not use occluders, but the tubing will still travel with the shuttle, moving when the shuttle moves under the influence of normal friction between the housing and the tubing. It any event, the occluder may be useful for other reasons, such as preventing loss of fluid during spiking, or allowing the controller to conduct connection integrity tests. Failsafe closure, described above, may help prevent cross-contamination in case of a power failure.
[0058] RFID chip housing 46 is sized to fit within channel 26 a , possibly with a snap fit. As seen from FIG. 6 , from the opposite side of shuttle 24 , back occluder 25 b has been translated to the right, in the direction of arrow B to capture tubing 43 . While arrows A and B seem opposite, the directions are the same because FIG. 5A views the shuttle from the tubing side, while FIG. 6 views the shuttle from the disposable cassette side. Each channel 26 a includes a front collar 26 g extending toward the cassette. In addition to the collapsible handle 44 b on the tubing end 44 , RFID housing 46 may also serve as a handle for placing tubing in the channel. The RFID chip should be durable and rugged, and should be able to withstand sterilization, whether by gamma-ray irradiation, steam autoclaving, typically conducted at about 1 atm gage pressure at 121° C., or by chemical methods.
[0059] RFID tag 47 (not shown in FIG. 6 ) includes an antenna that may, or may not, be coupled to an integrated circuit chip or chip that can store or contain additional product information, tracking information, shipping information or any other desired product information. In operation, the processor, powered by the power source, provides a signal that is transmitted by the transceiver. The transmission energy of the signal communicated by the transceiver serves to inductively and communicatively couple the RFID tag 47 to the reader 26 f . Reader 26 f is essentially a small circuit board with circuitry for communicating with RFID tag 47 . The circuitry usually includes its antenna, a controller or control circuit, and input/output circuitry for communicating with the autoconnect controller. When the RFID reader sends a signal, an electrical current is, in turn, inductively generated within the RFID tag antenna. The electrical current can serve as a “zero bit” to simply indicate the presence or absence of the RFID tag 47 . Alternatively, the electrical current can power the chip, thereby allowing the additional information stored thereon to be communicated between the RFID tag 47 and the reader 26 f . In one embodiment, RFID tag 47 records an indication each time the tag is read. In one embodiment, RFID tag 47 records and stores additional information from the system controller, including at least one of a patient identifier, an amount of dialysate or liquid administered, a date and time, and other helpful medical information.
[0060] The RFID tag 47 as illustrated is a passive tag, which includes no internal power source and instead is inductively powered and interrogated by the reader. In application with the present disclosure, RFID tag 47 can alternatively be a semi-passive device that includes a battery that is printed onto the substrate. The addition of the printed battery power source allows the antenna to be optimized for communication, as opposed to current generation. In another embodiment, the RFID tag can be an active tag that includes a long-life battery, one or more integrated circuits, display elements, storage elements, etc.
[0061] In some embodiments, the RFID tag 47 includes a transponder that operates at a relatively low frequency, about 125 kHz to about 134.2 kHz, or from about 140 kHz to about 148.5 kHz, and having a read range of as low as about one inch. A high frequency transponder typically operates at about 13.56 MHz with a read range of up to a meter. Further, transponders may even operate at an ultra-high frequency, such as 433 MHz, or typically between about 868 MHz to about 928 MHz, with a read range of about 3 m or beyond, such as those used for electronic toll collection and the like. In the present application, small, low frequency RFID tags with very short range are preferred, so that each tag is identified within its channel or range on the shuttle or other part of an autoconnect system. These ranges will preferably be less than one inch, in the range of about 20-25 mm. The reading range depends on the design of the reader or interrogator and can be kept short.
[0062] For purposes of the present disclosure, and regardless of physical configuration, an RFID tag includes any device configured to communicate information via radio waves transmitted at frequencies of about 100 kHz or higher. In fact, the operating frequencies of individual tags can be considered a secondary consideration given that the overall structures of typical tags are very similar. The RFID tags allow positive identification of each bag or container whose tag is placed into the shuttle. With this technique, the autoconnect controller, or the controller for the dialysis or other system, will know whether the placement made is correct and incorrect and notify or alert the operator or other personnel when an incorrect placement is made.
[0063] The above discussion focused on placing the containers of dialysate fluid, and their tubing and connectors, and automatically identifying the containers using RFID tags. It is clear from the above discussion, that other positive techniques may be used for identification, such as bar code labels or indicia on the tubing ends, and a bar code reader on the autoconnect device. Still other techniques may be used, such as i-buttons from Maxim Integrated Products, Sunnyvale, Calif. An i-button, similar to an RFID, is an integrated circuit with a unique identification, contained in a small, flat, metallic package. An i-button identification circuit usually requires touching to an i-button reader, but the principle of automatic and unique identification is similar to that used with a bar code or an RFID tag. It will also be obvious to those with skill in the art that the autoconnect device may be operated with no automatic identification feature, such as RFID tags or barcodes. Identification of the fluid dispensed may be made manually or by entering a information, such as a code, manually into a computer for tracking patient care.
Making Connections and Preserving Sterility
[0064] Once the tubing is in place, the tubing is connected so the fluid in the containers can be dispensed or otherwise distributed or used. FIG. 7 illustrates graphically the problem in connecting bags of dialysis solution to the disposable cassette. The upper line with three points represents testing at different temperatures, while the lower line represents testing with an improved spike design. The force required for connecting four bags at room temperature, 25 C, was about 140 lbs, or about 35 lbs force for each connection, which connections are of course made by hand, one at a time. At cooler temperatures, 15 C, the force for all four was about 160 lbs, or about 40 lbs force each, while at 35 C, the force dropped to about 120 lbs, or about 30 lbs force each. Even with the improvement of a stepped spike, as discussed for FIG. 8A below, the force required is still about 80 lbs, or about 20 lbs force for each connection.
[0065] FIG. 8A depicts the improvement in the spikes discussed above and also illustrates a technique used to insure that the connection between the disposable cassette and the tubing remains sterile. In this cross sectional view, tubing 43 with RFID housing 46 has been placed in position and membrane seal 45 has been penetrated and broken by hollow spike 51 of the disposable cassette port 52 . The outer diameter of the distal portion 51 a of the spike is less than the outer diameter of the spike main portion 51 b , which may be slightly less than the diameter of spike proximal portion 51 c . In addition, tubing end connection 48 may include three stepped portions, distal portion 48 a with a larger inner diameter, mid-portion 48 b with a smaller inner diameter, and proximal portion 48 c with a larger inner diameter, which provides clearance for material from the penetrated seal to fold or hinge out without occluding the lumen and without requiring additional force to complete the penetration.
[0066] Spike 51 is contained within port 52 . Spike 51 includes an inner lumen 53 so that when spike 52 penetrates membrane 45 , a fluid connection is established between the dialysate solution bag tubing 43 , and disposable cassette 5 . The parts are designed so that the connection between sterile parts is made before the membrane seal of the tubing is broken, thus preserving sterility of the connection. The spikes are preferable a relatively hard plastic, such as acrylic, polycarbonate, or acrylonitrile-butadiene-styrene (ABS). Cyclic-olefin containing polymers (COCs), especially those blended with ULDPE, may also be used for the cassettes and spikes. See, e.g., U.S. Pat. No. 7,011,872, assigned to the assignee of the present patent, and which is hereby incorporated by reference.
[0067] The distal portion 51 a of spike 51 does not extend beyond the outer rim of port 52 , i.e., the spike is shrouded within the port. In this embodiment, port 52 extends a distance d 1 beyond spike 51 and spike distal portion 51 a . This helps to prevent inadvertent touching and contamination of the spike after the port cap is removed. When tubing end connection 48 is seated within port 52 , the distal portion 51 a of the spike extends within tubing 43 for a distance d 2 .
[0068] Spike distal portion 51 a , as shown, has a smaller outer diameter than spike mid-portion 51 b . As noted above, tubing connection 48 inner portion 48 a has a larger inner diameter. When tubing 43 is connected to port 52 , spike distal portion 51 a with a small outer diameter encounters connector portion 48 a with a larger inner diameter. In this embodiment, and as seen in FIG. 8 , the outer diameter of the spike portion 51 a is less than the inner diameter of connector inner portion 48 a , allowing the spike to pass through without interference. Upon further insertion, when connector inner portion 48 a encounters spike mid-portion 51 b , a seal is made between them just before the spike tip penetrates seal membrane 45 . After penetration, spike mid-portion 51 b seals against tubing mid-portion 48 b . In addition, an outer seal is made between tubing proximal portion 48 a and spike proximal portion 51 c at the entrance to the tubing, i.e., the entrance to tubing portion 48 a.
[0069] This arrangement of a stepped spike and stepped connector tubing minimizes insertion forces while simultaneously minimizing opportunities for contamination of the connection parts. It will be recognized that other spikes may be used, such as tapered, non-stepped spikes, as well as tapered, non-stepped spikes with a leading edge on one portion of the spike arc. It will also be recognized that some spikes may have a sharp edge, while others will be blunt. Using a blunt edge helps to prevent injuries. In the present embodiment, designed for no contact with a person using or operating the autoconnect system, sharp edges are preferred, for minimizing the force necessary to make the tubing connections.
[0070] FIGS. 8B and 8C depict an autoconnect mechanism in which the tubing tips approach the cassette 54 and spikes 55 a - 55 d for sequential spiking. In this embodiment, shown with the tips of four containers of medical fluid, the autoconnect mechanism has four independently-moving tips, 57 a - 57 d , from four containers with outlet tubing 56 a - 56 d . Each tip has a membrane or seal 58 a - 58 d for spiking by the spikes 55 a - 55 d . The tubing and tips are mounted in independently-moving mounts 59 a - 59 d on a stationary platform 60 . As discussed below with respect to FIGS. 19-21 , separate movement for each mount may be provided by suitable devices, such as solenoids, air cylinders, electric motors, or even hydraulic cylinders. The mounts may be mounted on a shuttle or to tracks on the autoconnect frame directly. In this embodiment, the shuttle does not translate, but instead each device provides the separate back-and-forth movement described for the shuttle.
[0071] FIG. 8B depicts the four tips 57 a - 57 d and mounts 59 a - 59 d approaching spikes 55 a - 55 d in a sequential manner. In practice, one tip may be advanced at a time. Preferably only one spiking connection is made at a time. As seen in FIG. 8C , the top two tips, 57 a , 57 b and membranes 58 a , 58 b , have been spiked, one at a time, by spikes 55 a , 55 b . The third tip, 56 c , is approaching the third spike 55 c , and the fourth spike will be next. By using sequential spiking, the total force required for penetration of the membrane by each spike is spread over four time sequences, rather than all at once. Thus, the motor, cylinder, or solenoid that advances each mount may be smaller, since it needs only enough force to penetrate one seal, about 20-25 lbs force. Alignment of the mounts with the spikes may also be easier, since each mount, in its own channel or pathway, need only align with a single spike. Even though there may be a plurality of mounts and pathways to align, there are just as many to align in embodiments with a translating shuttle.
[0072] The above discussion focused on automatically making the connection between containers of dialysate fluid and the inlet ports of a disposable cassette. By analogy, the same technique with suitable geometries may be used for automatically making sterile connections between other containers of fluid and other dispensing or pumping systems. As previously noted, disposable cassettes may have their connection ports on the top of the cassette, or on the side. Of course, placement of the ports on the periphery of the pumping mechanism is preferable, whether top, bottom, side, or on an edge of the top, bottom, or side. The same principles apply to other fluid container connections, such as bags of blood or blood substitute being connected to an inlet port for a blood transfusion machine, such as a cardiopulmonary pump, bypass pump, or auto-transfusion machine. Still other applications are also possible.
Operation of the Fingers and Removal of the Caps
[0073] An important part of making the connections is the automatic removal of caps from both the tubing and the ports of the cassette or other pumping and dispensing mechanism. Automatic removal of the caps is an important part of the process because the caps, and the underlying ports and connections, may easily be touched and thus contaminated if the caps are removed by hand. Thus, as discussed above, special fingers are used to remove caps from both the product container tubing and from the ports of the pumping or dispensing machines, typically a disposable dialysis cassette.
[0074] One embodiment of cap removal fingers is disclosed in FIGS. 9-14 . FIG. 9 discloses a rear perspective view and FIG. 10 a front perspective view, of a finger 27 with left and right sides, 27 a , 27 b , a cap ejector plate 27 c , finger 27 assembled with fasteners 27 d . Ejector plate 27 c is mounted within pocket 27 and travels via slot 27 e within left and right sides 27 a , 27 b . In one embodiment, as shown in FIG. 12 , a torsional spring 27 j is mounted within finger 27 and under top surface 27 f of the ejector to resist advancement of the ejector plate and to return it to the resting position shown in FIGS. 9-10 . The top side of finger 27 includes a first pocket 73 with extended rails 71 , the rails forming an orifice 72 . Orifice 72 allows passage of tubing, as discussed above, but is smaller than the diameter of the cap for the tubing. The walls of rails 71 are curved, together forming about 290 degrees of a circle, i.e., the periphery of the cap, or the portion of the cap inside the outermost periphery, an inner periphery. This restraint allows the rails to retain the caps when the shuttle and tubing are retracted, as discussed above. The orifice is preferably at least about 180 degrees, and experiments have found that 290 degrees works well for removing caps. Other configurations with lesser coverage, such as several angularly spaced points, are also adequate for stripping the tubing cap from the tubing.
[0075] The top of finger 27 includes a second pocket 75 , formed by extended rails 74 of left and right sides 27 a , 27 b . In this embodiment, the pocket 75 is formed by the rails 74 and by inserts 74 a , spaced more closely than rails 74 . The inserts are designed for grasping the center portion of a cap from a dispensing or pumping machine, such as a dialysis cassette. As noted above, fingers 27 grasp the stepped, protruding nipple from the dispensing or port cap. The interference should be sufficient so that the cap is retained between the inserts. In one embodiment, inserts 74 a are sharp near the center, so that when the finger 27 is rotated and the shuttle translated into the nipple of the port or dispensing cap, the inserts cut into the nipple portion, grasping the nipple portion. When the finger begins to rotate in reverse, the cap remains captive and is pulled away from the port. Also visible from both the top and bottom of finger 27 is an ejector plate 27 c contained within the finger. Finger 27 includes a through shaftway 76 with a notched portion 77 . A shaft rotates within the shaftway to rotate the fingers and to advance and retract the ejector plate. When the caps have been removed as discussed above, and are resting in pockets 73 , 75 , the finger is rotated and the ejector plate is advanced to eject the caps, all without touching and contaminating the tubing or the ports.
[0076] As seen in FIGS. 11-12 , a shaft 81 actuated by motor 28 (see FIG. 1 ), input shaft 29 and gear train 80 extends through finger 27 and shaftway 76 . Also contained within each finger 27 inner space 79 is a leaf spring 78 , the leaf spring mounted against pin 82 . Finger 27 can rotate relative to shaft 81 , its travel limited by pin 82 . The leaf spring 78 biases finger 27 to the back position, as shown in FIG. 12 . There is sufficient clearance within space 79 so that pin 82 and leaf spring 78 can rotate back and forth, which limits travel, but also allows rotation of finger 27 in the general direction of the arrow C as shown, toward the cassette. When the shuttle is advanced, finger 27 rotates as shown and as allowed by the pin. In one embodiment, this is about 5 degrees. This is sufficient to allow the inserts 74 a to grasp the port cap from a dialysis cassette port. Once rotation has taken place, the shuttle prevents reverse movement or rotation of finger 27 . However, leaf spring 78 is engaged by rotation of the finger, and now urges finger 27 to rotate back, in the direction opposite arrow C. Thus, when the shuttle is reversed, and translates back, away from the cassette, finger 27 does indeed rotate away from the cassette, while gripping the port cap in second pocket 75 and removing it. The finger motor will cause the port cap to fall out as the finger is rotated down, out of the way. As discussed above, the cap from the tubing is held in first pocket 73 .
[0077] The caps have now been removed from the tubing and the port, and are disposed of before making the connections between the tubing and the port. FIGS. 13-14 depict rotation of finger 27 about shaft 81 . After the shuttle has been translated back, away from the fingers, the fingers may be rotated downward to remove the caps. Output shaft 81 from gear train 80 rotates the fingers to actuate the ejector plate 27 c and eject the caps from pockets 73 , 75 . Gear train 80 may include bevel gears on the shafts to turn motive power from motor 28 and input shaft 29 ninety degrees to rotate output shaft 81 . In the alternative, a worm on the input shaft and a worm gear on the output shaft, or crossed helical gears will also work.
[0078] As finger 27 is rotated counterclockwise in the direction of arrow D beyond horizontal, ejector plate 27 c will encounter protrusion or cam surface 85 on back wall 21 a of the autoconnect frame. The interference will cause the bottom edge of ejector plate 27 c to bear against cam surface 85 , advancing ejector plate 27 c through finger 27 . As seen in FIG. 14 , the top portions of the ejector plate, including a slide channel 27 e top portion and top surface 27 f , and a top ejector rear portion 27 g , now protrude from the finger 27 . Top surface 27 f will eject a cap from pocket 73 and top portion 27 h will eject a cap from pocket 75 . The fingers will remain in the down position, out of the way, during therapy.
Overall Operation of an Autoconnect Device
[0079] The above description may be better understood by disclosing sequential views of the operation. FIGS. 15-17 lead this discussion, and FIG. 18 provides a flow-chart version of the autoconnect process. In FIG. 15A and FIG. 15B , tubing 43 has been placed in a shuttle 24 channel 26 a of central area 26 , along with RFID housing 46 and RFID tag 47 . For comparison in FIG. 15A , an unoccupied channel 24 b , adjacent occupied channel 26 a is shown, along with the fingers corresponding to the used and unused channels. Shuttle 24 has been advanced in the direction of arrow E, causing slight rotation of finger 27 , but only the finger corresponding to channel 26 a . This slight movement can be seen by the fact that rails 71 , 74 of finger 27 in channel 26 a have been advanced slightly.
[0080] As can be seen in FIG. 15B , this causes a slight clockwise rotation of finger 27 in the direction of arrow F and in the general direction of frame back wall 21 a . As noted, finger 27 rotates about shaft 81 within shaftway 76 . Returning to FIG. 15A , the slight rotation is sufficient for second pocket 75 to capture port cap 34 , the port cap to the port and corresponding to shuttle channel 26 a . This can be seen in top view FIG. 15A , as the port cap 34 is captured between extended rails 74 . In contrast, in adjacent channel 24 b , extended rails 71 , 74 have not been advanced in the direction of arrow A, and extended rails 74 are not adjacent port cap 34 in the adjacent channel 24 b.
[0081] In FIGS. 16A and 16B , shuttle 24 has refracted in the direction of arrow G, away from frame back wall 21 a . In channel 26 a , but not in channel 24 b , tubing cap 44 has been removed from tubing tip 45 , the tubing cap retained in pocket 73 of finger 27 . Finger 27 in channel 26 a remains rotated rearward, as it was in the previous figures. Extended rails 71 , 74 in channel 24 b are thus offset from extended rails 71 , 74 of finger 27 in channel 26 a . Port cap 34 has been captured in pocket 75 of finger 27 , but only in channel 26 a , not in channel 24 b.
[0082] FIGS. 17A and 17B illustrate the next two sequences in automatically removing the caps. Shaft 81 rotates counterclockwise in the direction of arrow H, causing finger 27 to also rotate. As the rotation continues, ejector plate 27 c encounters a protrusion or cam surface 85 on back wall 21 a , causing ejector plate 27 c to advance within finger 27 in the direction of arrow J, causing the ejector plate to push caps 34 a , 44 out of pockets 73 , 75 and ejecting them from finger 27 . After the caps are removed, and after therapy is concluded, the fingers can be rotated clockwise back to their normal position, opposite the direction of arrow H. In this embodiment, all the fingers are rotated, including fingers with no caps. In other embodiments, gearing or other power is arranged to engage only the fingers corresponding to channels with tubing.
[0083] The process as described above, for a method or process of automatically connecting tubing, is easily visualized with the aid of the flow chart of FIG. 18 . The first step 91 is to place the tubing into an autoconnect shuttle. A cap of the tubing is then placed 92 into a pocket of a rotating finger. The tubing is grasped by closing 93 on the tubing with a holder or occluder. The shuttle is then translated 94 a short distance forward, moving forward tubing and the cap, along with the shuttle. This movement is sufficient to cause a slight rotation only of a finger which holds a tubing cap. When the finger is rotated, it captures 95 a port cap from a disposable cassette, or other dispenser, which will be connected to the tubing.
[0084] The shuttle is now translated 96 in the opposite direction, away from the cassette, removing the tubing cap, which is held in a pocket of the rotating finger. The finger is now rotated 97 away from the cassette, removing the port cap. The rotation may continue until the top of the rotating finger is below horizontal, and causing the caps atop the rotating finger to fall away. In one embodiment, the rotating finger includes an ejector plate that is actuated by a cam surface on the back wall of the autoconnect frame. After removal of the caps, the shuttle is translated forward 98 , piercing the tubing seal with spikes in the cassette port. It is understood that this process is applicable to tubing from containers of a number of other liquid products, and may be used for automatically connecting to dispensers or pumping stations for the products.
Alternative Mechanisms for Shuttle Translation
[0085] The above descriptions have used an electric motor and lead screws to translate the shuttle, i.e., to move the shuttle back and forth in the direction to and from the disposable cassette, or other pumping or dispensing mechanism. Many other techniques and equipment may be used, a few of which are described in FIGS. 19-21 .
[0086] A ballscrew, with a rotating nut and traveling balls, may also be used to translate the shuttle back and forth. FIG. 19 schematically depicts the use of ball screws in shuttle transport system 110 . The shuttle transport system includes an electric motor 111 and its controller, suitable power transmission elements 112 , and a power divider 113 , to split power from the motor and drive two ballscrews 114 . Each ballscrew is driven by a suitable interface 115 from power divider 113 . Each ballscrew may also include an encoder 116 for sensing the shaft or ballscrew rotation, and thus the position of the shuttle 117 . The shuttle 117 is mounted to the rotating nuts 114 a of the ballscrews 117 . As the ballscrews are rotated, the nuts translate or move back and forth, as does the shuttle. Other sensors may be used to determine shuttle position.
[0087] Pneumatic cylinders may also be used to move the shuttle back and forth, as shown in FIG. 20 , depicting pneumatic shuttle transport system 120 . Air may be supplied from a building compressor or plant air. For home use, however, a small air pump 121 and a suitable pressure regulator 122 and controller may be used. In this embodiment, shuttle 127 is mounted on the traveling or rod portions 124 of air cylinders 123 . The cylinders may be single acting with an internal return spring 125 within the cylinder, or may be double-acting cylinders, for which no return spring is necessary. Air cylinders 123 are mounted on mounts 126 , mounted on the autoconnect frame, for steady motion. The pneumatic driving system also includes a linear position sensor including linear transducers 128 mounted to the shuttle and the frame and sending out signals to the system controller of the position of the shuttle. As seen in the lower view of FIG. 20 , the pneumatic system may include the pneumatic motive system as described, with shuttle 127 moved by air cylinder rods 124 . Mounting rods or sliders 129 may also be used in parallel with the air cylinders.
[0088] Because of the relatively short distances involved in translating the shuttle, it is also appropriate to use solenoids, preferably electric actuated, to translate the shuttle. FIG. 21 depicts an application in which solenoids are used in a solenoid transport system 130 . Of course, more than one solenoid may be used, but solenoids with more than one position change are now available, such as the multi-position models from Guardian Electric Mfg. Co., Woodstock, Ill., U.S.A. In this application, shuttle 137 is mounted on the plungers 136 of solenoids 132 . The solenoids are powered and controlled by controller 131 . In addition, the position of the shuttle is noted by at least one hall effect sensor 138 on the shuttle and magnets 135 mounted at appropriate locations along the path of the shuttle. Other position sensors may also be used. In addition, the shuttle may use sliders 134 , above or below the plane of the plungers, for travel in addition to the plungers of the solenoids mentioned above for the pneumatic shuttle transport system.
[0089] In addition, other mechanical or fluid power devices may be used for shuttle transport, such as hydraulics. Hydraulics are typically not used for medical devices because of certain aspects of hydraulic fluid. However, the autoconnect device uses relatively low power, and non-toxic hydraulic fluids are now available, such as the UCON™ FDC 300 and 400 grades from Dow Chemical. These fluids are approved for incidental food contact and may be safely used. A hydraulic system for shuttle transport would include at least a motor, a hydraulic pump, a reservoir for the hydraulic fluid, and control lines and systems for two-way movement of the shuttle.
[0090] The control systems for operating the autoconnect and the associated equipment are also disclosed in FIGS. 22 and 23 . The control system 140 for the dialysis machine, the disposable cassette, and the autoconnect device are depicted in FIG. 22 . The patient autoconnect controller 143 is in communication with the disposable cassette controller 142 with an external interface. The autoconnect controller 143 is in communication with the dialysis machine controller 141 via an external patient autoconnect interface. Dialysis machine controller 141 includes a microcontroller 141 a and a memory 141 b for storing a computer program for operating the controller 141 . The individual containers or bags of dialysis solution 144 are supplied with unique identifiers and when these identifiers are read, the containers may be said to interface with the dialysis machine controller 141 , the disposable cassette controller 142 , or as noted above, the autoconnect controller 143 . The system controllers may also have other interfaces and connections. As noted above, the unique identifiers may be read in many ways, for example, by a camera 145 operably connected to the dialysis machine controller.
[0091] The term camera as used here also includes related optical devices capable of reading such a mark, including but not limited to, a visible/IR camera, a charge-coupled device (CCD), a CMOS image sensor or camera, an optical sensor, or other suitable device. Cameras for imaging in visible light are readily available. Cameras that capture infrared (heat) images are also available. Recently, cameras that can produce composite images using visible and infrared radiation are now available, such as those from Fluke Thermography and Fluke Corp., Everett, Wash., USA. Images that include an indication of temperature may also assist in the sense of letting users know when and if the containers have been warmed, for instance to body temperature. The camera may also be used to verify that the connectors are undamaged and that they are correctly loaded into the shuttle or other portion of the autoconnect device. If the connectors are damaged or the markings are inconsistent with the expected markings for the containers, the machine controller for the dialysis system or for the autoconnect device may signal an alarm or refuse to proceed. In one embodiment, the camera may also be used to inspect the color or other readily-determined optical property of the contents of the containers, and if the inspection of the color or other property does not yield the expected result, the system may signal an alarm or refuse to proceed.
[0092] The autoconnect control system 150 is depicted in FIG. 23 . The autoconnect system is controlled by a microcontroller 151 . A great many microcontrollers, and microprocessor controllers, are suitable for this application. Indeed, even application specific integrated controllers (ASICs) may be used. We have found that microcontrollers from STMicroelectronics, Austin, Tex., work well. Other microcontrollers that will be satisfactory include those from Freescale Corp., Austin, Tex., or Atmel Corp., San Jose, Calif. Other suitable microcontrollers may also be used.
[0093] System controller 151 is in communication with a great many other devices and parts of the autoconnect system, as discussed above. System controller 151 is in communication with RFID reader board 152 , bar code reader board 153 , if supplied, shuttle controller 154 a , shuttle position sensor 154 b , finger controller 155 a , and finger position sensors 155 b . In addition, the system controller 151 is in communication and control with the occluder controller 156 a and the occluder position sensors 156 b . In some systems, only a single occluder is used.
[0094] In addition, a number of additional sensors 157 are used in embodiments of the autoconnect system. For example, temperature sensors may be used near the tubing or the shuttle channels to detect a temperature related to the dialysis fluid or other liquid that is being auto-connected. Temperature sensors may also be used near the shuttle lead screws or other transport to insure that overheating is not occurring. If pneumatic cylinders or air solenoids are used, at least one or two pressure sensors should be used to keep a check on the health of the inlet air or air pump outlet that is used to supply air pressure. If hydraulic fluid is used, pressure sensors should be used to monitor and regulate hydraulic fluid pressure in the system.
[0095] It is also desirable to include a flow sensor 158 . For example, a non-contacting optical flow sensor may be used to detect flow of dialysis fluid within the tubing, based on minute changes in reflection or refraction of the fluid within the tubing. A single pressure sensor of a two-port delta-p pressure sensor may be used along the tubing to detect flow by the change in pressure, or pressure drop, between the ports. Actual rotating, contact-type flow sensors may also be used. Finally, it may also be prudent to add a fluid sensor 159 for measuring specific properties of the solution, such as pH or conductivity. The fluid sensor is preferably placed directly in the flow stream for accurate measurement of the appropriate property.
[0096] FIGS. 24-25 are flowcharts depicting how the automatic identification features of the autoconnect device operate in different embodiments. In one embodiment, depicted in FIG. 24 , there is an RFID reader in each channel or position on the shuttle. There is also an RFID tag on the tubing from each container of fluid, such as dialysate fluid. The user places 160 an RFID tag with a unique identifier on tubing from the fluid container that contains the fluid to be administered to a patient. The tubing and RFID tag is then placed 161 into separate channels or positions on the shuttle. The reader in each position then reads 162 the RFID tag on the tubing from one or more containers. If the computer recognizes that the RFID tags corresponding to the containers are in the proper place, the operation continues 163 . If one or more containers are not in the proper position, an alert or alarm is issued 164 to the user before proceeding.
[0097] In another embodiment, depicted in FIG. 25 , there is only a single RFID reader or bar code reader operably connected to the autoconnect device. In this embodiment, the unique identifier for each container of fluid may be located 165 on tubing or on the container or bag itself. The user, using the bar code reader or RFID reader, then reads 166 the unique identifiers on each container or tubing, the unique identifiers being an RFID chip or bar code indicia or label. The computer and computer program receives the information about the containers and then instructs 167 the user concerning the position to place the tubing for each of the containers. The user then places 168 the tubing from the containers into the instructed position on the shuttle in accordance with the instructions. The user then operates 169 the autoconnect device and administers fluids to the patient.
[0098] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those having skill in the art. For instance, the autoconnect machine may be used with pumping cassettes used in peritoneal dialysis machines. Embodiments of autoconnect machines may also be used for cassettes for hemodialysis systems, automated peritoneal dialysis, and continuous flow peritoneal dialysis systems. These cassettes may employ any suitable pump or other fluid transfer mechanism, used with the autoconnect machine. Such changes and modifications can be made without departing from the spirit and scope of the present disclosure and without diminishing its intended advantages. Such changes and modifications are included in the appended claims.
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A medical fluid machine with supply autoconnection, the machine comprising: a cassette-receiving wall; a disposable cassette held firmly by the wall, the disposable cassette including a port spike, the port spike fitted with a spike cap; a translating shuttle including a channel sized to hold a portion of a supply tube and including a fixture for releasably holding a supply tube end; a supply tube including an end configured to be releasably held by the fixture of the channel of the translating shuttle, the supply tube fitted with a supply tube cap; a cap removal device selectively positionable between the disposable cassette and the translating shuttle; and a controller programmed to (i) translate the shuttle holding the supply tube at the supply tube end towards the disposable cassette, so that the cap removal device is likewise moved towards the disposable cassette and the spike cap of the disposable cassette is engaged, (ii) translate the shuttle holding the supply tube at the supply tube end away from the disposable cassette and the cap removal device, so that the cap removal device can pull the spike cap off of the port spike and the tube cap off of the tube end, and (iii) translate the shuttle back towards the disposable cassette to allow the port spike of the cassette to spike the tube end.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the priority of German Patent Application, Serial No. 101 46 527.0, filed Sep. 21, 2001, pursuant to 35 U.S.C. 119(a)-(d), the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an inverter with a mains system side and load-side freewheeling pulse converter, and more particularly to an inverter which can operate at higher pulse frequency and with a higher DC intermediate voltage than conventional inverters
[0003] An inverter with freewheeling pulse converters on the mains system side and load-side, which are electrically connected on the DC side via a DC intermediate circuit, is commercially available. Inverters of this type are known, for example, from the Siemens catalog DA65.10.2000, entitled “Simovert Masterdrives Vector Control”. In this Siemens catalog, the diagram “Reduction Curves for the Motor-Side Converter” show that under standard operating conditions the pulse frequency f pL is, for example, 6 kHz which can be increased to a maximum pulse frequency of f pL max=16 kHz. However, an increase in the pulse frequency f pL to 16 kHz reduces the current rating by 50%, which also reduces by 50% the power available from the converter.
[0004] The conventional inverter described above can keep feedback to the power mains system to a minimum. A power factor of one is set for the mains system side freewheeling converter, so that only active power is supplied by the power mains. A supply controlled in this fashion is also referred to as an Active Front End (AFE).
[0005] The conventional inverter has switchable semiconductor switches which are implemented as insulated gate bipolar transistors (IGBT) and made of silicon (Si). The electrical losses in Si-components increase superlinearly with the operating voltage, so that the maximum blocking voltage has to be optimized. When operating from a conventional line voltage, conventional inverters have typically a blocking voltage of 1200 V. However, switching losses limit the switching frequency. The switching frequency is typically between 3 and 8 kHz. This switching frequency makes it difficult to optimally dimension the line filter and/or the output filter of the inverter. n addition, the current for a predetermined power is determined by the maximum available voltage, which in turn determines the size of the motor cables.
[0006] It would be desirable and advantageous to provide an improved inverter with a higher voltage rating, in particular in the intermediate DC circuit.
SUMMARY OF THE INVENTION
[0007] According to one aspect of the present invention, an inverter has a freewheeling pulse converter on the mains system side and another freewheeling pulse converter on the load-side, which are electrically connected on their respective DC sides via a DC intermediate circuit. A line filter is connected to the AC input side of the freewheeling pulse converter. The switchable current valves of the mains system side and load-side freewheeling pulse converters are semiconductor switches made of silicon carbide and have a high blocking voltage.
[0008] Embodiments of the invention may include one or more of the following features. An output filter can be connected to the AC output side of the load-side freewheeling pulse converter to filter the higher pulse frequencies on the load-side. Because of the higher pulse frequencies, the output filter as well as the line filter of the inverter can be implemented as a single structural unit. Each of the switchable semiconductor switches can be implemented in silicon carbide as an insulated gate bipolar transistor (IGBT).
BRIEF DESCRIPTION OF THE DRAWING
[0009] Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:
[0010] [0010]FIG. 1 shows schematically an inverter with freewheeling mains system side and load-side pulse converters in accordance with the present invention;
[0011] [0011]FIG. 1 a shows schematically the line current i N , line voltage u N and input voltage u E of the mains system side freewheeling pulse converter; and
[0012] [0012]FIG. 1 b shows schematically the load current i L , load voltage u L and output voltage u L as well as the associated fundamental oscillation u LG of the load-side freewheeling pulse converter.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals.
[0014] [0014]FIG. 1 illustrates an inverter 2 with a mains system side pulse converter 4 and a load-side freewheeling pulse converter 6 , which are electrically connected via a DC intermediate circuit 8 . A line filter 12 is connected between a power mains system 10 and the AC terminals of the mains system side freewheeling pulse converter 4 . Size and cost of the line filter 12 decrease with increasing pulse frequency f pN , which is also referred to as operating frequency, of the mains system side freewheeling pulse converter 4 . A load 14 , in particular a three-phase motor, can be connected to the AC terminals of the load-side freewheeling converter 6 . The mains system side freewheeling pulse converter 4 is controlled in such a way that the line current i N is almost free of harmonics. The remaining harmonics are filtered by the line filter 12 . The exemplary mains system side freewheeling converter 4 of inverter 2 operates with a standard pulse frequency f pL of 6 kHz.
[0015] [0015]FIG. 1 a shows one phase of a line current i N , a line voltage u N and an input voltage u E of the mains system side freewheeling pulse converter 4 during one period of the line voltage. The mains system side freewheeling pulse converter 4 can also be controlled so that energy is fed back into the power mains 10 . The load-side freewheeling pulse converter 6 is so controlled as to generate from the constant DC voltage U Z , supplied to the input side, multiple phases of an AC voltage with changeable amplitude and frequency.
[0016] [0016]FIG. 1 b shows one phase of a load current i L , a load voltage u L and an output voltage u L as well as the associated fundamental oscillation u LG . The mains system side power converter 4 has switchable current rectifier valves 16 and the load-side freewheeling pulse converter 6 has switchable current rectifier valves 18 , with the switchable current rectifier valves 16 , 18 implemented as insulated gate bipolar transistors, also referred to as IGBT.
[0017] In this inverter 2 , which can be operate under various line conditions and/or can feed back power into the power mains 10 , the line frequency f N and the output frequency f U of the inverter 2 are typically quite similar. A suitable design of the load-side freewheeling converter 6 requires that the ratio between the pulse frequency f pL of the converter 6 and the output frequency f U is always greater than a predetermined value.
[0018] By implementing the switchable current rectifier valves 16 , 18 of the mains system side and load-side freewheeling pulse converters 4 , 6 , respectively, as semiconductor switches fabricated of silicon carbide with a high reverse voltage, the DC voltage u Z in the DC intermediate circuit 8 can be increased, without requiring a change in the number of current rectifier valves that are connected in series on the mains system side and load-side pulse converters 4 , 6 . This makes it possible to reduce the complexity and in particular the cross-section of the load-side cables, since for a predetermined power the current decreases with increasing voltage. Because the mains system side pulse converter 4 is a freewheeling pulse converter, the voltage in the DC intermediate circuit can be increased very easily. For this purpose, the mains system side freewheeling pulse converter 4 is operated as a rectifier and voltage upconverter. Silicon carbide also allows operation with a higher switching frequency, which significantly reduces feedback into the power mains 10 so that a smaller line filter 12 can be used with the inverter 2 . The switching frequency and the voltage in the DC intermediate circuit 8 can be increased by making the semiconductor switch of the switchable current rectifier valve 16 , 18 of the mains system side and load-side freewheeling pulse converters 4 , 5 of the inverter 2 of silicon carbide, without increasing the losses.
[0019] According to an advantageous embodiment of the inverter according to the present invention, an output filter is connected to the AC output side of the load-side freewheeling pulse converter. The size of the output filter can be kept to a minimum by increasing the switching frequency of the switchable current rectifier valves 18 of the freewheeling load-side pulse converter 6 , so that the output filter can be integrated in the inverter. The optimized output filter also significantly improves the sinusoidal output voltage characteristic of the load-side converter 6 . This improvement reduces the stress on the load, which makes it unnecessary to change the isolation of the load when increasing the voltage in the DC intermediate circuit 8 . Characteristic frequencies of the system are also no longer excited, thus eliminating shielded cables between the output of the load-side current rectifiers 18 and the input terminals of the load, which facilitates handling for an end-user. The project specification for the cable runs between the load-side current rectifier and load are also simplified or eliminated altogether.
[0020] By using semiconductor switches made of silicon carbide for the switchable current rectifier valves 16 , 18 of the mains system side and load-side freewheeling converters 4 , 6 of the inverter 2 with a DC intermediate circuit 8 , the rated load 14 can be maintained even with a higher voltage of the DC intermediate circuit 8 of the inverter 2 . The inverter 2 has a reduced feedback to the environment and likewise a reduced feedback from the environment to the converter, which simplifies applications of the inverter for an end-user.
[0021] While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
[0022] What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and their equivalents:
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An inverter includes a mains system side freewheeling pulse converter and a load-side freewheeling pulse converter, which are electrically connected on the DC side via a DC intermediate circuit. The mains system side and load-side freewheeling pulse converters each include switchable current valves in form of semiconductor switches that are made of silicon carbide with a high blocking voltage. The inverter can operate at higher voltages and frequencies, without affecting the load rating.
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BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for automatically terminating the operation of a clothes dryer at optimum timing.
Most clothes dryers currently in use include a manually presettable timing device for setting the operating time of the machine. Since this manual setting is based on the user's own experience or manufacturer's guidelines, a substantial amount of energy would be lost if the timer has been set to a longer period than is actually needed or if the user would have to reset the timer again to repeat the operation if the timer is set to a shorter period than optimum.
One prior art approach employed a dryness detector which typically measures the electrical resistance of the clothes to automatically shut off the dryer when a predetermined resistance value is reached. However, there is almost no distinction in electrical resistance value when the dryness factor approaches a 100% value, and precision timing has been difficult to achieve.
SUMMARY OF THE INVENTION
An object of the present invention is therefore to eliminate the disadvantages mentioned above by estimating the time of continued heating operation from the time-varying rate of an operating parameter which varies with the dryness of articles to be dried.
A clothes dryer embodying the invention includes a heater for heating articles of wet clothes and a fan for exhausting moisture-laden air to the outside. With the heater being energized, an operating parameter of the dryer which varies with the dryness of the articles is monitored and the time-varying rate of change of the monitored operating parameter is detected. The detected time-varying rate is used to estimate the period of time during which the heating operation is to be continued. At the end of the estimated time, the heater is de-energized.
Preferably, the dryness of the articles and the temperature of the air exhausted from the dryer are monitored. At the instant the monitored dryness of the articles reaches a predetermined value, the time-varying rate of the monitored temperature is detected to allow estimation of the time period necessary to continue the heating operation.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in further detail with reference to the accompanying drawings, in which:
FIG. 1 is a cross-sectional view of a clothes dryer embodying the invention;
FIG. 2 is a graphic illustration of the operating characteristics of the dryer;
FIG. 3 is a circuit diagram of a dryer control circuit;
FIGS. 4a and 4b are illustrations of a flowchart describing the instructions performed by the microcomputer of FIG. 3; and
FIG. 5 is an alternative flowchart for the microcomputer.
DETAILED DESCRIPTION
A clothes dryer, represented in FIG. 1, comprises a rotary drum 1 rotatably mounted on a bearing 7c of a stationary member that forms part of a fan case 7 which is secured to a housing 2. A belt 5 is looped around the circumference of the drum and a drive pulley of a motor 4 to rotate the drum 1 to stir up articles 3 during operation. The housing 2 includes a front panel 2a formed with a flange 10 which defines an circular opening and a rear panel 2b. The front end of the drum 1 is inwardly flared to define a circular opening in which the flange 10 of the housing 2 is positioned with a small clearance therebetween. The rear end of the drum 1 is formed with slits 1a which form part of a filter unit 12 detachably mounted on a shaft 13. A door 9 having a slitted air inlet opening 9a is hinged on the flange 10. A heater 11 is located below the flange 10 to heat up air introduced through the opening 9a, the heated air being fed through a meshed opening 10a into the drum 1. In the fan case 7 is an exhaust suction fan 8 driven by a belt 6 supported between it and the motor shaft. The moisture laden air is forced out by the fan 8 through the filter unit 12 to trap lint, through openings 7a and then exhausted outside through a duct 7b.
A pair of resistance sensing electrodes 14 is mounted on the flange 10 in a position adjacent to the front edge of the drum 1 to make electrical contact with the wet articles to measure their electrical resistance. A thermistor 15, having a negative resistance-vs-temperature characteristic, is attached to the inner wall of the exhaust duct 7b to measure the temperature of the exhausted air.
Experiments have been conducted to determine the operating characteristics of the clothes dryer in terms of exhaust temperature and dryness factor for different sets of operating parameters as a function of time. The dryness factor was measured in terms of the weight of wet articles at periodic intervals and plotted on curves a' and b', while the exhaust air temperature was measured using a thermistor and plotted on curves a and b, as shown in FIG. 2. The curves a and a' were derived from a given set of operating parameters as a function of time, and curves b and b' were obtained from a different set of operating parameters.
Examination of these curves reveals that the exhaust temperature characteristic that prevails in the later period of operation varies in correlation with the dryness characteristic that prevails in the same period and that exhaust temperature varies more rapidly than dryness factor. It was found in the experiments that the electrical resistance of the wet article varies sharply when the dryness factor varies gradually between a value, typically, 95% and a 100% level, respectively designated A and B in FIG. 2. Therefore, the level A is easily determinable by measuring the electrical resistance of the article. It will be seen from FIG. 2 that the period of time T 1 between a point a-1 corresponding to the below-100% level A and a point a-2 corresponding to the 100% level B is determinable by the rate of increase in exhaust temperature on curve a, and likewise the time period T 2 between a point b-1 corresponding to the level A and a point b-1 corresponding to the 100% level B is determinable by the rate of temperature increase on curve b. Since exhaust temperature is variable as a function of operating parameters including the materials and amount of clothes, ambient temperature, and heater temperature (which depends on AC mains supply), such parameters are reflected in the periods T 1 and T 2 , and therefore, knowing these, the heat cycle can be terminated automatically at optimum time.
FIG. 3 is an illustration of a dryer control circuit embodying the present invention. The control circuit generally comprises a dryness detector 26, an astable multivibrator 43 of a known circuit and a microcomputer 35. The heater 11 is powered from an AC mains supply 18 through a door-operated switch 20 and a power switch 19, the amount of heat generated by the heater 11 being adjustable by a switch 22. The heating level of the heater 11 is controlled by a bidirectionally conducting thyristor 21 whose gating-on pulse is applied from a first gating control circuit 16 which is enabled by a command signal from the microcomputer 35. The motor 4 is similarly energized by the AC mains supply through the switches 19 and 20 and its speed is controlled by a bidirectionally conducting thyristor 23 whose gating-on pulse is applied from a gating control circuit 17. This gating control circuit is also enabled by the microcomputer 35.
A step-down transformer 24 is provided having its primary winding coupled through the power switch 19 to the AC mains supply 18. The dryness detector 26 receives DC power through a diode 25 from the secondary winding of the transformer 24. The resistance sensing electrodes 14 are connected in series with a Zener diode 30 to develop a voltage which is applied to the inverting input of a voltage comparator 27. The noninverting input of the comparator 27 is impressed with a reference voltage obtained from a junction between series-connected resistors 28 and 29. This reference voltage corresponds to the dryness factor A in FIG. 2. The comparator output is coupled through a resistor 31 to a light-emitting diode 33 which forms a photocoupler 32 with a phototransistor 34. The phototransistor 34 has its emitter connected in series with a diode 39 and a resistor 37 to one terminal of the mains supply and has its collector connected in series with a resistor 36 to the other terminal of the mains supply. When the phototransistor 34 is illuminated by the LED 33, a voltage is developed across the resistor 36 and applied to the input port of the microcomputer 35. A parallel combination of a capacitor 41 and a Zener diode 42 is connected to the diode 39 to stabilize the DC voltage supplied to the phototransistor 34, microcomputer 35 and multivibrator 43.
Since the electrical resistance of the articles 3 detected by the electrodes 14 is relatively low during the initial stage of drying operation, the voltage at the inverting input of the comparator 27 is lower than the reference voltage, causing a voltage of positive polarity to appear at the output of the comparator. Therefore, the light-emitting diode 33 is turned off by the positive comparator output until the dryness is lower than the predetermined factor A.
The thermistor 15 forms part of the astable multivibrator 43 which includes a comparator 51, resistors 44 to 48, a capacitor 50 and a Zener diode 49. The thermistor 15 is connected such that the frequency of the multivibrator 43 is proportional to the exhaust temperature. The resistors 44 and 45 serve to provide linearity between the frequency and the exhaust temperature. The output of the multivibrator 43 is applied to a counter of the microcomputer 35 which is reset in response to each oscillation of the temperature indicating signal to count clock pulses of the microcomputer. The output of the counter is a binary representation of the exhaust temperature.
The operation of the microcomputer 35 will now be described with reference to a flowchart shown in FIGS. 4a and 4b. With the dryer loaded with wet articles and door 9 being closed, the operation of power switch 19 energizes the microcomputer 35. The microcomputer 35 starts program execution at Step 100 by enabling the gating control circuits 16 and 17 to apply gating-on pulses to the thyristors 21 and 23 to start drying operation in a heat-up cycle. When the articles have been dried to the predetermined dryness value A, the voltage at the inverting input of comparator 27 exceeds the reference voltage, the output of this comparator switches to a negative voltage and turns on the light-emitting diode 33. As a result, the phototranistor 34 is rendered conductive, causing a voltage to develop across the resistor 36. When this occurs, the exhaust temperature value is registered in the microcomputer to introduce a delay time according to the rate of increase in the exhaust temperature.
More specifically, the microcomputer 35 checks whether the output of the dryness detector 26 is at high voltage level (logical "1") at Step 101, and if so, advances to a Step 102 to store the exhaust temperature datum "t" from the oscillator 43 into a first temperature counter TEMP1. Successively, at Step 103, the same temperature datum "t" is stored in a second temperature counter TEMP2. At Step 104, the datum stored in temperature counter TEMP1 is subtracted from the datum stored in temperature counter TEMP2 to derive a differential value T. A counter C is incremented at Step 105 each time the Step 104 is executed. The microcomputer checks if the differential value T equals a predetermined differential value ΔT at Step 106, and if not, it repeats the Steps 103 to 106 to increment the C value until T=ΔT is obtained, and goes to a Step 107. The C value thus obtained represents the time period during which the exhaust temperature has increased by an incremental temperature represented by the differential value ΔT.
The microcomputer includes a read only memory in which a set of coefficients f(C) is stored in locations addressible as a function of the count value C. The coefficient f(C) is predetermined by experiments to predict the amount of delay time to be introduced between the time of occurrence of the detector 26 output and the time at which the dryness will reach 100% level. To this end, the microcomputer 35 exits to a Step 107 when T=ΔT is obtained at Step 106 to multiply C by a coefficient f(C) to derive a delay time value DL. If the exhaust temperature curves a and b during the later stage of operation can be considered linear, the count value C may be multiplied by a constant K. The counter C is reset to zero at Step 108.
A delay time is now introduced by incrementing a delay time counter P by "1" at Step 109, which is followed by a Step 110 in which the count value P is checked against the delay time value DL. If the delay time value DL is not reached, the Steps 109 and 110 are repeated until P=DL is reached. When this occurs, the delay time counter P is reset to zero at Step 111 and the microcomputer goes to a Step 112 to remove the gating-on pulses applied to the thyristor 21 by disabling the gating control circuit 16, terminating the heat-up cycle.
A cool-down cycle now commences at Step 113 to allow the dried articles to be cooled down by cool air while the drum continues to be driven by motor 4. In this step, a counter Q is checked against a delay time value Qr which represents the time period necessary to continue the cool down cycle. A Step 114 is executed by incrementing the Q value if Q=Qr is not obtained at Step 113. Steps 113 and 114 are thus repeated until a "yes" decision is made in Step 113, whereupon the counter Q is reset to zero at Step 115 and the microcomputer removes gating-on pulses from the thyristor 23 at Step 116 by disabling the gating control circuit 17.
FIG. 5 shows another flowchart, in which Steps 200 to 204 replace the Steps 103 to 107 of the flowchart shown in FIG. 4a. From the Step 102, the microcomputer exits to Step 200 to increment the counter C by "1", followed by a Step 201 where the count value C is checked against a reference value Cr representing a unit time period during which the exhaust temperature has increased. If C is not equal to Cr, Steps 200 and 201 are repeated. When the predetermined value Cr is reached, the second temperature counter TEMP2 is loaded with the exhaust temperature value "t" at Step 202. A differential temperature value T is derived by taking the difference between the count values TEMP1 and TEMP2 at Step 203. This differential value is used in Step 204 to address a coefficient value f(T) from the read only memory as a function of T in a manner similar to that described previously and the T value is multiplied with the coefficient f(T) to obtain a delay time DL.
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In a clothes dryer, the electrical resistance of wet articles and the temperature of exhaust air are monitored. At the instant the monitored electrical resistance reaches a predetermined value, the time-varying rate of change of the monitored temperature is detected, to estimate the period of time for which the dryer operation is to be continued. At the end of the estimated time period, the heat cycle of the dryer is shut down.
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TECHNICAL FIELD
The invention relates to the leading edge of a hypersonic engine, and in particular to a heat pipe arrangement therefor.
BACKGROUND
Leading edges of structures for hypersonic flight are subject to high heat loads. They either have to be made of ablative material (sacrificial), or they need to be cooled. Most previous applications were ablative, (i.e. rocket noses, mercury, apollo), or were not conducive to small leading edge pieces as required in some new applications. Space shuttle tiles are not suitable for small nosepieces because they could not stand the heat flux generated on a small radius nose. No known material can withstand these heat fluxes if uncooled.
With a reusable air breathing vehicle there is a need for a leading edge that does not have to be replaced each flight. With air breathing engines mounted externally on these vehicles the leading edge heat flow problem is compounded. The interference shock wave caused by interference between the shock wave from the nose of the aircraft and from the leading edge of the engine inlet cowl creates extremely high leading edge heating. This creates higher heat fluxes than previously experienced. Also the leading edge of this type requires a small radius nosepiece for aerodynamic reasons.
The interference shock wave causes an extreme heating in an area over a width of about 10/1000 of an inch. Beyond this area there is a sharp drop off in heat loading to a high, but less extreme level. The localized heat flux can reach 100,000 btu's/ft 2 sec. The ability to locally remove this heat is critical to successful operation of any leading edge protection arrangement. Not only must the heat be removed rapidly from the interior surface of the leading edge, but the material thickness must be sufficiently minimized because of the temperature rise across the metal thickness at such high heat rates.
It is also important to effectively remove heat from the heat pipe in order to keep the operating temperature level within the heat pipe to an appropriate level.
SUMMARY OF THE INVENTION
A diamond shaped heat pipe containing lithium has a containment material thickness. The heat pipe has an acute angle leading wedge shape form which has sides at an included angle of 6 degrees and a radius joining the two sides of about 10 times the thickness of the containment material at this location. The containment material at the nose location may be less than in the remainder of the heat pipe because of the reduced bending stresses in a cylindrical component as compared to a flat component.
The heat pipe has an acute angle trailing wedge shape with sides also at an included angle of about 6 degrees. Outwardly extending heat exchange surface is located along the containment material of the trailing wedge shape for cooling of the heat pipe. Fuel supply for the engine passes in heat exchange relationship with this heat exchange surface. The fuel and pump are already required, and are not additional weight. The heat the fuel picks up from cooling actually enhances engine performance because of higher entry fuel temperatures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of the heat pipe as installed;
FIG. 2 is an exploded view of the heat pipe as installed;
FIG. 3 is a top partial section of the heat pipe;
FIG. 4 is a detail of the nose of the leading edge; and
FIG. 5 is a section through the coolant fuel path.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1 and 2, heat pipe 10 is of a substantially diamond shape and has a containment material 12 which contains a supply of lithium within the interior 14 of the heat pipe. This containment material is preferably an alloy of tungsten and rhenium which can withstand over 4000 F. The tungsten provides good thermal conductivity while the rhenium gives the part ductility. The alloy is optimized between conductivity and ductility and is compatible with lithium.
Internal capillary wicking 16 is provided within the heat pipe, in accordance with conventional heat pipe practice, to conduct lithium toward the leading edge 18 of the heat pipe. The lithium is vaporized at the nose by the heat being absorbed. The vapor is then condensed in the trailing section 20 which is cooled by the fuel. The liquid is then conveyed by the capillary action of the wick to the leading edge. In essence this device absorbs heat in large part from a small area of the nose and disperses it over the large area at the trailing edge.
As best seen in FIG. 3, a plurality of reinforcing ribs 22 extend substantially the full length of the heat pipe as reinforcing means for the containment surface. The front edge 24 of each plate is cut short which permits liquid and vapor equalization among the adjacent chambers.
Periodically a full length end plate 28 is located to provide isolation of the various lithium chambers.
FIG. 4 is a detail of the leading edge 26 of the heat pipe where the normal thickness 30 of containment 12 is 0.02 inches. This is reduced to a thickness 32 of 0.01 at the cylindrical portion of the leading edge 26 of the heat pipe. The radius 34 is 0.10 inches. The ratio of the radius to thickness is 10, and should preferably be between 2 and 20. It is important for aerodynamic and performance reasons that the overall width and therefore radius of this leading edge be as small as possible, preferably below 0.250 inches. The use of this radius avoids pointed projections at the leading edge which would locally increase the metal thickness, and therefore increase the maximum metal temperature. In order to successfully cool the local high temperature area right at the apex, it is necessary that the liquid be free to flow easily to this area. If the radius were too small, the local boiling would drive the liquid away precluding a uniform cooling flow. It could also interfere with the free flow of vapor from the heated area.
An exterior coating shown in phantom as coating 36 may be added to a portion or all of the exterior surface. The purpose of this coating is primarily to provide high temperature oxidation resistance and may be formed of a layer of iridium in turn coated with a high melting point oxide or material that forms a high melting point oxide. The iridium may be doped or alloyed to achieve required mechanical properties and diffusional stability. The iridium may be 0.001 to 0.005 inches thick. The oxide serves to pin the volatile oxides that will form on the iridium and also to reduce heating due to the catalytic recombination of disassociated gas species. This oxide may be aluminum oxide, beryllium oxide or stabilized hafnia. These oxides may be formed from carbide, boride or nitride precursors.
With aluminum oxide the nose of the heat pipe could withstand temperatures to 3,400 F., while with beryllium oxide it is anticipated that it could withstand temperatures up to 4,500 F. in a high velocity air environment. This coating may be very thin on the order of 0.0001 to 0.0002 inch.
The diamond shaped heat pipe 10 is formed of an acute angle leading wedge shape form 38 and an acute angle trailing wedge shape form 40. The angle 42 (FIG. 4) between side 44 of the leading wedge shape form and the centerline 46 is 3 degrees which establishes an included angle between the sides of 6 degrees.
The trailing edge wedge shape form 40 of heat pipe 10 is secured to support structure 48 by diffusion bonding or brazing. This trailing wedge shape is also at an angle 50 of three degrees with respect to the centerline for an included angle of 6 degrees. The use of an acute angle increases the support of the heat pipe by support structure 48 and also provides a more substantial heat exchange surface.
A plurality of ribs forming extending heat exchange surface 52 are located on the containment material of this wedge forming fluid flow paths 54 therebetween. The ribs 52 are in contact with the support structure so that coolant flow described later passes through these openings 54.
Thermal skin 56 is brazed to support structure 48 along the top of ribs 64. It is attached to the heat pipe at location 58, by sputter deposition of rhenium into space 60. The outside surface is machined with thermal skin 56 comprising a linear extension of side 62 of the leading wedge shape form.
The openings between the ribs 64 provide flowpath for coolant.
A fuel pump 65 establishes a flow of fuel passing to the engine which is directed into inlet 68 upstream of the heat pipe. This flow splits with a portion passing along the upper surface of the heat pipe and a portion passing along the lower surface. Flow passes through openings 54 between ribs 52 cooling the surface of the heat pipe. The flow reverses in chamber 70 and passes through space 66 between ribs 64. This provides a return flow to chamber 72 from which the flow 74 continues to the engine. Thus, a forced flow cooling is effected over the extending heating surface which has a substantial length. This provides substantial cooling for the heat pipe.
As best seen in FIG. 5, a plurality of openings 68 are located in parallel flow relationship across the heat pipe to facilitate the establishment of uniform flow across the width of the heat pipe.
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Heat pipe (10) includes an acute angle leading wedge shape form (38) with a radiused leading edge (26). Engine fuel supply (65) cools the trailing wedge shape form (40). The intense heat flux at the leading edge is cleanly dissipated and spread over substantial heat pipe cooling surface (64, 66). A coating (36) on the external surface of the leading edge wedge shape form is formed of a layer of iridium and a layer of oxide.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to labels and labeling, and more particularly to inmold labels and labeling.
[0002] In-mold labels and labeling are well known. Such labels are adhered to an article, such as a bottle, during the molding of the article. The label is placed within the cavity of a mold prior to molding, and the label adheres to the surface of the article during molding.
[0003] A typical application is in the production of blow-molded containers. A preprinted label with heat activated adhesive is placed against the inner surface of the mold cavity and held by vacuum ports in the mold. The mold is closed, and the plastic blank is heated and inflated within the mold. The hot plastic presses against the label, activating the adhesive and causing the label to be adhered to the outer surface of the newly molded container. The mold is opened and the labeled container is ejected from the mold. In-mold labels may be furnished as a stack of precut discrete labels or as a continuous web of adjacent labels joined edge to edge and subsequently cut and applied as disclosed in U.S. Pat. No. 5,344,305 to McKillip, incorporated by reference here.
[0004] Separate from in-mold labels and labeling, expanded contact labels (ECLs) are known. An ECL includes a booklet or leaflet, which includes information such as instructions, product warnings, or ingredients. The ECL is secured either directly to an article or to a base label that is in turn secured to the article. An ECL typically includes a pressure-sensitive adhesive for adhering the ECL to the article. Usually, an overlaminate is included over the booklet/leaflet to prevent inadvertent separation of the booklet/leaflet from the base label. ECLs are applied to molded articles after molding.
[0005] ECL's may be made from many materials including paper and thermoplastics. ECL's fabricated of thermoplastics are not as well suited to in-mold use as paper because of the elevated temperatures. The multiple layers of the plastic ECL are subject to different heat intensities as an article is blow molded. Specifically, the layer nearest the molded article is subjected to higher levels of heat than the layer adjacent the mold. This causes the ECL to buckle, and can even cause the layer to delaminate, rendering the label commercially and aesthetically unacceptable.
SUMMARY OF THE INVENTION
[0006] The aforementioned problems are overcome in the present invention comprising an expanded content label suitable for in-mold use. More specifically, the ECL includes a heat sensitive adhesive to enable application of the ECL in an in-mold process.
[0007] The present invention enables an ECL to be applied to an article during molding. The invention eliminates the need to apply an ECL to an article after molding. Accordingly, the manufacture of molded containers having expanded content labels is expedited with the resulting benefit of lower cost.
[0008] A second aspect of the invention is directed to a method of applying the novel expanded content label to articles during the molding of the articles. The method includes the steps of (1) placing an ECL having a heat-activated adhesive within a mold, (2) molding an article in the mold thereby activating the adhesive to adhere the ECL to the molded article, and (3) removing the labeled article from the mold.
[0009] In a third aspect of the invention, the ECL includes a protective overlaminate. The space between the base layer and the overlaminate—in which the booklet is enclosed—is substantially free of air to prevent air from expanding during the in-mold labeling process and consequently deforming or buckling the ECL.
[0010] In a fourth embodiment of the invention, the ECL includes a base label and an overlaminate that deform at different rates, so that together within the mold—where they are subjected to different temperatures—they deform at a uniform rate. For example, the base layer may be constructed from a thermoplastic that deforms due to heat at a rate faster than that at which the overlaminate material deforms. In this manner, the rates of deformation of the base layer and the overlaminate material are synchronized according to the levels of heat to which they are subjected. Accordingly, the ECL can be used in an in-mold process without unacceptable deformation of the ECL.
[0011] 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 drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a sectional view of an expanded content label of the present invention;
[0013] [0013]FIG. 2 is a top plan view of the expanded content label;
[0014] [0014]FIG. 3 is a diagrammatic perspective of the label being placed in a mold; and
[0015] [0015]FIG. 4 is a sectional view of a blow mold and a labeled article therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] A preferred embodiment of the expanded content label (ECL) of the present invention is illustrated in FIGS. 1 and 2, and generally designated 10 . The label includes a base layer or substrate 12 , a booklet 18 adjacent the base, and a protective overlaminate or cover 16 releasably adhered to either or both of the booklet and the base. Preferably, the base layer 12 , and the overlaminate 16 are constructed of paper. Alternatively, these items may be constructed of plastic or other suitable material.
[0017] The base 12 includes a linerless heat sensitive adhesive layer 14 on its undersurface. Preferably, the base 12 , and the overlaminate 16 are constructed of the same material. The adhesive layer 14 may be applied to the base 12 , in a variety of manners and patterns, as will be appreciated by those skilled in the art. The adhesive layer 14 is preferably made from adhesives that are responsive or activated by heat.
[0018] In alternative thermoplastic embodiments, the base layer 12 is constructed so that it is deformed by heat more effectively than the overlaminate 16 is deformed by heat, particularly in a blow mold process.
[0019] In the preferred embodiment, the booklet 18 , is generally rectangular and formed as a number of pages or panels of paper or plastic stacked in an overlying relationship. The booklet 18 may be also adhered to the base layer 12 with adhesive 19 , which may be opened like the pages of a book, folded open like a foldout map, or any configuration that makes viewing of the information convenient.
[0020] The overlaminate 16 overlays the booklet 18 uniformly and closely to avoid the entrapment of any substantial amount of air between the overlaminate layer 16 and the booklet 18 . The absence of air pockets prevents substantial distortion or destruction of the expanded content label during the application of heat thereto in an in-mold labeling process. For example, if there were large air pockets adjacent the booklet 18 , during the application of heat, these air pockets would expand, and potentially cause the overlaminate layer 16 , to be disengaged from the base.
[0021] The apparatus and method of applying ECLs to articles in an in-mold labeling process is generally illustrated in FIGS. 3 and 4. Generally included in the apparatus is a label supplying machine (not shown), a transfer device 14 , and a blow mold 50 . The label supplying machine may be any conventional roll or magazine supplier.
[0022] The transfer device 40 is a pick and place device including a suction cup 44 mounted at the end of a telescoping tube 46 , the opposite end of the tube 46 is mounted to a pivot 48 . As an alternative to a telescoping tube 46 , pivot 48 may be mounted to suitable machinery which moves the pivot suction cup toward and away from the molding device 50 .
[0023] As depicted in FIG. 4, the blow mold 50 includes first mold half 51 formed with a recess 52 . The recess of the first mold half 50 mates with a recess of a second mold half 53 to form a cavity in which the container or article will be molded. The surface 54 of the mold recess 52 is provided with several vacuum holes 56 . Vacuum holes 56 are disposed over the area of the recess in correspondence with the portion of the molded article to which the label will be adhered. A suitable source of vacuum is connected to the vacuum holes 56 . Pressurized gas is supplied through tube 60 .
[0024] In operation, preprinted and adhesive-coated ECLs are provided in roll, magazine, or other suitable forms (not shown) as known in the art. As shown in FIG. 3, the ECL 10 is advanced and transferred to the interior of the mold by a transfer device 40 . The transfer device 40 takes a label 10 , from suitable ECL supplying machinery (not shown), and transfers the ECL 10 to a mold 50 . The label supplying machinery (not shown), the transfer device 14 , and blow mold 50 are located in proximity to each other such that the transfer device 14 can transfer expanded content labels directly from the supplying machinery to the blow mold. Notably, any device capable of transferring the ECLs to the mold interiors may be used.
[0025] With reference to FIG. 3, when an expanded content label is advanced and provided by suitable machinery (not shown), the suction cup 44 is pivoted to a position in front of the label, the tube 46 is telescoped outwardly until the suction cup contacts the rear surface of the expanded content label, and a vacuum is delivered to 46 to suction cup such that the label is held against the suction cup. Tube 46 then withdraws such that the suction cup 44 picks the freshly cut label 36 and pivots toward the blow mold 50 .
[0026] After pivoting toward the blow mold 50 , tube 46 of the transfer device 14 is extended toward the first mold half 51 . The suction cup 44 and the label 36 carried by the suction cup enter the recess of the mold. The front surface of the label is placed against the recess surface 54 and held in position by vacuum mold 56 . The vacuum of the suction cup 44 is released and the suction cup is withdrawn from the mold half 51 .
[0027] As shown in FIG. 4, second mold half 53 is closed against the first mold half 51 , and a heated plastic blank is placed in the top opening 58 of the mold. The source of pressurized gas 60 inflates the blank, causing the blank to enlarge and line the mold cavity, thus forming the container C or other article. Heated plastic comes into contact with the expanded content label 10 , and, in particular, the heat-sensitive adhesive exposed to the interior of the mold cavity.
[0028] As depicted in FIG. 4, the surface of the ECL 10 , in particular, the base 12 , the booklet 16 , and the overlaminate are adhered to the container C without becoming integrated with the plastic of the container itself; however, as desired, the ECL itself; or any selected portions thereof, may be incorporated into the container. As a result, the ECL can be positioned so that its outermost surface, the overlaminate layer, is flush with the outer surface of the container. Alternatively as shown, the entire ECL may be substantially external to the container, thus having a raised configuration. While in the mold 50 , the heat activates the adhesive layer 14 on the rear surface of the base 12 causing the label 10 to be adhered to the container C.
[0029] As described above, because base layer 12 is in closer proximity container C, it is constructed so that it properly shrinks from the heat generated from the blow molding process that would otherwise ruin the aesthetics of the ECL, or worse, destroy the ECL by excessively shrinking or melting the base layer. Accordingly, the expanded content label may be subjected to elevated temperatures during the process of blow molding without incurring substantial deformation.
[0030] After the expanded content label has been sufficiently adhered to the blow-molded container, the mold is opened and the consequentially labeled container is ejected from the mold.
[0031] The above description is that of a preferred embodiment of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims. Further, any reference to claim elements in the singular, for example, using the articles “a,” “and,” “the,” or “said,” is not to be construed as limiting the element to the singular. The claims are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents.
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An expanded content label (ECL) having multiple layers and a heat-activated adhesive. The ECL is intended for use in an in-mold labeling process. A method for applying the ECL includes placing the ECL in a mold, molding an article within the mold thereby activating the adhesive, and removing the article with the label adhered thereto from the mold.
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REFERENCE TO CO-PENDING APPLICATION
[0001] This patent application claims priority to co-pending United States provisional application for patent filed on May 24, 2002, having serial No. 60/383,464, and titled “Surgical Instruments and Methods.”
BACKGROUND
[0002] The present disclosure relates to medical devices used in implant surgery. More specifically, the present disclosure relates to a penile prosthesis, or penile implant, adapted to receive rear tip extenders.
[0003] The study of impotence has recently become center stage in the field of medicine. In the early 1970's, the conventional view was that ninety percent of impotence cases were psychologically based, whereas only ten percent of the cases were caused by a physical condition. Today, doctors and scientists understand that the overwhelming majority of cases are caused by a physical condition. Accordingly, more and more resources are poured into the study of and treatment for impotence. In a recent study, fifty-two percent of men between the ages of forty and seventy self-reported that they suffer from some type of erectile dysfunction. Another study estimated that over thirty million American men and their partners suffer from erectile dysfunction.
[0004] Advertisements for pharmaceutical treatments for impotence have become ubiquitous, and include endorsements from celebrities that suffer from erectile dysfunction. More and more men and their partners now are seeking treatment for impotence. In the recent past, it was estimated that only one in twenty sufferers of erectile dysfunction sought treatment from their doctors. Pharmaceutical treatments are successful for only a subset of impotence sufferers. More invasive treatments are necessary for many men. These treatments include injection therapy, vacuum devices and penile prostheses.
[0005] For many impotence sufferers, the penile implant is the only solution to restore a happy and healthy sex life. The penile implant has been used for decades and provides a selected and reliable erection. The penile implant includes a pair of cylinders. In some instances, these cylinders are inflatable, and are connected to a fluid-filled reservoir with a pump and valve assembly. The two cylinders are normally implanted into the corpus cavernosae of the patient's penis and the reservoir is typically implanted into the patient's abdomen. The pump assembly is implanted in the scrotum. During use, the patient actuates the pump and fluid is transferred from the reservoir through the pump and into the cylinders. This results in the inflation of the cylinders and produces rigidity for a normal erection. Then, when the patient desires to deflate the cylinders, a valve assembly within the pump is actuated in a manner such that the fluid in the cylinders is released back into the reservoir. This deflation returns the penis to a flaccid state.
[0006] A type of inflatable penile implant includes two cylinders each having an inflation chamber side that is disposed within the penis (distal corpus cavernosae) and rear tip side that is disposed within the body (proximal corpus cavernosae.) The penile implant includes a remote pump assembly that is connected via tubing to the cylinders. Fluid is transferred from the pump assembly, through the tubing, and into the inflation chambers. The rear tip is not inflated.
[0007] The penile prosthesis is an invasive treatment and requires a delicate and painful surgery to implant. To reach the corpus cavernosae and implant the cylinders, the surgeon will first make an incision at the base of the penis, such as where it meets the scrotum. The patient is prepared for the cylinder after the surgeon has dilated each corpus cavernosum to create space for the cylinders. The distal end of the cylinder, i.e., the inflation chamber, is inserted into the corpus cavernosum. The proximal end of the cylinder, i.e., the rear tip, is inserted back into the body toward the pubic bone. To ensure a proper fit, the surgeon may choose to attach one or more rear tip extenders to the rear tip. One example of a rear tip extender is a silicone rubber cap that fits onto the rear tip or another rear tip extender that will provide the proper length of the cylinder.
[0008] A concern during implant surgery is infection around the prosthesis. One straightforward method of reducing the chances of infection is to impregnate antibiotics into the tissue-contacting surfaces of the prosthesis. One such antibiotic formulation is minocycline hydrochloride and rifampin. A second method is to coat the tissue-contacting surfaces of the prosthesis with a hydrophilic material. Prior to implantation, the surgeon will soak the prosthesis in an antimicrobial solution such as a bath including a bacterio-static product like poly vinyl pyrollidone (PVP). The hydrophilic material will hold the solution on the surface of the prosthesis. This second method, however, suffers from some disadvantages. For example, the prosthesis becomes slippery when soaked in the antimicrobial solution. The prosthesis is more slippery than one with impregnated antibiotics from the first method, and is more slippery than one without a surface treatment.
[0009] A slippery prosthesis can cause problems when used with rear tip extenders. Prostheses applying the second method use slide-on friction-fit rear tip extenders. These extenders look like hollow versions of the tapered rear tip, or hollow cones. The hollow cones slide on the end of the rear tip and stay on because of the friction created with the rear tip against the inside of the cone. Surgeons have determined that in some cases, the rear tip extender will slide off the rear tip of a prosthesis prepared with the second method. The rear tip extender then can be lost in the body.
[0010] Another difficulty of these rear tip extenders is that the shape itself can cause trauma to the patient in what otherwise is a very sensitive area. Imagine stacking a hollow cone on another cone. The stack is efficient, but there is not a smooth profile at the wide end of the hollow cone, i.e., the wide end of the rear tip extender. The discontinuity or protuberance at the end of the rear tip extender can cause trauma to the patient. This trauma is compounded if more than one rear tip extender is applied.
[0011] Accordingly, there is a need in the art for a less invasive rear tip extender that does not include an irritating discontinuity when attached to a prosthesis, and one that can be reliably attached to a slippery prosthesis after it has been soaked in a antimicrobial solution.
SUMMARY
[0012] The present disclosure is directed to an improved rear tip and rear tip extender where the rear tip securely attaches to a rear tip extender, even when slippery, and can avoid creating an irritating discontinuity in the profile.
[0013] In a first aspect, the disclosure is directed to a penile implant having a cylinder with a rear tip. The rear tip includes a section having a generally smooth profile and a section having a connector end. A rear tip extender is adapted to fit over the section having the connector end. The rear tip extender includes a base, wherein the base fits over the rear tip at an interface. The rear tip is adapted to receive the rear tip extender with a ring in groove attachment. The base is aligned with the generally smooth profile of the rear tip without a protuberance at the interface.
[0014] In a second aspect, the disclosure is directed to a penile implant including a cylinder having a rear tip. The cylinder includes a hydrophilic coating adapted to receive an antimicrobial solution. A rear tip extender is adapted to fit over the rear tip, and the rear tip and rear tip extender are connected together with a ring in groove attachment.
BRIEF DESCRIPTION OF THE FIGURES
[0015] [0015]FIG. 1 is a schematic side view of a penile prosthesis implanted in a patient.
[0016] [0016]FIG. 2 is a perspective view of the penile prosthesis of FIG. 1.
[0017] [0017]FIG. 3 is a side sectioned view of a portion of the penile implant of FIG. 2.
[0018] [0018]FIG. 4 is an enlarged side sectioned view of the portion of the penile implant of FIG. 3.
DESCRIPTION
[0019] This disclosure relates to penile prostheses or penile implants adapted to accept a rear tip extender. The disclosure, including the figures, describes the penile implants and rear tip extenders with reference to a several illustrative examples. Other examples are contemplated and are mentioned below or are otherwise imaginable to someone skilled in the art. The scope of the invention is not limited to the few examples, i.e., the described embodiments of the invention. Rather, the scope of the invention is defined by reference to the appended claims. Changes can be made to the examples, including alternative designs not disclosed, and still be within the scope of the claims.
[0020] [0020]FIG. 1 is a schematic side view of a penile prosthesis 10 implanted in a patient. The prosthesis 10 includes a pair of cylinders, of which only one cylinder 12 is shown, implanted in a penis 14 . The prosthesis can also include a pump 16 , often implanted into the patient's scrotum 18 . The tubing 20 attaches the pump 16 to the cylinder such that the pump 16 is in fluid communication with the cylinder 12 . In still an alternative example, the pump 16 can be in fluid communication with a fluid reservoir (not shown) that is often implanted into the patient's abdomen. The prosthesis including a pair of cylinders, pump, and fluid reservoir is referred to as a three-piece device. In the present example, the prosthesis 10 includes cylinders 12 and a pump 16 and is known as a two-piece device. Still, in some examples, the pump and fluid reservoir are included within the cylinders. These are known as single piece devices. Some devices do not include a pump and a fluid reservoir. In these devices the cylinders do not inflate and are malleable. The disclosure predominantly describes a two-piece device, but one skilled in the art can easily recognize the applicability of this disclosure to other penile implants.
[0021] The cylinder 12 includes an inflation chamber 22 that is disposed within the penis 14 . The distal end 24 of the cylinder 12 is disposed within the crown 26 portion of the penis 14 . The cylinder also includes a proximal end 28 that often includes the tubing junction 30 , i.e., the structural portion of the cylinder 12 connected to the tubing 20 , and the rear tip 32 of the cylinder 12 . The proximal end 28 is typically implanted into the patient's pubic region 34 with the rear tip 32 having a rear tip extender 39 proximate the pubic bone 36 .
[0022] The prosthesis 10 is shown by itself in FIG. 2. The prosthesis includes a pair of cylinders 12 connected by tubing 20 to a pump 16 . Like parts of each cylinder are given the same reference number. Accordingly, the prosthesis 10 is a two-piece device. The prosthesis includes two cylinders 12 , one for each side of the penis. Each cylinder includes a distal end 24 having a distal tip 37 , an inflation chamber 22 and a proximal end 28 including a tubing junction 30 , a rear tip 32 and a rear tip extender 39 . The rear tip extender is an interchangeable piece that fits on the rear tip 32 and provides the appropriate length of the cylinder depending on the anatomy of the patient. The pump 16 serves to inflate both cylinders 12 . In the case of a three-piece device, typically one fluid reservoir is connected in fluid communication with the pump.
[0023] In order to implant the cylinders 12 , the surgeon first prepares the patient. The surgeon often makes an incision in the penoscrotal region 38 , i.e., where the base of the penis 14 meets with the top of the scrotum 18 . From the penoscrotal incision, the surgeon will dilate the patient's corpus cavernosum 40 (the distal corpus cavernosae) to prepare the patient to receive the cylinders 12 . The corpus cavernosum is one of two parallel columns of erectile tissue forming the dorsal part of the body of the penis 14 , i.e., two slender columns that extend substantially the length of the penis. The surgeon will also dilate two regions of the pubic area (the proximal corpus cavernosae) to prepare the patient to receive the proximal ends 28 . The surgeon will measure the length of the corpus cavernosum from the incision and the dilated region of the pubic area to determine an appropriate length of the cylinders 12 and rear tip extenders 39 to implant.
[0024] After the patient is prepared, the prosthesis 10 is implanted into the patient. The distal tip 37 of each cylinder often is attached to a suture. The other end of the suture is often then attached to a Keith needle. The Keith needle is inserted into the incision and into the dilated corpus cavernosum. The Keith needle is then advanced through the crown of the penis. The surgeon tugs on the suture to pull the cylinder into the corpus cavernosum. This is done for each cylinder. Once the inflation chamber 22 is in place, the surgeon removes the suture from the distal end 37 . The surgeon then inserts the proximal end 28 . The surgeon inserts the rear tips 32 , with rear tip extenders if needed, into the incision and forces the proximal ends 28 toward the pubic bone 36 until the cylinders are in place.
[0025] [0025]FIG. 3 shows a side sectioned view of one of the cylinders 12 and includes distal end 24 and proximal end 28 . The cylinder 12 includes an axis 42 . The distal end 24 forms part of the inflation chamber 22 . The distal end 24 is generally solid but can include a hole 44 that is adapted to receive the suture described above. In the example, the distal end 24 is constructed from a silicone rubber or silicone elastomer. The inflation chamber 22 in the example includes a multilayer tube. The example includes three layers and an outer coating. The innermost layer is an extruded silicone elastomer, the middle layer is a distensible fabric such as a polyester and spandex blend, and the outer layer is also an extruded silicone. The outer coating in the example is parylene. Parylene coating is a medical grade polymer intended to reduce friction-based wear occurrences. Parylene can be applied to other layers as is known in the art.
[0026] In addition, the prothesis can be coated with a hydrophilic material as is known in the art. One such material is described in U.S. Pat. No. 5,295,978 titled “Biocompatible Hydrophilic Complexes and Process for Preparation and Use” and assigned to the Union Carbide Chemicals and Plastics Technology Corporation of Danbury, Conn. In short, the hydrophilic complexes are comprised of a carboxylic acid polymer with either a poly(lower-alkylene oxide) or a poly(N-vinyl lactam). A complex of an antimicrobial agent such as iodine can be formed with the hydrophilic complex to provide antimicrobial activity. The hydrophilic complex is particularly suitable for forming biomedical coatings on the prosthesis. The hydrophilic complex also has the property of rendering the surface of the prosthesis lubricious (slippery) when exposed to aqueous solutions, such as the antimicrobial solution and body fluids.
[0027] The proximal end 28 includes the rear tip 32 and the tubing junction 30 . In the example, the rear tip 32 is solid and formed from a silicone rubber or silicone elastomer. The rear tip can also include barium sulfate, so that it can be easily visible in an X-Ray of the region. The barium sulfate can also be added to other parts of the prosthesis including the rear tip extender 39 for the same purpose. Alternatively, other radio-opaque markers, such as aluminum oxide or iridium, can be used. The rear tip 32 is adapted to receive the rear tip extender 39 . The rear tip 32 and rear tip extender 39 are described in more detail with reference to FIGS. 3 and 4.
[0028] [0028]FIG. 4 is an enlarged view of FIG. 3 showing a portion of the proximal end 28 and the rear tip extender 39 . The rear tip extender 39 includes a generally solid tip portion 50 and a hollow skirt 52 . The skirt 52 fits over the rear tip 32 .
[0029] The tip portion 50 is abutted against the rear tip 32 . In these examples, the tip portion 50 provides the extra length. A typical rear tip extender 39 can add between 0.5 centimeters to several centimeters in length to the cylinder. The skirt 52 includes a wall 56 having a thickness. The rear tip extender 39 of the example includes a ring 58 that protrudes from the inner surface 59 of the skirt wall 56 proximate the base 60 of the skirt.
[0030] The rear tip 32 in the example includes a first section 62 having a generally smooth profile and a second section having a connector end 64 . The connector end 64 is adapted to fit within the rear tip extender 39 , and the smooth profile first section 62 is adapted to fit against the patient. The diameter of the connector end 64 is smaller than the diameter of the proximate first section 62 . The difference in diameter between the proximate first section and the connector end is approximately the thickness of the wall 56 at the base 60 of the skirt of the rear tip extender. Preferably, the difference is about the same or greater than the thickness of the wall 56 of the rear tip extender 39 . The connector end 64 in the example includes a groove 66 . The groove 66 mates with the ring 58 to securely attach the rear tip extender 39 onto the rear tip 32 .
[0031] The rear tip is attached to the rear tip extender with a “ring in groove” attachment. In the example shown, the rear tip 32 includes a full groove 66 and is adapted to fit a full ring 58 on the rear tip extender 39 . Variations of this are contemplated. For example the rear tip could include the ring and the rear tip extender could include the groove. The ring or groove on either example need not be full, or all the way around the perimeter, but could only be partially around the perimeter, or selectively around the perimeter. Also, the ring and groove could be replaced with at least one indent mating with at least one detent. For the purposes of this disclosure, attachments using indents and detents are a form of ring in groove attachment.
[0032] The first section 62 having the generally smooth profile meets the base 60 of the rear tip extender at an interface 68 . The rear tip extender is aligned with the generally smooth profile of the first section 62 . In one example, the base 60 is immediately proximate, or in contact with the first section 62 . In the example shown, however, the base 60 is spaced-apart from the first section 62 . The rear tip 32 includes an angled transition section 70 used to space apart the base 60 from the first section 62 . A small indent exists in the profile at the transition section 70 .
[0033] The transition section 70 is provided in the example to reduce wear between the skirt 52 and the first section 62 of the rear tip. When disposed inside the body, the proximal end 28 is not axial as shown in FIG. 3, but more curved or bent as indicated in FIG. 1. Accordingly, one side of the skirt 52 is closer to the first section 62 than the opposite side of the skirt 52 . The transition section 70 is provided to account for this configuration. In examples of the related art, the transition section was angled upward at a maximum of 45 degrees from the connector end to the first section. In cases where the rear tip extender was of a slide on type, the “transition section” starts at the interface and ends at the point where the diameter of the rear tip is the same as the diameter of the base of the skirt. The angle in the slide-on example is substantially less than 45 degrees. The angle is measured from the connector end to the first section relative to the axis.
[0034] Angles of 45 degrees or less cause substantial discontinuities in the profile of the proximal end 28 when a rear tip extender 39 is attached. These discontinuities are considered in this disclosure to be protuberances. The protuberance can cause irritation to the surrounding tissues of the body during surgery or after implant.
[0035] The wear created between the rear tip 32 and the rear tip extender 39 is not as large an issue as previously believed. The transition section 70 in the examples is angled at greater than about 45 degrees, and preferably about 60 degrees to reduce the space of the indent in the transition section 70 . The transition section 70 having an angle of greater than 45 degrees creates a substantially smooth profile when the diameters of the first section 62 and the base 60 of the skirt are substantially the same. In this configuration, the transition section 70 does not include a length to create an indent that would substantially irritate the surrounding tissue.
[0036] In this example, the transition section 70 is not substantial in length and thus continues the generally smooth profile of the first section 62 . In addition, the interface provides only an indent in the profile. For the purposes of this disclosure an indent at the transition section 70 still continues the generally smooth profile of the rear tip. The rear tip does not provide a protuberance to the generally smooth profile. In other words, the rear tip extender is not wider in diameter than the first section by at least the thickness of the wall at the interface. In the example shown, the wide end of the rear tip extender is not larger in diameter than the smallest diameter of the first section.
[0037] The present invention has now been described with reference to several embodiments. The foregoing detailed description and examples have been given for clarity of understanding only. Those skilled in the art will recognize that many changes can be made in the described embodiments without departing from the scope and spirit of the invention. Thus, the scope of the present invention should not be limited to the exact details and structures described herein, but rather by the appended claims and equivalents.
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The present disclosure is directed to an improved rear tip and rear tip extender where the rear tip securely attaches to a rear tip extender, even when slippery, and can avoid creating an irritating discontinuity in the profile. In a first aspect, the disclosure is directed to a penile implant having a cylinder with a rear tip. The rear tip includes a section having a generally smooth profile and a section having a connector end. A rear tip extender is adapted to fit over the section having the connector end. The rear tip extender includes a base, wherein the base fits over the rear tip at an interface. The rear tip is adapted to receive the rear tip extender with a ring in groove attachment. The base is aligned with the generally smooth profile of the rear tip without a protuberance at the interface. In a second aspect, the disclosure is directed to a penile implant including a cylinder having a rear tip. The cylinder includes a hydrophilic coating adapted to receive an antimicrobial solution. A rear tip extender is adapted to fit over the rear tip, and the rear tip and rear tip extender are connected together with a ring in groove attachment.
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BACKGROUND
[0001] 1. Field of the Invention
[0002] The invention relates to a tool with which rotationally symmetrical and in particular cylindrical apertures can be made in a workpiece in a machining production method, in short a drilling tool.
[0003] 2. Background Information
[0004] Conventional drilling tools can be of both one-part and multi-part design. Multi-part drilling tools which are composed of a support shank and a cutting insert interchangeably fitted to the support shank, that is to say of two main components, are especially common. The multi-part drilling tools offer the advantage, inter alia, that, in the event of wear or damage, the complete drilling tool does not have to be exchanged, but rather only the components affected. The invention explained herein is based on this type of multi-part drilling tool.
[0005] A high machining quality is desired in particular during the finish machining of workpieces. In the case of a drilling tool, good concentric running properties are a prerequisite for a correspondingly high machining accuracy.
[0006] A very advantageous drilling tool embodiment in this respect is disclosed in DE 10 2006 025 294 A1 originating from the applicant. Said document discloses a one-part drilling tool having a drill region or drilling head, in which drilling tool the elements in the drill region or on the drilling head, which guide the drilling tool on an inner wall of the drill hole, are configured asymmetrically with respect to the rotation thereof about the center longitudinal axis. With this asymmetry, disadvantageous vibration resonances (i.e., “chatter”) can be avoided.
[0007] A further, hitherto unpublished patent application having the DPMA reference DE 2009 012 725 and originating from the applicant relates to a drilling tool composed of a tool shank and a cutting insert which can be fixed thereto. In such a two-part drilling tool, the cutting insert has the function of the tool head of a one-part drilling tool and accordingly carries the cutting and the guiding elements of the two-part drilling tool. The basic principle of the asymmetrical configuration of the drilling head has been adapted to the modular construction of a two-part drilling tool.
SUMMARY OF THE INVENTION
[0008] The present invention improves upon known drills by providing a multi-part drilling tool with further-improved concentric running properties.
[0009] Such improvement is achieved in an inventive manner by the combination of features in claim 1 . The dependent claims contain partly advantageous developments of this invention and partly developments of this invention that are inventive on their own.
[0010] In a drilling tool produced according to the teaching of this invention, an interchangeable cutting insert is fitted to a support shank. Both main components, which are to be offered separately for the end user market, can be produced both from one piece and from a plurality of parts. The cutting insert has an asymmetrical main lip which is split in two into a guide lip and into a clearance lip. The guide lip is provided with a supporting land and with a guide land trailing the supporting land. The clearance lip leads a clearance portion. A guide land and a supporting land are likewise provided in a complementary manner on the lateral surface of the support shank. The guide land and supporting land extend the respective guide land and the respective supporting land on the cutting insert continuously and therefore—within the limits of the production tolerances—seamlessly. As a result of the lands which go beyond the cutting insert into the support shank, the drilling tool, during the drilling operation, is guided on the inner wall of the drill hole not only in the region of the cutting insert but also in the region of the support shank, as a result of which the concentric running properties of the drilling tool are further improved. Both the supporting lands, which go from the cutting insert into the support shank and are assigned to the lips, and the guide land act as guide elements in the region of the support shank. The effect of the lands in the region of the support shank is comparable with the effect of guide elements on rotating tools of a different kind.
[0011] According to a preferred embodiment, the guide land and the supporting land define a secondary flank lying in between. In this way, it is possible to vary the peripheral effective region of the guide land relative to the position of the two parts of the main lip and thus relative to the position of the two lip corners defining the partial lips independently of the characteristic width of the lands, that is to say to displace the effective region on a circumferential circle of a drilling tool cross section. The drilling tool can thus be balanced in an especially simple manner with respect to its rotational movement.
[0012] In addition, in this connection, the characteristic widths of the guide land and of the supporting land can expediently be established independently of one another, for the characteristic width of the supporting land depends substantially on the loading, to be expected, of the lip to be supported, whereas the characteristic width of the guide land is intended to optimize the concentric running properties.
[0013] In addition, an embodiment is advantageous in which, in addition to the guide land, the supporting land and the two lip corners guide the drilling tool on the inner wall of the drill hole during the drilling operation. In this case, these guiding elements are preferably arranged on a virtual circumferential circle on the drilling tool in such a way that the smallest circle circumference segment connecting all the elements defines an angle greater than 180°. Thus, the drilling tool, despite an asymmetrical configuration, can be guided to the greatest possible extent free of play and in a radially centered manner in the drill hole. In addition, secondary lips can be provided, which secondary lips adjoin the lip corners in the axial direction and likewise help to guide the drilling tool. Furthermore, it is conceivable to provide lands having an additional guiding and supporting effect, for example next to a secondary lip adjoining the clearance lip.
[0014] Since drilling tools according to the invention are mainly produced as drilling tool inserts for machines, a clamping region is normally provided on the support shank, the clamping region being clamped in a chuck for connecting the drilling tool to a machine. In many cases, this clamping region corresponds to the unmachined region of the cylindrical drilling tool blank and accordingly has a uniform diameter. The machined or fluted region of the support shank interacts with the cutting insert as an actual tool and can be varied in its radial extent along the center longitudinal axis in accordance with the application.
[0015] An embodiment is preferred in which the support shank in the fluted region which directly adjoins the cutting insert has a constant diameter and then tapers in the direction of the clamping region, a reduction in the nominal diameter of 1% to 2% being considered to be perfectly suitable. That fluted region of constant diameter, which directly adjoins the cutting insert, supports, with the guiding elements thereof, the guiding elements on the cutting insert. The axial extent of this supporting region can be adapted, for example, to the intended drill hole depths which are to be produced with a drilling tool. In this case, it is necessary to take into account the fact that, on the one hand, as exact a guidance of the drilling tool as possible is to be ensured, on which guidance an increasing extent of the supporting region has an advantageous effect, and that, on the other hand, a low degree of material-abrading friction, which increases with increasing extent of the supporting region, is desired between the guide elements and the inner wall of the drill hole. In this connection, it has proved to be very expedient to restrict the supporting region to up to 50% with respect to the axial length of the fluted region.
[0016] In addition, it is advantageous if the flutes are incorporated helically into the drilling tool. In this case, the focus is on an efficient chip disposal. Therefore, depending on the material to be cut, it may be helpful to design the helix angle of the flutes to be variable in the axial direction.
[0017] According to a preferred embodiment, however, the chip forming is substantially effected in two chip spaces at the cutting insert. These chip spaces contain chip-forming surfaces and are an integral part of the cutting insert. Assigned to both parts of the main lip is a respective chip space which leads this main lip part and which is, in turn, extended continuously by a flute on the support shank.
[0018] On account of the asymmetrical form of the cutting insert, the two chip spaces likewise have geometries differing from one another. In order to promote the chip disposal, the respective geometry of each chip space is preferably continued and continuously extended by the corresponding flute on the support shank.
[0019] As already mentioned at the beginning, the main components, that is to say the support shank and the cutting insert in the two-part drilling tool, can in turn be produced from a plurality of parts. This may be advantageous, for example, when the cutting and/or the guiding elements are to be produced from a special material, since the complete main component does not then have to be produced from this usually higher-grade material. In addition, it is thereby also possible to use various materials for the cutting and for the guiding elements and thus combine them in accordance with the specific applications. For example, a drilling tool made completely of high-speed steel can thereby be used in adaptation to a specific intended use, or the cutting and/or guiding elements can each be produced from a special material, such as, for example, high-speed steel, ceramic or cermet, and can be fixed to a drilling tool parent body produced from a simple tool steel. The type of fixing, for example adhesively bonding in place or brazing in place, is in this case adapted to the materials used.
[0020] In addition to the use of different materials for the individual tool parts, various subsequent treatments for improving the tool properties are also suitable. In this connection, the possibility of specifically subsequently treating or refining individual regions or functional elements should especially be emphasized. For example, it is advantageous for the chip disposal to smooth the surfaces of the flutes by grinding and polishing. A similar production process step for the guide elements is likewise appropriate. In this case, improved sliding ability is thus achieved, which in turn results in a lower degree of friction. Finally, it is also possible to harden or coat the drilling tool or else individual regions or functional elements. A coating can in this case both replace and supplement separate production of the cutting and/or guiding elements from a special material differing from the material of the drilling tool parent body. Accordingly, materials such as high-speed steel, ceramic or cermet are also suitable for coating.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] A full understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:
[0022] FIG. 1 shows a drilling tool according to an embodiment of the invention in a perspective view;
[0023] FIG. 2 shows a drilling tool according to an embodiment of the invention in a side view;
[0024] FIG. 3 shows a drilling tool according to an embodiment of the invention in a plan view;
[0025] FIG. 4 shows a cutting insert according to an embodiment of the invention in a side view;
[0026] FIG. 5 shows a cutting insert according to an embodiment of the invention in a perspective view; and
[0027] FIG. 6 shows a cutting insert according to an embodiment of the invention in a plan view.
[0028] Parts corresponding to one another are provided with the same designations in all the figures.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] A drilling tool 1 according to an embodiment of the invention is shown in a perspective view in FIG. 1 , in a side view in FIG. 2 and in a plan view in FIG. 3 . The drilling tool 1 is composed of a support shank 2 and of a cutting insert 3 fitted to the support shank 2 . In the axial direction 4 , the support shank 2 has essentially two different functional regions—a cylindrical clamping region 5 of constant diameter, which is clamped in a chuck (not depicted) for connecting the drilling tool 1 to a machine, and a fluted region 6 which has a maximum radial extent varying in the axial direction 4 and which functions together with the cutting insert 3 as an actual cutting tool.
[0030] Arranged on the end of the fluted region 6 which is remote from the clamping region 5 is the cutting insert 3 , which can be seen separately from various perspectives in FIG. 4 to FIG. 6 . In simple terms, the cutting insert 3 is fixed to the support shank 2 by inserting a fastening pin 7 , integrally formed on the cutting insert 3 , into a central recess (not shown) in the end face of the support shank 2 and by pressing two peripherally arranged lobes 8 on the cutting insert 3 into correspondingly formed receptacles 9 on the support shank 2 on the basis of a rotation of the cutting insert 3 relative to the support shank 2 . The details of this fastening can be seen from patent document EP 1 476 269 B1, which comes from the applicant, the disclosure of which is incorporated by reference herein.
[0031] The configuration of the cutting insert 3 , in particular the cutting edge geometry, is likewise based on inventions of the applicant. These inventions are described in DE 10 2006 025 294 A1 and in DE 2009 012 725 already mentioned and not yet published, the contents of which are also incorporated by reference herein.
[0032] Accordingly, the cutting insert 3 has an asymmetrical main lip 15 split in two into a guide lip 10 having a supporting land 12 and a guide land 23 trailing the supporting land 12 and into a clearance lip 13 having a trailing clearance portion 14 . It should be noted here that, depending on the point of view, it is also possible to refer to two main lips A, B connected to one another by a chisel edge 16 , instead of a two-part main lip 15 . Both alternatives are common in the corresponding technical literature.
[0033] In the case of the exemplary embodiment, the asymmetry of the main lip 15 is produced by one part of the main lip 15 being swung by an angle α ( FIG. 5 ), which is about 13° here, relative to its symmetrical position. This symmetrical position corresponds in this case to a position relative to the other part of the main lip at which an imaginary 180° rotation of the one part of the main lip about the center longitudinal axis 17 of the drilling tool 1 leads to a congruent superimposition with the other part of the main lip. However, the shapes of the end cutting edges of the two main lip parts show no relevant differences and are each substantially characterized by adjoining machined point thinning 18 .
[0034] The asymmetrical design of the cutting insert 3 is continued consistently by the further cutting and guiding elements provided. Secondary lips 21 adjoin the lip corners 20 in the axial direction 4 , the lip corners 20 peripherally defining the two parts of the main lip 15 , in each case in the radial direction 19 . A respective supporting land 12 , 22 is assigned to both secondary lips 21 . A guide land 23 is integrally formed peripherally on the lobe 8 , which is connected to the guide lip 10 via a main flank 24 . This guide land 23 has a significantly larger characteristic width than the two supporting lands 12 , 22 . All the other peripheral or secondary flanks 25 of the cutting insert 3 without a cutting or guiding effect are reduced in the radial extent thereof relative to the secondary lips 21 or the lands 12 , 22 , 23 on the cutting insert 3 . In this way, the risk of canting or seizing of the drilling tool 1 is kept low.
[0035] Three guiding lands are likewise provided on the support shank 2 . These are the guide land 28 and the two supporting lands 27 , 29 . These lands complement the corresponding lands 12 , 22 , 23 on the cutting insert 3 and form a continuous development. In interplay, the guide lands 23 , 28 and the supporting lands 12 , 22 , 27 , 29 of cutting insert 3 and support shank 2 thus guide the drilling tool 1 on the inner wall of the drill hole during the drilling operation. In analogy to the cutting insert 3 , secondary flanks 30 having a reduced radial extent are provided between the lands 27 , 28 , 29 of the support shank 2 . The region of the support shank 2 which actively guides the drilling tool 1 corresponds, in the exemplary embodiment, approximately to the first third, adjoining the cutting insert 3 , of the fluted region 6 . In that third, the support shank 2 has a constant radial extent. After that, the support shank 2 tapers in the axial direction 4 . Outside the guiding region of the support shank 2 , the guide land 28 and the supporting lands 27 , 29 have no technical function, and so the geometry thereof may be varied there, for example, for the benefit of a simplified production process.
[0036] Furthermore, the shaping of two chip spaces 31 is essential for the asymmetrical configuration of the cutting insert 3 . One chip space 31 each is incorporated into the cutting insert 3 in such a way as to lead one part each of the main lip 15 . The chips are formed in the chip spaces 31 during the drilling operation. The walls of the chip spaces 31 thus form chip-forming surfaces. To ensure as effective a chip disposal as possible, the flutes 32 formed in the support shank 2 are adapted in their configuration to the chip spaces 31 . In this way, the flutes 32 also extend the chip spaces 31 in the axial direction 4 continuously and—apart from production tolerances—seamlessly. The asymmetrical design of the chip spaces 31 and accordingly of the flutes 32 originates in turn from the asymmetry of the main lip 15 and from the angle α resulting therefrom, which in the exemplary embodiment is about 13°. The corresponding swing of the main lip 15 by the angle α is compensated for on the support tool by the flutes being correspondingly adjusted continuously by the magnitude of the angle α. Outlet openings 33 of cooling passages open into the flutes 32 on the support shank 2 . These cooling passages serve to introduce a cooling lubricant into the drill hole during the cutting process. This configuration of the cooling passages with the outlet openings 33 thereof opening out into the flutes 32 is the subject matter of the applicant's European Patent Application EP 16 48 642 B1, the contents of which are incorporated by reference herein.
[0037] In summary, the invention enables any desired asymmetrical configuration of the cutting insert 3 to be combined with a correspondingly adapted support shank 2 , the support shank in this case being provided with guide elements which also control and thereby improve the concentric running behavior of the drilling tool.
[0038] While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to the details provided herein could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the claims appended and any and all equivalents thereof.
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The invention relates to a drilling tool ( 1 ) comprising a support shank ( 2 ) and an interchangeable cutting insert ( 3 ) which is fitted to the support shank ( 2 ) and which has an asymmetrical main lip ( 15 ) divided into a guide lip ( 10 ) having a supporting land ( 12 ) and a guide land ( 23 ) trailing the supporting land ( 12 ), and into a clearance lip ( 13 ) having a trailing clearance portion ( 14 ), wherein a guide land ( 28 ) and a supporting land ( 29 ) are formed on the lateral surface of the support shank ( 2 ) and continuously extend the guide land ( 23 ) and the supporting land ( 12 ), respectively, on the cutting insert ( 3 ) and additionally guide the drilling tool ( 1 ) on the inner wall of a drill hole during a drilling operation.
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BACKGROUND OF THE INVENTION
This is a continuation-in-part of application Ser. No. 07/537,666 filed on Jun. 1, 1990, and now abandoned.
The present invention relates to an enclosed structure. More particularly, it relates to a structure providing for the guttering of internally generated condensation fluids in greenhouses and for extending the life of the roof covering sheet material.
Many different structures have been proposed, such as are described in U.S. Pat. Nos. 2,910,994; 3,765,134; 3,911,632; 3,925,942; 4,117,636; 4,173,101 and 4,313,279; British Patent Nos. 1,416,993; 1,447,043; 1,498,945; French Patent No. 1,479,336 and many others. Most of these structures are intended for use as greenhouses, while some are intended as storage sheds or swimming pools (U.S. Pat. No. 2,996,729). The provision of guttering for the drainage of rain has been given attention. However, in certain types of greenhouses and in structures used for storage, fluids condensing on the internal side of the roof sheeting should not be allowed to drip onto the supporting structure between roof spans, as this results in undesirably high humidity which induces corrosion of such supports and facilitates the spread of plant diseases in greenhouses. Furthermore, the dripping of fluids onto persons passing along the inner sides of such enclosures is highly aggravating and should be avoided. Surprisingly, almost no attention has been given to this problem in the prior art, possibly because of the difficulty of providing such drainage without thereby allowing the escape of substantial quantities of warm air.
It is therefore one of the objects of the present invention to obviate the disadvantages of the prior art enclosed structures and to provide a structure which allows for the collection of condensation fluids in the same guttering means provided for rain drainage.
A further object is to provide a structure having an easily assembled and retensionable roof cover.
Yet a further object is to provide such a structure allowing for the secure anchorage of the roof cover, thereby extending the life of the roof cover sheeting material beyond a single season.
A last object is to provide such a structure provided with a ventilation aperture which may be conveniently opened or closed and yet retain the advantage of condensation fluid drainage.
BRIEF DESCRIPTION OF THE INVENTION
This the present invention achieves by providing a plastic-covered, gutter-connected sheltering horticultural structure, essentially constructed of a framework and flexible cover sheet material, comprising at least two frames located side by side as a double or multi-span protective structure, each frame defining a span and including roof members and attached longitudinal side frame members of adjacent spans, gutter means associated with said side frame members and interconnecting side by side frames, said gutter means being constituted by a bottom wall and two side walls forming a channel delimiting a space therebetween, and flexible covering sheet material covering a roof span, said structure further comprising means for the guttering of internally-generated condensation fluids, characterized in that the longitudinal edges of said sheet material are respectively affixed to anchor means, said anchor means extending along an inner surface of said gutter means and being affixed thereto to maintain said flexible covering means in a tensioned state, the line of first contact between said flexible covering means and said anchor means being located in said delimited space or thereabove, whereby said condensation fluids dripping from the underside of said flexible covering means are drained by said gutter means.
In preferred embodiments of the present invention, said anchor means are located in said delimited space or thereabove, whereby said condensation fluids from the underside of said flexible covering means pass along the surfaces of said anchor means and drip therefrom onto said inner surface of said gutter means.
In U.S. Pat. No. 4,173,101 there is described and claimed a greenhouse gutter assembly including an extruded channel member having a horizontal drainage bottom and upper side members projecting upwardly therefrom. A flange extends across the upper end of the channel member and includes an inwardly projecting leg which serves to support the plastic roof material and a pair of diverging legs which are accommodated within a slot carried within a bracket which has a portion for extending inwardly of the tubular bow member as a support thereof. While said assembly bears resemblance to the assembly of the present invention, it can be realized and seen that the inner surface of the plastic roof material spread between the spaced bow members comes in contact with the projecting legs of the flange and thus condensation fluids will accumulate at this contact line and drip into the greenhouse, as opposed to dripping into the gutter as provided for by the present invention.
The invention also provides for a strong gutter channel as well as convenient means to tension, retension and replace the roof sheeting material as required.
In a further preferred embodiment of the present invention there is provided an arrangement for the opening and closing of a ventilation aperture along at least part of the length of the roof and for the retraction and rolled storage of a lower part of the roof sheeting without necessitating its removal from the structure. More particularly, in this embodiment there is provided a plastic-covered, gutter-connected ventilated horticultural structure, essentially constructed of a framework, fixed upper flexible cover sheet material and rollable retractable lower flexible sheet material, and including roof members, upper and lower gutter means associated with said roof members, said upper gutter means comprising two side walls delimiting a space therebetween, said fixed upper flexible cover sheet material covering a roof span, said structure further comprising means for the guttering of internally-generated condensation fluids, characterised in that the longitudinal edges of said sheet materials are respectively affixed to upper and lower anchor means, said upper anchor means extending along an inner surface of said upper gutter means and being affixed thereto to maintain said flexible covering means in a tensioned state, the line of first contact between said flexible covering means and said anchor means being located in said delimited space or thereabove, whereby said condensation fluids dripping from the underside of said flexible covering means are received by said upper gutter means and subsequently by said lower gutter means, and whereby said rollable retractable lower flexible sheet material serves for the opening and closing of a ventilation aperture along at least part of the length of the structure.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in connection with certain preferred embodiments, with reference to the following illustrative figures so that it may be more fully understood.
With specific reference now to the figures in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
In the drawings:
FIG. 1 is a general perspective view without details, of a structure according to the invention;
FIG. 2 is a perspective view of the preferred embodiment of the guttering means and roof sheeting attachments;
FIG. 3 is a fragmented end view showing further details of the embodiment of FIG. 2;
FIG. 3a is an end view of an additional embodiment of that shown in FIG. 3;
FIG. 4 is a perspective view of the clamping member shown in FIG. 3;
FIG. 5 is a perspective view of a tool useful for the insertion of the anchor means and for tensioning of the roof sheeting;
FIG. 6a shows a tool useful for removal from the structure of an anchor means;
FIG. 6b is a perspective view of the jaws of this tool;
FIGS. 7, 8 and 9 are end views of three further embodiments of the anchor means;
FIG. 10 is an end view of an additional embodiment provided with upper gutter means and a ventilation aperture;
FIG. 11 is a perspective view of a tool useful for rolling-up the lower sheet material shown in FIG. 10;
FIG. 12 is a second embodiment of the upper gutter means shown in FIG. 10; and
FIG. 13 is a cross-section taken at AA of FIG. 12.
DESCRIPTION OF THE PREFERRED EMBODIMENT
There is seen in FIG. 1 a general view of a sheltering horticultural structure supported on a framework 10. A plurality of roof members 12 form roof spans 14 of arches or pitted shape, the roof members 12 being stabilized by tie rods 16. Side-by-side roof spans are connected and supported by gutter means 18. End walls, pillar foundations, the methods of attaching the roof members 12 to the gutter means 18 and various strengthening strusses are omitted or not detailed, these being known in the prior art and not forming part of the present invention.
Roof spans 14 are formed as a flexible cover sheet material 20 which is tensioned over the roof members 12 by means which will be described. The sheet material 20 is made of a transparent, flexible plastic film preferably with an UV stabilizer added to ensure that the film is usable for at least one growing season. Suitable materials include engineering plastics such as polyethylene, polyester, polypropylene and polycarbonate.
Referring now to FIGS. 2 and 3, gutter means 18 have the general form in cross-section of a flat-bottomed vee, constituted by a bottom wall 15 and two side walls 17 forming a channel delimiting a space 19 therebetween. The side walls 17 preferably include several secondary bends 27 providing additional rigidity and enabling it to carry its loads without necessitating the use of thick sheet steel in its construction. It can conveniently be manufactured by roll-forming a galvanized steel strip.
An anchor means 22 retains one longitudinal edge 24 of the sheet material 20 which is wrapped at least around the inner side surface 26, the bottom surface 28 and the outer side surface 30 of the anchor means 22, this wrap-around enabling the anchor means 22 to exert a firm grip on the sheet material 20 for the purpose of tensioning. This method avoids local stress concentrations on the sheet material 20, and its useful life is thereby extended, typically for at least one growing season.
It is to be noted that the first line of contact 23 between the sheet material 20 forming the flexible covering means and the anchor means 22 is located in said delimited space 19 or thereabove, whereby condensation fluids dripping from the underside of said flexible covering sheet 20 fall onto a fluid-receiving upper portion 34 of gutter means 18.
Optionally, extra gripping security may be provided by inserting a nail 36 through the clamping member 32. A small puncture 37 is thereby formed in the sheet material, but experience has shown that there is no noticeable detrimental effect therefrom.
The anchor means 22 is preferably held by means of clamping members 32 within said delimited space 19 or thereabove, and thereby is also above a fluid-receiving upper portion 34 of the gutter means 18. The anchor means 22 shown in this embodiment is made of timber and is of rectangular cross-section. In further embodiments, a trapezoid timber section, or a rectangular section steel tube (not shown) are used.
Experience has shown that the clamping members 32 should be spaced approximately at 90 cm centers along the longitudinal extension of the anchor means 22.
When the structure is in use, condensation fluids 38 are formed on the lower side of the sheet material 20 and will accumulate above the upper surface 40 of the anchor means 22, and they will overflow and pass down the inner side surface 26. Due to natural unevenness of said timber anchor means 22 the line of contact of the corner 42 to the gutter means 18 does not provide a fluid barrier, so subsequently these condensation fluids 38 will flow to the lower portion of gutter means 18.
FIG. 3a shows an embodiment similar to that of FIG. 3, similar numbers being used to designate similar parts. A screw 44 is used to attach the anchor means 22 to the upper leg of the clamping member 32. Consequently, the corner 42 is spaced from the gutter means 18 and an unobstructed passage is available to drain condensation fluids 38 down the fluid receiving upper portion 34 of gutter means 18.
FIG. 4 shows in detail the clamping member 32 which serves to affix the anchor means 22 adjacent to the upper portion 34 of gutter means 18. The clamping member 32 has an inverted U-shaped section, but the internal angle 46 between the base 48 of the U and the upper leg 50 is greater than 90 degrees, the upper leg 50 being substantially parallel to the lower leg 52. Preferably, apertures 54 are provided to allow passage to fasteners. The advantage of this shape becomes apparent when an anchor means of trapezoidal cross-section is used, whereby the runoff of condensation fluids 38 onto the gutter means 18 is facilitated.
The tool shown in FIG. 5 is useful for the tensioning of the roof sheeting 20 and for the subsequent insertion of the anchor means 22 into the clamping members 32. A jaw section 56 is provided with an opening slightly wider than the thickness of the anchor means 22. A long handle 58 rigidly attached to the jaw section 56 makes possible the wrenching and subsequent insertion of an anchor means 22 into the clamping members 32, thereby tensioning the sheet material 20. Engagement of the jaw section is preferably at a position adjacent to a clamping member 32, and the tool is disengaged after the anchor means 22 is reinserted in the clamping member 32. The nail 36 shown in FIG. 3 and the screw 44 shown in FIG. 3aare, of course, inserted only on completion of this tensioning operation.
FIGS. 6a and 6b show a tool useful for removal from the clamping member 32 of an anchor means 22 following prior removal of nails 36 and screws 44, if such had been inserted. An outer jaw 60 and an inner jaw 62 are mounted for sliding movement towards and away from each other and, after engaging an anchor means 22, may be used to push out the latter from the open ends of the U of the clamping members 32. As shown in FIG. 3, the clamping members 22 remain attached to the gutter means 18. The jaws' gripping action is hand-operated by means of a toggle plier 64 through a long rod-in-tube 66, providing convenient reach to a person standing on ground level. The anchor means 22 may then be unwound from old sheet material 20 and replacement new sheet material 20 assembled thereon.
FIG. 7 shows an anchor means 67 comprising a shaped aluminum alloy extrusion 68 provided on one side with a first hollow section 70, shaped to receive the head of a fastener 72 which is provided with a nut 73. On its opposing side, the extrusion 68 is provided with a second hollow section 74, shaped to allow entry to the sheeting material 20 and also to a clamping element 76, which may conveniently be formed from a second aluminum alloy extrusion. The extrusion 68 is so shaped that when assembled, a tensile force applied to the lower end 78 of the sheeting material 20 will dislodge the clamping element 76, thus providing a convenient method of removing worn-out sheeting material 20; but a tensile force applied to the upper portion of the sheeting material 20 will be resisted by the extrusion 68 without dislodging the clamping element 76. Spacer washers 80 are used at spaced intervals at the points where the extrusion 68 is attached to the gutter means 18, so an unobstructed passage remains at locations between the spacer washers 80, and condensation fluids 38 are therefore free to flow from the underside of the sheeting material 20, over the upper part of the extrusion 68 and towards the center of the gutter means 18.
FIG. 8 shows an anchor means 81, comprising a rolled sheet metal shaped profile section 82, which may be made of galvanized mild steel. The head of a fastener 84 projects into the hollow section 86, and the clamping element 88 is shaped to allow room for the fastener head. In other respects, this embodiment is similar to the embodiment described with regard to FIG. 7, but shows advantages in lower costs and slower corrosion rates, due to the metal being used being identical to the metal used for the gutter means 18.
FIG. 9 shows an embodiment of an anchor means 89 made of a wooden strip 90 provided with a wooden clamping element 92 attached thereto by nails 94, thereby gripping the sheet material 20. The wooden strip 90 is held by screws 96 in spaced relationship to gutter means 18 by means of spaced-apart spacer washers 80 for draining condensation fluids 38 below the wooden strip 90. Before replacing or retensioning the sheeting material 20, it is necessary to pry off the clamping element 92, an operation requiring only a simple screwdriver. The advantage of the anchor means 89 lies in the low material cost and ready availability of the wooden strips.
There is seen in FIG. 10 an embodiment provided with rollable retractable lower sheet material 98 usable for the opening and closing of a ventilation aperture 100. Upper gutter means 102 are provided additionally to lower gutter means 104, both being associated with the roof members 12 and defining therebetween the ventilation aperture 100. The sheeting material 20 covers only the upper portion of the roof span 14, and is held tensioned by an upper anchor means 22 described with reference to FIG. 3, and is affixed adjacent to an inner surface 105 of the upper gutter means 102.
Condensation fluids ,38 dripping from the underside of the flexible sheet material 20 within delimited space 19' defined by inner side surface 105 and the opposite side surface (not shown) overflow the upper anchor means 22 and flow down a fluid receiving surface 103 of the upper gutter means 102 and subsequently cascade onto the lower gutter means 104. The upper longitudinal edge 106 of the lower sheet material 98 is affixed to a lower anchor means 108, the latter being supported by the upper gutter means 102, and being affixed adjacent to an inner surface 110 thereof. The lower edge 112 of the lower sheet material 98 is rolled on a mandrel 114. At the start of a growing season, the ventilation aperture 100 may be closed by unrolling the major portion of the lower sheet material 98 from the mandrel 114, which will then rest on the lower gutter means 104. The lower sheet material 98 is protected against excessive vibrational movement due to wind forces by a rope 116 suspended between eyelets 118, 118'. To open the ventilation aperture 100, the mandrel 114 is revolved, thus rolling-up the lower sheet material 98. It is to be noted that the mandrel 114 is free to move vertically and will be pulled upwards during the rolling-up operation, because the upper longitudinal edge 106 is affixed to the lower anchor means 108.
Typically at the end of a growing season, or even during a growing season if horticultural considerations so indicate, the lower sheet material 98 will be fully rolled up as shown at numeral 109, and will be shielded from the elements by the upper gutter means 102.
FIG. 11 shows a tool useful for rolling-up the lower sheet material 98 shown in FIG. 10. A square hollow section 120 of the tool is engagable with a projection 122 of the mandrel 114. A shaft 124 and an universal joint 126 combine to allow operation of the handle 128, while the operator remains at ground level holding the shaft 124 in one hand and the handle 128 in the other. As the lower sheet material 98 is wound up, and the mandrel 114 rises to a higher level, the square hollow section 120 of the tool will also rise. However, the handle 128 will still be conveniently operable from ground level, the universal joint 126 allowing the axis of the square hollow section 120 to remain while the shaft 124 takes up an angle sloped from the horizontal.
FIG. 12 shows a second embodiment of the upper gutter means. A lower face 130 of an upper gutter element 132 terminates in a retention pocket 134, which is positioned below the lower face 130 and is configured for the insertion therein of the lower anchor means 108. The lower face 130 of upper gutter element 132 is sloped in a direction causing condensation fluids 38, as well as rainwater above the lower face 130, to flow away from the retention pocket 134 in the direction of attachment locations 136 of the upper gutter element 132 to the roof member 12. Drainage apertures 138 are provided at spaced-apart longitudinal locations adjacent to the attachment locations 136, and drainage channels 140 are positioned to accept fluids including condensation fluids 38 which pass through the drainage apertures 138 for transfer to the lower gutter means 104.
The drainage channels 140 furthermore serve to provide support to the rolled-up lower sheet material 109 and also serve to provide additional support to the upper gutter element 132 to which they are attached. As shown in FIG. 13, preferably one drainage channel 140 is positioned halfway between each pair of roof members 12, thus providing effective drainage and a strong structure.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrated embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
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This invention is directed to a plastic-covered, gutter-connected sheltering horticultural structure constructed of a framework and flexible cover sheet material. The structure is constructed with a number of gutters with arched roof trusses connected at their ends between side walls of a consecutive pair of the gutters. Anchor means are provided to join each of the gutters for engagement to longitudinal edges of flexible covering sheet material and maintaining the sheet material in a tensioned state over the roof trusses. A plurality of fastening means are spaced at intervals along the length of the gutters to maintain the anchor means spaced apart from the gutters to provide unobstructed passages between the anchor means and the gutters. This permits condensation fluids generated within the structure to travel down the underside of the flexible covering sheet material, over the anchor means, through the unobstructed passages into the gutters and fluid precipitation generated exterior to the structure to fall on the flexible covering sheet material and to travel down directly into the gutters.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a filter device for separating gaseous organic impurities from waste gases.
2. Background of the Prior Art
As used herein, the term gaseous organic impurities means all waste gases which originate from organic degradation processes, for example, from animal farms, from processing operations in animal carcass utilization plants, from fermentation and rotting or digestion processes, as well as from industrial plants.
It is well known that gaseous impurities may be separated from waste gases by using filters which consist of a drum-shaped, rotating separating unit which rotates about an axis and contains filter material, e.g., low-temperature coke from peat, brown coal, bituminous coal or wood charcoal, such as those described in the German Offenlegungsschrift 1,619,861. Of course, whenever the adsorption capacity is exhausted, a new charge has to be introduced into the separating unit.
By these processes, gaseous impurities, especially in the form of sulfur dioxide, can be removed by adsorption from waste gases since sulfuric acid is formed in the presence of oxygen and water vapor, and the sulfuric acid must be released in a processing step that follows the absorption.
Experience has shown that the organic impurities mentioned hereinabove can only be incompletely separated and converted with such devices. The impurities and extraneous materials that occur, cannot all be adsorbed and the porous surface of such absorbents, and of filters that may be positioned before the absorbents are quickly blocked by suspended matter in the waste gases.
BRIEF DESCRIPTION OF THE DRAWING
The drawing is a cross-sectional view of an apparatus in accordance with the present invention.
SUMMARY OF THE INVENTION
It has been discovered that the filtration of organic compounds from waste gases can be significantly improved, if they are passed through an absorbent that moves, in the manner of a migrating layer, from top to bottom through a vessel, through which the waste gases flow. The absorbent for the process is an incompletely decomposed compost of organic waste, obtained by an aerobic digestion process and/or settled sludge. The spent filter material is continuously removed from the vessel and continuously replaced by fresh filter material.
Such a filter device therefore requires a digestion reactor and organic waste in sufficient amounts. However, these requirements cannot be fulfilled everywhere.
The object of the present invention is to create, using the exchange of filters, a filter device that is easy to operate, that produces, without a digestion reactor, a significantly improved filtration result in comparison with known filters and that is constructed in such a way, that the filter material can be exchanged readily.
The objects of the invention have been accomplished by a vessel which has a coupling flange, is connected to a stationary rack by means of quick-release couplings and which contains as an absorbent, a biologically highly active compost of a medium degree of maturity. This absorbent is obtained by an aerobic digestion process from organic waste and/or settled sludge and that contains about 30% to 35% water and about 55% to 70% organic material and is treated with microorganisms of the species. Actinomyces globisborus, flavus and farinus, and fungi of the Coprinus variety, the Aspergillus and Mucor species.
DESCRIPTION OF THE PREFERRED EMBODIMENT
According to a preferred embodiment of the invention, the vessel is in the form of a portable container and has an inlet in its base and an outlet in its lid. The inlet is connected to an inlet connecting piece attached to a supporting frame for the container. The inlet connecting piece fits into registration with the inlet of the container to form a gas-tight connection. This is further connected to a jet system within the vessel at its base and has an indicator for showing the biological effectiveness of the absorbent.
In the filter device of the invention, the actual filter accordingly is a container, which holds a biologically active humus as a filter material and which is connected, in such a way that it can readily be connected to and removed from a stationary device that has all the connections and and auxiliary units. As a result, the container having the fresh humus therein may be easily connected to the stationary device, utilized to process the gas, and when the activity of the humus has deteriorated to an insufficient level, the entire container can be easily disconnected and another container with fresh humus be substituted in its place.
The filter material is highly populated with microorganisms. As the organic, gaseous impurities, which are to be purified, are passed into the vessel, the microorganisms in the filter material receive nourishment once again and therefore become active once more. In this biologically active filter material, a vigorous reaction takes place, that is to say, further decomposition as well as biological degradation reactions proceed.
Sulfur dioxide compounds are filtered out by the filter, as generally is the case with the known filters. Also all of the remaining organic compounds, that occur in the waste gases, are converted or degraded and even heavy metal ions are immobilized, if suitable additives, such as, bentonite, are used.
The exhaust air leaving the filter device is absolutely free of any odors and has been purified to remove all injurious materials. This is due to the use of a filter material which is highly active biologically. Thus, in contrast to the known filter materials, continuous reactions take place in this material which contribute biologically to the rotting or digestion of the material and in which the odoriferous and injurious materials of the waste air or gas are included and thereby converted or degraded.
It has therefore turned out that this filter material can also be used to advantage in those situations where a filter material, consisting of dried humus -- a so-called earth filter -- has hitherto been used. It ought to be mentioned that, while the filter of the invention is being used, the filter material contained therein digests further and, after biological reactions can no longer be detected and the filter therefore has only limited usefulness, the filter material can also be used as a humus material, possibly after a post-composting.
After the filter material is spent, as shown bby suitable indicators, for example, by conductivity measurement, by biological activity measurements, by measurement of a certain gas in the waste air, etc., the container is lifted from the rack and a second container, which is already filled with fresh filter material is put in its place. The container, that has been lifted off, is emptied at a suitable site and filled with fresh filter material.
In order to maintain the effectiveness of the filter at a high level, it may be advantageous that a blower, that can also draw in fresh air be connected to a waste-air connecting piece on the rack in order to regulate the waste air flowing through the container and that this blower be connected by means of quick-release couplings with the corresponding connecting piece of the container.
This measure depends essentially on the amount and the rate of flow of the waste air. The correct rate of flow can be determined by simple experiments.
The capacity of such a container is selected to be between two and ten cubic meters, in order to hold the amount of filter material necessary for maintaining biological activity, while keeping the size of the container such that it can still be transported. Containers of this size can easily be brought to the site of the filter and lifted, by means of a crane mounted on a truck, onto or off the rack and transported from there to the place where they are to be filled.
Referring now to the drawing, a device for filtering waste gases is shown consisting of a stationary rack 1, on which is placed a vessel 2 in the form of a container or chamber, which is adapted to be lifted from the rack 1. The vessel 2 consists of a middle piece 3 in the form of a cylindrical jacket, which is connected with upper and lower lids 4 and 5, respectively, by means of tightening screws 6 and locks 7 so as to be gas-tight and detachable.
The upper lid 4 has an outlet 8 and the lower lid 5 an an inlet 8, as well as a system of jets 10 as means for distributing the gas. Also attached to lower lid 5 are supporting legs 11. By means of rings 12, the vessel can be lifted from the rack 1.
The rack has a seating means 13 for centering the vessel thereon. An inlet connecting piece is arranged centrally in this seating and is connected with a quick-release coupling, which is not shown, to pipe 15, which leads to the waste air which is to be purified.
When placed on the rack, inlet 9 of the vessel matches or is in registration with the inlet connecting piece 14 of the rack 1, so as to be form-fitting and gas-tight. The inlet 9 is in turn connected with the system of jets 10, which has already been mentioned and which is arranged in the base of the vessel. As indicated, a suction blower 17 can, if necessary, be connected via a waste-gas connecting piece 16 with the outlet 8.
The vessel 2 is filled with aggregate 18, which is used as filter material and which consists of a biologically highly active compost of a medium degree of maturity, which may be obtained by a process according to German Auslegeschrift 2,253,009. The degree of maturity and thereby the biological activity of the filter material is measured by a suitable probe. Typically, the means for measuring the biological activity may include a conductivity measurement, a biological activity measurement, measurement of a certain gas in the waste air, etc. The activity is shown on an indicating instrument 20. This instrument determines and can be adapted to continually check whether the filtering material still has the desired filtering properties. The probe may be mounted in the waste-air connecting piece 16 at 19a.
The compost, used as filter material, contains about 30-35% water and about 55-70% organic material, as well as microorganisms of the Actinomuces globisborus, flavus and farinus species and fungi of the Coprinus variety, the Aspergillus and Mucor species.
When the waste gas containing the organic impurities flows by way of the jet distribution system 10 through the filter material and is distributed over the area of the vessel, the organic compounds become involved in the biological reactions which cause the compost to rot, and thus they are completely converted or degraded. Even heavy-metal ions in the waste air are immobilized in the filter material, if bentonite is introduced as additive into the aggregate.
As soon as the filter material no longer has the desired properties, the pipe connections are loosened and the vessel is lifted off the rack, transported away and emptied at a central site and filled up again. Since the rotting has continued while the filter was in use, the spent filter material is a hygienically unobjectional humus material.
When the first vessel is taken off the rack, it is replaced by a second one, which is already filled with fresh filter material. This second vessel is then connected to the feed pipes.
Using the device, described in the invention, for filtering organic impurities from waste gases, it is possible, by a simple and economic procedure, to filter and completely free such waste gases which may originate, for example, from animal farms, from fermentation or rotting processes, from industrial plants and from odoriferous materials.
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A method for removing gaseous organic impurities from waste gases comprising contacting the waste gas with an absorbent composed of a biologically active compost having a medium degree of maturity obtained by the aerobic digestion of settled sludge or organic waste which has been treated with Actinomyces globisborus or Coprinus fungi. An apparatus for carrying out the process is also disclosed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application No. 61/706418, which was filed on 27 Sep. 2012 and is incorporated herein by reference.
BACKGROUND
[0002] Turbomachines, such as gas turbine engines, typically include a fan section, a compression section, a combustion section, and a turbine section. Turbomachines may employ a geared architecture connecting portions of the compression section to the fan section.
[0003] Variable vanes are widely used in commercial and military gas turbine engines, especially within compression sections. Variable vane position is typically scheduled as a function of corrected engine parameters and additional factors, such as throttle movements, foreign object detection, and stall detection. Variable vane positioning permits optimal airfoil incidence to protect compressor stability.
SUMMARY
[0004] A method of variable vane scheduling according to an exemplary aspect of the present disclosure includes, among other things, adjusting variable vanes from a position based on a first schedule to a position based on a different, second schedule in response to a control feature.
[0005] In a further non-limiting embodiment of the foregoing method of variable vane scheduling, the control feature comprises an amount of bleed air.
[0006] In a further non-limiting embodiment of either of the foregoing methods of variable vane scheduling, the first schedule may include positions that permit a first amount of flow into a compressor, and the second schedule may include positions that permit a second amount of flow into the compressor. The first amount is less than the second amount.
[0007] In a further non-limiting embodiment of any of the foregoing methods of variable vane scheduling, the variable vanes may be adjusted according to the first schedule when the amount of bleed air is relatively low, and the variable vanes may be adjusted according to the second schedule when the amount of bleed air is relatively high.
[0008] In a further non-limiting embodiment of any of the foregoing methods of variable vane scheduling, the variable vanes may be adjusted based on the first schedule when the amount of bleed air is zero.
[0009] In a further non-limiting embodiment of any of the foregoing methods of variable vane scheduling, the variable vanes may control flow through a compressor of a turbomachine, and the first and the second schedules determine the position based on a variable that includes at least a rotational speed of a rotor of the compressor and a temperature of the compressor.
[0010] In a further non-limiting embodiment of any of the foregoing methods of variable vane scheduling, the variable may include the rotational speed divided by the temperature.
[0011] In a further non-limiting embodiment of any of the foregoing methods of variable vane scheduling, the temperature may be a compressor inlet temperature.
[0012] In a further non-limiting embodiment of any of the foregoing methods of variable vane scheduling, the method may use a position of a bleed valve to determine the amount of bleed air.
[0013] A turbomachine controller assembly according to an exemplary aspect of the present disclosure includes, among other things, a controller configured to adjust an array of variable vanes within a compressor, wherein the controller adjusts the array according to a first schedule when a first amount of bleed air is communicated from the compressor, and adjusts the array according to a second schedule when a different, second amount of bleed air is communicated from the compressor.
[0014] In a further non-limiting embodiment of the foregoing turbomachine controller assembly, the first schedule may include positions that permit less flow through the compressor than the positions of the second schedule.
[0015] In a further non-limiting embodiment of either of the foregoing turbomachine controller assemblies, the second amount of bleed air may comprise no bleed air communicated from the compressor.
[0016] In a further non-limiting embodiment of any of the foregoing turbomachine controller assemblies, the controller may monitor a bleed valve position to determine whether the first amount or the second amount of bleed air is communicated from the compressor.
[0017] In a further non-limiting embodiment of any of the foregoing turbomachine controller assemblies, the first and the second schedules may be determined based at least on a compressor rotor speed and an inlet temperature.
[0018] A method of controlling flow through a compressor of a turbomachine according to another exemplary aspect of the present disclosure includes, among other things, moving variable vanes to positions that allow more flow into the compressor in response to bleed air being communicated away from the compressor.
[0019] In a further non-limiting embodiment of the foregoing method of controlling flow through a compressor of a turbomachine, the variable vanes may be moved according to at least a first schedule or a second schedule.
DESCRIPTION OF THE FIGURES
[0020] The various features and advantages of the disclosed examples will become apparent to those skilled in the art from the detailed description. The figures that accompany the detailed description can be briefly described as follows:
[0021] FIG. 1 shows a section view of an example turbomachine.
[0022] FIG. 2 shows example schedules for variable vanes of the turbomachine of FIG. 1 .
[0023] FIG. 3 shows a highly schematic view of flow entering a compression section of the turbomachine of FIG. 1 when a bleed valve is in a position permitting less bleed flow.
[0024] FIG. 4 shows a highly schematic view of flow entering a compression section of the turbomachine of FIG. 1 when a bleed valve is in a position permitting more bleed flow.
[0025] FIG. 5 shows example bounded schedules for variable vanes of the turbomachine of FIG. 1 .
DETAILED DESCRIPTION
[0026] FIG. 1 schematically illustrates an example turbomachine, which is a gas turbine engine 20 in this example. The gas turbine engine 20 is a two-spool turbofan gas turbine engine that generally includes a fan section 22 , a compression section 24 , a combustion section 26 , and a turbine section 28 .
[0027] Although depicted as a two-spool turbofan gas turbine engine in the disclosed non-limiting embodiment, it should be understood that the concepts described herein are not limited to use with turbofans. That is, the teachings may be applied to other types of turbomachines and turbine engines including three-spool architectures. Further, the concepts described herein could be used in environments other than a turbomachine environment and in applications other than aerospace applications.
[0028] In the example engine 20 , flow moves from the fan section 22 to a bypass flowpath. Flow from the bypass flowpath generates forward thrust. The compression section 24 drives air along a core flowpath. Compressed air from the compression section 24 communicates through the combustion section 26 . The products of combustion expand through the turbine section 28 .
[0029] The example engine 20 generally includes a low-speed spool 30 and a high-speed spool 32 mounted for rotation about an engine central axis A. The low-speed spool 30 and the high-speed spool 32 are rotatably supported by several bearing systems 38 . It should be understood that various bearing systems 38 at various locations may alternatively, or additionally, be provided.
[0030] The low-speed spool 30 generally includes a shaft 40 that interconnects a fan 42 , a low-pressure compressor 44 , and a low-pressure turbine 46 . The shaft 40 is connected to the fan 42 through a geared architecture 48 to drive the fan 42 at a lower speed than the low-speed spool 30 .
[0031] The high-speed spool 32 includes a shaft 50 that interconnects a high-pressure compressor 52 and high-pressure turbine 54 .
[0032] The shaft 40 and the shaft 50 are concentric and rotate via bearing systems 38 about the engine central longitudinal axis A, which is collinear with the longitudinal axes of the shaft 40 and the shaft 50 .
[0033] The combustion section 26 includes a circumferentially distributed array of combustors 56 generally arranged axially between the high-pressure compressor 52 and the high-pressure turbine 54 .
[0034] In some non-limiting examples, the engine 20 is a high-bypass geared aircraft engine. In a further example, the engine 20 bypass ratio is greater than about six (6 to 1).
[0035] The geared architecture 48 of the example engine 20 includes an epicyclic gear train, such as a planetary gear system or other gear system. The example epicyclic gear train has a gear reduction ratio of greater than about 2.3 (2.3 to 1).
[0036] The low-pressure turbine 46 pressure ratio is pressure measured prior to inlet of low-pressure turbine 46 as related to the pressure at the outlet of the low-pressure turbine 46 prior to an exhaust nozzle of the engine 20 . In one non-limiting embodiment, the bypass ratio of the engine 20 is greater than about ten (10 to 1), the fan diameter is significantly larger than that of the low-pressure compressor 44 , and the low-pressure turbine 46 has a pressure ratio that is greater than about 5 (5 to 1). The geared architecture 48 of this embodiment is an epicyclic gear train with a gear reduction ratio of greater than about 2.5 (2.5 to 1). It should be understood, however, that the above parameters are only exemplary of one embodiment of a geared architecture engine and that the present disclosure is applicable to other gas turbine engines including direct drive turbofans.
[0037] In this embodiment of the example engine 20 , a significant amount of thrust is provided by the bypass flow B due to the high bypass ratio. The fan section 22 of the engine 20 is designed for a particular flight condition—typically cruise at about 0.8 Mach and about 35,000 feet. This flight condition, with the engine 20 at its best fuel consumption, is also known as “Bucket Cruise” Thrust Specific Fuel Consumption (TSFC). TSFC is an industry standard parameter of fuel consumption per unit of thrust.
[0038] Fan Pressure Ratio is the pressure ratio across a blade of the fan section 22 without the use of a Fan Exit Guide Vane system. The low Fan Pressure Ratio according to one non-limiting embodiment of the example engine 20 is less than 1.45 (1.45 to 1).
[0039] “Low Corrected Fan Tip Speed” is the actual fan tip speed in ft/sec divided by an industry standard temperature correction of [(Tram° R)/(518.7 ° R)]̂0.5. The Temperature represents the ambient temperature in degrees Rankine. The Low Corrected Fan Tip Speed according to one non-limiting embodiment of the example engine 20 is less than about 1150 fps (351 m/s).
[0040] The engine 10 includes arrays of variable vanes 58 extending radially from the axis A. The variable vanes 58 are positioned, in this example, near the inlet to the high-pressure compressor 52 . The low-pressure compressor 44 may include variable vanes in some examples.
[0041] The variable vanes 58 are adjusted between positions that permit more flow and positions that permit less flow into the high-pressure compressor 52 . The variable vanes 58 are typically adjusted by rotating the variable vanes 58 about radially extending axes, as is known.
[0042] Referring the FIG. 2 with continuing reference to FIG. 1 , the example controller 60 adjusts the positions of the variable vanes 58 according to a first schedule 72 or a second schedule 74 . The first schedule 72 specifies a first position for the variable vanes 58 for a given variable from the engine 20 . The second schedule 74 specifies a different, second position for the variable vanes 58 for the variable from the engine 20 . At a given variable, the first position of the first schedule 72 permits less flow through the variable vanes 58 to the high-pressure compressor 52 than the second position of the second schedule 74 .
[0043] The variable is typically the rotational speed of the high-speed spool 32 divided by a temperature at an inlet to the high-pressure compressor 52 . Other variables are possible. The first positions in the first schedule 72 and the second positions in the second schedule 74 are functions of the variables in this example.
[0044] Referring now to FIGS. 3 and 4 , the controller 60 moves the variable vanes 28 according to the first schedule 72 depending on a control feature, such as when a bleed valve 80 of the high-pressure compressor 52 is closed and not communicating bleed air from the high-pressure compressor 52 . The controller 60 moves the variable vanes 28 according to the second schedule 74 when the bleed valve 80 of the high-pressure compressor 52 is open and communicating bleed air from the high-pressure compressor 52 .
[0045] In another example, the controller 60 moves the variable vanes 28 according to the first schedule 72 when horsepower extraction of an aircraft associated with the engine 20 is above a set value, and moves the variable vanes 28 according to the second schedule 72 when horsepower extraction of the aircraft is below the set value.
[0046] In some examples, the set value represents different levels of horsepower, such as no horsepower, normal horsepower, and maximum horsepower. The specific value of the horsepower (hp) may vary significantly based on the type of engine 20 and aircraft. For example, one engine may use 0 hp, 100 hp, and 200 hp. In such an example, 0 hp may correspond to a failure case when a generator of the engine 20 is malfunctioning and is turned off, 100 hp may be ‘normal’ load on the engine 20 during the entire mission (having no flight condition dependence), and 200 hp may correspond to a maximum load during icing conditions with multiple flight surfaces moving and gear deploying. Another engine may use 0 hp, 75 hp, and 150 hp as the different levels of horsepower.
[0047] This mode of operation, which uses horsepower extraction rather than bleed air as the control feature, may be especially relevant if the engine 20 has all electric offtakes. Example of such engines include engines that rely on mechanical energy extraction (horsepower) to provide breathing air and run aircraft control surfaces. Other engines, by contrast, extract bleed air from the compressor for the cabin and use hydraulic pumps attached to the engine to power the control surfaces. Both bleed air and horsepower extraction influence stability of the high-pressure compressor 52 . Other examples use control features other than bleed air or horsepower extraction.
[0048] In this example, opening the bleed valve 80 permits bleed air to move from the high-pressure compressor 52 . The bleed valve 80 may be a single valve, or several valves and passages that selectively permit movement of bleed air from the high-pressure compressor 52 . The valves and passages may be at several stages of the high-pressure compressor 52 .
[0049] Bleed air is moved from the high-pressure compressor 52 to, for example, cool various components of the engine 20 , such a vanes and blades. Moving bleed air from the high-pressure compressor 52 means that less air passes from the high-pressure compressor 52 to the combustors 56 , and to the turbine section 28 . Less air moving to the turbine section 28 may reduce the useful life of components within the turbine section 28 , especially in high-bypass ratio engines.
[0050] The example controller 60 compensates for the bleed air moving from the high-pressure compressor 52 by adjusting the variable vanes 58 according to the second schedule 74 when the bleed air is moving from the high-pressure compressor 52 . The second schedule 74 , at a given speed and temperature, permits more flow into the high-pressure compressor 52 than the first schedule 72 .
[0051] The controller 60 may monitor a position of the bleed valve 80 to determine whether bleed air is moving from the high-pressure compressor 52 . The controller 60 may monitor whether bleed air is moving from the high-pressure compressor 52 in some other way, such as via a sensor that detects bleed air.
[0052] Various vane schedules are created to optimize performance of the engine 10 . The first and second schedules may include a range of positions, as shown in the schedules 72 a and 74 a of FIG. 5 . The upper boundaries of the schedules 72 a and 74 a may represent the stability limits associated with the variable vanes 58 .
[0053] Although described as two distinct vane schedules, more than two vane schedules may be used. For example, the variable vanes may be adjusted according to a first schedule when a bleed valve is closed, a second schedule when the bleed valve is partially open, and a third schedule when the bleed valve is fully open.
[0054] The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. Thus, the scope of legal protection given to this disclosure can only be determined by studying the following claims.
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An example variable vane scheduling method includes adjusting variable vanes from a position based on a first schedule to a position based on a different, second schedule in response to a control feature. An example method of controlling flow through a compressor of a turbomachine includes moving variable vanes to positions that allow more flow into the compressor in response to bleed air being communicated away from the compressor.
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TECHNICAL FIELD
[0001] The present disclosure is related generally to user interface protection technologies for mobile devices, and, more particularly, to a system and method for determining whether a screen protector has been removed from the device display screen.
BACKGROUND
[0002] Many portable communications devices, e.g., smart phones and the like, have traditionally utilized glass lenses over the device display. The glass provides a hard, scratch-resistant surface that is easy to clean and maintain. However, such lenses are also easily cracked if the device is dropped or struck by a hard object.
[0003] While it is possible to use plastic lenses to eliminate or reduce this type of breakage, there are a number of drawbacks associated with the use of plastic lenses. One of the primary challenges for this type of lens is the lack of adequate scratch and abrasion resistance. Plastic materials do not have the same hardness as glass and therefore do not offer the same abrasion and damage resistance.
[0004] Before proceeding, it should be appreciated that the present disclosure is directed to a system that can eliminate some of the shortcomings noted in this Background section. However, any such benefit is not a limitation on the scope of the disclosed principles, or of the attached claims, except to the extent expressly noted in the claims. Additionally, the discussion of technology in this Background section is reflective of the inventors' own observations, considerations, and thoughts, and is in no way intended to accurately catalog or comprehensively summarize any prior art reference or practice. As such, the inventors expressly disclaim this section as admitted or assumed prior art. Moreover, the identification herein of desirable courses of action reflects the inventors' own observations and ideas, and should not be assumed to indicate an art-recognized desirability.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0005] While the appended claims set forth the features of the present techniques with particularity, these techniques, together with their objects and advantages, may be best understood from the following detailed description taken in conjunction with the accompanying drawings of which:
[0006] FIG. 1 is a simplified schematic of an example device with respect to which embodiments of the presently disclosed principles may be implemented;
[0007] FIG. 2 is a front view of a device in accordance with an embodiment of the disclosed principles, showing the device screen and logo;
[0008] FIG. 3 is a simplified schematic of the face of a device in accordance with an embodiment of the disclosed principles including the device screen and conductive sense contacts;
[0009] FIG. 4 is a cross-sectional layer diagram of a display screen assembly in accordance with an embodiment of the disclosed principles; and
[0010] FIG. 5 is a flow chart illustrating a process of screen protector detection in accordance with an embodiment of the disclosed principles.
DETAILED DESCRIPTION
[0011] Before presenting a detailed discussion of embodiments of the disclosed principles, an overview of certain embodiments is given to aid the reader in understanding the later discussion. As noted above, glass lenses on portable communication devices are hard, resulting in scratch resistance, but brittle, resulting in breakage if the lens is struck.
[0012] While many users already make use of replaceable screen protectors over glass lenses to prevent breakage, these screen protectors are easily removed, leaving the lens vulnerable. Moreover, the easy application and removal of such protection measures prevents manufacturers from employing a plastic lens. In particular, if a manufacturer were to build a device with a plastic lens, the lens would be easily scratched in the event a protector is used or a protector is provided but is later removed by the user.
[0013] In an embodiment of the disclosed principles, a replaceable plastic screen protector is used in conjunction with a plastic lens, essentially eliminating lens breakage from drop events. In concert with this form of lens protection, a detection system is provided for determining whether the plastic lens has been exposed by removal of the screen protector.
[0014] To automatically detect if the screen protector is present, an additional capacitive sensor is employed outside of the active display area in an embodiment. In one implementation, a conductive (e.g., metallic) logo decoration is included as part of the screen protector, such that when the screen protector is assembled to device, the conductive logo is aligned between two sense contacts of the capacitive touch button. This causes coupling and essentially closes a circuit having the two sense contacts as end points.
[0015] The device is configured to monitor the circuit for an open condition, indicating either that the screen protector has been removed or that another unknown type of screen protector is being used. In either case, the user may be reminded to use an a screen protector and to make sure that the screen protector they use is approved by the device manufacturer.
[0016] In addition, a notification may be sent to the device manufacturer or the carrier for use as it relates to warranty tracking or internal data collection, e.g., for tracking refurbishment rates. The user may also be provided with links to replacement products or instructional information such as videos regarding installation of a screen protector. In an embodiment, the user is prompted to take a brief survey as to why the screen protector has been removed (e.g., poor visibility).
[0017] With this overview in mind, and turning now to a more detailed discussion in conjunction with the attached figures, the techniques of the present disclosure are illustrated as being implemented in a suitable computing environment. The following generalized device description is based on embodiments and examples within which the disclosed principles may be implemented, and should not be taken as limiting the claims with regard to alternative embodiments that are not explicitly described herein. Thus, for example, while FIG. 1 illustrates an example mobile device within which embodiments of the disclosed principles may be implemented, it will be appreciated that other device types may be used, including but not limited to laptop computers, tablet computers, embedded automobile computing systems and so on.
[0018] The schematic diagram of FIG. 1 shows an exemplary device 110 forming part of an environment within which aspects of the present disclosure may be implemented. In particular, the schematic diagram illustrates a user device 110 including several exemplary components. It will be appreciated that additional or alternative components may be used in a given implementation depending upon user preference, component availability, price point and other considerations.
[0019] In the illustrated embodiment, the components of the user device 110 include a display screen 120 , applications (e.g., programs) 130 , a processor 140 , a memory 150 , one or more input components 160 such as speech and text input facilities, and one or more output components 170 such as text and audible output facilities, e.g., one or more speakers.
[0020] The processor 140 may be any of a microprocessor, microcomputer, application-specific integrated circuit, or the like. For example, the processor 140 can be implemented by one or more microprocessors or controllers from any desired family or manufacturer. Similarly, the memory 150 may reside on the same integrated circuit as the processor 140 . Additionally or alternatively, the memory 150 may be accessed via a network, e.g., via cloud-based storage. The memory 150 may include a random access memory (i.e., Synchronous Dynamic Random Access Memory (SDRAM), Dynamic Random Access Memory (DRAM), RAMBUS Dynamic Random Access Memory (RDRM) or any other type of random access memory device or system). Additionally or alternatively, the memory 150 may include a read only memory (i.e., a hard drive, flash memory or any other desired type of memory device).
[0021] The information that is stored by the memory 150 can include program code associated with one or more operating systems or applications as well as informational data, e.g., program parameters, process data, etc. The operating system and applications are typically implemented via executable instructions stored in a non-transitory computer readable medium (e.g., memory 150 ) to control basic functions of the electronic device 110 . Such functions may include, for example, interaction among various internal components and storage and retrieval of applications and data to and from the memory 150 .
[0022] Further with respect to the applications 130 , these typically utilize the operating system to provide more specific functionality, such as file system service and handling of protected and unprotected data stored in the memory 150 . Although many applications may provide standard or required functionality of the user device 110 , in other cases applications provide optional or specialized functionality, and may be supplied by third party vendors or the device manufacturer.
[0023] With respect to informational data, e.g., program parameters and process data, this non-executable information can be referenced, manipulated, or written by the operating system or an application. Such informational data can include, for example, data that are preprogrammed into the device during manufacture, data that are created by the device or added by the user, or any of a variety of types of information that are uploaded to, downloaded from, or otherwise accessed at servers or other devices with which the device is in communication during its ongoing operation.
[0024] The device 110 further includes one or more screen protector sensors 180 configured to provide a signal indicative of the presence or absence of a screen protector on the device display screen 120 . In an embodiment, as noted above, the screen protector sensors 180 include a capacitive sensor or other non-contact sensor.
[0025] In an embodiment, a power supply 190 , such as a battery or fuel cell, may be included for providing power to the device 110 and its components. All or some of the internal components communicate with one another by way of one or more shared or dedicated internal communication links 195 , such as an internal bus.
[0026] In an embodiment, the device 110 is programmed such that the processor 140 and memory 150 interact with the other components of the device 110 to perform a variety of functions. The processor 140 may include or implement various modules and execute programs for initiating different activities such as launching an application, transferring data and toggling through various graphical user interface objects (e.g., toggling through various display icons that are linked to executable applications).
[0027] Turning to FIG. 2 , this figure shows a front view of a device 201 in accordance with an embodiment of the disclosed principles. From the front, the appearance of the device 201 is dominated by the device display screen 120 . As noted above, the screen may be made of, or comprise, plastic to avoid breakage. To protect the screen 120 from scratches and abrasion, a screen protector 203 is applied over the display screen 120 as in the illustrated embodiment. The screen protector 203 is substantially transparent, allowing the screen 120 to be viewed through the screen protector 203 .
[0028] The screen protector 203 in the illustrated embodiment includes a conductive logo 205 . The conductive logo 205 may be made of printed metallic ink, an adhesive metallic piece or other suitable design, and is substantially permanently joined to or into the screen protector 203 . The precise shape and design of the logo 205 is not important. However, as will be appreciated from the following discussion, the logo 205 should be of sufficient extent to allow sensing by an underlying sensor mechanism.
[0029] Turning to FIG. 3 , this figure illustrates the underlying elements on the face of the device 201 in greater detail, i.e., beneath the screen protector 203 and display lens. In particular, as can be seen, the active area of the screen 120 covers most but not all of the face of the device 201 . A pair of sense contacts 309 is located in the remaining area 307 on the device 201 front. The location of the sense contacts 309 on the device 201 is such that when the screen protector 203 is installed on the screen 120 , the conductive logo 205 overlies and bridges the sense contacts 309 . In an embodiment, the sense contacts 309 are configured for capacitive rather than conductive sensing, and as such, the conductive logo 205 need not physically touch the sense contacts 309 .
[0030] The relationship between the various lens and display components in a layered screen structure can be better seen in the partial cross-sectional view of FIG. 4 . In particular, FIG. 4 shows a cross-section of a display screen assembly 400 in accordance with an embodiment of the disclosed principles. The illustrated cross-section is taken perpendicularly through the device screen region in a plane that cuts through each contact in the pair of sense contacts 309 .
[0031] The display screen 120 is made up of a film touch sensor 401 covered by a plastic display lens 403 . As noted above, while the plastic display lens 403 is more resistant to breakage than an equivalent glass lens, the plastic display lens 403 is more susceptible to scratching and abrasion. As such, a replaceable plastic screen protector such as plastic screen protector 203 is placed over the plastic display lens 403 .
[0032] The conductive logo 205 in the illustrated embodiment is adhered to the underside of the plastic screen protector 203 by any suitable means, e.g., ultrasonic bonding, adhesives and so on. The plastic screen protector 203 as whole, bearing the conductive logo 205 , is adhered to the top surface of the plastic display lens 403 via a suitable replaceable optical adhesive 405 .
[0033] With this structure, the plastic screen protector 203 can be sensed at the pair of sense contacts 309 by capacitively sensing the associated conductive logo 205 . In particular, the capacitance across the pair of sense contacts 309 is changed by the presence of the conductive logo 205 such that removal of the plastic screen protector 203 , and with it the conductive logo 205 , causes a detectable change in capacitance across the pair of sense contacts 309 . The device is configured to monitor the circuit for an open condition, indicating either that the screen protector 203 has been removed or that another unknown screen protector is being used. In either case, the user may be reminded to use a screen protector and to make sure that the screen protector is approved by the device manufacturer.
[0034] In addition, a notification may be sent to the device manufacturer or the carrier for use as it relates to warranty tracking or internal data collection, e.g., for tracking refurbishment rates. The user may also be provided with links to replacement products or instructional information such as videos regarding installation of a screen protector. In an embodiment, the user is prompted to take a brief survey as to why the screen protector has been removed (e.g., poor visibility, inadequate touch sensing, etc.). In an alternative embodiment, the conductive logo 205 is made of a transparent conductive material such as ITO (Indium Tin Oxide)
[0035] Turning to FIG. 5 , this figure provides a flowchart of a process in accordance with an embodiment of the disclosed principles. In particular, the illustrated process 500 shows the detection of the presence and absence of the plastic screen protector 203 having a conductive patch such as a logo. Also, as noted above, the mobile communication device 110 ( FIG. 1 ), 201 ( FIGS. 2-3 ) comprises a processor 140 configured to run an operating system and one or more applications 130 . It will be appreciated that the described process 500 is executed by the processor 140 as part of the operating system, an application, or other software. In an embodiment, in order to execute software, the processor 130 reads computer-executable instructions from a non-transitory computer-readable medium such as a local or remote memory 150 .
[0036] At stage 501 of the process 500 , the processor 130 causes a measurement or probe of the status of the connection between the sense contacts 309 , and at stage 503 determines whether the connection is open or closed. It will be appreciated that in an embodiment wherein the conductive logo 205 is capacitively coupled with the sense contacts 309 , the connection between the sense contacts 309 will always be open at DC but will act closed at higher AC frequencies when the conductive logo 205 is present.
[0037] The processor 130 determines at stage 503 whether the circuit acts open or closed to a predetermined AC frequency. If the circuit acts closed to this frequency then the conductive logo 205 is present, meaning that the screen protector 203 is present, and the process 500 accordingly returns to stage 501 . Otherwise, e.g., if the circuit acts open to the selected frequency, then the process 500 moves to stage 505 , wherein the processor 140 determines whether a responsive action has already been taken. If such an action has already been taken, the process 500 returns to stage 501 .
[0038] If it is determined at stage 505 that a responsive action has not already been taken, then the processor 130 executes a responsive action at stage 507 . The responsive action may be one that alerts the user, instructs the user or stores data for more general use, e.g., for data tracking and behavioral analysis. Thus for example, the responsive action may comprise presenting an alert on the device screen indicating to the user that a screen protector is not present and that the user should secure and apply a protector. The alert in this embodiment may include a link or directions usable to obtain an approved screen protector.
[0039] In an alternative embodiment, the responsive action includes opening a survey screen and soliciting information related to the use or non-use of a screen protector. In addition to or instead of the foregoing options, the device may store the time, date, duration or other data related to the absence of the screen protector in local or remote storage. This information may assist in evaluating warranty claims, product design and other tasks requiring product usage information. From stage 507 , the process returns to stage 501 .
[0040] It will be appreciated that various systems and processes for screen protector detection have been disclosed herein, along with methods and configurations for enabling the use of plastic display lenses in mobile devices. However, in view of the many possible embodiments to which the principles of the present disclosure may be applied, it should be recognized that the embodiments described herein with respect to the drawing figures are meant to be illustrative only and should not be taken as limiting the scope of the claims. Therefore, the techniques as described herein contemplate all such embodiments as may come within the scope of the following claims and equivalents thereof.
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Systems and methods for protecting a mobile device screen utilize a screen protector overlying the display screen lens, wherein the screen protector includes a conductive region. The device face includes a plurality of conductors underlying the screen protector at the conductive region. The conductors are capacitively coupled in the presence of the screen protector, and are capacitively decoupled when the screen protector is removed. This allows the device to detect removal of the screen protector and to perform a responsive action such as alerting a device user that the screen protector is not installed, instructing the user to install a screen protector, storing an indication that the screen protector is not installed and transmitting an indication that the screen protector is not installed.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method, system, and program for using a heartbeat signal to maintain data consistency for writes to source storage copied to target storage.
2. Description of the Related Art
Disaster recovery systems typically address two types of failures, a sudden catastrophic failure at a single point in time or data loss over a period of time. In the second type of gradual disaster, updates to volumes may be lost. To assist in recovery of data updates, a copy of data may be provided at a remote location. Such dual or shadow copies are typically made as the application system is writing new data to a primary storage device. Different copy technologies may be used for maintaining remote copies of data at a secondary site, such as International Business Machine Corporation's (“IBM”) Extended Remote Copy (XRC), Coupled XRC (CXRC), Global Copy, and Global Mirror Copy. These different copy technologies are described in the IBM publications “The IBM TotalStorage DS6000 Series: Copy Services in Open Environments”, IBM document no. SG24-6783-00 (September 2005) and “IBM TotalStorage Enterprise Storage Server: Implementing ESS Copy Services with IBM eServer zSeries”, IBM document no. SG24-5680-04 (July 2004).
In data mirroring systems, data is maintained in volume pairs. A volume pair is comprised of a volume in a primary storage device and a corresponding volume in a secondary storage device that includes an identical copy of the data maintained in the primary volume. Primary and secondary control units, also known as storage controllers or enterprise storage servers, may be used to control access to the primary and secondary storage devices. In certain backup system, a sysplex timer is used to provide a uniform time across systems so that updates written by different applications to different primary storage devices use consistent time-of-day (TOD) value as a time stamp. Application systems time stamp data sets when writing such data sets to volumes in the primary storage. The integrity of data updates is related to ensuring that updates are done at the secondary volumes in the volume pair in the same order as they were done on the primary volume. The time stamp provided by the application program determines the logical sequence of data updates.
In peer-to-peer remote copy operations (PPRC), multiple primary control units may have source/target pairs, i.e., volume pairs, included in consistency groups so that data copied to target volumes by the different primary control units maintains data consistency. A host system includes a program, referred to as a consistency manager, to maintain data consistency across the different primary control units having source/target pairs in a consistency group. In the current art, if a primary control unit detects an error, such as a failure with the connection to secondary control unit managing access to the target storage in the source/target pair, then the primary control unit may initiate a freeze operation to block any further writes to the source volumes. In response to the freeze operation, application programs blocked from writing data would not write any more data to any primary control unit. After initiating the freeze operation, the primary control unit would send an interrupt to the consistency manager identifying the freeze and set a freeze timeout timer. At the expiration of the freeze timeout timer, the primary control unit would initiate a thaw operation to start accepting writes from the application to the source storage in the source/target pair, but not copy the writes to the target storage.
In the current art, if the primary control unit cannot communicate the interrupt to the consistency manager to allow the consistency manager to send freeze commands to all primary control units, then applications writing to primary control units other than the primary control unit where the freeze occurred may have their data writes transferred to the target storage even though data at the primary control unit where the freeze occurred would not copy writes to the target storage. This may result in data inconsistency at the target storage.
For these reasons, there is a need in the art to provide techniques for maintaining data consistency.
SUMMARY
Provided are a method, system, and program for using a heartbeat signal to maintain data consistency for writes to source storage copied to target storage. A copy relationship associates a source storage and target storage pair, wherein writes received at the source storage are transferred to the target storage. A determination is made whether a signal has been received from a system within a receive signal interval. A freeze operation is initiated to cease receiving writes at the source storage from an application in response to determining that the signal has not been received within the receive signal interval. A thaw operation is initiated to continue receiving write operations at the source storage from applications after a lapse of a freeze timeout in response to the freeze operation, wherein after the thaw operation, received writes completed at the source storage are not transferred to the target storage.
In an additional embodiment, there is information on multiple source storage and target storage pairs maintained by control units, wherein the control unit maintaining the pair copies writes to the source storage to the target storage. A determination is made of freeze timeouts used by control units maintaining the source and target pairs. In response to a freeze operation with respect to one source and target pair managed by one control unit, the control unit blocks writes to the source storage. The control unit initiates a thaw operation to continue receiving write operations at the source storage after a lapse of the freeze timeout for the source and target pair in response to the freeze operation. After the thaw operation, received writes completed at the source storage are not transferred to the target storage. A determination is made of a send signal interval based on the determined freeze timeouts. A signal is communicated at the send signal interval to the control units maintaining the source and target pairs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an embodiment of a network computing environment.
FIG. 2 illustrates an embodiment of information maintained for a copy relationship.
FIG. 3 illustrates an embodiment of copy relationship and other information maintained at the primary control units.
FIG. 4 illustrates an embodiment of session information.
FIG. 5 illustrates an embodiment of consistency group information.
FIG. 6 illustrates an embodiment of primary control unit information.
FIG. 7 illustrates an embodiment of operations to register source/target pairs maintained by primary control units to include in a consistency group.
FIG. 8 illustrates an embodiment of operations performed by a consistency manager to send heartbeat signals to primary control units.
FIG. 9 illustrates an embodiment of operations for a primary control unit to monitor for heartbeat signals from a consistency manager to maintain data consistency.
DETAILED DESCRIPTION
FIG. 1 illustrates an embodiment of a network computing environment. A network 2 includes a plurality of primary control units 4 a . . . 4 n ; primary storages 6 a . . . 6 n ; secondary storages 12 a . . . 12 n ; a host 14 writing updates to the primary storages 6 a . . . 6 n ; and a consistency manager 16 maintaining data consistency among source and target storage pairs managed by the primary 4 a . . . 4 n and secondary 10 a . . . 10 n control units. The components 4 a . . . 4 n , 6 a . . . 6 n , 12 a . . . 12 n , 14 , 16 , and 18 , are connected to the network 2 and the network 2 enables communication among these components. The network 2 may include one or more switches to provide one or more paths of communication between the different network 2 elements.
The primary 4 a . . . 4 n and secondary 10 a . . . 10 n control units include copy manager software 20 a . . . 20 n and 22 a . . . 22 n , respectively, that manages the copying of writes to locations in the primary storages 6 a . . . 6 n in a source/target copy pair to target storage 10 a . . . 10 n indicated in the source/target copy pair information. The primary copy manager 20 a . . . 20 n may read updates from the primary storages 6 a . . . 6 n and send the writes to the primary control unit 4 a . . . 4 n that manages the copying of the writes in the order in which they were written to the primary storages 6 a . . . 6 n to the corresponding secondary storage 12 a . . . 12 n (target). The dependent order of the writes may be maintained by writing the data synchronously, so that the data will be on the target and source storage before the application 24 is allowed to proceed with a next write. Therefore, the data will be consistent on the targets as a result of the application 24 using ordered dependent writes for data that needs to be consistent with itself. Thus, when data is recovered from the target storage, i.e., secondary storage 12 a . . . 12 n , the recovered data will be consistent.
The copy managers 20 a . . . 20 n , 22 a . . . 22 n may copy data by sending the writes to the primary control units 4 a . . . 4 n , which then manage and initiate the synchronously copying from the source to the storage using a technique such as peer-to-peer remote copy (PPRC). Complete may be returned to the application 24 providing the writes upon completing the write at the primary control unit 4 a . . . 4 n or the secondary control unit 10 a . . . 10 n . Alternatively, the primary control units 4 a . . . 4 n may copy data asynchronously using remote copy technology.
The consistency manager 16 maintains consistency across storage/target pairs managed by primary control units 4 a . . . 4 n . Each primary control unit 4 a . . . 4 n includes information on one or more copy relationship, each copy relationship specifying source locations in the primary storage 6 a . . . 6 n , e.g., LSSs, volumes, etc., copied to corresponding target locations in the secondary storage 12 a . . . 12 n.
The network 2 may comprise a Storage Area Network (SAN), Local Area Network (LAN), Intranet, the Internet, Wide Area Network (WAN), peer-to-peer network, arbitrated loop network, etc. The storages 6 a . . . 6 n , 12 a . . . 12 n may comprise an array of storage devices, such as a Just a Bunch of Disks (JBOD), Direct Access Storage Device (DASD), Redundant Array of Independent Disks (RAID) array, virtualization device, tape storage, flash memory, etc.
The consistency manager 16 may be implemented within one of the primary or secondary control units or in a separate system, such as shown in FIG. 1 .
FIG. 2 illustrates an embodiment of copy relationship information maintained by the copy managers 20 a . . . 20 n and, in certain embodiments, 22 a . . . 22 n . Each copy relationship 50 instance includes: a copy relationship identifier (ID) 52 ; the source storage 54 locations, e.g., LSS, in the primary storages 6 a . . . 6 n involved in the copy relationship; the corresponding target storage 56 locations in the secondary storages 12 a . . . 12 n to which writes to the source storage 54 locations are copied; and a freeze timeout 58 for the copy relationship 52 , e.g., LSS pair. For instance, if a freeze operation is performed at the primary control unit 4 a . . . 4 n due to some error, then after the freeze timeout time 58 has elapsed for the particular copy relationship 52 , the primary control unit 4 a . . . 4 n automatically initiates a thaw operation to start accepting writes to the source storage 54 locations from the application 24 without copying the writes to the corresponding target storage 56 location. In one embodiment, the copy manager 20 a . . . 20 n may issue the thaw to the primary control unit 4 a . . . 4 n before the timeout time if the copy manager 20 a . . . 20 n determines that all the source LSS pairs have been frozen to ensure data consistency. In this way, the copy manager 20 a . . . 20 n may maintain different freeze timeouts for different source storage locations 54 involved in copy relationships to allow writes to resume at different times for different source storage locations 54 , depending on the freeze timeout times 58 defined in the copy relationship information 50 for that storage location 54 .
FIG. 3 illustrates further information maintained in a primary control unit 4 a . . . 4 bn for use by the copy manager 20 a . . . 20 n , including one or more copy relationships 50 , a minimum freeze timeout time 60 indicating a consistency group minimum freeze timeout time used across all the copy relationships in the primary control units 4 a , 4 b . . . 4 n that are managed by the consistency manager 16 in a single consistency group. The consistency manager 16 may provide the copy manager 20 a . . . 20 n in the primary control units 4 a . . . 4 n with this value. The receive heartbeat interval 62 is an interval in which the copy manager 20 a . . . 20 n expects to receive a heartbeat signal from the consistency manager 16 .
If the copy manager 20 a . . . 20 n does not receive the heartbeat signal within the receive heartbeat interval 62 , then the copy manager 20 a . . . 20 n will initiate a freeze operation to quiesce further writes. The freeze operation may be issued to those source-target locations, e.g., LSS pairs, registered in the sessions managed by the copy manager 20 a . . . 20 n . In one embodiment, the copy manager 20 a . . . 20 n calculates the receive heartbeat interval 62 as a function of the consistency group minimum freeze timeout time 60 , such that the receive heartbeat interval 62 is less than the consistency group minimum freeze timeout time 60 . Using the consistency group minimum freeze timeout time to determine the receive heartbeat interval ensures that any one primary control unit 4 a . . . 4 n would perform a freeze operation before another primary control unit 4 a . . . 4 n would thaw as a result of the expiration of that primary control unit's 4 a . . . 4 n freeze timeout times. For instance, if a primary control unit 4 a . . . 4 n loses connection with the consistency manager 16 , then there is a concern that another primary control unit 4 a . . . 4 n may initiate a freeze operation as a result of some failure to copy writes to the target storage. If one primary control unit lost its connection with the consistency manager 16 , then it may continue to copy writes to the target storage after the primary control unit that performed the freeze operation thaws. If this occurs, then target storage may include inconsistent data because one primary control unit is writing dependent data to the target side, while other primary control units that performed the freeze operation do not copy dependent data, resulting in data inconsistency at the target side. With the described embodiments, if the consistency manager 16 is assumed to send the heartbeat signal more frequently than the receive heartbeat interval 62 and the receive heartbeat interval 62 is less than the consistency group minimum freeze timeout time 60 across all primary control units 4 a . . . 4 n , than all primary control units will freeze before any one of them thaws and permits the application 14 writes to continue. This ensures that all primary control units 4 a . . . 4 n will not send any further data to the target after any other primary control unit thaws because all primary control units involved in the consistency group will have initiated a freeze operation before any of them would thaw and permit writes after a freeze.
In one embodiment, the receive heartbeat interval 62 may be calculated by subtracting from the minimum freeze timeout time 60 the time it would take the copy manager 20 a . . . 20 n to issue a freeze operation to all copy relationships 50 maintained at the primary control unit 4 a . . . 4 n , also known as a command runtime. This takes into account the command runtime for the freeze to be implemented at all copy relationships 50 , i.e., all LSSs, so that a primary control unit will issue a freeze operation in enough time to allow the freeze to be implemented at all of its copy relationships 50 before any other primary control unit can thaw and allow the application 14 to continue writes to all primary control units 4 a . . . 4 n.
In one embodiment, the consistency manager 16 may maintain a consistency group comprised of one or more sessions. A session includes source/target pairs on one or more primary control units 4 a . . . 4 n and multiple sessions may include source/target pairs on the same or different primary control units 4 a . . . 4 n . FIG. 4 illustrates an embodiment of session information 70 having: a session identifier (ID) 72 and then one or more source/target pair instances for each source/target pair included in the session. For each source/target pair included in the session 72 , the session information 70 includes the primary control unit 74 a . . . 74 n and the source/target pair 76 a . . . 76 n in the primary control unit 74 a . . . 74 n included in the session 72 . The source/target pair 76 a . . . 76 n information may identify an LSS pair or other storage unit pairs in the primary 6 a . . . 6 n and secondary 12 a . . . 12 n storages.
FIG. 5 illustrates an embodiment of consistency group information 80 the consistency manager 16 maintains for each consistency group being managed. The consistency group information 80 includes a consistency group identifier (ID) 82 ; the one or more sessions 84 included in the consistency group 82 , where each session includes one or more source/target pairs in one or more of the connected primary control units 4 a . . . 4 n ; a consistency group minimum freeze timeout time 86 indicating the minimum freeze timeout time across all primary control units 4 a , 4 b . . . 4 n including source/target pairs in the consistency group 82 ; and a send heartbeat interval 88 calculated from the consistency group minimum freeze timeout time 86 at which the consistency manager 16 sends heartbeat signals to the primary control units 4 a . . . 4 n managing source/target pairs in the consistency group 82 .
FIG. 6 illustrates an embodiment of primary control unit information 90 the consistency manager 16 maintains for each primary control unit including source/target pairs in a one consistency group 80 . The primary control unit information 90 indicates the control unit 92 and the minimum freeze timeout time 94 of the source/target pairs at that control unit 92 .
FIG. 7 illustrates an embodiment of operations performed by the consistency manager 16 and the copy manager 20 a . . . 20 n in the primary control units 4 a . . . 4 n to exchange information to maintain data consistency with respect to the freeze operation. The consistency manager 16 performs the operations at blocks 100 - 110 and the copy manager 20 a . . . 20 n performs the operations at blocks 150 - 156 . Upon the consistency manager 16 initiating (at block 100 ) operations to register source/target pairs from the primary control units 14 a . . . 14 n in a consistency group 82 ( FIG. 5 ), the consistency manager 16 sends (at block 102 ) a registration to each connected primary control unit 4 a . . . 4 n . Upon receiving this registration request, the copy managers 20 a . . . 20 n at the primary control units 4 a . . . 4 n determine (at block 150 ) a minimum freeze timeout across all source/target pairs (e.g., LSS pairs) to be added to the consistency group being registered. The minimum freeze timeout may be determined across all source/target pairs registered in the sessions managed by the copy managers 20 a . . . 20 n . The copy manager 20 a . . . 20 n sends (at block 152 ) the consistency manager 16 the minimum freeze timeout time at the primary control unit 4 a . . . 4 n and the source/target pairs to register in the consistency group. The consistency manager 16 saves (at block 104 ) the received information for source/target pairs (e.g., LSS pairs) for the primary control unit 4 a . . . 4 n and the minimum freeze timeout time 94 ( FIG. 6 ) for the primary control unit 92 with the primary control unit information 90 .
Upon receiving registrations from all the primary control units 4 a . . . 4 n , the consistency manager 16 determines and saves (at block 106 ) the consistency group minimum freeze timeout time 86 ( FIG. 5 ) as the determined minimum of the received control unit minimum freeze timeout times 94 ( FIG. 6 ). The consistency manager 16 determines (at block 108 ) the send signal interval as a function of the consistency group minimum freeze timeout time 86 . In one embodiment, the send signal interval comprises a fraction of the receive heartbeat interval 62 ( FIG. 3 ) used by the copy managers 20 a . . . 20 n . In this way, the consistency manager 16 sends the heartbeats to the primary control units 4 a . . . 4 n at a higher frequency then the receive heartbeat interval to ensure that the primary control units 4 a . . . 4 bn initiate freeze operations before other primary control units 4 a . . . 4 n thaw and begin allowing application 24 writes. The consistency manager 16 sends (at block 110 ) the determined consistency group minimum freeze timeout time 86 to each primary control unit 4 a . . . 4 n including source/target pairs in the consistency group 82 ( FIG. 5 ) at issue.
Upon the copy manager 20 a . . . 20 n at the primary control unit 4 a . . . 4 n receiving (at block 154 ) the consistency group minimum freeze timeout 94 , the copy manager 20 a . . . 20 n calculates (at block 156 ) the receive signal interval as a function of the consistency group minimum freeze timeout time. As discussed, the calculated receive heartbeat interval 62 may comprise the consistency group minimum freeze timeout time 86 less then the freeze command runtime. In an alternative embodiment, the consistency manager 16 may calculate the receive heartbeat interval 62 and then transmit that calculated value to the copy managers 20 a . . . 20 n to use.
FIG. 8 illustrates an embodiment of consistency related operations performed by the consistency manager 16 . The consistency manager 16 initiates consistency operations (at block 200 ) and communicates (at block 202 ) a heartbeat signal at the send heartbeat interval to the primary control units 4 a . . . 4 n maintaining the source and target pairs in the consistency group 82 ( FIG. 5 ) being managed. The consistency manager 16 may send the heartbeat signals at the send heartbeat interval 88 ( FIG. 5 ) rate to all primary control units 74 a . . . 74 n ( FIG. 4 ) in all sessions 84 ( FIG. 5 ) identified in the consistency group information 80 for the consistency group 82 being managed. The consistency manager 16 may perform such operations for multiple consistency groups.
FIG. 9 illustrates an embodiment of operations performed by the copy managers 20 a . . . 20 n to perform heartbeat signal management related operations. Upon initiating (at block 220 ) heartbeat signal monitoring from the consistency manager 16 , the copy manager 20 a . . . 20 n sets (at block 222 ) a timer for the receive heartbeat interval 62 ( FIG. 3 ). If (at block 224 ) a signal (heartbeat) is received from the consistency manager 16 before the timer expires, then control proceeds back to block 222 to reset the timer and wait for the next heartbeat. Otherwise, if a heartbeat signal is not received from the copy manager 20 a . . . 20 n within the timer period (receive heartbeat interval 62 ), then the copy manager 20 a . . . 20 n initiates (at block 226 ) a freeze operation to block further writes from applications 24 ( FIG. 1 ) for all source/target pairs managed by the primary control unit 4 a . . . 4 n . The freeze operation may be sent to source/target pairs in the sessions registered with the copy manager 20 a . . . 20 n . In response to being blocked, the applications 24 would stop sending writes to any primary control unit 4 a . . . 4 n until the application 24 is notified that writes are allowed as part of the thaw operation. The copy manager 20 a . . . 20 n further sends (at block 228 ) an interrupt to the consistency manager 16 indicating a freeze. If the connection is available and the consistency manager 16 receives this interrupt, then the consistency manager 16 sends freeze commands to all the primary control units 4 a . . . 4 n in the consistency group including the primary control unit from which the interrupt was received. After commencing the freeze operation, the copy manager 20 a . . . 20 n starts (at block 230 ) the freeze timeout timer for each source/target pair, where after a freeze timeout timer expires, the source (primary control unit) may initiate the thaw procedure and accept writes for that source storage, e.g., LSS. After the freeze thaws, the copy manager 20 a . . . 20 n would not copy writes over to the target storage (secondary storage 12 a . . . 12 n ), so that data consistency is maintained at the secondary (target) storages 12 a . . . 12 n.
In a further embodiment, if a source/target pair is added or removed to a consistency group 82 ( FIG. 5 ), then the consistency manager 16 may perform the operations of FIG. 7 to recalculate the consistency group minimum freeze timeout time 86 to allow adjustment of the send 88 ( FIG. 5 ) and receive 62 ( FIG. 3 ) heartbeat intervals.
Described embodiments provide a technique to ensure that all primary control units having source/target pairs in a consistency group will all initiate freeze operations if one primary control unit initiates a freeze operation before any primary control unit thaws, or begins accepting writes after a freeze. With described embodiments, a primary control unit maintaining communication with a consistency manager initiates a freeze operation if the consistency manager sends a freeze command in response to being notified of a freeze command by another control unit. Alternatively, if a primary control unit loses its connection with the consistency manager, then that primary control unit would automatically begin a freeze operation if it did not receive a heartbeat signal from the consistency manager before any other primary control unit could thaw after its freeze timeout time.
Additional Embodiment Details
The described operations may be implemented as a method, apparatus or article of manufacture using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof. The described operations may be implemented as code maintained in a “computer readable medium”, where a processor may read and execute the code from the computer readable medium. A computer readable medium may comprise media such as magnetic storage medium (e.g., hard disk drives, floppy disks, tape, etc.), optical storage (CD-ROMs, DVDs, optical disks, etc.), volatile and non-volatile memory devices (e.g., EEPROMs, ROMs, PROMs, RAMs, DRAMs, SRAMs, Flash Memory, firmware, programmable logic, etc.), etc. The code implementing the described operations may further be implemented in hardware logic (e.g., an integrated circuit chip, Programmable Gate Array (PGA), Application Specific Integrated Circuit (ASIC), etc.). Still further, the code implementing the described operations may be implemented in “transmission signals”, where transmission signals may propagate through space or through a transmission media, such as an optical fiber, copper wire, etc. The transmission signals in which the code or logic is encoded may further comprise a wireless signal, satellite transmission, radio waves, infrared signals, Bluetooth, etc. The transmission signals in which the code or logic is encoded is capable of being transmitted by a transmitting station and received by a receiving station, where the code or logic encoded in the transmission signal may be decoded and stored in hardware or a computer readable medium at the receiving and transmitting stations or devices. An “article of manufacture” comprises computer readable medium, hardware logic, and/or transmission signals in which code may be implemented. A device in which the code implementing the described embodiments of operations is encoded may comprise a computer readable medium or hardware logic. Of course, those skilled in the art will recognize that many modifications may be made to this configuration without departing from the scope of the present invention, and that the article of manufacture may comprise suitable information bearing medium known in the art.
The terms “an embodiment”, “embodiment”, “embodiments”, “the embodiment”, “the embodiments”, “one or more embodiments”, “some embodiments”, and “one embodiment” mean “one or more (but not all) embodiments of the present invention(s)” unless expressly specified otherwise.
The terms “including”, “comprising”, “having” and variations thereof mean “including but not limited to”, unless expressly specified otherwise.
The enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise.
The terms “a”, “an” and “the” mean “one or more”, unless expressly specified otherwise.
Devices that are in communication with each other need not be in continuous communication with each other, unless expressly specified otherwise. In addition, devices that are in communication with each other may communicate directly or indirectly through one or more intermediaries.
A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary a variety of optional components are described to illustrate the wide variety of possible embodiments of the present invention.
Further, although process steps, method steps, algorithms or the like may be described in a sequential order, such processes, methods and algorithms may be configured to work in alternate orders. In other words, any sequence or order of steps that may be described does not necessarily indicate a requirement that the steps be performed in that order. The steps of processes described herein may be performed in any order practical. Further, some steps may be performed simultaneously.
When a single device or article is described herein, it will be readily apparent that more than one device/article (whether or not they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether or not they cooperate), it will be readily apparent that a single device/article may be used in place of the more than one device or article or a different number of devices/articles may be used instead of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features. Thus, other embodiments of the present invention need not include the device itself.
The illustrated operations of FIGS. 7 , 8 , and 9 show certain events occurring in a certain order. In alternative embodiments, certain operations may be performed in a different order, modified or removed. Moreover, steps may be added to the above described logic and still conform to the described embodiments. Further, operations described herein may occur sequentially or certain operations may be processed in parallel. Yet further, operations may be performed by a single processing unit or by distributed processing units.
The foregoing description of various embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
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Provided are a method, system, and program for using a heartbeat signal to maintain data consistency for writes to source storage copied to target storage. A copy relationship associates a source storage and target storage pair, wherein writes received at the source storage are transferred to the target storage. A determination is made whether a signal has been received from a system within a receive signal interval. A freeze operation is initiated to cease receiving writes at the source storage from an application in response to determining that the signal has not been received within the receive signal interval. A thaw operation is initiated to continue receiving write operations at the source storage from applications after a lapse of a freeze timeout in response to the freeze operation, wherein after the thaw operation, received writes completed at the source storage are not transferred to the target storage.
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TECHNICAL FIELD
The present invention relates to a starter, and more particularly to an auxiliary mesh type starter.
BACKGROUND ART
FIG. 1 is a cross-sectional view of the currently existing auxiliary mesh type starter. As shown in FIG. 1 , the auxiliary mesh type starter which applies a starting torque to an engine has the following structure: a speed reducer 2 is adapted to decelerate the rotational torque of an armature 11 in a motor 1 and to increase rotational torques, and an isolator 4 is mounted on a driving gear 6 of an output shaft 5 and is driven by the motor 1 to rotate.
Referring to FIG. 2 , an auxiliary mesh type starter comprises a motor 1 , an electromagnetic switch 3 and relays 12 . In the auxiliary mesh type starter, the electromagnetic switch 3 comprises an attracting coil 36 , a holding coil 37 (the holding coil 37 and the attracting coil 36 are arranged on a coil frame 43 ), an solenoid body 7 circumferentially surrounds the outer sides of the attracting coil 36 and the holding coil 37 and constitutes a portion of a magnetic circuit, a stop seat 16 is arranged at the rear end parts of the attracting coil 36 and the holding coil 37 and constitutes a portion of the magnetic circuit, a plunger 8 is arranged on the inner circumferences of the attracting coil 36 and the holding coil 37 and is capable of sliding in an axial direction, a return spring 14 applies a return force to the plunger 8 , and a movable contact point 17 is mounted at the rear end of the plunger 8 , and a pair of stationary contact points 30 a and 30 b are arranged relative to the movable contact point 17 and are connected to the external wiring. An electromagnetic attraction force in the B-direction as shown in FIG. 1 is generated in the plunger 8 by energizing the attracting coil 36 and the holding coil 37 of the electromagnetic switch 3 . Owing to the electromagnetic attraction force, the upper end of a shift fork 9 in cooperation with the plunger 8 moves towards the right direction (indicated by arrow B) and the lower end thereof moves towards the left direction (indicated by arrow A) as shown in FIG. 1 . Thus, a force is applied to the isolator 4 and the driving gear 6 on the output shaft 5 to cause them to move towards the left direction (indicated by arrow A) as shown in FIG. 1 , then the driving gear 6 moves towards such a direction that it is going to mesh with a flywheel gear ring 10 of the engine.
Also referring to FIG. 2 , the positive terminal of a storage battery 13 is connected to a terminal 18 of the electromagnetic switch 3 , and the negative terminal is grounded or connected to a terminal 31 of the motor 1 . The relay 12 which switches on/off a terminal 50 of the electromagnetic switch 3 includes: a terminal 50 c connected to the storage battery 13 , a contact point 32 connected to the terminal 18 , and a coil 34 for controlling the contact point 32 and a contact point 33 . The terminal 50 c located at one end of the coil 34 is connected via a key switch 35 to the positive terminal of the storage battery 13 . The other end of the coil 34 is grounded or connected to the negative terminal 31 .
In FIG. 2 , if the key switch 35 is closed to start the engine, then the coil 34 of the relay 12 is energized to form a closed circuit between the contact point 32 and the contact point 33 , and the storage battery 13 energizes the motor 1 via the attracting coil 36 of the electromagnetic switch 3 while energizing the holding coil 37 . The two energized coils generate an attraction force in the plunger 8 , so that the plunger 8 compresses the return spring 14 while moving in the B-direction, and the driving gear 6 moves towards one side of the flywheel gear ring 10 via the shift fork 9 (i.e., in the A-direction).
At this time, if the driving gear 6 smoothly meshes with the flywheel gear ring 10 , then the plunger 8 further moves until it contacts the end face of an arresting disc 16 , the movable contact point 17 comes into contact with the two stationary contact points 30 a and 30 b , the motor 1 is directly energized by the storage battery 13 to generate a usual rotational torque, and the driving gear 6 drives the flywheel gear ring 10 to rotate, thereby applying a starting torque to the engine. When the movable and stationary contact points are in contact with each other, the potentials of the terminal 50 and the terminal 19 are substantially the same, so no electric current flows through the attracting coil 36 , and the plunger 8 is kept in the position where it contacts the end face of the arresting disc 16 only with the holding force generated by the holding coil 37 .
After starting, if the key switch 35 is disconnected, then the coil 34 is not energized, a circuit break occurs between the contact point 32 and the contact point 33 , and no voltage is applied to the terminal 50 . So, the holding force generated by the holding coil 37 disappears, the plunger 8 returns to the state as shown in FIG. 1 with the aid of the spring force generated by the return spring 14 , and, partly with the aid of the shift fork 9 cooperating with the plunger 8 , the driving gear 6 breaks away from the flywheel gear ring 10 . Meanwhile, the movable contact point 17 also returns to the state as shown in FIG. 1 , thereby stopping energizing the motor.
As can be seen from FIG. 2 , the coil of the electromagnetic switch 3 consists of the attracting coil 36 and the holding coil 37 . The numbers of turns of the two coils are substantially equal, their head ends are connected together, and the tail end of the attracting coil 36 is connected to the power supply terminal (also the output terminal of the main contact point of the electromagnetic switch 3 ) of a DC motor, and the tail end of the holding coil 37 is kept grounded.
In addition, the attracting coil 36 of the electromagnetic switch 3 has low resistance, which is typically about 100 milliohms or so. In this way, the starter can turn slowly at a low torque before the closure of the main contact point of the electromagnetic switch 3 , so that when the driving gear 6 is pushed against the end face of the flywheel gear ring 10 , it can rotate slowly so that it is not pushed against the gear and then meshes with the flywheel gear ring 10 ; only after it meshes with the flywheel gear ring 10 , will the main contact point of the electromagnetic switch 3 be closed (i.e., will the movable contact point 17 come into contact with the two stationary contact points 30 a and 30 b ), will a large current flow through the motor 1 , and will a high torque be output from the starter, thereby avoiding a gear milling failure in the starter. Therefore, such starters are also called flexible mesh starters.
Such conventional auxiliary mesh type starters have the following problems:
(1) Since the head end of the attracting coil and the head end of the holding coil of the electromagnetic switch in this type of starter are connected together, in order to guarantee the reliable power off of the electromagnetic switch, the attracting coil and the holding coil of the electromagnetic switch must have substantially the same effective number of turns and, in the meanwhile, the holding coil must not have too few turns. This means that the attracting coil must also have quite a few turns. Although the starter can be enabled to rotate slowly before the closure of the main contact point of the electromagnetic switch by a method which comprises appropriately increasing the coil diameter of the attracting coil and reducing the number of turns of the attracting coil, the number of turns of the attracting coil cannot be reduced sharply, otherwise the number of turns of the holding coil has to be reduced drastically with an eye to the reliable power off of the electromagnetic switch. Because of the limited torque for the flexible meshing of this type of starter, in some cases, the driving gear cannot mesh with the flywheel gear ring and accordingly is pushed against the gear. As a consequence, the driving gear cannot mesh with the flywheel gear ring, thus the attracting coil is forced to be energized for a long time while a relatively large current flows through the coil, so the electromagnetic switch is prone to failure.
(2) Because a relatively large current flows through the attracting coil which has quite a few turns, a large electromagnetic force is generated by the electromagnetic switch and accordingly the driving gear applies a too large acting force to the end face of the flywheel gear ring, thereby badly damaging the end face of the flywheel gear ring; furthermore, since the driving gear applies a too large acting force to the end face of the flywheel gear ring, the driving gear of the starter is liable to be pushed against the gear, and if so, the transmission of the driving gear will be impeded by a high drag torque, and the fault that the electromagnetic switch is burnt out will easily occur as the driving gear is pushed against the gear for a long time.
(3) In order to ensure that a sufficiently large current flows through the attracting coil, the attracting coil has not many turns, thus the holding coil has not many turns, too, the coil has a higher current density, and the starter works for a long time, keeping elevating the temperatures of the coils too rapidly. Due to heat conduction, the attracting coil has a too high temperature, the starter has a too small braking torque for flexible meshing when it starts up again, then the faults of pushing against the gear and of burning out the electromagnetic switch would easily occur in the starter. If a method comprising increasing the coil diameter of the holding coil and rewinding it is employed for reducing the current density of the holding coil, such coil assembly is poor in winding process and the cost of the holding coil is high.
(4) In some abnormal conditions, e.g., when the flywheel gear ring and the driving gear do not match properly, the main contact point of the electromagnetic switch cannot be closed, then the attracting coil is compelled to have a large current flowing through it for a long time, so the fault of burning out would occur to the electromagnetic switch easily.
DISCLOSURE OF THE INVENTION
The technical problem to be solved by the present invention is to provide an auxiliary mesh type starter to solve the above-mentioned problems of the existing auxiliary mesh type starters.
To this end, the auxiliary mesh type starter according to the present invention comprises a motor, an electromagnetic switch connected to the motor and relays connected to the electromagnetic switch, wherein the electromagnetic switch comprises a holding coil, an attracting coil, a stop seat arranged at the rear end parts of the holding coil and the attracting coil, a plunger arranged on the inner circumferences of the holding coil and the attracting coil and capable of sliding in an axial direction, a return spring for applying a return force to the plunger, and a contact point arranged at the rear end of the plunger and the relays are connected to a key switch, wherein the relays comprise a first relay and a second relay, with the head end of the attracting coil being connected to the key switch via the first relay, and the head end of the holding coil being connected to the key switch via the second relay.
In said auxiliary mesh type starter, the number of turns of the attracting coil is less than the number of turns of the holding coil.
In said auxiliary mesh type starter, the number of turns of the attracting coil is zero.
In said auxiliary mesh type starter, the attracting coil is a means for limiting the magnitude of current.
In said auxiliary mesh type starter, the first relay is a time relay.
In said auxiliary mesh type starter, the second relay is a time relay.
In said auxiliary mesh type starter, the attracting coil is an aluminum enamelled wire, copper clad aluminum enamelled wire, constantan enamelled wire or iron wire.
The beneficial effects of the present invention are as follows:
(1) The head end of the attracting coil and the head end of the holding coil in the electromagnetic switch are connected separately and are controlled separately by different relays. In this way, the number of turns of the attracting coil needs not be the same as that of the holding coil, the number of turns of the holding coil may differ greatly from the number of turns of the attracting coil, and the attracting coil can be freely adjusted according to the required torque for meshing. Thus, the starter can generate a sufficiently large slow-turning torque, avoid the fault that the driving gear cannot rotate to mesh with the flywheel gear ring when the driving gear contacts the end face of the flywheel gear ring, avoid the faults of pushing against the gear, effectively decrease the possibility of burning out the electromagnetic switch, and prolong the service life of the starter.
(2) The holding coil may have quite a few turns and needs not be rewound. Thus it is ensured that the holding coil has a relatively low current density, the temperature rising rate of the holding coil will be significantly reduced, and the thermal damage to the holding coil will not occur. Besides, the following problem would not occur: the longtime work of the starter results in a high temperature of the holding coil, and due to heat conduction, the starter generates a small slow-turning torque in the case of another meshing. Moreover, the problem that the temperature of the holding coil rises too rapidly during the dragging of the starter can be effectively prevented, thereby effectively preventing the problem of a too high temperature of the attracting coil when the starter starts up again, i.e., preventing the problem that, due to the high temperature of the attracting coil, the current flowing through the holding coil is small, the slow-turning torque for meshing is too small, and the fault of pushing against the gear or meshing too long would occur in the starter.
(3) When power is off, the attracting coil and the holding coil of the electromagnetic switch would not form a series circuit, the two coils are in the off state, and thus the main contact point of the electromagnetic switch can be smoothly disconnected.
(4) When the relay that controls the attracting coil is a time relay, after the attracting coil is powered on for a short time (e.g., within 2 s), it is forced to be powered off, that is, the attracting coil stops working, so that in abnormal conditions (e.g., when the flywheel gear ring and the driving gear do not match properly and the latter cannot mesh with the former), the attracting coil would not have a large current flowing through it for a long time, thereby avoiding the fault of burning out the electromagnetic switch that is caused for particular and abnormal conditions. Similarly, a time relay (e.g., which is automatically disconnected after 30 s) can also be chosen as the relay that controls the holding coil, thereby avoiding the longtime power on of the holding coil that is caused for particular and abnormal conditions, and thereby preventing the armature, electromagnetic switch, isolator or the like from breaking down.
(5) The attracting coil may be made of a material having a higher resistivity, such as an aluminum enamelled wire, copper clad aluminum enamelled wire, constantan enamelled wire, iron wire, etc., thereby not only reducing the acting force that the driving gear of the starter applies to the end face of the flywheel gear ring but also reducing the cost of the electromagnetic switch.
(6) After the acting force that the driving gear applies to the end face of the flywheel gear ring is reduced, the extent of damage to the end face of the flywheel gear ring can be significantly reduced, thereby significantly prolonging the service time of the flywheel gear ring and fully satisfying the requirement for a starter with an idle start-stop system. In addition, as a small acting force is transmitted, the service lives of other parts (e.g., the shift fork, the driving gear, the isolator, and the electromagnetic switch, etc.) of the meshing system in the starter can be improved accordingly.
Hereinafter, the present invention is described in detail with reference to the accompanying drawings and embodiments, which, however, are not to limit the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of an auxiliary mesh type starter in the prior art;
FIG. 2 is an electrical wiring diagram of a starting circuit of the auxiliary mesh type starter shown in FIG. 1 ;
FIG. 3 is an electrical wiring diagram of a starting circuit of the auxiliary mesh type starter of Example 1 in the present invention;
FIG. 4 is an electrical wiring diagram of a starting circuit of the auxiliary mesh type starter of Example 2 in the present invention;
FIG. 5 is an electrical wiring diagram of a starting circuit of the auxiliary mesh type starter of Example 3 in the present invention;
FIG. 6 is an electrical wiring diagram of a starting circuit of the auxiliary mesh type starter of Example 4 in the present invention.
The following are the drawing reference signs:
1 —motor 2 —speed reducer 3 —electromagnetic switch 4 —isolator 5 —output shaft 6 —driving gear 7 —solenoid body 8 —plunger 9 —shift fork 10 —flywheel gear ring 11 —armature 12 —relay 13 —storage battery 14 —return spring 16 —arresting disc 17 —movable contact point 18 , 19 —terminal 30 a , 30 b —stationary contact point 31 —negative terminal 32 , 33 —contact point 321 , 322 —contact point 331 , 332 —contact point 34 —coil 341 , 342 —coil 35 —key switch 36 —attracting coil 36 ′—current limiting resistor 37 —holding coil 43 —coil frame 50 , 50 i , 50 ii —terminal 50 c , 50 c i , 50 c ii —terminal
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the technical solution of the present invention is described in detail with reference to the accompanying drawings and embodiments, so as to further make clear the object, solution and effect of the present invention, rather than limit the protection scopes of the appended claims of the present invention.
The auxiliary mesh type starters according to the present invention differs distinctly from the auxiliary mesh type starters in the prior art in that the head ends of an attracting coil and of a holding coil in an electromagnetic switch are connected separately and are controlled separately by different relays. Next, the aforesaid difference will be introduced in detail with reference to embodiments.
EXAMPLE 1
Referring to FIG. 3 , the auxiliary mesh type starter according to the present invention, which is substantially similar in structure to the auxiliary mesh type starter as shown in FIG. 1 , also comprises a motor 1 , an electromagnetic switch 3 connected to the motor 1 and relays 12 connected to the electromagnetic switch 3 , wherein the relays 12 are connected to a key switch 35 . The electromagnetic switch 3 is essentially the same as a common auxiliary mesh type electromagnetic switch, i.e., the electromagnetic switch 3 still controls the power on/off of the motor 1 using a pair of contact points, except that the head end of the attracting coil 36 and the head end of the holding coil 37 are connected separately and are controlled separately by two relays. To be specific, the relays 12 include a first relay and a second relay, wherein the first relay includes contact points 321 , 331 and a coil 341 , with the head end (which is connected to the terminal 50 I) of the attracting coil 36 being connected to the key switch 35 via the first relay, and wherein the second relay includes contact points 322 , 332 and a coil 342 , with the head end (which is connected to the terminal 50 II) of the holding coil 37 being connected to the key switch 35 via the second relay.
Other detailed structures of the auxiliary mesh type starter are the same as those in the prior art (for example, see FIG. 1 ). Details are not repeated herein.
In this example, since the attracting coil 36 and the holding coil 37 of the electromagnetic switch 3 are connected via two pairs of the contact points of relays (i.e., the head end of the attracting coil 36 and the head end of the holding coil 37 are not directly connected), the number of turns of the attracting coil 36 may differ greatly from the number of turns of the holding coil 37 , that is, the numbers of turns need not be identical. Preferably, the number of turns of the attracting coil 36 can be far less than the number of turns of the holding coil 37 , so that the attracting coil 36 has low resistance, which ensures that after the contact points of the relays 12 close and before the movable contact point 17 and the stationary contact points 30 a , 30 b of the electromagnetic switch 3 are connected, the current in the attracting coil 36 can enable the motor 1 to turn slowly.
In this example, the attracting coil 36 may be made of a material having a higher resistivity, such as an aluminum enamelled wire, copper clad aluminum enamelled wire, constantan enamelled wire, iron wire, etc. The coil diameter and the number of turns of the coil are adjusted according to the required slow-turning torque, thereby not only reducing the acting force that the driving gear 6 of the starter applies to the end face of the flywheel gear ring 10 but also reducing the cost of the electromagnetic switch 3 .
Referring to FIG. 3 and FIG. 1 , the auxiliary mesh type starter of the above-mentioned structure operates as follows: when the starter starts to work, the key switch 35 is turned on, the coil 341 in the first relay and the coil 342 in the second relay are excited respectively, and the movable and stationary contact points of the two relays are closed respectively. The terminals 501 and 5011 of the electromagnetic switch 3 are energized respectively, the attracting coil 36 and the holding coil 37 are powered on simultaneously, the electromagnetic force generated by the two coils causes the plunger 8 to move towards the arresting disc 16 , and the motor 1 starts to rotate slowly to drive the driving gear 6 rotate. In the meanwhile, with the aid of the shift fork 9 , the plunger 8 enables the driving gear 6 to move towards the flywheel gear ring 10 , and the driving gear 6 flexibly meshes with the flywheel gear ring 10 while turning slowly. After that, the movable contact point 17 comes into contact with the main contact point of the electromagnetic switch 3 under the action of the plunger 8 , the attracting coil 36 is short-circuited, a large electrical current flows through the motor 1 , and then the motor 1 starts to output a full torque to start the engine. After the completion of starting, the key switch 35 is disconnected, the coils in the two relays are powered off simultaneously, the movable and stationary contact points of the two relays are disconnected respectively under the action of the return spring 14 , the storage battery 13 is disconnected, no current flows through the attracting coil 36 and the holding coil 37 , the electromagnetic force generated by the electromagnetic switch 3 disappears, the movable and stationary contact points of the electromagnetic switch 3 are disconnected under the action of the return spring 14 , the motor 1 is powered off, the starter stops working, and the driving gear 6 returns to the initial state.
EXAMPLE 2
Referring to FIG. 4 , the structure in this example is substantially the same as the structure in Example 1. The difference is: in this embodiment, the number of turns of the attracting coil is zero; preferably, the attracting coil 36 is a means for limiting the magnitude of current, i.e., the attracting coil 36 can be regarded as a current limiting resistor 36 ′, and the slow-turning torque of the starter is adjusted by adjusting the current limiting resistor 36 ′. That is to say, in this example, the electromagnetic switch 3 only has one coil (the holding coil 37 ), the electromagnetic force generated by the coil plays a role in holding the plunger 8 and also in attracting the plunger 8 . Since the other structures are essentially the same as those described in Example 1, details are not repeated herein.
This example has the following advantages:
(1) Since the slow-turning torque of the starter is adjusted through the current limiting resistor, the magnitude of current limiting resistance can be arbitrarily designed based on the demand of the starter for a slow-turning torque and would not be subject to other factors. Therefore, the slow-turning torque can be increased, thus the slow-turning of the starter would not disappear with an increase in rotational resistance, and it is ensured that the starter can successfully achieve flexible meshing in any case.
(2) The number of turns of the holding coil can be set to a larger number, so that the thermal power generated by the electromagnetic switch is small and the fault of burning out the electromagnetic switch is unlikely to occur.
(3) The holding coil and the current limiting resistor are controlled by two relays, respectively. The electromagnetic switch is still of a common single-contact structure. In this way, under the circumstance that a relatively high reliability and reliable meshing of the starter are guaranteed, the structures and manufacturing processes of the starter and of the electromagnetic switch are not changed a lot on the whole.
EXAMPLE 3
Referring to FIG. 5 , the structure in this example is substantially the same as the structure in Example 1, i.e., two relays are used to control the attracting coil 36 and the holding coil 37 , respectively. The difference is: in this embodiment, the first relay that controls the attracting coil 36 is a time relay, i.e., the attracting coil 36 is controlled by a delay relay, so, after the attracting coil 36 is powered on for a short time (e.g., within 2 s), the contact points of the first relay are compelled to be disconnected so that in abnormal conditions (e.g., when the flywheel gear ring 10 and the driving gear 6 do not reasonably match and the latter cannot mesh with the former), the attracting coil 36 would not have a large current flowing through it for a long time, thereby avoiding the fault of burning out the electromagnetic switch that is caused for particular and abnormal conditions.
Similarly, the second relay that controls the holding coil 37 can also be a time relay. Thus, when a time relay (e.g., which is automatically disconnected after 30 s) is chosen as the second relay to control the holding coil 37 , the fault that the electromagnetic switch 3 is burnt out due to the longtime power-on of the holding coil 37 can be avoided.
Since the other structures in this example are essentially the same as those described in Example 1, details are not repeated herein.
In this example, since the attracting coil 36 and the holding coil 37 of the electromagnetic switch 3 are connected via the contact points of two pairs of relays (i.e., the head end of the attracting coil 36 and the head end of the holding coil 37 are not directly connected), the number of turns of the attracting coil 36 may differ greatly from the number of turns of the holding coil 37 , that is, the numbers of turns need not coincide. Preferably, the number of turns of the attracting coil 36 can be far less than the number of turns of the holding coil 37 , so that the attracting coil 36 has low resistance, which ensures that after the closure of the contact points of the relays 12 and before the movable contact point and the stationary contact points of the electromagnetic switch 3 are turned on, the current in the attracting coil 36 can enable the motor 1 to turn slowly.
In this example, the attracting coil 36 may also be made of a material having a higher resistivity, such as an aluminum enamelled wire, copper clad aluminum enamelled wire, constantan enamelled wire, iron wire, etc. The coil diameter and the number of turns of the coil are adjusted according to the required slow-turning torque, thereby not only reducing the acting force that the driving gear 6 of the starter applies to the end face of the flywheel gear ring 10 but also reducing the cost of the electromagnetic switch.
Referring to FIG. 5 in combination with FIG. 1 , the working process of the auxiliary mesh type starter having the above-mentioned structure is described as follows: when the starter starts to work, the key switch 35 is turned on, the coil 341 in the first relay (a time relay) and the coil 342 in the second relay are excited separately, and the movable and stationary contact points of the two relays are closed separately. The terminals 50 I and 50 II of the electromagnetic switch 3 are energized separately, the attracting coil 36 and the holding coil 37 are powered on simultaneously, the electromagnetic force generated by the two coils causes the plunger 8 to move towards the arresting disc 16 , and, with the aid of the shift fork 9 , the plunger 8 enables the driving gear 6 to move towards the flywheel gear ring 10 ; in the meanwhile, the motor 1 starts to rotate slowly and the driving gear 6 rotates accordingly, the driving gear 6 flexibly meshes with the flywheel gear ring 10 while turning slowly; then, the movable contact point 17 comes into contact with the main contact point of the electromagnetic switch 3 under the action of the plunger 8 , the attracting coil 36 is short-circuited, a large electrical current flows through the motor 1 , and then the motor 1 starts to output a full torque to start the engine; during the starting, the time relay is powered off in advance according to the designed power-off time. After the completion of starting, the key switch 35 is disconnected, the coil in the second relay is powered off, the movable and stationary contact points of said relay are disconnected under the action of the return spring 14 , the storage battery 13 is disconnected, no current flows through the attracting coil 36 and the holding coil 37 , the electromagnetic force generated by the electromagnetic switch 3 disappears, the movable and stationary contact points of the electromagnetic switch 3 are disconnected under the action of the return spring 14 , the motor 1 is powered off, the starter stops working, and the driving gear 6 returns to the initial state. The working process in this example is substantially the same as that described in Example 1, and they only differ when the main contact point of the electromagnetic switch 3 cannot be closed and the attracting coil 36 is forced to be powered on for a long time.
In abnormal conditions, e.g., when the flywheel gear ring 10 and the driving gear 6 do not match properly, when the starter is energized, the main contact point of the electromagnetic switch 3 cannot be closed and the attracting coil 36 is forced to be powered on for a long time. However, a time relay has the function of delaying forced power-off, for example, the attracting coil 36 is energized for 2 s, then the time relay stops the process, the contact points are disconnected, the attracting coil 36 and the storage battery 13 are in an off state, and then no current flows through the attracting coil 36 , thereby effectively avoiding the occurrence of a fault in the attracting coil 36 of the electromagnetic switch 3 .
EXAMPLE 4
Referring to FIG. 6 , the structure in this example is substantially the same as the structure in Example 3, i.e., the attracting coil 36 and the holding coil 37 are still controlled by two relays, respectively, the first relay that controls the attracting coil 36 is a time relay, and the holding coil can also be controlled by a time relay. The difference is: in this embodiment, the number of turns of the attracting coil 36 is zero; preferably, the attracting coil 36 is a means for limiting the magnitude of current, i.e., the attracting coil 36 can be regarded as a current limiting resistor 36 ′, and the slow-turning torque of the starter is adjusted by adjusting the current limiting resistor 36 ′. That is to say, in this example, the electromagnetic switch 3 only has one coil (the holding coil 37 ), the electromagnetic force generated by the coil plays a role in holding the plunger 8 and also in attracting the plunger 8 .
Since the other structures are essentially the same as those described in Example 3, details are not repeated herein.
This example has the following advantages:
(1) Since the slow-turning torque of the starter is adjusted through the current limiting resistor, the magnitude of current limiting resistance can be arbitrarily designed based on the demand of the starter for a slow-turning torque and would not be subject to other factors. Therefore, the slow-turning torque can be increased, thus the slow-turning of the starter would not disappear with an increase in rotational resistance, and it is ensured that the starter can successfully achieve flexible meshing in any case.
(2) A time relay is used to control the attracting coil of the electromagnetic switch, thereby effectively avoiding the fault that the electromagnetic switch is burnt out in some exceptional case, e.g., when the main contact point of the electromagnetic switch cannot be closed.
(3) The holding coil and the current limiting resistor are controlled by two relays, respectively. The electromagnetic switch is still of a common single-contact structure. In this way, under the circumstance that a relatively high reliability and reliable meshing of the starter are guaranteed, the structures and manufacturing processes of the starter and of the electromagnetic switch are not changed a lot on the whole.
(4) The number of turns of the holding coil can be set to a larger number, so that the thermal power generated by the electromagnetic switch is small and the fault of burning out the electromagnetic switch is unlikely to occur.
Of course, the present invention may have a variety of other embodiments. Those skilled in the art can make all kinds of corresponding changes and modifications according to the present invention without departing from the spirit and essence of the present invention. It is intended that all these changes and modifications be covered by the appended claims of the present invention.
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An auxiliary mesh type starter, including a motor, an electromagnetic switch connected with the motor and relays connected with the electromagnetic switch, wherein the electromagnetic switch includes a holding coil, an attracting coil, a stop seat arranged at the rear end parts of the holding coil and the attracting coil, a plunger arranged on the inner circumferences of the holding coil and the attracting coil and capable of sliding in an axial direction, a return spring for applying return force to the plunger, and a contact point arranged at the rear end of the plunger; and the relays are connected to a key switch, wherein the relays include a first relay and a second relay, with the head end of the attracting coil connects to the key switch via the first relay, and the head end of the holding coil connects to the key switch via the second relay.
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BACKGROUND
[0001] 1. Field
[0002] The present invention relates to servers and, more particularly, to networked platforms.
[0003] 2. Background Information
[0004] One problem with accessing the Internet using software executing on a computer, such as a personal computer (PC), referred to in this context as a browser, is the delay or latency perceived by users until the web site or web page being accessed is displayed on the computer screen. Recently, so-called “auto-fetch” utilities have gained popularity with users who routinely browse the World Wide Web (the Web). These utilities are designed to “guess” and retrieve web objects or data objects of particular interest to the user in the background (e.g., while the user is reading a web page), thereby reducing the user's visible latency for page loading if the pages they subsequently browse are already available via their PC. Another application of this approach is Soften used in off-line browsers, which allows users to browse these cached web pages without Nonbeing connected to the Internet. When the user accesses the Web through a network proxy, that is, a network device or platform executing proxy software employed to access the Web, however, such auto-fetch utilities may have an undesirable adverse effect on a proxy cache, that is, the local cache for a platform executing proxy software, that uses a conventional least-recently-used (LRU)-based replacement policy, for example. Since the auto-fetch utility may continuously generate arbitrary large numbers of requests for web objects to the network proxy, popular objects or pages for the majority of so-called “typical users,” that is, those not using such auto-fetch utilities, are replaced by those objects requested by the auto-fetch utilities. As a result, typical users may experience a greater latency than they may otherwise, due at least in part to the abnormally large volumes of cached objects attributable to auto-fetch requests. A similar problem may also arise on a network server, such as a content server, which serves large numbers of users. Again, users may experience degraded performance when accessing such a server due at least in part to the inordinate resource demands of auto-fetching utilities.
[0005] Other on-line pre-fetching schemes have also been proposed to reduce the latency perceived by users by predicting and pre-fetching those web pages that are likely to be requested next, while the user is browsing through the currently displayed-web page. See, for example, “Using Predictive Pre-fetching to Improve World-Wide Latency”, by V. Padmanabhann and J. C. Mogul, appearing in ACM SIGCOMM Computer Communication Review, pp. 22-36, 1991. The proposed scheme executes a prediction process on the server side to compute the probability or likelihood that a particular web page will be accessed next and conveys this information to the client. The client program executing on the client PC then decides whether or not to actually “pre-fetch” the page. Two recently introduced commercial products offer an on-line pre-fetching feature: Peak Net.Jet available from Peak Technologies Inc. and Blaze from Datatytics, Inc. Net.Jet does not rely on server computation information to make pre-fetching decisions. Instead, client Java code performs this operation. Blaze, however, implements a server side program to assist the pre-fetching.
[0006] Several problems exist with these proposed approaches. First, the server side program imposes extra computational load on already frequently overworked Web servers. In addition, technologies like Blaze employ the technique of making changes to all deployed Web servers in order to operate. However, these Web servers may number in the millions. Second, the technique employing pure client side pre-fetching typically generates a lot of network traffic and may jam Web servers with requests that may not ultimately improve performance.
[0007] A need therefore exists for a technique of predictive pre-fetching that overcomes the foregoing disadvantages.
SUMMARY
[0008] Briefly, in accordance one embodiment of the invention, a method of suspending a network connection used for low priority transmissions between a client platform and a server platform includes: determining a characteristic of a transmission between the client platform and the server platform, said characteristic consisting essentially of a high priority transmission and a low priority transmission; and suspending the connection if the characteristic of the transmission comprises a high priority transmission.
[0009] Briefly, in accordance with another embodiment, a method of using a network connection between a client platform and a server platform includes; producing on one of the platforms a list of Uniform Resource Locators (URLs) from a requested network page, said list comprising links in said requested network page; and pre-fetching via said connection at least one of said URLs to said remote proxy server.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a schematic diagram illustrating an embodiment of a topology between platforms coupled or communicating via the Internet in which an embodiment of a method of proxy-assisted predictive pre-fetching in accordance with the present invention may be employed;
[0011] [0011]FIG. 2 is a schematic diagram illustrating the flow of signal information between the platforms of FIG. 1; and
[0012] [0012]FIG. 3 is a schematic diagram illustrating selected software modules of the client and server platforms of FIG. 1.
DETAILED DESCRIPTION
[0013] The embodiments of the present invention may be implemented according to the general architecture described, for example, in U.S. patent application Ser. No. 08/772,164, titled “System for Enhancing Data Access Over a Communications Link”, by M. Tso, J. Jing, R. Knauerhase, D. Romrell, D. Gillespie and B. Bakshi, filed on Dec. 12, 1996; U.S. patent application Ser. No. 08/799,654, titled “System for Scaling Image Data”, by M. Tso D. Romrell and S. Sathyanarayan, filed on Feb. 11, 1997; U.S. patent application Ser. No. 08/925,276, titled “System for Dynamically Transcoding Data Transmitted Between Computers”, by M. Tso, T. Willis, J. Richardson, R. Knauerhase and D. Macielinski, filed on Sep. 8, 1997; U.S. patent application Ser. No. 08/943,215, titled “Dynamically-Chainable Network Proxy”, by R. Knauerhase and Tso, filed on Oct. 24, 1997, U.S. patent application Ser. No. 08/957,468, titled “Method for Dynamically Determining Effective Speed of a Communications Link”, by R. Knauerhase and M. mTso, filed on Oct. 24, 1997; U.S. patent application Ser. No. 09/000,711, titled “System for Dynamically Controlling a Network Proxy”, by R. Knauerhase, M. Tso, filed on Dec. 30, 1997; U.S. patent application Ser. No. 09/000,762, titled “Method for Detecting a User-Controlled Parameter from a Client Device Behind a Proxy”, by B. Bakshi and M. Tso, filed on Dec. 30, 1997; U.S. patent application Ser. No. 09/001,294, titled “Method for Dynamic Determination of Client Communications Capabilities”, by B. Bakshi, R. Knauerhase and M. Tso, filed on Dec. 31, 1997; U.S. patent application Ser. No. 09/000,635, titled “Method for Auto-Fetch Protective Cache Replacement”, by J. Jing and M. Tso, filed on Dec. 30, 1997; U.S. patent application Ser. No. 09/000,636, titled “System for Transparent Recovery from Disruption of a Data Transfer”, by D. Romrell, filed on Dec. 30, 1996; U.S. patent application Ser. No. 09/000,761, titled “Method for Reducing User-Visible Latency in HTTP Transactions”, by B. Bakshi, filed on Dec. 30, 1997; U.S. patent application Ser. No. 09/000,760, titled “System for Providing Non-Intrusive Dynamic Content to a Client Device”, by B. Bakshi, R. Knauerhase and M. Tso, filed on Dec. 30, 1997; U.S. patent application Ser. No. 09/000,759, titled “Method and Apparatus for Dynamically Filtering Network Content”, by M. Tso, filed on Dec. 30, 1997; U.S. patent application Ser. No. 09/000,778, titled “System for Virus Checking Network Data”, by M. Tso and B. Bakshi, filed on Dec. 30, 1997; U.S. patent application Ser. No. 09/000,709, titled “System for Delivery of Dynamic Content to a Client Device”, by M. Tso, D. Romrell and B. Bakshi, filed on Dec. 30, 1997; U.S. patent application Ser. No. 09/002,164, titled “Method and Apparatus for Collecting Statistics from a Network Device”, by S. Sathyanarayan and R. Knauerhase, filed on Dec. 31, 1997; U.S. patent application Ser. No. 09/001,293, titled “System for Prevent Multiple Instances of the Same Dynamic Executable Module”, by B. Bakshi and M. Tso, filed on Dec. 31, 1997; and U.S. patent application Ser. No. 08/928,645, titled “System for Collecting and Displaying Performance Improvement Information for a Computer”, by M. Tso, Ba. Bakshi and R. Knauerhase, filed on Sep. 12, 1997, all of which are assigned to the assignee of the present invention. Of course, the invention is not limited in scope to these embodiments.
[0014] Referring now to FIG. 1, according to one embodiment of the present invention, a network device or platform, such as remote server 10 , may be coupled or communicate via the Internet with a client platform 20 and a content server platform 30 . In this embodiment, remote server 10 includes software that, when executing, allows a client, such as client platform 20 , to access the internet, as explained in more detail below. Therefore, in this context, remote server 10 is referred to as a remote proxy server. Although the invention is not limited in scope in this respect, remote proxy server 10 , also referred to in this context as a network device, may include Software executing on the network device capable of parsing text or other information provided in the form of electronic signals, such as parsing software module 14 . Likewise, remote server or remote proxy server 10 may also include software executing on the network device referred to in this context as a filtering module. In this particular embodiment, as suggested previously, the network device comprises a remote proxy server through which a plurality of client devices, such as client 20 , for example, may access network resources, such as content server 30 , for example. Of course, in other embodiments, network device 10 may comprise a client device, a content server, a network router, a bridge, a switch, or any other suitable data processing platform capable of being used in a communications network between a requesting client device and responding content server. As previously indicated, the parsing module and/or filtering module may be implemented as software modules executing on a network device or other platform, such as a PC, for example, including instructions for carrying out the particular functionality indicated. Remote proxy server 10 also includes bit stream interceptor 10 , such as a proxy or protocol stack, pre-fetching agent software module 30 including pre-fetching software policy software 40 , transcoding software module 12 , and cache memory 18 , as explained in more detail below.
[0015] In one embodiment, remote proxy server 10 may include a client preference table executed or executing in software coupled to communicate with or communicatively coupled with a parsing module and a filtering module. Although the invention is not restricted in scope in this respect, a client preference table may comprise in software, for example, a set of user controlled content selection criteria and preferences that may be indexed by a user name and/or an IP (Internet Protocol) address, for example. Each user name/IP address entry may optionally have an associated security password stored in the client preference table. According to this embodiment, when a user begins a session with remote proxy 10 for the first time, such as when client 20 requests a network data object via remote proxy server 10 , use of client 20 may be employed to “sign-on” To proxy server 10 . In this context, the term data object, web data object, or network data object refers to a set of related electrical data signals intended to be transmitted, stored, or received as a set.
[0016] Upon receipt of information identifying a user, such as a user name (e.g., user ID) or IP address, such as for client 20 , for example, contained in a registration request packet, for example, the parsing software module may be adopted to attempt to retrieve from the client preference tables any previously stored filtering parameters for that user or client, although the invention is again not limited in scope in this respect. The parsing software module may optionally be configured to perform authentication processing to ensure the user is properly authorized to access the remote proxy server. Such authentication may be accomplished using any existing or later developed authentication mechanism. If previously stored filtering parameters are found in the preference table, the parsing software module executing On the network device may store those parameters in a dynamic table keyed, for example, by IP address. This dynamic table may then be used in connection with dynamic filtering of content received via proxy server 10 in the form of electrical signals to be passed to client 20 during a session. In this context, the term session refers to a continual or persistent communication connection between the client platform executing software and the remote platform executing software. In addition to the foregoing, the parsing software module may include instructions for validating any existing entries and client preferences upon receipt of more up-to-date user preference information.
[0017] Likewise, in one embodiment, client 20 may include browser software, such as module 15 illustrated in FIG. 3, executing on the network device, such as Netscape Navigator(™), for example, which enables a user of client 20 to retrieve and display network data objects, such as web pages, originating from, for example, content server 30 . Content server 30 may reside, for example, on the Internet and be accessible through standard HTTP (Hyper Text Transfer Protocol) messages, however, the present invention, of course, is not limited to any particular network or communications method or protocol.
[0018] It is well known to deploy a network proxy, or proxy server, as an intermediary between one or more client computers and a network, such as the Internet, for example. Network proxies are described generally in HTML Source Book: A Complete Guide to HTML 3.0 (2d Ed. 1996), by Ian S. Graham and available from Wiley Computer Publishing, New York, N.Y. The network proxy is commonly used in conjunction with so-called a “firewall” software module to protect a local area network (LAN) from unauthorized access over the Internet. Such a firewall, typically installed on a “gateway computer,” that links a LAN to other networks, such as the Internet, restricts externally originated TCP/IP (Transmission Control Protocol/Internet Protocol) packets from entering the local network, thereby protecting local devices from hazards, such as unauthorized access. Network proxies are often used to address this shortcoming. A firewall, however, also prevents network users from directly accessing external resources, such as the Web.
[0019] Network proxies are usually configured to have free access to both internal LAN resources and external resources, and include the capability to pass data in the form of electrical signals back and forth across the firewall. Users may then be given indirect access to Web resources by configuring the user's Web browser to reference the firewall proxy instead of external resources. When the Web browser is used to retrieve information in the form of electronic signals, such as packets, for example, from the other side of the firewall, it sends a request to the firewall proxy, which then completes the request and passes the result back via the firewall to the requesting device. This is illustrated by FIG. 2, for example.
[0020] While firewall/network proxy architecture effectively shields a LAN from external hazards, this two staged access procedure is often relatively slow. It is, therefore, common for a network proxy to cache retrieved Web pages. In this context, a cache refers to a locally accessible, high speed memory to which electronic signal information may be stored and from which it may be retrieved. Typically, cache memory is distinguished from system random access memory or even sower memories, such as a hard drive, for example. The act of storing signal information in one of these high-speed memories is referred to as caching. For example, the first time a document from the Web is requested, the network proxy retrieves the document and forwards it to the browser for a presentation to the user, but also retains a copy of the document in its own local cache memory. If the same or another user makes the subsequent request for that same document, the network proxy returns the locally-cached copy of the document instead of retrieving it from the Web. An example of a cache for use by a network proxy is described in “A Hierarchical Internet Object Cache” by A. Chankhunthod et al., Nov. 6, 1995 (available from the Computer Science Department of the University of Southern California).
[0021] As previously described, proxy software or a proxy server executing on a PC may be located on a networked device or platform, such as on the Internet or on a content server. In this context, the term platform refers to a hardware and software system on top of which a software application may reside. Typically, an operation occurs, such as completing a request for accessing information in the form of electronic signals via the Internet, more quickly if the proxy software is physically located either near or on the client device. As was previously described, one technique for improving or reducing the latency associated with accessing a web page is employing pre-fetching. In this context, pre-fetching refers to a process in which network data objects are retrieved and stored in local cache before a specific user request for that data object has occurred. However, one disadvantage of this approach is that the cache may get overloaded. For example, on a remote proxy server that is shared by a large number of users, where it or any users' client device also fetches embedded links on the web page, the cache may be overloaded disproportionately by a small number of users. When this occurs, more cache misses may occur, as previously described, and, therefore, reduce or degrade performance. A content server may experience a similar as well.
[0022] Nonetheless, a proxy server provides a number of advantages. In addition to the previous advantage described with respect to employing the proxy server as a firewall, it also has the advantage of saving cost on Internet links because caching reduces the desirability of fetching pages from remote content servers.
[0023] As previously described in previously referenced patent application Ser. No. 09/000,635, one technique for addressing some of the disadvantages of an “auto-fetch” utility is to monitor the IP address of the requester, for example. Then, if a disproportionate number of requests originate from a single source, such as above a predetermined threshold, in one embodiment, the cached web pages associated with that source will no longer be maintained in the cache of the particular platform. This technique may also be employed on a remote proxy server in order to perform better load balancing of its received requests for web pages or other network data objects.
[0024] Referring to FIG. 1, client device 20 includes software executing to communicate via a persistent Internet connection with remote proxy server 10 . As illustrated, an embodiment of network device assisted pre-fetching in accordance with the invention may be used advantageously to provide benefits similar to traditional client side pre-fetching methods, but without some of the previously described disadvantages. In one embodiment, as illustrated in FIGS. 1 and 2, the network device comprises a proxy server 10 including a cache 18 , a pre-fetching agent software module 30 , and a parsing software module 50 . In this embodiment, instead of just sending requested URLs to the client, on the remote proxy server the parsing software module parses the HTML files and creates a list of URLs which were linked or embedded in the HTML file. The proxy server may then fetch some or all of the URLs in that list and store them in its cache, without first waiting for the client to issue requests for these URLs. This has the desirable effect of reducing end user visible latency because instead of fetching the information from the content server after the client requests the linked URLs, the content is stored in the proxy server's cache ready to download to the user when the user request comes. In addition, transcoding services, such as by module 12 , such as language translation or compression, for example, may be performed on the data objects and cached, prior to the client requesting them. Caching of transcoded data objects may significantly speed up end user visible latency for applications, particularly on computationally intensive transcodings, such as on-the-fly language translation. In this context, the term transcoding refers to a process in which data signals coded for one particular medium are recoded so that they may be read, transmitted, stored and/or manipulated in another medium. In one embodiment, the proxy server would be multithreaded or otherwise multitasking, such that pre-fetching and any subsequent transcode service applied to pre-fetched objects may take place in the background, while user requests are served as arelatively high priority. Prior to pre-fetching any URL, the pre-fetching agent may check to see if the data object it “points to” is stored in its cache already, and if it is, may check to see if it has “expired”. In this context, the term expired refers to a period of time that a cache management system may allow to elapse before determining whether any update to the data object have taken place. This may occur many possible ways well known to one of ordinary skill in the art. If the cached data object hasn't expired, then no pre-fetching occurs. If it is expired, then the pre-fetching agent may attempt to check with the content server to see if the data object has changed, using methods such as “get HTTP header,” which provides information in the terms of electronic signals regarding the last modified time and size. If the object hasn't changed, then the pre-fetching agent may reset the expired time according to any cache management process and no pre-fetching occurs. If the object has changed or has not been stored in the cache, then the pre-fetching agent may pre-fetch the data object from the content server.
[0025] One embodiment, as illustrated in FIGS. 1 and 2, may advantageously include a policy software module 40 to be used in conjunction with the pre-fetching agent software module. Policy software modules may be used to balance pre-fetching's undesirable effects with its benefits. In general, these modules when executed implement tradeoffs between data manipulation applications (such as transcoding or caching) and resource constraints (such as network bandwidth usage or cache memory usage). One example pre-fetching policy capable of being implemented includes, instead of pre-fetching all linked URLs on an HTML page, pre-fetching only the embedded URLs (e.g., images and applets, for example). Embedded URLs may be identified by their HTML tag. For example, images may be identified by the tag or their file extension and applets may be identified by the tag. Pre-fetching only embedded URLs is advantageous for both cache utilization and compression applications. Most browsers will automatically request embedded URLs on an HTML page, so little or no bandwidth is used unnecessarily by the remote proxy to perform pre-fetching. It provides an additional advantage of putting the images through compression(or other transcoding applications), which may be computationally intensive, prior to the browser issuing a request for the image. Another example pre-fetching policy includes selective pre-fetching based on the likelihood that a user will actually access the linked URL, to reduce bandwidth and cache space used unnecessarily. This policy could be implemented by examining how “popular” a link is. This information may be obtained, for example, by implementing a special HTTP protocol extension where the pre-fetch agent software module when executed obtains signal information about the probability of any link on the page being accessed from the content server. Then, depending on the load on the proxy server and the relative “cost” of bandwidth, the pre-fetching agent software module may, in execution, set a cut off probability so that the links whose reported probabilities are above that cut off are pre-fetched. In one embodiment, embedded URLs are set to a probability of 1 because browsers fetch them automatically. Also, different pre-fetching policy methods may be combined with others. These previously described pre-fetching policy methods are included for example purposes and do not limit the scope of the invention, of course.
[0026] For example, the probability may be advantageously calculated as follows using access frequency information that is already available to a server, although the invention is not limited in scope in this respect. The probability of a linked URL being followed is equal to the total number of accesses (call it “A”) to the linked URL in a given time period, divided by the total number of accesses (call it “B”) to the “parent” HTML (the one that contains the linked URL) during the same time period. If “A” is bigger than “B,” then 1 is assigned to the probability. “A” may be bigger than “B” because the linked URL may be accessible without clicking a link on the parent HTML page (e.g., if a user types in the linked URL directly or it is linked from another page). The period of time before “A” and “B” gets reset may be advantageously chosen to start when either the content for either the linked URL or the parent HTML page are updated, or it may be periodically reset if the pages do not change often. Periodic resets of the time period may have the effect of keeping up with changes in user's browsing habits (e.g., as the content becomes less current, repeat visitors to the page may go down alternate linked URLs from those they had accessed on a prior visit). For content which is dynamically generated (and, thus, certain objects may be different for different users), for example, for pages using cookies or ASP (active server pages), the server may optionally set the probability of the dynamically generated pages to “0” since there is little or no value in pre-fetching them.
[0027] Although a proxy server is used in the above description, it should be noted that other embodiments of the invention may be implemented on any network device capable of capturing the data signal stream and processing it. This particular embodiment employs a proxy server, but similar extensions may be implemented on other network devices, such as routers, switches, hubs, and bridges, for example.
[0028] Likewise, in this embodiment, the pre-fetching occurs up to one level of links, a similar technique may be applied recursively to the pages or other signal information that is pre-fetched. in one embodiment, the probability (and thus prioritization in the pre-fetching) advantageously decreases proportionally to the number of levels away from the page the user is currently accessing by multiplying the link probabilities. For example, the probability may be calculated as follows, although this approach makes several assumptions and where these assumptions are relaxed other approaches might be employed. Suppose HTML page A contains linked URL L 1 , which is itself an HTML page. Linked URL L 1 contains a link to URL L 2 . Assume the platform calculation for probability of L 1 access is P 1 , and for L 2 is P 2 . The probability the pre-fetch agent software module would assign to L 1 is P 1 since it is on the current page. The probability the pre-fretch agent software agent would assign to L 2 is P 1 ×P 2 , since P 2 can only be accessed if P 1 is accessed first. This method may be repeated for arbitrary levels of links by simply multiplying the probabilities of all the “parent” pages. In the case where multiple parent pages are possible, the probabilities may be calculated for each parent, and then averaged.
[0029] In this embodiment, client device 20 also includes local proxy software, so that operations typically performed by the remote proxy server may be off loaded to the client device advantageously. For example, in an embodiment of a method of using a persistent network connection, such as via the Internet, between a local client platform and a remote proxy server platform in accordance with the present invention, the local proxy on the client device may implement parsing, such as previously described. When executing on the local client platform, parsing software module may produce a list of URLs that are linked in the requested page, which is parsed first. The parsing software module when executing on the local client platform may then send a request to pre-fetch these URLs to the remote proxy server. The pre-fetch request may be different from a regular request, so that the pre-fetching agent 30 executing on the remote proxy server can prioritize it so that it is assigned with a lower priority than regular user requests, as described before. The request may also include user preference information, such as language preference, for example. Pre-fetch agent 30 optionally pre-fetches and transcodes the content according to such preferences, and transmits the signal information to the parsing software module, executing on the client platform. The parsing software receives these data signals stores it in a cache on the client. When the browser or other locally executing application requests this stored signal data, the local proxy, which is one mechanism, for example, for intercepting requests locally, retrieves it from the cache instead of retrieving it from the network, resulting in reductions in user visible latency. This is advantageous over current approaches where pre-fetch requests appear identical to regular requests, resulting in network devices, such as proxy caches and content servers behaving inefficiently.
[0030] Although a local proxy implementation on a client platform, for example, is referenced in the previous description, this invention is not limited in scope to a proxy implementation. All client software that is capable of both intercepting network requests on the client, and implementing the pre-fetching protocol, as described, while executing on a platform would suffice. Other examples where this capability may be implemented on a platform include protocol stacks e.g. TCP/IP), network interface card drivers, or browsers.
[0031] As previously suggested, one advantage of employing this approach with a client device is that load balancing is performed between the client device and the remote proxy server. In addition, where local proxy software is executed on the client device, this also provides compatibility between the browser on the client device and the remote proxy server. Without the local proxy executing on the client device, the browser on the client device may not be able to format pre-fetch requests differently from regular or typical user requests to the remote proxy server.
[0032] In yet another embodiment, when the client parsing software module 40 transmits a pre-fetching request to the pre-fetch agent software executing on the remote proxy server, the pre-fetching agent makes a determination regarding whether a given URL in the pre-fetching request is located in the cache of the remote proxy server. If the URL in the cache on the remote proxy, then the content of the URL may be transmitted to the client device. Alternatively, if the URL is not found in the cache, the remote proxy server transmits a “not found” message to the client device. This could be implemented as a pre-fetching policy where all pre-fetch URLs are assigned probability 0 (meaning never implement the request) unless they are in the cache, in which case they are assigned probability 1 (meaning always implement the request). An advantage of this approach is that it effectively implements pre-fetching without increasing traffic between the proxy and content servers. Keeping traffic and congestion reduced is a desirable attribute for networking and Internet-related technology.
[0033] Another advantageous capability may be implemented using the ability to distinguish low priority requests, such as pre-fetch requests, from high priority requests, such as regular requests. In an embodiment of a method of suspending a pre-fetched transmission between a local proxy client platform and a remote proxy server platform in accordance with the present invention, the local proxy client and the remote proxy server maintain a low priority transmission persistent network connection, such as via the Internet, such that low priority pre-fetched transmissions may be suspended or stopped relatively quickly once a high priority browser request transmission is transmitted between the local and remote proxies. Once the pre-fetching transmission is stopped, the connection may be optionally closed or left open for use next time to avoid connection creation overhead. The local proxy executing on the client device may begin a new parsing process for the new requested browser page or data object and optionally establish another persistent preemptive pre-fetching connection with the remote proxy server or alternatively reuse the existing connection. It is desirable in order to quickly suspend the persistent connection that the relative size of the transmissions between the proxies be relatively small, such as on the order of 512 or 1024 bytes for Plain Old Telephone Service (POTS) connections. The desirable packet size is related to a function of the bandwidth of the effective usable bandwidth between the network device and the client, approximately the amount of bytes that may be transmitted in a small time frame, such as 1 second or 500 milliseconds. The effective usable bandwidth across an Internet connection may be computed, such as described, for example, in previously referenced patent application Ser. No. 08/957,468. In this context, the desirable packet equals the desired time frame (e.g., 1 second) divided by the effective usable bandwidth. The reason this results in a relatively quick suspension of the connection is because typically a packet that is in transmission is completed before a new packet is transmitted. Alternatively, in another embodiment, a special escape character or other out of band signaling, for example, may be employed in the signal stream so that the transmission may be terminated once the special character or signal is received, without waiting for the packet to complete. Typically, it is desirable if the preemptive pre-fetching transmission not coexist with a browser request transmission because otherwise this will slow the “regular” browser request transmissions. Thus, the desirability of suspending the persistent preemptive connection between the local and remote proxies.
[0034] An advantage of employing this preemptive pre-fetching approach is a more efficient use of available bandwidth between the client device and the remote proxy server. Without this approach, regular browser requests compete with pre-fetching requests. Therefore, bandwidth may already be exhausted or utilized by pre-fetching requests when a user makes a request for a web page. This is an undesirable outcome because it increases the perceived latency experienced by the user. However, in the embodiment previously described, if the local proxy obtains a request from the user via the client device, a request is transmitted to the remote proxy server to stop pre-fetching so that the browser request may instead be accommodated. Therefore, advantages with regard to bandwidth management prioritization and resource allocation are accomplished. Ultimately, the latency that the user experiences when requesting a web page will be reduced.
[0035] While certain features of the invention have been illustrated as described herein, many modifications, substitutions, changes and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such embodiments and changes as fall within the true spirit of the invention.
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Briefly, in accordance one embodiment of the invention, a method of suspending a network connection used for low priority transmissions between a client platform and a server platform includes: determining a characteristic of a transmission between the client platform and the server platform, said characteristic consisting essentially of a high priority transmission and a low priority transmission; and suspending the connection if the characteristic of the transmission comprises a high priority transmission.
Briefly, in accordance with another embodiment, a method of using a network connection between a client platform and a server platform includes producing on one of the platforms a list of Uniform Resource Locators (URLs) from a requested network page, said list comprising links in said requested network page; and pre-fetching via said connection at least one of said URLs to said remote proxy server.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to pleated window coverings in general, and more specifically relates to a novel take up reel means that ensures that laterally opposed ends of a window covering remain in a horizontal plane when the covering is being raised of lowered.
2. Description of the Prior Art
Modern home construction techniques use substantial amounts of glass since home buyers like to have substantially unrestricted views of their home settings.
Greenhouses or solarium structures and are becoming increasing popular in particular; they often include glass panes positioned in horizontal, vertical, and sloped planes.
Skylights are also in great demand since they provide free lighting.
The major drawback of these glass using structures is that they suffer from the drawbacks of "the Greenhouse Effect."
The wavelength of light changes as it passes through glass; heat reflected from a surface inside a solarium, for example, cannot escape as readily as it entered because the wavelength of infrared radiation (heat) is shorter than that of visible light. Thus, the inside of a solarium is a heat trap because once the wavelength of the light has been shortened, it cannot so easily pass through the glass again.
The most popular solution to the problem has been the use of window shades in general.
The most practical type of window shade is believed to be the pleated variety; these shades reflect incoming light to substantially offset the Greenhouse Effect but they do not spoil the view because they can be drawn up whenever desired.
Moreover they can be provided in translucent or transparent form as well to enhance the view even when they are in their lowered position.
Pleated window coverings are easier to clean than the outdated venetian blinds and their modern day counterparts which have narrower slats. More importatnly, perhaps, pleated window coverings, since their accordion-like structure is a continuous, integrally formed structure, they do a better job of reflecting light vis a vis discrete slat blinds.
Unfortunately, pleated window coverings of the prior art suffer from one of the more aggravating drawbacks that afflict the discrete slat blinds; they have a tendency for their base to skew from the horizontal when raised or lowered.
This skewing is caused by uneven take up of the cord used to draw the blinds or coverings. Specifically, a take up reel in the form of a roller member is positioned at the top of the pleated window covering. One or more cords extending the length of the window covering having their top ends secured to the roller member so that as it rotates in response to drawing or lowering of the covering, the cord or cords wrap around the roller member.
The uneven raising or lowering is attributed to the different overlapping patterns that affect the laterally spaced coils, i.e., a coil on the left hand side of the roller member may experience substantial overlap with the result that a single rotation of the roller member can take up a large amount of cord due to the larger effective diameter of the roller member caused by the winding of the cord upon itself whereas the cord being wound at the other end of the roller member might experience less overlapping. Since the coiling is allowed to occur without any control means, the amount of overlapping is entirely random and a tilt of the base of the window covering as a result of different amounts of overlapping almost always occurs.
There is a need for a window covering assembly that can be raised or lowered in the substantial absence of skewing.
Another drawback of heretofore known pleated window coverings is that their track assemblies are deficient in several respects. For example, solarium structures and the like often have vertical glass sections that meet sloped glass sections; to cover such structures, a gentle curve must be formed in the track which mounts the window covering. Unfortunately, the tracks that have been developed are heavy and require special bending tools to adapt them to particular settings.
Moreover, since wheel members are generally used to rollingly engage the tracks, the art has developed means for interconnecting laterally spaced sets of track-engaging wheel members. Again, the means developed by the art have been inadequate; specifically, cloth mateials are generally employed to interconnect the laterally spaced wheels, with unfortunate results.
There is therefore a need for an improved, easily bendable track and a need for an improved means for interconnecting laterally spaced track-engaging wheel members.
SUMMARY OF THE INVENTION
The inventive assembly overcomes the shortcomings of the prior art by providing a novel track, a novel wheel member housing, a novel wheel member housing interconnecting means, and perhaps most importantly of all, a novel roller member that prevents cord overlapping during the take up process so that skewing is eliminated.
The novel track has the general appearance of the letter "F" when seen in plan view; the vertical portion of the "F" is the base portion of the track in that the wheel members of the novel assembly rollingly engage that portion. More specifically, the portion ofthe "F" positioned intermediate the truncate, horizontally extending arms thereof is the portion of the track means base upon which the wheels actually roll. Thus, said arms provide a guide means for the wheels.
Due to the thin structure of the track, it can be bent on site so that installation of the window covering is easily accomplished.
In the preferred embodiment of the invention, a pair of vertically spaced wheel members rollingly engagement the guide portion of the track means, i.e., the base portion of the track means intermediate the parallel arms of the "F"-shaped member, on the "back" side of the track (the side of the track facing the mullion), and one wheel member rollingly engages the "front" side of the track. The "front" wheel is masked from view by a portion of the wheel member housing that covers it.
The wheel member housing thus mounts three (3) wheel members. They are positioned at the corners of an imaginary equilateral triangle.
Laterally opposed wheel member housings are interconnected by an elongate, horizontally disposed, rigid interconnecting means. The interconnecting means is a hollow, triangular in transverse section extruded piece of aluminum; each wheel member housing has a complementally formed triangular insertion member projecting laterally therefrom that is adapted to press fittingly engage the interconnecting member when inserted into the hollow interior thereof. Each side wall of the interconnecting member has the dimension of an individual slat in the window covering.
The triangular shape of the rigid interconnecting member ensures that it will conform to the shape of the window covering as it is drawn, i.e., the pleated, integrally formed slats of the covering will overlie the flat side walls of the triangular interconnecting member and the presence of the interconnecting member will thereby be effectively concealed. A plurality of the interconnecting means are provided at vertically spaced intervals along the extent of the window covering as design applications require.
The novel roller member of the inventive assembly has a standard driving means positioned at one of its ends. The driving means itself is housed in a non-rotating housing, and said non-rotating housing is fixedly secured to a slideably mounted base means.
The base means has a disc-shaped appearance and is slideably mounted in a cylindrical housing; both the base means and the housing are formed of a suitable low friction material to allow the base to slide relative to the fixed position housing with little resistance.
The opposite end of the roller member is plugged with a centrally bored plug member. A fixed position, elongate screw member having a preselected number of threads per inch formed therein is mounted by a suitable bracket assembly so that the longitudinal axis of symmetry of the screw member is coincident with the axis of rotation of the roller member.
The bore in the plug is threaded so that when the roller rotates responsive to activation of its driving means, the screw threaded engagement of the screw member and said bore effects axial travel of the slideably mounted roller member.
Since the roller member undergoes axial displacement as it rotates, each winding of cord about its periphery is presented with an empty, unoccupied space and no cord is wound upon itself. Thus, the effective diameter of the roller is not increased by overlapping cord, and both cords on the roller member, affixed thereto at opposite ends thereof, will coil up at the same rate and the window covering will not skew.
The invention accordingly comprises the features of construction, combination of elements and arrangement of parts that will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:
FIG. 1 is a perspective view of the novel structure, taken from the rear side thereof so that the rear wheels of the novel wheel assembly can be seen and so that the novel rigid interconnecting members can be seen as well;
FIG. 2 is a plan view of the novel track;
FIG. 3 is a plan view depicting the track mounted directly on a mullion;
FIG. 4 is a plan view depicting the track mounted in spaced relation to a mullion, showing how a pair of track members can be overlapped to narrow the spacing between laterally adjacent wheel members;
FIG. 5 is a side elevational view of the novel wheel housing;
FIG. 6 is an elevational view taken along line 6--6 of FIG. 5;
FIG. 7 is an elevational view showing how the wheel members positioned within the wheel member housing rollingly engage the track member. The insertion member that is integrally formed with the wheel member housing has been eliminated from this FIG. to simplify it;
FIG. 8 is an end view of the novel interconnecting member;
FIG. 9 is an end view showing the triangular portion of the wheel member housing snugly positioned within the hollow interior of the interconnecting member;
FIG. 10 is a side elevational view of a bore lining that prevents cord fraying;
FIG. 10A is an end view of the bore lining member shown in FIG. 10;
FIG. 11 is a side elevational view of the novel roller member and its associated mounting means; and
FIG. 12 is a side elevational view of the roller member similar to that of FIG. 11, but showing a motor-driven roller member instead of the chain driven roller member of FIG. 11.
Similar reference numerals refer to similar parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, it will there be seen that a window covering that incorporates all of the teachings of this invention is designated by the reference numeral 2 as a whole.
It should be understood from the outset that several features of the inventive structure 2 represent advances in the art, and that any one of them or any combination of them could be incorporated into window coverings of the prior art.
For example, as will become clear as this description proceeds, the novel roller ember and its precision winding means could be incorporated into an otherwise "old" window covering, i.e., it could be incorporated into a window covering lacking the other novel means disclosed hereinafter.
As a further example, the interconnecting members of this invention, described hereinafter in detail, could be incorporated into "old" window coverings to dramatically improve them, even if the other features of the inventive assembly were not adopted; moreover, the same is true of the novel track member disclosed hereinafter, the novel wheel housing, and other inventive elements of this invention.
FIG. 1 shows that the window covering selected as the preferred environment for the new parts disclosed hereinafter is of the pleated type; the pleats have an accordion-like structure and are denoted 4.
The particular window covering illustrated in FIG. 1 has a vertical section 6 and a sloped, generally horizontal section 8; one of the important teachings of this invention relates to a novel track construction that allows a gentle bend to be formed in the structure as depicted in FIG. 1 in the absence of heavy duty bending tools.
Referring now to FIG. 2, it will there be seen that the novel track member 10 has the appearance of the letter "F" when seen in end view; the relatively thin construction of track 10 enables it to be bent on site instead of at the installer's place of business. Accordingly, the construction of track 10 eliminates the need to pre-measure the curvatures of the glass areas to be covered and allows the installer to bend the tracks on site.
Track 10 includes base 12 and parallel arms 14, 16 normal thereto.
The portion of base 12 intermediate arms 14, 16 is the portion upon which the wheel members of the novel assembly roll when the invention assembly is in use and will hereinafter be referred to as the guide portion 18.
The portion of base 12 lying outwardly of arms 14, 16 is denoted 20; a screw-receiving bore 22 is formed in outlying portion 20 and the utility of such bore 22 is shown in FIG. 3 to which FIG. attention is now directed.
A window formed by a plurality of glass sections will have a plurality of horizontally disposed trunions and vertically disposed mullions separating the individual glass panes. A mullion 24 is shown in FIGS. 3 and 4 in vertical section; in each of FIGS. 3 and 4, mullion 24 separates two windows, each of which is provided with the novel window covering assembly of the present invention.
The track mounting shown in FIGS. 3 and 4 is shown to illustrate the versatility of track member 10; FIG. 3 shows it mounted directly on a mullion, and FIG. 4 shows a spaced mounting.
Referring specifically to FIG. 3, it will there be seen that a screw member 26 extends through bore 22 shown in FIG. 2 and serves to fixedly and abuttingly secure track 10 to mullion 24. When so mounted, guide portions 18 of the respective tracks 10 are laterally spaced from their respective mullions and are accordingly capable of receivng the wheel members of the inventive assembly.
The mounting of FIG. 3 will leave visible the mid-portion 28 of mullion 24. Where it is desired to cover the mullion, the track mounting arrangement of FIG. 4 may be employed.
In FIG. 4, outlying portions 20 of track 10 are positioned so that one of said portions overlies the other as depicted; this aligns bores 22. Spacer 30 is then positioed between mullion 24 and the innermost track 10 and an elongate screw 26a is positioned through the aligned bores 22 and screwed into the mullion as depicted. This mounting covers mullion 24 from view; the space between guide portions 18 of the tracks 10 and the surface of mullion 24 accommodates the wheel members of the novel assembly.
Referring now to FIG. 5, it will there be seen that the wheel housing is denoted 32 as a whole.
Housing 32 houses three rotatably mounted wheel members 34, 36, 38, all of which are shown in phantom lines because they are positioned on the "hidden" side of such housing 32 in the view of FIG. 5. (Actually, only the hubs of the wheels are depicted in FIGS. 5 and 6 to simplify the drawings).
Wheel members 34, 36 are positioned in a vertical plane when operatively deployed, and rollingly engage portion 18 of track 10. Wheel member 38 is positioned on the visible side of track 10, however, and is preferably hidden from view by opaque cover 40, shown in FIGS. 1, 5, 6 and 7.
Cover 40 is integrally formed with housing 32; housing 32 also includes a pair of outwardly turned covers 42, 44 for wheel members 34, 36, respectively. The term "outwardly" is used because the direction "inwardly" will hereinafter be used to indicate the direction toward the center of a window covering, i.e., the term "outwardly" refers to the direction away from the center of the covering, or to the direction of the next adjacent covering on the opposite side of a mullion.
In keeping with the aforementioned terminology, then, FIG. 6 should be understood as depicting wheel member housing 32 positioned so that wheel coverings 40, 42 and 44 are extending outwardly, and the member 46 is extending inwardly.
As best shown in FIG. 5, member 46 is triangular in configuration; it is so shaped because it fits in the triangular shaped hollow interior of the rigid interconnecting member that interconnects laterally spaced wheel member housings as best shown in FIG. 1 and as will become more clear as this description proceeds.
A pair of small, triangular in configuration ridges, collectively designated 48, are integrally formed on each flat wall of member 46 as best shown in FIG. 5; each ridge 48 gradually diminishes in height as it extends from base wall 50 of member 46 as shown FIG. 6. (Member 46 projects inwardly from base wall 50 whereas cover members 40, 42, 44 project outwardly therefrom; thus, the height of ridges 48 diminishes as they extend inwardly).
The purpose of member 46 and ridges 48 is made clear in FIG. 8; member 46 will hereinafter be referred to as insertion member 46 because it is inserted into the hollow interior of the elongate, rigid interconnecting member 52 the end of which appears in FIGS. 8 and 9. Member 52 is preferably formed of aluminum and extruded; its inner dimension is slightly larger than the outer dimension of insertion member 46 so that the latter may be inserted thereinto. Ridges 48 provide a wedging action as insertion member 46 is inserted into the triangular hollow cavity of interconnecting member 52. Due to the narrow line of contact formed by each triangular ridge 48, the friction resistance to insertion of the insertion member 46 into the cavity of member 52 is minimized while the wedging action nevertheless insures against inadvertant separation of the wedged-together members.
Thus, a wheel member housing 32 on a first side of a window covering associated with a first track is rigidly interconnected with its horizontally aligned, laterally spaced counterpart on the opposite side of the same window covering by interconnecting member 52. Specifically, each wheel member housing 32 is positioned so that its insertion member 46 is inwardly directed and the members 46 are inserted into the opposite ends of interconnecting member 52. Due to the triangular shape of interconnecting member 52, it conforms to the shape of the individual slats or pleats 4 (FIG. 1) as they fold upon one another, accordion style, attendant drawing of the window covering. Interconnecting members 52 are of course positioned at intervals on the hidden or rear side of the covering as shown in FIG. 1.
To prevent cord fraying as it passes through the bores (not shown) formed in the insertion member 46 and interconnecting member 52, bore lining member 54 is provided (see FIGS. 10 and 10A).
Bore lining member 54 includes main body portion 55 that is bored as at 56 to slidingly receive a cord therethrough (not shown). An annular flange 57 is angled as shown to conform to the shape of the interconnecting member 52 as is the unflanged opposite end 58 of the liner 54.
Referring now to FIGS. 11 and 12, it will there be seen that the slideably mounted roller member of the present invention is designated by the reference numeral 60 as a whole.
Numerous means for slideably mounting the same are of course available and the means shown in FIGS. 11 and 12 are merely illustrative.
Bracket 61 is secured by suitable means to roller housing 62 as shown, and is apertured to receive elongate screw member 64. Threaded lock nuts 63 (FIG. 11) or a permanent mounting means 65 (FIG. 12) may be employed as a part of the slideable mounting means.
In the embodiment of FIG. 11, screw 64 engages threads formed in plug 66 so that rotation of roller member 60 effects axial travel of said roller 60 because the position of screw 64 is fixed.
In the embodiment of FIG. 12, the distal free end 67 of screw 64 is not threaded but since roller 60 is slideably mounted and since screw member 64 is fixed position, the same rotation-responsive axial travel of roller 60 occurs; a compression fit effectively unites screw member 64 and plug 66 in this embodiment.
Referring now to the left side of FIGS. 11 and 12, it will there be seen that the means for effecting rotation of roller 60 in FIG. 11 is a manual bead chain 68 and the rotation means in FIG. 12 is an electric motor means 69.
In both embodiments, the means for effecting rotation of roller member 60 is housed in a non-rotatable housing designated 70. Housing 70 is fixedly secured to a base member 72 which is slideably mounted with respect to roller member housing 62. Base member 72 is preferably formed of nylon or other suitable low friction material so that the sliding movement of base 72 relative to housing 62 is relatively friction free.
A string or cord 74 has its lowermost end secured to the lowermost portion 3 of the window covering 2 (FIG. 1). The uppermost end of string 74 is fixedly secured to roller 60 as at 76 (FIG. 11).
As chain 68 is pulled or motor means 69 is activated, roller 60 rotates about its axis of rotation and slides along said axis under the driving influence of the screw member 64. In the embodiment shown in FIG. 11, roller member 60 is rotating in a direction that causes it to travel to the right as viewed in said FIG. Accordingly, string 74 winds about roller member 60 in the non-overlapping manner designated 78 because an open or unoccupied section of roller 60 will be presented to each length of string 74 as it undergoes coiling.
Another string, not shown, coils about the other end of roller 60. Only one string is shown in FIG. 11 to simplify the drawing and both strings are omitted from FIG. 12 for the same reason.
The means for slideably mounting roller 60 is thus seen to be simple yet effective. The elimination of string overlapping, the provision of the versatile "F"-shaped track member, the novel wheel housing and the rigid interconnecting member that aesthetically conforms to the pleats of the window covering, individually and collectively represent important advances in the art of window coverings.
It will thus be seen that the objects set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or 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.
Now that the invention has been described,
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A slideably and rotatably mounted roller member performs a precision take up reel function in the environment of a track mounted, drawable, pleated window covering. The roller member slides along an axis coincident with its axis of rotation as it rotates so that cord being wound therearound attendant its rotation is taken up in the absence of overlapping. One end of the roller member is provided with a centrally bored and threaded plug that screw threadedly engages a fixed position screw member; as the roller member rotates, the engagement of the screw member and the bore drives the plug and hence the roller member in an axial direction. The slideable mount of the roller member is provided in the form of a base member which is slideably received within the roller member housing. A novel "F"-shaped track member is engaged by wheel members positioned in a novel wheel housing, and laterally opposed wheel housings are interconnnected by a rigid interconnecting member that conforms to the shape of the pleats formed in the window covering. The assembly ensures that the window covering remains level at all of its functional positions.
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BACKGROUND OF THE INVENTION
1. Field of Invention
My invention pertains to policeman's clubs, billies, night sticks, judo sticks and riot batons.
2. Description of Prior Art
Prior art consists of policeman's billies, night sticks, judo sticks and riot batons. The present day clubs depend on overhead blows and need space to work in. My invention is capable of delivering a blow along a straight trajectory with the wrist extended in a straight forward position. When a blow is delivered, the wrist remains almost rigid. My invention is capable of delivering short, rapid, and powerful blows at a distance of 3 inches or less without changing the position or angle of the wrist.
SUMMARY OF THE INVENTION
The invention relates to a multi-purpose protection device which is capable of being used in a close quarter situation. It may be held in a night stick position or in a pistol grip position. It can be readily changed from one position to the other or reversed.
An object of this invention is to provide a self-defense weapon which is capable of delivering a blow along a straight trajectory with the wrist extended in a straight forward position.
Another object of this invention is to provide a self-defense weapon which is designed to be used at very close quarters.
Still another object of this invention is to provide a self-defense weapon which is capable of delivering two blows with one thrust.
A still another object of this invention is to provide a self-defense weapon which may be used by a man, woman or child.
Another object of this invention is to provide a self-defense weapon which protects the fingers of the user.
Still another object of this invention is to provide a self-defense weapon which can be used to deflect or entrap weapons or wrists.
A still another object of this invention is to provide a self-defense weapon which can be thrust forward with the entire arm and not merely on wrist action alone.
A further object of this invention is to provide a self-defense weapon with deflector knobs.
Another object of this invention is to provide a self-defense weapon for women who wish to protect themselves from physical harm against muggers, rapists or other criminals.
Still another object of this invention is to provide a self-defense weapon which is so compact that it could easily fit in a woman's handbag or could be worn in the standard issued club holster or mace holster.
A further object of this invention is to provide a self-defense weapon which can deliver not only overhead, side, and right angle blows, but also long and short range punches and jabs, vertically and horizontally.
Another object of this invention is to provide a self-defense weapon which can be held in a fashion similar to that of holding a pistol or handgun with the blow delivered by a forward thrust with either the point or butt end.
Other objects, features and advantages of the present invention will be readily apparent from the following detailed description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the invention.
FIG. 2 is a partial perspective view of the prong assembly, butt assembly and point assembly and a sectional view of the remainder of the invention along line 2--2 of FIG. 1.
FIG. 3 is an exploded view of the parts of the invention.
FIG. 4 is a perspective view of the invention being held in a night stock position.
FIG. 5 is a perspective view of the invention being held in a pistol grip position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.
Referring now to the drawings wherein like reference numerals refer to like and corresponding parts throughout the several views, the preferred embodiment of the invention disclosed in FIGS. 1 to 3 inclusive includes a point assembly A, a handle assembly B, a prong assembly C, and a butt assembly D. The point assembly A, the prong assembly C, and the butt assembly D are all made of metal. The handle assembly B is made out of plastic. The point assembly A, the prong assembly C, and the butt assembly D are joined together by the process of molding the handle assembly B onto them. (See FIG. 2)
Point assembly A includes a point 1, a stem 2, internal screw thread 3, external screw thread 4, and stem locking lugs 5. Stem 2 is screwed into point 1 by means of external screw thread 4 and internal screw thread 3.
Handle assembly B includes point handle front 6, point handle base 7, butt handle base 8, and butt handle front 9.
Prong assembly C includes a rod 10, prong bases 11 and 12, prong fronts 13 and 14, prong points 15, and deflector knobs 16. Prong bases 11 and 12 are bent in opposite directions from each other so that prong fronts 13 and 14 face in opposite directions. Prong bases 11 and 12 are bent at a 90° angle. The prong bases 11 and 12 are of sufficient length to allow the last three fingers of a person's hand to fit comfortably side by side when a pistol grip is used.
Butt assembly D includes a butt 17, a butt stem 18, and butt locking lugs 19.
In the preferred embodiment of my invention, the point assembly A, the prong assembly C, and the butt assembly D are all made of metal and the handle assembly B is made of Monpac plastic or a similar material with similar properties of strength, lightness and good gripping qualities. Metal used may be of mild tool steel, high tensile steel alloy, high tensile stainless steel or tensile aluminum.
The entire invention may be made of metal by investment forging or casting to save time and to help cut operating costs. However, the most practical and most efficient unit that would serve both the needs of police, military and civilian applications would be the unit with a Monpac plastic grip. The wider plastic grip would be easier to grip and to manipulate. The plastic mounted weapon allows for greater flexibility.
The point assembly A, the prong assembly C and the butt assembly D are joined together to form a complete unit by the process of molding the handle assembly B onto them. With the point assembly A, the prong assembly C and the butt assembly D firmly anchored to handle assembly B, it is practically impossible for any of them to work their way free after the device is subjected to prolonged use.
Point 1 may be pointed, rounded or blunted. At its base it has a diameter of 1 inch. The base is made wide so that the point tip will not brush or touch the surface of the user's arm when the device is held in the pistol grip position with butt 17 in a forward position. Point 1 is 1 inch or longer in length. With a threaded point and a threaded stem, different types of points may be used. If it is deemed desirable, the point 1 and stem 2 may be made of one piece.
Handle assembly B is round in cross section with a diameter of one inch throughout except for point handle front 6 and butt handle front 9, which are 11/4 inch in diameter. Point handle base 7 and butt handle base 8 are each 41/2 inches in length. The handle assembly B may be partly or entirely grooved if a better gripping surface is desired.
The gripping areas of the plastic grip that are located within the prong assembly area must not exceed one inch in diameter; otherwise, this gripping area would be too wide to allow for a pistol grip hold. Any part of the plastic handles that extend beyond the prong assembly area may be slightly increased in diameter 11/4 inch on devices exceeding 111/2 inches in length, to improve gripping and to improve the overall balance.
Rod 10 and prong bases 11 and 12 are round in cross section with a diameter of one-half inch. Prong fronts 13 and 14 taper toward prong points 15. Prong points 15 have a diameter of three-fourths inch. The prong bases 11 and 12 should be of sufficient length to allow the last three fingers of a person holding the device in a pistol grip to fit comfortably side by side along the prong base.
In my preferred embodiment the length of prong bases 11 and 12 in 21/2 inches and the length of prong fronts 13 and 14 to prong points 15 is three inches. The length of the prong fronts 13 and 14 to prong points 15 may be increased to further protect the fingers of the person grasping the device.
Prong fronts 13 and 14 are approximately parallel to each other and face in opposite directions to each other. The reason for the prong fronts 13 and 14 facing in opposite direction to each other is to provide protection to the user of the device when it is held in the forward or rearward pistol grip hold. Prong points 15 are rounded to reduce the hazard of cutting and injuring a person struck therewith. They may be pointed if it is desired to inflict serious cutting and injury to an adversary.
Prong fronts 13 and 14 and prong points 15 may be used to hook onto the clothing of an adversary.
Deflector knobs 16 prevent a staff or long cutting edge weapon from sliding over the prong fronts 13 and 14 to inflict injury to the fingers or to the wrist of the person using the device to block an overhead or side blow with the prong fronts 13 and 14. Deflector knobs are one-half inch in diameter.
Butt 17 is round in cross section with a diameter of one/half inch. The ends are rounded off to prevent serious injury to an opponent. It is two inches in length. Two inches is roughly equal to the width of three fingers fully extended. It is used to deliver a straight finger or spear thrust.
The main target of butt 17 are the soft and vulnerable parts of the anatomy. A blow from the forward part of butt 17 can be executed facing horizontally or vertically: horizontally -- neck, vertically -- arm pit, solar plexus. It is used strictly for stunning an opponent.
In the pistol grip position, butt 17 acts as a stabilizer to guide point 1 to the target. The principle is similar to the steadying hold of a rifle butt.
My invention may be held in a night stick position (FIG. 4) or in the pistol grip position (FIG. 5). For the night stick position, the device is grasped with the hand around the butt handle base 8, or around point handle base 7. It can also be held upside down by grasping the point handle base 7, without reversing the direction of point 1. For the pistol grip position, place the prong base 11 in the V formed by the thumb and forefinger of the user, curl the thumb so that it rests on portions of prong base 11 and point handle base 7, extend the forefinger in a straight almost rigid position along the point handle base 7, and grip prong base 12 with the last three fingers. The device can be readily reversed by flipping it. It can be flipped to change positions, point to butt, or pistol grip to night stick or vice versa.
My invention may be entirely coated or insulated with rubber, fiberglass, vinyl, nylon or some other shock absorbent material to lessen the chance of injury, if it is deemed desirable to do so.
My invention may be carried in a woman's handbag, in a club holster or in a mace holster. In a holster my device is carried with the point protruding through the bottom of the holster and with butt 17 and butt handle base 8 secured to the holster by a narrow leather flap which snaps over the prong base 11.
My invention is 111/2 inches in length. It may be increased to 24 inches if it is deemed desirable to do so. If the length is increased, the length of butt 17 may be reduced from two inches to one inch as with the increased length of the device, butt 17 will no longer be used as a stabilizer to guide the device and as it makes it much easier to grip the device in the classic two-handed position in rifle-bayonet or kendo fashion. The diameter of the handle assembly B may be increased to 11/4 inches on longer models to greatly improve the gripping characteristics of the device and to improve their overall balance.
In the preferred embodiment, my device is only 111/2 inches in length. When it is held in the pistol grip position, only 2 inches or less of the device is exposed with the rest of the device concealed, thereby presenting an element of surprise to an adversary.
My invention is designed to be maneuvered at very close quarters in tight or guarded situations. Consequently, it should be as small as possible. I have been able to reduce its length to 111/2 inches and yet provide a devastating self-defense weapon. It could be reduced further if it is deemed desirable to do so.
My invention can deliver overhead, side and right angle blows. It can also deliver long and short range punches and jabs vertically and horizontally. It is capable of delivering a blow along a straight trajectory with the wrist extended in a straight forward position. It can be used from practically any angle, position or distance within its range. It is really as easy to use as pointing your finger. Your forefinger is on the trigger (handle) at all times!
My invention can deliver a series of short, rapid and powerful blows at a distance of three inches or less without changing the position or angle of the wrist. When a blow is delivered, the wrist remains almost completely rigid. It can be manipulated from a reclining, prone or sitting position.
Because of the unique construction of the prongs, the amount of kinetic energy applied on the forward thrust is almost double the force of a thrust generated by other conventional means. This is made possible because the forward thrust is generated with the entire arm and not merely on wrist action alone. The forefinger in the extended position is always pointed at the target. Because most women lack the physical power and stamina necessary to deliver strong, powerful blows to an adversary, my invention is particularly suited for women who wish to protect themselves from physical harm from muggers, rapists or other criminals.
My invention can be used to deliver two blows with one thrust. In addition to the blow from the forward thrust, a karate-like blow can be executed at very close quarters with a short, fast, powerful flick of the wrist. Prong points 15 are used to deliver the blow. Also, if the forward thrust blow misses its target, the forward prong may be utilized to execute a karate-like blow. If the point 1 or butt 17 should miss striking the target, prong point 15 of the forward prong could score -- a backup unit.
The forward prong of my invention can be used to hook onto a person's clothing, belt, arm or wrist to incapacitate the person.
My invention can be held in upside down night stick position. Instead of grasping the butt handle base 8 as shown in FIG. 4, the point handle base 7 is grasped. In this upside down position, it could be used with devastating effect.
My invention can be manipulated in almost the same fashion as the Sai, standard police billy club and riot baton, depending on the models and the length of the device. Aside from the pistol grip position, it can be wielded as a short quarter staff utilizing any of the prongs to block or entrap an opponent's weapon to disarm him.
My invention may be designed with quick, detachable handles which fold in or will unscrew at the prong assembly into three separate parts for transportation. Point handle with point permanently secured, butt handle with butt permanently secured, and the prong assembly. Even when unassembled, anyone of the three parts could still be used as a separate weapon. Also in its unassembled form, my invention would not come under the category of a concealed weapon.
Although but a single embodiment of the invention has been disclosed and described herein, it is obvious that many changes may be made in the size, shape, arrangement and detail of the various elements of the invention without departing from the scope of the novel concepts of the present invention.
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A multi-purpose protection device with a point on one end of a shaft and a butt on the other end, two opposite facing bent prongs connected to the middle of the shaft, and a deflector knob located near the bend of each prong on the outside surface of the prong. The weapon is used in a close quarter situation. It may be held in a night stick position or in a pistol grip position. It can be readily changed from one position to the other -- point to butt or pistol grip to night stick, or vice versa.
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This application is a divisional of application Ser. No. 09/883,957, filed Jun. 20, 2001, the subject matter of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to semiconductor memory devices and, more particularly, to data masking circuits and data masking methods for semiconductor memory devices.
2. Description of the Related Art
Electronic equipment and electronic-based systems require some form of high-speed memory devices for storing and retrieving information. While the type of such memory devices vary, semiconductor memory devices are most commonly used in memory applications requiring implementation in relatively small areas. Within this class of semiconductor memory devices, random access memory (RAM) is one of the common types. A RAM incorporates an array of individual memory cells. A user may execute both read and write operations on the memory cells of a RAM. A typical example of a RAM is a dynamic random access memory (DRAM), as is well known in the art.
To allow a DRAM to operate at high speed, “synchronous” DRAMS, also referred to a SDRAMs, have been developed. A synchronous DRAM can receive a system clock that is synchronous with the processing speed of the overall system. The internal circuitry of the SDRAM can be operated in such a manner as to accomplish read/write operations in synchronism with the system clock.
SDRAMs include Single Data Rate (SDR) SDRAMs and Double Data Rate (DDR) SDRAMs. In a SDR SDRAM, data can be input and output at either only the rising edge or only the falling edge of a clock signal. In a DDR SDRAM, data can be input and output at both the rising and falling edges of the clock signal. Therefore, the DDR SDRAM can have a data bandwidth which is twice the clock frequency.
It is also known to use a data input/output mask signal applied externally to the memory device to mask output data from the memory device during a read operation and to mask input data to the memory device during a write operation. For example, situations occur when it is desired to send a data stream to a memory device, but it is also desired that some of the data stored in the memory device remain the same. A data mask can be used to block some of the data in the data stream from reaching the individual memory cells that should remain undisturbed.
FIG. 1 illustrates in block diagram form a portion of a conventional memory device 20 in which data write masking is used. The memory depicted illustrates a single bank (BANK 0 ) of a 64 Meg SDRAM. BANK 0 memory array 22 includes memory cells arranged in rows and columns for storing data. Command decoder 24 , included in control logic 26 , receives control signals from a command bus CMD to place control logic 26 in a particular operation sequence. Control logic 26 controls the various circuitry of SDRAM 20 based on decoded commands such as reads or writes from or to memory bank 22 . A specific address for which a read or write command is to occur is provided to address register 28 , which provides the address to row-address multiplexer 30 and column-address counter 32 . Row address multiplexer 30 provides a row address to row decoder 34 , which decodes the row address and activates one of the lines corresponding to the row address in BANK 0 22 for a read or write transfer operation. Column address counter 32 provides a column address to column decoder 36 , which activates the I/O gating 38 of the column corresponding to the column address. Data being written to the memory 20 is input on data lines (DQ) via the input/output datapath logic circuit 40 , driven by write drivers 42 and passed to the I/O gates 38 for writing to the array 22 . During a read operation, data from the array 22 is passed through the I/O gates 38 to read latch 44 to datapath logic circuit 40 and output on the data lines (DQ).
Conventional data masking during a write operation is accomplished by sending a mask control signal (DM) through the datapath logic circuit 40 to the write drivers 42 at the same time the data stream is being routed through the write drivers 42 . This mask control signal causes the write driver 42 to go “tri-state” or high impedance, blocking the data stream's path to the I/O gates 38 . As illustrated in FIG. 1, each write driver 42 drives 8 bits of data (D 0 -D 7 , D 8 -D 15 , D 16 -D 23 , D 24 -D 32 , respectively) for a total of 32 bits or 4 bytes. Four data mask signals are provided (DM 0 , DM 1 , DM 2 , DM 3 ), one for each group of 8 bits or byte.
FIGS. 2A and 2B are timing diagrams of various signals generated in the memory device 20 during a write operation with data masking. In order to save space, in FIGS. 2A, 2 B, 4 A, and 4 B, the data lines (DQ 0 -DQ 31 ) are not individually shown. Instead, each group of data lines corresponding to each byte of data are shown. Thus, XB 0 represents the group of data lines corresponding to the first byte of data (DQ 0 -DQ 7 ), XB 1 represents the data lines corresponding to the second byte of data (DQ 8 -DQ 15 ), XB 2 represents the data lines corresponding to the third byte of data (DQ 16 -DQ 23 ), and XB 3 represents the data lines corresponding to the fourth byte of data (DQ 24 -DQ 31 ). Additionally, several signals are prefixed with “X”, “Y”, or “Z”. These prefixes indicate different points in time, wherein X designates the time at which a memory device is presented with the write command, Y designates the time after the write command and the associated memory address has been decoded, but before the time when the data is written to the memory arrays of the memory device, while Z indicates the time when the memory arrays are written. Thus, the timing diagrams of FIGS. 2A, 2 B, 4 A, and 4 B, permit the reader to follow the relationship between the data signals and data mask signals relative to other signals in the memory device as the data travels through the memory device.
In FIG. 2A, the illustrated memory device 20 is a 32-bit wide (x32) memory undergoing 16-byte write of data bytes B 0 -B 15 . Since the memory device is 32-bit or 4-bytes wide, the memory device accepts 4-bytes per clock cycle for writing on data byte lines XB 0 -XB 3 . In order for the memory device to support per-byte data masking, the memory device must support one data mask line (XDM 0 -XDM 3 ) per data byte line (XB 0 -XB 3 ). At a first clock cycle of the clock CLK, the WRITE command is present on the command bus CMD. Not illustrated, but also present is the address associated with the first data byte B 0 . Present shortly after the write command are the data (B 0 -B 15 ) to be written as well as an associated data mask on data mask lines XDM 0 -XDM 1 .
Referring now to FIG. 2B, it can be seen that data on signal lines YB 0 -YB 3 and the data mask on data mask signal lines YDM 0 -YDM 3 have been delayed by an identical amount due to the need for the command decoder 24 to decode the write command and the column decoder 36 and row address decoder 34 to decode the address. At this point data is present on the data lines YB 0 -YB 3 can be driven by the write drivers 42 to the I/O gates 38 if the write driver enable lines WD 0 -WD 3 are high. As shown, data which is to be written, for example data B 0 -B 5 , B 8 -B 10 , and B 12 -B 15 , are accompanied by a high write driver enable signal to permit the data to be driven to the I/O gates 38 while the column select signal ZCS 0 -ZCS 3 associated with those bytes are also driven high to activate the proper column in the memory array, thereby permitting the data to be written to the array 22 . On the other hand, when data needs to be masked from writing, for example data B 6 , B 7 , and B 11 , the data mask signal YDM 0 -YDM 3 is high, causing the write driver signal WD 0 -WD 3 to go low, thereby preventing masked data from being driven to the I/O gates 38 and written to the array 22 .
As illustrated in FIG. 2B, the column select lines ZCS 8 -ZCS 3 are fired each time regardless of whether data is to be masked nor not. Between each successive firing of the column selects, there is a time period x at which the column select is off. This time period x is provided to give a margin for the mask to turn on, i.e., to disable the write driver. Additionally, the data lags the firing of the column selects by a period of time y. Thus, the effective cycle time for each write operation to occur can be calculated as follows:
Effective write cycle=Minimum write time+ x+y (1)
The data masking operation described above effectively masks data being written to a DRAM. As processor frequencies have increased, however, additional speed is being demanded of memory. The data masking operation described above is an impediment to faster write operations in ways that affect transparency of the DRAM. For example, the masking operation is an additional operation that must be accomplished by the DRAM. The time required to perform data writes utilizing the data masking as described above limits the speed at which the writes can be performed to the effective cycle time as calculated by Equation 1. This necessarily limits that speed at which the memory device can operate, and thus the speed at which the overall system in which the memory device is located can operate. It is therefore desirous to provide a memory device with a decreased effective cycle time for performing write operations to allow operation at faster speeds.
SUMMARY OF THE INVENTION
The present invention alleviates the problems associated with the prior art and provides a method and apparatus for masking data written to a memory device that reduces the effective write cycle time of the memory device. In accordance with the present invention, firing of the column selects is pre-empted, thereby masking data to be written to a memory device. By pre-empting the column selects, the margin required for disabling a write driver can be eliminated, thereby reducing the effective write cycle. Additionally, data masking can be performed on a per-byte basis by associating independent column selects with each data byte on multi-byte wide devices, e.g. x16 or x32. These and other advantages and features of the invention will become more readily apparent from the following detailed description of the invention which is provided in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other advantages and features of the invention will become more apparent from the detailed description of the preferred embodiments of the invention given below with reference to the accompanying drawings in which:
FIG. 1 is a block diagram of a portion of a conventional memory device;
FIGS. 2A and 2B are timing diagrams of various signals generated in the memory device of FIG. 1 during a write operation with data masking;
FIG. 3 is a block diagram of a portion of a memory device having data masking according to the present invention;
FIGS. 4A and 4B are timing diagrams of various signals generated in the memory device of FIG. 3 during a write operation with data masking according to the present invention; and
FIG. 5 is a block diagram of a processor system that includes a memory circuit having data masking according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described as set forth in the exemplary embodiments illustrated in FIGS. 3-5. Other embodiments may be utilized and structural or logical changes may be made without departing from the spirit or scope of the present invention. Like items are referred to by like reference numerals.
In accordance with the present invention, firing of the column selects is pre-empted to mask data to be written to a memory device, thereby reducing the effective cycle time and allowing operation at faster speeds. FIG. 3 illustrates in block diagram form a portion of a memory device 120 having data masking according to the present invention. FIG. 3 is similar to FIG. 1 except as noted below, and the description of like items will not be repeated here.
Data masking during a write operation according to the present invention is accomplished by sending a mask control signal (DM 0 -DM 3 ) through the datapath logic circuit 140 to an associated column decoder 36 a - 36 d . The column decoder 36 a - 36 d receiving an active data mask signal DM 8 -DM 3 will be pre-empted from firing its column select, thus preventing the data stream from passing from the I/O gating 38 a - 38 d to the memory array 22 .
FIGS. 4A and 4B are timing diagrams of various signals within the memory device 120 of the present invention. As before, the illustrated memory device 120 is a 32-bit wide (x32) memory undergoing a 16-byte write of data bytes B 0 -B 15 . Since the memory device is 32-bit or 4-bytes wide, the memory device accepts 4-bytes per clock cycle for writing on data byes lines XB 0 -XB 3 . In order to support per-byte data masking, the memory device must support one data mask line per byte width. Thus, the illustrated memory device includes 4 data mask lines XDM 0 -XDM 3 .
On a first clock cycle of the clock signal CLK, a write command is presented on command bus CMD, along with an associated address for data B 0 (not illustrated). On the following clock cycle, data to be written (e.g., B 0 -B 3 ) to the memory device 120 appears on data lines XB 0 -XB 3 and the write mask for that data appears on data mask lines XDM 0 -XDM 3 . On each of the following 3 clock cycles additional data and data masks are presented on the data lines XB 0 -XB 3 and data mask lines XDM 0 -XDM 3 .
The data B 0 -B 15 and the data mask signals are accepted by the memory device 120 and are routed within the memory device. The data makes its way through the write drivers 44 and are driven to the I/O gates 38 , as shown on signal lines YB 0 -YB 3 . The data mask signals are routed within the memory device 120 to the column decoders 36 a - 36 d , as represented by signal lines YDM 0 -YDM 3 . There is one data mask signal per column decoder, and each column decoder is associated with generating the column select signal for one byte of data.
Each column decoder 36 a - 36 d decodes the address associated with the data in order to generate a column select signal. The addresses presented to the column decoders are preferably delayed so as to arrive coincident with the data mask signals YDM 0 -YDM 3 . The column decoders 36 a - 36 d also examine the state of the data masking signals YDM 0 -YDM 3 . Each column decoder 36 a - 36 d asserts its column select signal ZCS 8 -ZCS 3 only if its associated data masking signal YDM 0 -YDM 3 is not asserted. If a column select signal ZCS 8 -ZCS 3 is asserted, the selected column is turned on thereby permitting data to be written into that column. If a column select signal ZCS 0 -ZCS 3 is not asserted, the data cannot be written to that column, thereby masking the data from being written.
Thus, as illustrated in FIG. 4B, column select lines are associated with different bytes of the data stream and are fired only for data bytes which are not being masked. Accordingly, since the column selects fire only if a data byte is not being masked, there is no need for any delay between the firing of the column selects to give a margin for the mask to turn on, i.e., to disable the write driver, as in the conventional memory devices. The effective cycle time for each write operation according to the present invention can be calculated as follows:
Effective write cycle=Minimum write time+ y (2)
where y is the time period the data lags the firing of the column select to provide a margin to ensure the next data stream will not write to a previous column. Thus, the effective write cycle time according to the present invention (Equation 2) is reduced by the value of x (from Equation 1) as compared to conventional memory devices, thereby allowing operation at faster speeds.
In addition, the data masking according to the present invention can be provided as a user selectable option. For example, a Data Mask Enable bit can be provided in a mode register. When the Data Mask Enable bit is set to a “1,” data masking is operational, requiring increased timing parameters for the data masking to occur. When set to a “0,” data masking is disabled, thus allowing decreased timing parameters for the memory device to be used.
It should be noted that pre-empting of the firing of the column selects according to the present invention can be done in addition to or instead of pre-empting the firing of the write drivers as described with respect to FIGS. 1 and 2.
A typical processor based system that includes memory circuits according to the present invention is illustrated generally at 200 in FIG. 5. A computer system is exemplary of a system having memory circuits. Most conventional computers include memory devices permitting storage of significant amounts of data. The data is accessed during operation of the computers. Other types of dedicated processing systems, e.g., radio systems, television systems, GPS receiver systems, telephones and telephone systems also contain memory devices which can utilize the present invention.
A processor based system, such as a computer system, for example, generally comprises a central processing unit (CPU) 210 , for example, a microprocessor, that communicates with one or more input/output (I/O) devices 240 , 250 over a bus 270 . The computer system 200 also includes dynamic random access memory (DRAM) 260 , and, in the case of a computer system may include peripheral devices such as a floppy disk drive 220 and a compact disk (CD) ROM drive 230 which also communicate with CPU 210 over the bus 270 . Data masking by DRAM 260 is preferably performed according to the present invention as previously described with respect to FIGS. 3 and 4. CPU 210 and memory 260 may be integrated on a single chip.
While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. For example, the principles of the present invention are also applicable to wider or narrower memory devices, such as a 16-bit wide memory device, which would have two independent column decoders and two data mask signal lines. Additions, deletions, substitutions, and other modifications can be made without detracting from the spirit or scope of the present inventor. Accordingly, the invention is not to be considered as limited by the foregoing description but is only limited by the scope of the appended claims.
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A method and apparatus for masking data written to a memory device that reduces the effective write cycle time of the memory device is disclosed. Firing of the column selects is pre-empted, thereby masking data to be written to a memory device. By pre-empting the column selects, the margin required for disabling a write driver can be eliminated, thereby reducing the effective write cycle. Additionally, data masking can be performed on a per-byte basis by associating independent column selects with each data byte on multi-byte wide devices, e.g., x16 or x32.
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STATEMENT OF GOVERNMENT LICENSE RIGHTS
This invention was made with government support by the Maine Department of Transportation and the Federal Highway Administration. The government has certain rights in the invention.
BACKGROUND OF THE INVENTION
Technical Field
The present invention relates generally to the field of culverts. More particularly, the present invention is directed to a diffuser intended to be attached to the outlet of a culvert used under roadways in order to increase the capacity of the culvert and to reduce the effects of erosion from the outflow of water from the culvert outlet.
Description of Prior Art
Aging infrastructure and changing weather patterns present the need to increase the capacity of existing highway culverts. Water traveling through a straight pipe culvert has a rate of flow which, relative to the inside diameter of the culvert, dictates the amount of water that can flow through the culvert. Older culverts were often undersized, or if initially properly sized, changing environmental conditions resulting in more water needing to be moved therethrough resulted in culverts becoming undersized. Additionally, older culverts often have deteriorated through normal use over the years to the extent that they no longer function correctly. Correcting the problem of undersized and/or deteriorated culverts has traditionally meant replacement of the culverts. This, though, is costly, and often times the geography of the location, or later added infrastructure, prevents easy replacement or the ability to upsize culvert capacity.
In addition, the flow of water from a culvert often causes erosion to the terrain onto which the water flows. Over time, this erosion can greatly alter the terrain and cause changes to how the outflow of water travels away from the culvert. Minimizing erosion from the outflow of water is therefore a desired goal.
One solution for repairing deteriorated culverts is to place a liner within the existing culvert. The liner may be made of metal or, more typically, a plastic or composite material, such as high density polyethylene, polyvinyl chloride, or fiberglass. While placing a liner within an existing culvert is a simple and cost effective method of addressing deteriorated culverts, the liner necessarily reduced the inside diameter of the culvert, thereby exacerbating capacity issues.
It is evident that there is a need for a system for repairing or retrofitting culverts that addresses the need for increased culvert capacity. Additionally, there is a need to reduce erosion from the outflow of water from culverts.
It is therefore an object of the present invention to provide a culvert diffuser which can increase culvert capacity.
It is another object of the present invention to provide a culvert diffuser which can decrease the outlet velocity of the water which is, to a large extent, responsible for the erosion caused by water at the culvert outlet.
It is yet another object of the present invention to provide a culvert diffuser which can be used with a culvert liner.
It is yet another object of the present invention to provide a culvert diffuser which can be used with a culvert liner to provide for less expensive repair of a deteriorated culvert while maintaining or increasing water flow therethrough.
It is yet another object of the present invention to provide a culvert diffuser which can be used with a culvert liner to provide for less expensive retrofit of an undersized culvert to increase water flow therethrough.
It is yet another object of the present invention to provide a culvert diffuser which reduces erosion from the outflow of water from a culvert.
Other objects of the present invention will be readily apparent from the description that follows.
SUMMARY OF THE INVENTION
The present invention comprises an outlet diffuser which is used with a highway culvert to increase pipe capacity and reduce outlet losses. Coupled with properly designed culvert inlets and outlet weirs, the diffuser of the present invention allows existing culverts to be retrofitted for increased life while maintaining, or even increasing, performance. Moreover, erosion from the outflow of water is reduced. The present invention solves both these problems by using hydrodynamic principles to increase the rate of flow of water through a culvert having the same inside diameter. Thus, a liner can be used to repair deteriorated culverts, and the reduced inside diameter of the repaired culvert is more than offset by the increased rate of flow of the water, thereby increasing previous capacity of the culvert. Even where the culvert is in good condition, adding a liner modified with the present invention will result in increased culvert capacity.
The second benefit of the present invention is achieved by different hydrodynamic principles acting on the same device. Water flowing through a culvert has a substantial amount of kinetic energy, and that energy contributes to the erosion of the terrain onto which the water flows. The diffuser of the present invention reduces the kinetic energy of the water as it exits the culvert, thereby reducing erosion.
In simplified form, both effects described herein—increased culvert capacity and reduced erosion at the culvert outlet—are achieved by mounting the diffuser of the present invention to the outlet of the culvert. The diffuser widens the outlet end of the culvert by having sides which angle outward relative to the longitudinal axis of the culvert, thereby providing a larger cross-sectional area at the outlet of the culvert. The precise flare angles and overall length of the diffuser result in hydrodynamic properties creating forces on the water which cause an increase in the rate of flow. The larger cross-sectional area diffuses the kinetic energy as the water exits the culvert. A more detailed explanation is provided below.
Other features and advantages of the present invention are described below.
DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a the relationship between the increased flow rate from a flared inlet to a pipe and the relationship between the increased flow rate from a flared outlet, as originally posited by Giovani Batista Venturi.
FIG. 2 depicts a schematic rendition of Venturi's test rig for determining pressures within a fluid flow.
FIG. 3 depicts, in graphical format, the hydraulic gradient for a straight pipe, as tested by Yarnell (1926).
FIG. 4 depicts, in graphical format, the hydraulic gradient for a pipe with diffuser outlet, as tested by Yarnell (1926).
FIG. 5 depicts, in graphical format, a comparison of performance curves for an 18″ VCP and an 18″ VCP with a diffuser (Yarnell in 1926).
FIG. 6 depicts a schematic side view of a pipe with an outlet diffuser, showing the geometric relationships related to diffuser outlets.
FIG. 7 depicts, in graphical format, the velocity and turbulent boundary layer in a diffuser.
FIG. 8 depicts a CFD representation of Yarnell's VCP and Diffuser System.
FIG. 9 depicts a CFD pressure diagram of Yarnell's VCP and Diffuser System.
FIG. 10 depicts, in graphical format, HGL and EGL for Yarnell's 18″ VCP and CFD model of Yarnell's VCP.
FIG. 11 depicts, in graphical format, the performance curve comparison of Yarnell's physical model and the CFD model.
FIG. 12 depicts a CFD representation of an improved diffuser system with a Bell and tapered inlet and a diffuser with a high A R .
FIG. 13 depicts, in graphical format, the performance curves for CFD and Yarnell's diffuser data compared to pipe performance.
FIG. 14 depicts, in graphical format, the performance curves of the Venegas and the Maine DOT diffuser models.
FIG. 15 depicts, in graphical format, the inlet pool water surface area relative to water levels.
FIG. 16 depicts, in graphical format, water levels and rainfall for two storm events in October of 2014.
FIG. 17 depicts a schematic side view of one embodiment of a pipe with an oval outlet diffuser.
FIG. 18 depicts, in graphical format, the profile of a pipe, diffuser, and outlet weir at the road crossing. (Vertical scale is exaggerated.)
FIG. 19 depicts, in graphical format, hydrographs of the September 30th storm and the three subsequent beaver-generated drawdowns.
FIG. 20 depicts, in tabular format, storm events and active diffuser dates, for the Fall of 2015 through the Spring of 2016.
FIG. 21 depicts, in tabular format, depth to performance characteristics for experimental pipe and diffuser.
FIG. 22 depicts, in graphical format, the Apr. 18, 2016 drawdown curve for the experimental diffuser.
FIG. 23 depicts, in tabular format, drawdown flow rate estimates for experimental diffuser, Apr. 18, 2016.
FIG. 24 depicts, in graphical format, the comparison of flow rates and velocities during drawdown analysis, Apr. 18, 2016.
FIG. 25 depicts, in tabular format, diffuser outlet velocity distributions, at a head of 3.25 feet, on Sep. 30, 2015.
FIG. 26 depicts, in graphical format, the performance curve comparison of the experimental diffuser data to CFD diffuser data & Yarnell's diffuser data.
FIG. 27 depicts, in graphical format, diffuser performance relative to straight pipe performance.
FIG. 28 depicts, in graphical format, dimensionless diffuser performance efficiency, for free discharge diffusers (Miller 1990).
FIG. 29 depicts, in tabular format, estimates of water surface area and water volume of a containment pond at different water levels.
FIG. 30A depicts a plan side view of one embodiment of the diffuser of the present invention attached to a culvert.
FIG. 30B depicts a plan front view of the embodiment of the diffuser of the present invention shown in FIG. 30A .
FIG. 30C depicts a plan top view of the embodiment of the diffuser of the present invention shown in FIGS. 30A and 30B .
FIG. 30D depicts a perspective top view of the embodiment of the diffuser of the present invention shown in FIGS. 30A, 30B, and 30C .
FIG. 31 depicts a schematic side view of an embodiment of the culvert diffuser system of the present invention, with the culvert pipe passing through an embankment having a roadbed on top, with ponded water on either side of the embankment and on either side of a weir.
DETAILED DESCRIPTION OF BACKGROUND AND RESEARCH RESULTS
Water flow capacity within a straight pipe, such as a traditional culvert, is subject to capacity loss, or more precisely loss of total throughput of volume per unit time. These losses occur at the entrance to the pipe and at the outlet of the pipe. Typically, entrance losses and friction losses each constitute approximately one quarter of the total losses in a culvert, and outlet losses account for the remaining half (Bauer, 1959, p. 53). A significant amount of research has been focused on inlet design. Comparatively little research has been directed toward reducing outlet losses because of a commonly held belief that little can be done to improve outlet efficiency. However, in their review of literature related to culvert hydraulics, Larson and Morris of St. Anthony Falls Hydraulic Laboratory came to the following conclusion regarding the reduction of outlet losses through the use of diffusers:
“In submerged culverts of uniform bore, outlet loss often is the largest head loss, particularly if the culvert is relatively short. Therefore, reduction of outlet loss, if possible, can be expected to produce a substantial increase in capacity. If the outlet is completely submerged, the capacity of a culvert can be increased by an enclosed, diverging outlet section, which reduces the outlet velocity and thereby the kinetic energy lost at the outlet. In the Iowa tests [by Yarnell, 1926, p. 15], flared outlets were used with both pipe and box culverts and were found to produce capacity increases up to 60 percent.” (Larson and Morris, 1948, p. 14)
The ability to increase the capacity of existing pipes, rather than replacing them, has substantial advantages. Replacing pipes, especially in deep fills, urban areas, and high traffic areas, has significant construction costs, as well as costs related to traffic disruption. Slip-lining, the process of relining a pipe and injecting grout to fill any voids and secure the liner in place, is an inexpensive way to repair existing pipes. However, slip-liners reduce pipe diameter and therefore pipe capacity. Bell inlets, for example Hydro-Bell by Snap-Tite, are used by slip-liner companies to partially compensate for this reduced capacity. The combination of both a bell inlet and a flared diffuser outlet would be far more effective at increasing the pipe capacity of slip-lined pipes. Similarly, the capacity of undersized pipes could be increased without major construction costs by the addition of a diffuser at the outlet and an improved inlet.
Increasing rainfall intensities associated with changing weather patterns are placing a higher demand on existing culverts, leading to more undersized pipes. The aging highway infrastructure and increased peak flows from both weather and development make rehabilitation of existing pipes particularly attractive. In addition, the reduced outlet velocity associated with diffuser outlets would help to minimize outlet scour that often accompanies undersized pipes.
Herein is summarized the results of research related to outlet diffusers, done under the auspices of a Maine DOT Research Grant supported by Federal Highway Administration (FHWA). The first section provides a brief summary of what is known about diffuser design and function. During the initial research phase, Computational Fluid Dynamics (CFD) computer modeling was used to explore diffuser design and function. The second section summarizes the results of this study. During the literature review, questions arose regarding the effect that different materials would have on diffuser function. Two diffuser models were constructed and subsequently tested at the University of Maine Hydraulics Lab flume. The third section briefly presents the results of these tests. The fourth section summarizes results of field tests of an oval fiberglass diffuser attached to the local pipe mentioned above. This 15 inch pipe was regularly observed to be under pressure flow, with water overtopping the road several times a year. The site had been monitored for both rainfall and water depth for 3 years prior to the installation of the diffuser. The final section discusses opportunities for future research, including the proposed addition of diffuser outlets to several existing pipes in the state of Maine that are known to be undersized or in need of repair.
To gain understanding and background on the concept of diffuser outlets, an extensive literature search was conducted. Many papers and references were reviewed covering the basic physics of diffusers, and how inlet and outlet geometries affect diffuser function and efficiency. A brief summary of this material is included below.
The first extensive testing of outlet diffusers was performed in the late 1700s by Giovani Batista Venturi. A brilliant researcher, Venturi designed and tested optimal geometries for diffuser outlets and flared inlets. To test his designs, he measured the amount of time it took for a fixed amount of water to pass through a fixed aperture with various attached pipe systems. He expressed his results in terms of ratios, comparing the results from modified pipe systems to those of the simple aperture. See FIG. 1 .
To summarize Venturi's results, the addition of a flared inlet improved performance by 21% over the simple aperture. The addition of the flared outlet to the flared inlet improved performance by 98% over the flared inlet alone. The combination of the inlet and the outlet improved performance by 140% over the simple aperture (Tredgold, 1862, p. 154).
In further experiments, Venturi attached a conical inlet to a conical outlet. He attached three glass tubes (early versions of piezometers) to the diffuser, one at the throat of the diffuser, one a third of the way through the diffuser, and one two thirds of the way through the diffuser. As illustrated in FIG. 2 , the lower ends of the tubes were placed in a reservoir of mercury (Tredgold, 1862, p. 146). When water flowed through the device, mercury rose to varying degrees in the three tubes, indicating a strong negative pressure. As shown in FIG. 2 , the negative pressure is strongest at the throat of the diffuser, and progressively decreases in the two subsequent tubes. Although Venturi didn't use this terminology, his tests were the first known confirmation of the vacuum created by a diffuser. This vacuum appears to be central to increasing capacity and decreasing losses in the diffuser systems.
In 1887, Clemens Herschel used Venturi's combination of a flared inlet and a flared diffuser outlet to create the “Venturi Meter”. When the Meter was inserted in a large pipe, measurements of the difference between the upstream pressure and the diffuser throat pressure allowed Herschel to accurately measure the flow rate in the pipe.
Herschel's primary interest was in being able to measure flow rates, not in being able to increase pipe capacity. However, the results of his Venturi Meter tests nonetheless indicate the effect of diffusers on pipe capacity. Herschel worked with two Venturis, one with a nine foot diameter pipe and a three foot diameter throat, and one with a one foot diameter pipe and a one-third foot diameter throat. In both cases, at high flows, the flow of water through the Venturi was 98% as efficient as through the pipe without the Venturi. In other words, at a given pressure, the diffuser allowed 98% as much water to flow through a three foot diameter opening as was able to flow through the nine foot diameter straight pipe. As flow rates decreased, the efficiency of the Venturi Meter and the accuracy of the measurements of flow decreased (Herschel, 1898, p. 36).
In the 1920s, David Yarnell did the first research and experimentation on the possible use of diffusers in highway applications. Yarnell, a drainage engineer with the Bureau of Public Roads, was asked to conduct a study on the hydraulics of culverts. He experimented with many different inlets and outlets at the University of Iowa. The increased flow rate which resulted from the use of diffusers, “increasers” in his terminology, led him to experiment with a number of diffuser geometries. This remains the largest set of data on the design of diffusers for highway culverts (Yarnell, 1926, pp. 105-106). Yarnell tested both a conical diffuser attached to a round vitrified clay pipe (VCP) and a number of flared rectangular diffusers attached to square box culverts. A meticulous researcher, he was able to record and process massive amounts of data, including flow rates and piezometer readings along the length of pipes and diffusers.
FIG. 3 illustrates Yarnell's hydraulic grade line (HGL) for a straight pipe. Piezometer readings along the length of the pipe are depicted as small circles. Pressure decreases consistently from the entrance, on the right, to the outlet, on the left. The hydraulic gradient is above the pipe for the entire length, and is the result of the raised outlet weir which maintains submergence of the pipe. This forces the pipe to operate under pressure flow and outlet control.
In contrast, FIG. 4 illustrates the HGL of a pipe with a diffuser outlet. The small circles again depict the measured piezometer readings. The pressure decreases consistently and steeply from the entrance of the pipe on the right to the entrance of the diffuser, at piezometer 11 . In this pipe section, all of the piezometer readings are shown below the top of the pipe, indicating that a vacuum is created by the diffuser and extends upstream from the entrance of the diffuser to the pipe inlet. The piezometer readings from 11 to 15 increase rapidly, reaching atmospheric pressure at the submerged outlet. This represents the recovery of pressure head in the diffuser. Note, in FIG. 4 , the line to the left shows the pressure recovery in the diffuser outlet. This increasing pressure gradient opposes the flow and is therefore considered an adverse pressure gradient, which contributes to the decrease in outlet velocity. The vacuum generated at the entrance of the diffuser increases the hydraulic gradient from the culvert inlet to the entrance of the diffuser, and represents a second force, in addition to the inlet head, acting on the water and increasing the flow in the pipe.
The contrast between these FIGS. 3 and 4 is striking. Both pipe systems have similar inlet and outlet water levels and are under pressure flow. However, the difference between the HGL in the two systems illustrates the effects of adding a diffuser. The HGL in the pipe with the diffuser clearly demonstrates both the creation of the vacuum and the recovery of head. With the diffuser, the effective pressure head is the difference between the pressure created by the inlet water level and the pressure at the throat of the diffuser, 3.27′−(−0.09′)=3.36′. Without the diffuser, the effective head is the pressure created by the inlet water level minus the low pressure reading just before the outlet, 3.17′−1.82′=1.29′. This major difference in effective head is the result of the vacuum created by the diffuser and accounts for the increase in capacity.
Yarnell summarized the effects of a diffuser on the capacity of a box culvert as follows:
“If the outlet end of a 36-foot box culvert with a rounded lip entrance is flared by diverging the sides at an angle 6°30′ throughout a distance of 10 to 12 feet from the outlet headwall, thus doubling the area of its cross-section at the outlet, the capacity of the culvert is increased about 60 percent above the capacity of a similar pipe with a uniform bore extending the entire length of the culvert.” Yarnell (1926, p. 15)
In the round VCP, Yarnell found a 40% increase in flow rate with the addition of a conical diffuser outlet in comparison with a straight pipe. (Yarnell, 1926, p. 13) FIG. 5 presents performance curves for an 18″ VCP with and without a diffuser based on Yarnell's data.
The range in increased capacity from 40% found in the vitrified clay pipe to 60% found in the box culvert reflects the range in performance that can be expected with the addition of an efficient diffuser with improved inlet and outlet conditions (Yarnell, 1926).
Concurrent with Yarnell's work, Julian Hinds did extensive work with the use of diffusers (siphon outlets in his terminology) in aqueducts. His focus was primarily on reducing head losses in order to maintain flow over long distances. Hinds documented the use of flared transitions from diffusers into open channels. This resulted in extremely low outlet losses that Hinds recorded (Hinds, 1927, p. 1452)
It is noteworthy that the flare in the open channel had an impact on overall performance. In the context of this current project, the implication is that although the diffuser needs to be full to create a vacuum and be fully functional, some benefit is still derived when the diffuser is not full and functions as an efficient channel transition from a narrow pipe to a wider channel.
Comparison of pipes of various sizes requires a method of eliminating the variation created by scale. To do this, the following dimensionless relations are defined:
Q*=Q /(2 g) 0.5 D 2.5 (1)
H*=ΔH/D (2)
In these equations, Q is the flow rate, Q* is the dimensionless flow rate, D is the pipe diameter, ΔH is the change in head, defined as the difference between inlet and outlet water surfaces, and ΔH* is the dimensionless head.
Pipes operate under inlet control, barrel control, or outlet control. When inlet losses are high, resulting from poor inlet geometry, the inlet is the limiting factor in that the inlet cannot accept as much flow as the barrel can convey. The pipe does not completely fill, and is said to be under inlet control. In inlet control situations, the head is defined as the height of water above the inlet invert, or headwater (H W ).
Under barrel control, the barrel cannot move as much water as the inlet can deliver and the outlet can accept because of friction losses, the flow in the culvert is subcritical. In highway applications, the pipe does not typically run completely full, and the outlet is not submerged. In this case, the head is defined as the difference between the inlet water level and the water level in the pipe (H p ) at the outlet, H W −H p =ΔH (BC) .
Under outlet control, the inlet and the outlet are both submerged, and the pipe is full and under pressure flow for the entire length. In this case, the head is defined as the difference between the inlet water level and the tail-water level, H W −T W =ΔH (OC) .
Note that ΔH is used for both outlet and barrel control. This is because most sources (including the standard reference HDS 5) do not differentiate between the two, referring to both as outlet control. For a given H W , the difference is that in barrel control, the pipe length and friction are the limiting factor, whereas in outlet control, the Tail-water level is the limiting factor.
With the addition of an outlet weir to fully submerge the outlet, pipes under either barrel control or outlet control would be candidates for the addition of a diffuser. (See HDS 4, 2001, pp. 136-141, and HDS 5 pp. 3.22-3.40 for more details on Inlet and Outlet Control and Skogerboe and Markley (1996) for details on Barrel Control).
For a diffuser to work in a given situation, certain site conditions, as well as design requirements for the inlet and the diffuser outlet, must be met. First, the pipe and the diffuser must be full to be fully effective. This requires adequate cover above the pipe. Typically a water depth of 1.5 pipe diameters (1.5D) above the bottom of the pipe is required to fill a pipe, with at least 1.6D required to fill the diffuser as well. In other words, to obtain the full benefit from the diffuser, there must be adequate cover over the pipe to allow the required depth of water at the culvert inlet.
In addition, improved inlets reduce inlet losses, further contributing to the filling of pipes. Improved inlets commonly used are bell inlets and tapered inlets. In some situations, inlets with overhanging projections, known as hooded inlets, have been shown to both facilitate the filling of pipes at low inlet heads and prevent vortices from forming at the inlet (Rouse, 1959, Blaisdell, 1958, pp. 38-39). Bell inlets and tapered inlets have an additional advantage in that they help to establish symmetric flow in pipes, and therefore diffusers. Symmetric flow is important for diffuser functioning. (See FIG. 28 for a representation of symmetric flow in diffusers.)
There are two fundamental geometric variables in diffuser design: flare angle and area ratio A R . Diffuser flare angle is the crucial variable in diffuser design. Flare angle can be expressed as either a half flare angle θ or as a total flare angle 2θ. Area ratio is defined as the ratio of the diffuser outlet area to the pipe area, A R =A O /A P . Given θ, either an area ratio or a diffuser length (L d ) must be included to fully define the diffuser outlet geometry. These geometric relationships are illustrated in FIG. 6 .
In 1912, Gibson performed extensive tests exploring diffuser function at the University College, in Dundee, England. His research indicated that for a conical diffuser on either a round or a square pipe, 6° was an optimal total flare angle (3° half flare angle). With a rectangular diffuser with the two vertical sides flaring, the optimal total flare angle was found to be 10° to 12° (5° to 6° half flare angle) (Larson & Morris, 1948, pp. 118-120).
In 1950, Venegas also investigated optimal flare angles in rectangular diffusers, obtaining similar results to Gibson's. One of his models was used as the basis for the models tested at the University of Maine flume as part of this current research, and reported in the third section of this paper.
It is instructive that the optimal flare angle of a diffuser closely approximates the natural expansion of water exiting a pipe. The mechanical confinement of the water by the diffuser forces the flow into contact with the diffuser wall, a necessary condition for attachment. This natural expansion is a limiting factor: as the angle exceeds this expansion, the water exiting the pipe and entering the diffuser will not follow and remain attached to the diffuser wall, a condition necessary for the diffuser to function. Without this attachment, the vacuum will not be established, the flow will not increase, the outlet velocity will not decrease and outlet losses will remain high. It is safer to err in the direction of a smaller flare angle rather than a larger flare angle, as the latter will not perform reliably.
The last important design consideration that allows the pipe and diffuser to be full and functional is submergence of the outlet. This can be accomplished by the construction of an outlet weir. The location of the weir would be dependent on site conditions, but would ideally be at least 1.5 diffuser lengths from the outlet of the diffuser. Ideally an outlet weir would be high enough to allow water to pool to the top of the diffuser. The weir height would be matched to a design flow, so that the diffuser would activate at that flow. A diffuser that flares horizontally, rather than vertically, will allow for the use of a lower outlet weir. The flow that causes the inlet pond to reach 1.6 pipe diameters would be the height at which the diffuser would ordinarily activate. This would be a logical design flow for the outlet weir. This is an area for further research. Although this is a higher inlet water level than would be acceptable for most new pipe installations, for a retrofit, repair, or a pipe with size limitations this could provide a reasonable solution.
In summary, adequate cover to provide adequate head at the inlet, an improved inlet, symmetric inlet flow, a properly flared diffuser, and submergence of the diffuser outlet are all necessary design factors for a functional diffuser.
In the February 1943 edition of California Highways and Public Works , a brief article reported the construction of a “flare-siphon culvert”, or diffuser, at Vallejo Creek.
Subsequently a flared extension was added to a second culvert. The fact that this type of design did not continue to be used suggests that the culverts did not meet expectations. However, it is clear from the description of the diffusers that the necessary design requirements listed above were not met. No mention was made of the use of improved inlets or outlet weirs for either design. The Vallejo Creek culvert was constructed as a three-cell box culvert. The flare angle of the diffuser on the central cell was 14.25°, which is well above the optimal angle. The outer flare angle in the two outer cells was 20.56°, with a bend at the diffuser inlet creating asymmetric flow. Both the bend and the flare angle were not conducive to effective performance of these two cells. In addition, the amount of cover at the culvert site was 1.375D above the bottom of the culvert, which would not allow adequate head for the diffuser to function.
In the second culvert, the total flare angle was 17.1° (8.55° half flare angle), again well above optimal. The flare angles for both culverts were in line with design recommendations from the “California Culvert Practice” (1955), which states “The flare angle tangent “t” should not exceed 0.2 [11.3° half flare angle or 22.6° total flare angle] for moderate velocities or 0.1 [5.7° half flare angle or 11.4° total flare angle] for high velocities, or the diverging jet will not wet the outer walls (causing a gurgling turbulence as prime is intermittently lost).” (California Culvert Practice, 1944, pp. 53-55). Although there is an acknowledgement of the importance of the vacuum, or “prime”, based on the consensus of the literature, the suggested 11.3° half flare angle is considerably too wide to be effective.
In addition, although it appears that adequate cover over the pipe was present, the apparent lack of an outlet weir made it unlikely that the pipe was submerged. Despite these design issues, the California Division of Highways reported a 20% increase in capacity as a result of the addition of the diffuser (California Culvert Practice, 1955, p. 75).
The apparent failure of these two culverts to perform as well as hoped probably discouraged further research and funding of diffuser outlets. In addition, two sources of information regarding hydraulics and culvert design also dampened interest. In 1959, Rouse, a prominent hydraulic engineer from the University of Iowa, co-authored the paper “Hydraulics of Box Culverts”. It concluded:
“Brief mention has been made of the custom of repeating the inlet shape at the outlet. Hydraulically this is of no use whatever, and it is doubtful whether more than a very gentle outlet flare would effectively reduce the erosive effect of the outflow.” (Metzler and Rouse, 1959, pp. 28-29)
Metzler and Rouse's point that the flare angle used in inlets is not appropriate for outlet diffusers is valid. However, their downplaying of the effectiveness of a gradual flare on decreasing scour, and their failure to note the increase in flow associated with flared outlets, seems a bit surprising. Rouse was teaching at the same University of Iowa where Yarnell conducted research and provided a significant amount of data supporting the effectiveness of outlet diffusers at both increasing pipe capacity and reducing outlet velocity.
The most recent hydraulic FHWA culvert design manual, HDS 5 (Schall et al, 2012) briefly touched on the use of diffusers, citing the California ‘flared-siphon’ experience and the lack of further data:
“A flared-siphon culvert has an outlet which diverges, much like a side-tapered inlet. The Venturi (expanding tube) principle is used to salvage a large part of the kinetic energy and thereby increase the culvert capacity. The State of California was experimenting with these designs in the early 1940-1950s. Obviously, submergence of the outlet is necessary to achieve the siphoning action. Presumably, the added capacity was not dependable, and their design is rare.” (Schall, et al, 2012, p. 5.6).
Unfortunately, the California experiments were based on problematic designs, and negative conclusions based on their results have discouraged further research. Because diffusers have specific requirements, they must be carefully designed. The lack of research and data regarding the design and use of diffuser outlets with highway culverts, the effective use of diffusers in other industries and applications, and the large potential benefits of rehabilitating existing culverts to maximize flows and minimize erosion, indicate that further experimentation with field applications, as well as a deeper understanding of the physics of diffuser functioning, would be merited.
Discussion of diffuser function requires an understanding of outlet losses and some of the basic equations related to these losses. Traditionally, in highway design, the velocity of water leaving a pipe represents “lost energy”, with the loss of kinetic energy expressed as an outlet head loss:
H o =K o V p 2 /2 g K o =1 (3)
In this equation, H o is the outlet head loss, V p is the velocity of the water in the pipe, g is the gravity constant, and K o , is the outlet loss coefficient, which is typically assigned a value of 1. Tullis (2012) reported results from lab experiments measuring outlet losses and associated loss coefficients. He used his results to assess the accuracy of various equations used to calculate outlet head loss. He found that at high flow rates, Equation 3 overestimated head losses by up to 187% (Tullis, 2012, p. 26).
The second and slightly improved method for calculating H o is found by subtracting the velocity head in the downstream channel from the pipe's velocity head. In practice, an estimate of the downstream velocity (V d ) is used to calculate the outlet head loss (Larson and Morris, 1948, p. 48).
H o =K o ( V p 2 −V d 2 )/2 g K o =1 (4)
At high flow rates, Tullis found this equation overestimated losses by as much as 143% (Tullis, 2012, p. 26).
The third equation is the Borda-Carnot Equation, originally derived to be used for abrupt expansions in pipe systems, and subsequently used to calculate diffuser losses (Gibson 1912, pp. 205-206, Larson and Morris, 1948, p. 48, Tullis, 2012, p. 26):
H o =K o ( V p −V d ) 2 /2 g, K o =α(typically 1)
or H o =K o V p 2 /2 g, K o =(1− A p /A d ) 2 (5)
In this equation, A p is the area of the pipe and A d is the area downstream of the outlet. The kinetic energy correction factor α is equated to the outlet loss coefficient K o (Larson & Morris, 1948, p. 14). For a pipe emptying into a channel, A d would be the area of the channel. In the case of a diffuser, A d would be the outlet of the diffuser. Note that A p /A d =1/A R , the inverse of the area ratio A R .
This equation proved to be much more accurate, with errors at high flow rates of only 6.2%. Rather than assuming K o =1, the Borda-Carnot Equation bases its loss coefficient on the ratio of the pipe area to the outlet area. The Borda-Carnot Equation is derived from the combination of three equations: the Bernoulli Equation (the energy equation), the momentum equation, and the continuity equation (the mass-balance equation). (For a complete derivation of the Borda-Carnot Equation, see Tullis, 2012, p. 26, also see Larson and Morris, 1948, p. 48). HY8 uses equation 3 as the default method for calculating outlet losses and flow through a culvert. The Borda-Carnot Equation is referred to as the Utah State University (USU) equation and has been included in HY8 as an alternative method.
The Borda-Carnot Equation incorporates momentum into its derivation and is considered the most accurate formula for outlet head loss. This suggests that momentum is an important factor in outlet losses. A change in momentum in a diffuser, related to the change in velocity from the entrance of the diffuser to the outlet of the diffuser, indicates that an additional force is acting on the water in the diffuser. It seems reasonable to assume that the low pressure at the diffuser entrance serves as a suction force that increases the flow rate and decelerates the water in the diffuser. This results in a reduction of velocity (and hence momentum) in the diffuser, as well as higher flow rates and lower exit velocities. Additional research would be required to understand how the low pressure zone is created and its impact on diffuser function.
Miller (1990) presents a graph predicting diffuser loss coefficients based on area ratio and dimensionless length ratio. This is an interesting design tool. See FIG. 28 .
In order to fully understand diffusers, it is important to explore the role of the boundary layer and its attachment in a diffuser pipe system. A boundary layer is a layer of fluid near a solid boundary, as in a pipe wall, that has zero velocity at the solid boundary surface, where it is attached. The importance of the attachment of the fluid to the pipe wall can best be understood by discussing what happens when it fails and the flow separates from the wall. In a zone of separated flow, the flow can reverse, creating eddies which push against the primary jet, constricting the area of the primary flow. In addition, the combination of the flow separation from the wall and the force created by the effect of eddies on the primary jet can cause the flow to oscillate in the pipe. Because of the importance of symmetric flow and a well-established boundary layer at the entrance of the diffuser, this oscillation has a major detrimental effect on the functioning of the diffuser. If the flow is oscillating, it will move from side to side in the diffuser, and the diffuser will not function in the way that it should (Miller, 1990, pp. 61-63, Kline, et al, 1959, p. 322).
In the boundary layer, the velocity increases rapidly from the wall to the edge of the primary jet. Just beyond the zone of attachment, there is a zone of laminar flow, followed by a zone of turbulence. This turbulence is generated from shear at the interface of the boundary layer and the primary flow, and has an important role in pipe systems that will be discussed below (Miller, 1990, p. 64, Kalinske, 1944, pp. 356-357, Senoo & Nishi, 1977, pp. 379-380).
It is well known that in an unimproved inlet, a vena contracta forms, a narrowing of flow just inside the inlet of the pipe, where the flow separates from the pipe wall, leaving the actual area of flow constricted in the central portion of the pipe and disrupting the boundary layer. If the pipe is long enough, more than 10 pipe diameters, the flow spreads, eventually filling the entire pipe, reattaching, and reestablishing the boundary layer. In contrast, a bell inlet allows the water to stay attached, developing a uniform velocity distribution and a thin, well-established boundary layer. As the flow enters the diffuser, the boundary layer thickens and the velocity distribution is altered (Larson & Morris, 1948, pp. 4-14). FIG. 7 shows the changing velocity distribution and the changing thickness of the boundary layer (y o ) as the flow passes though the diffuser.
Because the boundary layer is a turbulent low velocity zone, as it thickens, the average velocity in the diffuser decreases. This further contributes to the decrease in velocity that is the direct result of the widening of the diffuser, as required by the Continuity Equation. In addition, the shear between the primary flow and the boundary layer uses a significant amount of energy to create vortices which form on both sides of the shear interface. These vortices serve a number of important functions. They create a pressure on the boundary layer in the direction of the diffuser wall, helping to maintain its attachment. They transfer energy from the primary jet to the boundary layer, which helps to maintain both the boundary layer and its forward motion against the adverse pressure gradient (Miller, 1990, p. 61; Azad, 1990, p. 327; Senoo and Nishi, 1977, pp. 379-380). If the adverse pressure gradient stops the forward movement of the water in the boundary layer, and if the boundary layer does not remain attached to the diffuser wall, the flow separates from the wall, and little additional benefit is derived from the diffuser. The vortices in the central jet also create what is known as eddy viscosity, which further helps to slow the flow (Kalinske, 1944, p. 357, 374).
In summary, a well-designed pipe system will have symmetric flow entering a well-designed inlet that allows the water to attach to the wall and establish a thin and uniform boundary layer and stable flow. As the symmetric flow enters the properly flared diffuser, the boundary layer thickens, stabilizing and slowing the velocity in the central jet. The net result of this process is an increase in efficiency of the culvert system, with increased capacity and reduced outlet velocity. These design considerations can be illustrated graphically in CFD models. In addition CFD modeling can be used to pre-test designs of actual culvert systems, high-lighting design flaws like those that prevented the California Highways flare-siphon culverts from functioning properly.
At the outset of this project, a connection was made with Kornel Kerenyi of the Turner-Fairbanks Highway Research Center, who was very supportive of this work and suggested utilizing Computational Fluid Dynamics (CFD) computer modeling as a way of exploring and understanding the design and function of outlet diffusers. The Transportation Research and Analysis Computing Center (TRACC) at Argonne National Lab located Chicago-West provided online access to the STAR-CCM+CFD program, as well as offering online tutorials and support. This CFD program has tools that facilitate the creation of models, which proved helpful in illustrating many of the design concepts involved with diffuser systems. However, obtaining a thorough understanding of the use of the CFD modeling takes time and practice, and this researcher is far from an expert.
Various inlets, inlet chambers, outlets and outlet chambers were modeled and tested at different flow rates. The inlet chambers in the CFD models attempt to represent the ponding of water in an inlet pool, the pressure head at the inlet, and the direction of flow entering the inlet. The outlet chambers in the models attempt to represent the water level in the outlet pool and the presence or absence of an outlet weir.
The CFD program presented the results graphically, using color coding to illustrate velocity and pressure gradients. Performance curves for each design could be created from the model data. Having this information presented visually was extremely helpful, supporting and extending the concepts encountered in the literature.
FIG. 8 shows a CFD representation of Yarnell's 18″ VCP with a diffuser outlet. The diffuser expands from 18″ to 26″ over a length of 5′, creating a total flare angle 7.6° (3.8° half flare angle).
The color gradient increases from blue to red for velocity, as well as for pressure, in all CFD figures. This illustration depicts the velocity of the flow rapidly decreasing from a maximum (red) in the pipe to a minimum (light blue) as it passes through the diffuser, reducing the kinetic energy lost at the outlet. The flow continues to expand and decrease in velocity within the outlet chamber, further reducing the kinetic energy available to create scour related issues. The black area at the edge of the pipe is created by close contour lines and represents the high velocity gradient of the boundary layer. This layer thickens and remains symmetric along the length of the diffuser.
In the CFD pressure diagram in FIG. 9 , the low pressure zone at the entrance to the diffuser and the rapid increase in pressure through the diffuser are shown. The total effective head is the difference between the pressure at the inlet and the low pressure at the throat of the diffuser. This makes the effective head significantly higher than the difference between headwater and tail-water that drives flow in a straight pipe. The red line represents atmospheric pressure, indicating that almost the entire pipe is below atmospheric pressure. The low pressure, extending to the pipe inlet, increases the hydraulic gradient at the inlet which in turn increases the flow rate.
The pressure data from the piezometers in Yarnell's 18″ VCP and the pressure data from the CFD model of this pipe (in FIG. 9 ) are plotted and compared in FIG. 10 . The CFD model was not able to capture the full extent of the vacuum generated by Yarnell's diffuser as is shown in the two HGL curves. The energy grade line (EGL) was calculated for each of these models by combining the HGL values and the mean velocity head (V 2 /2 g). The kinetic energy correction factor (a) was not calculated for either of these examples, which may account for the slight rise in the EGL of the CFD output data at the culvert inlet and diffuser outlet (see Larson and Morris, 1948, pp. 5-11 for a review).
FIG. 11 shows the performance curve created from the CFD model and the performance curve from Yarnell's original data. The two curves are similar, confirming the accuracy of CFD modeling. In the CFD model, ΔH was determined using inlet and outlet pressures, whereas Yarnell used inlet and outlet water levels. This could account for a portion of the shift in the data. Another portion of the shift could be related to a number of fluid dynamics characteristics that are difficult to duplicate with CFD modeling. The way turbulence, adhesive properties of the diffuser wall, and pipe roughness interact in a CFD model may be slightly different from a physical model. These factors could influence the efficiency of the CFD diffuser.
In the CFD model in FIG. 12 , an efficient bell and taper inlet and a longer diffuser with a higher area ratio was tested. This diffuser had an A R of 4 and a total flare angle of 5.72° (2.86° half flare angle).
The combination of the improved inlet and diffuser outlet performed well, as noted in Venturi's early paper. FIG. 13 compares this CFD model, a CFD pipe without a diffuser, Yarnell's 18″ pipe with a diffuser outlet, and Yarnell's 24″ straight pipe. The graph uses dimensionless performance curves, allowing comparison of pipes of different diameters at different heads.
A performance curve generated from calculations made using HY8, a computer program created by Federal Highways to analyze culvert hydraulics, is also shown above. Since the default option for HY8 utilizes the velocity head (equation 3) to calculate outlet losses, the calculated performance is significantly lower than the performance measured using Yarnell's pipe data, as well as the CFD pipe data.
In this graph, the CFD pipe data lines up with Yarnell's pipe data and the CFD diffuser data lines up with Yarnell's diffuser data. This reconfirms the efficacy of CFD modeling. The diffuser curves are considerably to the right of the pipe curves, demonstrating the increased capacity of pipes with diffusers. This graph also clearly indicates that the effect of the diffuser on performance increases with higher heads, as the curves diverge as head increases.
CFD modeling supported and extended the concepts and information that was found in the literature, and confirmed that diffusers could be used to advantage in highway culverts. However, physical modeling is also necessary to confirm and better understand concepts alluded to in the literature. The role of the attachment of the boundary layer to the culvert surface is one such concept.
In Hydraulics of Box Culverts Metzler and Rouse (1959) noted that coating a culvert surface with hydrophobic materials such as wax or grease adversely affects the performance of the culvert. In addition, the separation of water from the top of the culvert at the outlet could be shifted upstream by coating the culvert with grease (hydrophobic), or downstream by coating the culvert with a wetting agent (hydrophilic). The effect of using tallow or wax on the flow of fluid through a pipe is also addressed in Spon's Dictionary of Engineering (E & F. N. Spon, 1874, p. 1900). It states: “some lines of water are carried towards the sides, either by a divergent direction, by an attractive action, or by the two causes united. As soon as they arrive in contact, they are strongly retained by molecular attraction . . . by an effect of this same force they draw the neighboring lines, and by degrees the whole vein, which then rushes out, filling the tube, and passes through the contracted section more rapidly.” However, “by rubbing tallow or wax on the sides, the water will not follow them as it did before.” (Spon, 1874, p. 1900) This seems to imply that the hydrophobic-hydrophilic nature of the pipe surface could affect the ability of the water to attach to the pipe wall and thus affect both the ability of the pipe to fill and to form a boundary layer. Because both the boundary layer and the filling of the pipe are important aspects of diffuser function, it seemed prudent to test possible materials before investing in the construction of the large diffuser planned for the Thorndike field test. Miller notes that surface properties have a definite effect on flow through lab scale models. However, surface properties produce a negligible effect at full scale (Miller personal communication Jun. 28, 2016).
Laboratory data was available from Venegas (1950) experiments with Plexiglas box culvert models with and without diffusers. The straight culvert model was 3″ by 3″ and 24″ long. The diffuser model was a 3″ by 3″ box section 18″ long followed by a 6″ long diffuser with a 10° total flare angle (5° half flare angle) on the vertical sides; the top and bottom were not flared. For the current project, two fiberglass models were made to these same specifications, one with a gel coat surface and the other with a fiberglass resin surface.
The models were tested at the University of Maine at Orono (UMO) Civil Engineering Hydraulics Lab. This flume unfortunately had a lower capacity than anticipated, and was limited to a maximum flow rate of 0.22 ft 3 /s. This limited the maximum head that could be tested.
A mount was constructed so that the models could be easily exchanged in the flume. Flow rates and inlet and outlet water levels were recorded. From this data, performance curves were generated.
The performance of the two fiberglass diffuser models was not significantly different from each other. However, both models performed slightly better than Venegas' Plexiglas diffuser model (approximately 8% better). This could be attributable to different lab set-ups, to slight differences in the configuration of the models, or to the surface properties of the models.
FIG. 14 shows performance curves for Venegas' box culvert with a diffuser outlet (represented by red triangles), his box model without a diffuser (represented by orange diamonds), the Gel Coat fiberglass box culvert with a diffuser (represented by black triangles), and the Resin fiberglass box culvert with a diffuser (represented by blue triangles) tested at the UMO flume.
Note that Venegas' culvert with a diffuser performed approximately 17% better than his straight culvert, and the Maine DOT diffuser models performed approximately 23% better than Venegas' straight culvert. Although this is not as impressive as Yarnell's 60% increased capacity, it is nonetheless significant. Yarnell's superior performance is due to a better design. Yarnell used a rounded inlet and a diffuser with a larger area ratio, A R =2. Venegas had an unimproved inlet and a low area ratio, A R =1.34.
Based on the comparison of the UMO flume data with Venegas' data, it was concluded that fiberglass would be a viable material for the diffuser outlet to be used in the Thorndike field tests. In addition, it was noted that the resin coat fiberglass diffuser was transparent enough to observe the transition from water to air as the flow detached from the diffuser. Since attachment is necessary for effective diffuser function, the ability to observe attachment was incorporated into the Thorndike diffuser design.
There is an undersized pipe on Cilley Road, a local discontinued road in Thorndike, Me., where the stream regularly overtops the dirt road. This seemed like an ideal place to explore diffuser performance in a real world setting. Because it was local, the location was easy to monitor for rainfall and flooding. Because the pipe was small, only 15″ in diameter, and the inlet pool helped to regulate flow, the scale was manageable. A relatively small diffuser could be constructed and installed with minimal cost and equipment. Furthermore the observations and the installation were facilitated by the lack of traffic.
Starting in 2009, rainfall, water levels, and conditions when the pipe was operating under pressure flow were observed and recorded. Water depth loggers and a rain gage were installed in 2013. The site is located a half mile down the Cilley Road from the intersection of Files Hill Road and East Thorndike Road in the town of Thorndike, Me. The drainage area for this stream, a tributary to Wing Brook, is 0.52 square miles. The stream flows through a large wetland, which covers 9.62% of the drainage area. A beaver dam approximately 200′ upstream from the pipe creates a large upper storage area. Between the beaver dam and the road, there is a lower storage area that acts as in inlet pool. The height of the road is 3.25′ above the culvert invert, but stones along the upstream side of the road allow water to pond roughly 3″ above the road surface. Two-foot Lidar contours were superimposed on the Site Map, and the 476′ and 478′ contours between the road and the upper beaver dam were used to define the inlet pool and to estimate the surface area and volume of the water in the pool at different water levels. These estimates are presented in FIG. 29 and graphically in FIG. 15 .
The original pipe was a 15″ diameter 12′ long smooth cast iron pipe (CIP). Given the size of the drainage, a 4′ diameter pipe would be appropriate, making this pipe significantly undersized. The pipe was most likely installed in the early 1900s, and had rusted through in places near the inlet and outlet. The pipe had a reverse slope, with a 0.85″ rise over the 12′ length. The inlet to the pipe was set into the stone headwall and overhung by large flat stones, creating the effect of a hooded inlet. The second pipe, installed by the local property owner, was a 15″ “repurposed” corrugated metal pipe (CMP). The pipe outlet was flush with the bottom of the downstream channel, and the banks were approximately 1.5′ above the channel. The channel had a very low slope. Rough stone outlet weirs were assembled approximately 9′ from the end of the pipe to create an outlet pool.
Starting in October, 2009, a calibrated cylinder rain gage was used to collect year round precipitation data. Starting Apr. 15, 2013, a tipping-bucket rain gage was used in addition to the calibrated cylinder gage. The tipping-bucket gage was calibrated using storm totals from the cylinder gage. The tipping-bucket was retired each fall when freezing temperatures were likely, generally around November 1.
Solinst Level Loggers were installed in the inlet and outlet pools on Mar. 30, 2013. The head (ΔH) was determined by subtracting the outlet level from the inlet level. The Level Loggers are unvented and read total pressure so it was necessary to subtract barometric pressure from the level loggers. Local barometric pressure was initially collected from online sources. In spring 2015, a Solinst Baralogger was set up to take barometric pressure readings locally. FIG. 16 shows hydrographs and cumulative rainfall for two storm events in October 2014.
During 2015, the diffuser was designed and built. The design of the diffuser is shown in FIG. 17 . The diffuser was fabricated from ⅜″ fiberglass. The outside surface was covered with a UV resistant coating, with the exception of a 6″ wide viewing area at the top that runs the length of both the diffuser and the pipe. This window allows observation of the transition from attached to detached flow. The diffuser expands from a circular pipe to a horizontal oval outlet with a total flare angle of 11.9° (5.95° half flare angle) in the horizontal plane and a width of 30″. The diffuser section is 6′ long, with an area ratio (A R ) of 2. At the inlet end of the diffuser, a 6′ long straight pipe section was incorporated. This was included because the holes in the CIP pipe would likely prevent the development of the vacuum necessary for the diffuser to function. Three flanges were added on the outside of the pipe to allow the pipe to be secured in place. At the inlet to the pipe section, a socket was incorporated to allow the CIP pipe to be inserted, and to allow the inner surface of the diffuser pipe to be continuous with the CIP pipe. Kenway Corporation of Augusta, Me. fabricated the pipe and diffuser for $5110.00.
The installation of the diffuser turned out to be reasonably quick and easy. The abutting landowner had a small tractor with a bucket, which he used to remove the previously mentioned large rock that had been dislodged and was sitting in the channel where the diffuser was to be installed. It also became apparent that the CMP pipe that had been installed would interfere with the installation of the diffuser, and the tractor was used to bend it out of the way. The diffuser was then carried by hand and placed in position. Tar paper was placed over the joint between the CIP and the fiberglass pipe, and sand and stones were placed over this junction. Metal hoops in front of the flanges and sand bags on the top and sides were used to secure the pipe and diffuser in place.
After the diffuser installation was completed, the outlet weirs were reset approximately 9′ from the diffuser outlet to accommodate the additional pipe length.
FIG. 18 provides the geometric characteristics of the profile of the diffuser site. Note the slight reverse slope to culvert and diffuser. The weir includes a one foot wide outlet channel that is offset approximately 2′ to the right of where the projected centerline of the diffuser intersects the weir. This allows the pool to drain to the level shown in the chart.
From the beginning of data collection in October, 2009 until the installation of the diffuser in September, 2015, the stream overtopped the road an average of 2 to 3 times per year. The combination of rainfall data, water level data and observations prior to the installation of the diffuser indicated that in general, 1.5″ of rainfall were required for the pipe to fill and 3″ were required for the stream to overtop the road. However, rainfall data does not tell the whole story. Three inches of rain falling onto frozen ground with snow cover during a warm winter rainstorm affects runoff and resulting water levels very differently than 3″ of rain on a day during a dry summer.
The winter following the installation of the diffuser was unusual in that it was an “El Nino” year, with warmer and rainier weather. During the fall and winter of 2015-2016, with the combination of rainfall and snowmelt, the stream overtopped the road 4 times. The previous El Nino in 2010 was similar, with 5 storms with over 3″ of rain during the late fall and winter.
The diffuser was installed on Sep. 17, 2015. On September 30, 5″ of rain fell in approximately 16 hours. This was the largest rainfall event recorded since the beginning of data collection for this project, and is considered a 75 year rainfall event for this location (NOAA Atlas 14, Volume 10, Version 2). The capacity of the diffuser and the culvert was exceeded, and the stream overtopped the road. The maximum inlet water elevation during this storm was 3.54′, 0.29′ above the road elevation. The water in the outlet pool stabilized approximately 2.8″ over the top of the diffuser, which was full and appeared to be working well. As the inlet water dropped, the outlet pool also dropped, and when the pool reached a level of approximately 1″ below the top of the diffuser, the flow detached from the diffuser. The hydrograph of this event indicates the diffuser was operating for about 9.25 hrs. As this was the first major rainfall event, it was good to see that the installation had been successful and the diffuser and the outlet weirs incurred no damage from such a significant storm. FIG. 19 is a hydrograph of this storm and three subsequent beaver-generated drawdowns. On the vertical axis, the numerical values refer to feet for the water level and inches for the rainfall.
FIG. 20 records major rainfall events during the fall, winter and spring of 2015-2016, presenting peak flows and observations regarding the operation of the diffuser. This figure highlights two important points. First, the inlet has a significant impact on the diffuser. As previously mentioned, during the February 17 event, despite the 3′ inlet water level, the flow was not attached to the diffuser. An inspection of the inlet showed that the headwall had been damaged. A number of stones were missing, essentially creating a projecting inlet. Simple projecting inlets are much less efficient than hooded or tapered bell inlets, and inhibit development of full pipe flow. The inlet was repaired, with the missing stones replaced. During two storms that followed, the diffuser was once again fully functional at a peak water level of 2.36′ and 3.25′.
Second, although the diffuser was not functioning at a peak water level of 2.03′ (March 27-28), it was functioning at a peak level of 2.11′ (October 29). This gives an indication of the necessary inlet level required to activate the diffuser.
FIG. 21 records the effect of the receding inlet level on the attachment of water to the diffuser during the October 29 rainfall event. As can be seen in this figure, as the water recedes, the flow remains attached to the diffuser at an inlet level of 2.03′. When the same level was a peak level on March 27-28, rather than a receding level, there was no attachment to the diffuser. Although more data would be necessary to confirm this, it appears that the inlet level at which the flow attaches to the diffuser as the water rises is higher than the level at which the water detaches as the inlet level recedes, suggesting a hysteresis in the attachment/detachment phenomenon. A possible explanation for this is that the vacuum created by the diffuser once it is fully functional may help to maintain the attachment of the water to the diffuser wall.
FIG. 21 also shows that the transition from fully attached to fully detached flow in the diffuser occurs in a very narrow range. The water in the diffuser went from fully attached at an inlet level of 2.03′ and an outlet level of 1.17′ to fully detached at an inlet level of 2.00′ and an outlet level of 1.16′. This is an inlet difference of 0.36″ and an outlet difference of 0.1″. Above this transition, the diffuser is fully functioning. Below this transition, the lack of attached flow does not allow the vacuum to exist that significantly increases flow.
Although the diffuser performed well during storm events, the stream continued to overtop the road. This is not a reflection on the efficacy of the diffuser, but on how massively undersized the pipe was to begin with. As previously mentioned, based on the drainage area, a 4′ pipe would be required. This difference in capacity was beyond what the diffuser could remedy.
During a storm event, there are interacting and uncontrolled variables that affect the amount of runoff entering the inlet pool, such as changing rainfall intensities and the effect of snowmelt during winter events. This makes it difficult to accurately quantify the flow rate through the pipe by hydrologic methods, and therefore difficult to create accurate empirical performance curves. In order to create accurate empirical performance curves, a method of creating controlled drawdown data was developed. This method does not rely on hydrologic calculation and therefore is an independent check on the hydrologic model.
Another major advantage of the controlled drawdown method is that it does not rely on major storms for the collection of data, and it allows experiments to be repeatable and reproducible.
A 15″ mooring buoy proved to be an ideal piece of equipment for creating a controlled drawdown. It closely fit the pipe, blocking most of the flow and allowing the inlet pool to fill, and it had an attachment point that allowed the connection of a chain and come-along (i.e. a portable winch). Several trial runs were successfully conducted. For the actual drawdown trial, the inlet pool level logger was switched to 1 minute intervals.
At 5:20 AM on Apr. 18, 2016, the mooring buoy was attached to the chain and come-along and placed in the inlet. It took 13.5 hours for the pool to fill to a maximum inlet water level of 2.54′. The inlet pool stabilized at this level because of leakage through the second pipe and around the mooring ball. At 6:51 PM, the buoy was removed from the pipe, and the pool began to drain. The drawdown curve for this trial is shown in FIG. 22 .
Note that drawdown continues at a constant rate even after the flow detaches from the diffuser. This is believed to be related to the positive effect the flared outlet has on reducing transition losses in open channel (free surface) flow conditions. This association was noted by Hinds in his paper “Flume and Siphon Transitions” (Hinds, 1927). This suggests that diffusers offer real benefits even when they are not operating under pressure flow.
Flow rate (Q), pipe velocity (V P ), and diffuser outlet velocity (V D ) were calculated using the drawdown data and the stage-surface area function listed in FIG. 29 . In FIG. 23 , Column 1 shows the inlet water surface level above the invert, based on physical measurement and level logger data. The interval of these measurements was 0.25 ft. Column 2 gives dimensionless head (H W /D) used subsequently in drawdown analysis calculations (see FIG. 24 ). Column 3 is the estimated water surface area at the given elevation based on Lidar contours and listed in Table 1. Column 4 gives rates of change for the head water level (ΔH W ) as measured by the level loggers at the given intervals. Because the changes in level were small, and near the accuracy limits of the logger, two adjoining minutes are recorded and used to calculate flow rates. An estimated leakage of 1 ft 3 /sec is then subtracted from these flow rates, and the results are listed in Column 5 (Q tota l−Q leakage ). The two sequential measurements are then averaged in Column 6 (Q avg ). These average flow rates are divided by pipe area to calculate the mean pipe velocity in Column 7 (V P ). The pipe velocity, V P , is divided by the area ratio, 2, to calculate the mean velocity at the diffuser outlet in Column 8 , (V D ). FIG. 24 plots flow rates. (Note the shift in performance when the flow detaches from the diffuser at stage h=2′; this is illustrated by the gap between the diffuser line (blue) and the pipe line (red).)
Because the flows and velocities were based on inlet pond surface area estimates, a comparison with measured velocity data was used to confirm the validity of these values. During the Sep. 30, 2015 storm when the inlet water level was 3.25′, a velocity meter was used to measure the velocity at the diffuser outlet. Velocities were taken at five different locations across the diffuser, 6″ above the stream bed. Turbulent fluctuations at the diffuser outlet led to large fluctuations in the velocity readings, which are expressed as ranges in FIG. 25 . However, it is clear that the velocity is highest in the center and drops off toward the sides of the diffuser. Although these velocity readings are from a higher head, they are consistent with the range found in FIG. 23 .
To further substantiate the calculated flow rates from this drawdown analysis, comparison was made between dimensionless performance curves of Yarnell's 18″ VCP with diffuser, an optimal CFD model of a pipe with a bell inlet and a diffuser outlet, and this drawdown data. The three different data sets are depicted together in FIG. 26 .
The data from the three different sources form a clearly defined curve with minimal scatter. Yarnell used outlet weirs that kept the pipe submerged, and was therefore able to run tests with low heads and low flow rates. Because of his set-up, however, he was unable to test high heads. Therefore, his data covers the lower end of the curve. The Thorndike diffuser was only submerged, and therefore fully functional, at higher heads and higher flow rates. In addition, because of the available flow entering the basin and the low cover over the pipe, there was a limit to the maximum head achievable by the mooring buoy method. Therefore, the Thorndike data is constrained to the central part of the curve. If there had been more flow into the inlet pool, as in a high flow event, and if there were more cover over the pipe, the Thorndike data could have extended farther up the curve. For this site the maximum achievable head (ΔH*=1.6) is due to the road overtopping elevation.
In FIG. 26 , as well as FIG. 27 , dimensionless head difference (ΔH*=ΔH/D) was used for Yarnell's data, the CFD data, and the Thorndike diffuser data. The scatter in the Thorndike diffuser data is associated with the estimate of water surface area and relative drawdown rate. Improvement in the stage water surface area curve is possible with more advanced analysis of the Lidar data. This will reduce the scatter in the calculated flows.
In addition to providing flow rates and performance data, the ability to create artificial drawdowns allows a method for testing the installation of a pipe system for function and capacity before a major storm event. This allows for adjustments to the inlet flow configuration and the outlet weir geometry to assure stable operation, maximize performance, assess actual capacity, determine outlet velocity and assess how the flow would affect the weirs and the downstream channel.
The combination of drawdown testing and performance during storm events prove both the efficacy of this specific diffuser design and the concept that diffusers can be utilized to increase capacity and decrease outlet velocity in actual field situations. To the best of our knowledge, this is the first successful field test of a diffuser in a highway application. The only other known field tests were the California diffusers, which were not considered successful.
Each of the components of a diffuser pipe system needs careful consideration. Suggestions follow.
Inlet Pool: Diffusers begin to be effective when the headwater (H W ) has a depth of 1.6 pipe diameters (D). As the head increases, so does the performance of the diffuser. It is therefore recommended that diffusers be used in situations where there is enough fill above the pipe to allow ponding of at least 2.5 pipe diameters above the invert. Since shallow pipes are relatively easy to replace, they are not likely candidates for diffusers. Pipes in deep fills benefit from the potential head created by the fill, and are costly to replace. They are therefore good candidates for diffusers.
Understanding the topographic characteristics of the inlet pool can be important, especially if the stream entering the pool is not aligned with the diffuser inlet. This becomes less problematic as the water level increases and the flow into the inlet is driven by the pressure head of the water in the pool, rather than directly from the stream flow. In some cases, modification of the inlet pool would be beneficial.
Improved Pipe Inlets: Much research in the past has focused on inlet design. Because diffusers must be under outlet control to be fully functional, it is important that inlet losses be minimized by the use of an improved inlet. Bell inlets are a commonly used improvement for round culverts, and are often attached to slip-lined pipes. The combination of a bell inlet and a tapered throat would be a further improvement. For square culverts, side tapered inlets are the preferred inlet improvement. In addition, for both pipes and box culverts, hooded inlets can be beneficially paired with a diffuser outlet. Hooded inlets force pipes to fill at very low heads, causing the pipe to operate under outlet control. They also minimize the formation of vortices that draw air into the inlet. Hooded inlets would work well with bell and tapered inlets and are especially advantageous in situations with cover between 2D and 3D, where vortices can be drawn into the inlet, disrupting flow.
Diffuser Outlet Design: The most important design considerations for diffusers are flare angle and area ratio. Horizontally flared outlets with total flare angles of 10° to 12° (half flare angle 5° to 6°) have been shown to have the best performance and to produce stable flow. From a sample size of one (this field project), it appears that a round pipe flaring to an oval diffuser outlet with a 12° total flare angle (6° half flare angle) is effective.
An area ratio A R =A O /A P of 2 to 3 is considered optimal for diffuser design. The area ratio determines the outlet velocity relative to the pipe velocity. The flare angle combined with the area ratio will determine the length of the diffuser. If a given length is required, this length, paired with the flare angle will determine the area ratio (see FIG. 6 ). Of these three variables, the flare angle is most important for diffuser function.
Outlet weirs: Because diffuser outlets must be submerged to be fully functional, outlet weirs are used to create an outlet pool. The weir must be high enough to pond water to the height of the top of the diffuser during high flows. The weir would be designed for a specific design flow, as discussed above. As a rule of thumb, the weir should be located at least 1.5 diffuser lengths from the end of the diffuser.
Properly designed diffusers are effective at both increasing pipe capacity and decreasing outlet velocity. Diffusers provide a straight-forward, inexpensive, and non-disruptive method of both retrofitting and improving the performance of existing pipes that are either undersized or in need of repair. The combination of the literature review and the CFD modeling that were part of this research provided both support for the concept and enough information and background to successfully design, install, and test the Thorndike prototype diffuser system. The work of Venturi and Yarnell clearly demonstrated the ability of diffusers to increase flow rates. Their work gave detailed information about effective designs for improved inlets and diffuser outlets, as well as data strongly supporting their use in combination. CFD modeling allowed the exploration and refinement of diffuser system designs. Visual depiction of pressure and flow fields helped provide further understanding of the dynamics of diffuser system function. During the research and development of field diffusers, the use of CFD modeling provides a powerful tool that can be used to design and pre-test diffuser systems, especially in situations where site conditions preclude following suggested design guidance. The Thorndike diffuser proved to be both inexpensive and easy to install. The stable flow consistently observed during high flow events was an indication of reliable performance. The implementation of a method of creating artificial drawdowns provided data that agreed with both Yarnell's data and CFD modeling. The performance curves in FIG. 27 , created from Yarnell's data, an optimal CFD diffuser system, and the Thorndike data, show the consistency of diffuser performance as well as the significant improvement in performance of diffuser systems over straight pipes. To the best of our knowledge, this is the first successful field test of a diffuser in a highway application. The only other known field tests were the California diffusers, which were not considered successful.
The importance of understanding the specific design requirements of diffuser systems cannot be overstated. These requirements, though not generally onerous, are necessary, and failure to incorporate them into diffuser system design is likely to lead poor performance. The following design considerations are important:
Adequate cover over the pipe to allow for the necessary head Symmetric flow into inlet; may require modifications to inlet area Improved inlet: bell, tapered and/or hooded Proper diffuser design: oval or rectangular with correct flare angle Wide flare angles will perform poorly. Outlet weirs to provide submergence of the diffuser outlet
Changing weather patterns with increasing intensities of rainfall make this research particularly timely. Diffuser systems provide an effective adaptation to the demands of increasing flow, aging infrastructure, and limited financial resources.
Definitions
Adverse Pressure Gradient—A condition where the pressure increases along a streamline in the downstream direction. In a diffuser, this is related to the flow expanding and slowing in the diffuser cone. Much of the kinetic energy from the decrease in velocity is converted directly into potential energy which results in the adverse pressure gradient. In diffusers the adverse pressure gradient is also enhanced by the vacuum that forms at the diffuser inlet.
Area Ratio—The area ratio compares the diffuser outlet area to the diffuser inlet area, A R =Ao/Ap. The change in the fluid's velocity between the inlet and outlet of the diffuser when the outlet flow is symmetric and attached to the diffuser walls is directly related to the area ratio. The Borda-Carnot equation uses an inverse of the area ratio to determine the outlet loss coefficient (see FIG. 6 ).
Attached Flow—Attached flow in a diffuser is a condition where the velocity is zero at the wall and consistently increases away from the wall. The near wall portion of the attached flow is called the boundary layer. Flow attachment is crucial for the formation of the boundary layer, which plays a central role in diffuser function.
Bell Inlet—An inlet that has a curved expanding opening. A radius of curvature of 0.14 pipe diameters is typically considered optimal. The entrance loss coefficient with this type of opening is 0.2.
Boundary Layer—A typically thin layer of fluid near a solid boundary that has zero velocity at the solid boundary surface and rapidly increases away from the surface. The boundary layer in a diffuser is thicker than is typically encountered in a pipe, with the thickness increasing as it moves farther into the diffuser from the throat (see FIGS. 8 and 9 ). The thickened boundary layer is associated with the decelerating flow in the adverse pressure gradient. In certain situations, the decreased velocity gradient in the diffuser's boundary layer lacks the energy required to resist the adverse pressure. This can allow the flow to separate from the diffuser wall and backflow to occur.
Conic Outlets—See diffusers. Conic Outlets was the term used in Tredgold's 1862 translation of Venturi's paper.
Detached Flow—The condition that exists when the fluid (water) is no longer able to remain attached to the surface (culvert wall) and air is allowed to enter the culvert. Detached flow is also used as a synonym for separated flow.
Diffuser—A pipe outlet that expands along the flow direction. The expansion can be conic, expanding evenly in all directions, planar, expanding in two directions, or a combination (typically by expanding along the bottom and sides). Diffusers cease to function if the expansion angle is too large. The accepted expansion angles are 6° for conic diffusers, 10° to 11° for rectangular diffusers, and about 12° for oval diffusers. Area Ratios of 2 to 3 are generally accepted as the upper limit for effective diffusers. Miller provides an excellent review of the relationship between the A R and the non-dimensional length as well as the conditions where an asymmetric diffuser may be appropriate (Miller, 1990, pp. 59-87). The vacuum created at the diffuser inlet, the decreased outlet velocity and increased outlet pressure are utilized in many fluid dynamics situations involving minimizing losses in pipe systems. However, few references are made to the increased flow rate that results from the increased hydraulic gradient created by the vacuum at the diffuser inlet. Diffusers are also known as Conical Outlets (Venturi), Increasers (Yarnell), Siphon Outlets (Hinds), and Flared Siphon Outlets (California DOT).
Drawdown—The rate of drop of the inlet pool's ponded water surface with time. An artificial drawdown can be used to assess pipe capacity, as well as to test an installation. The instantaneous rate of drawdown at a specific water elevation can be used in combination with the surface area of the ponded water at that same elevation to determine the rate of flow out of the pool. If there is inflow into the inlet pool, this inflow must be added.
Flare angle—the angle that the side of a diffuser deviates from the longitudinal axis of the pipe.
Flared Siphon outlets—See diffusers. This term is used by The California Culvert Practice Manual 1940s through 1950s and FHWA HDS 5 from 2012.
Hood—A projection over the inlet to a pipe that allows the pipe to fill at low inlet water levels and prevents vortices from forming at the pipe inlet. See Blaisdell's paper on Hooded Inlets for a more complete review (Blaisdell, 1958).
Hydraulic Gradient—The change in pressure with distance, typically along a pipe. This is associated with the friction losses along the system and the pressure difference (head) imposed on the system. The vacuum created at the diffuser inlet increases the hydraulic gradient through the entire pipe. In a diffuser outlet, the hydraulic gradient opposes the flow and is typically referred to as an Adverse Pressure Gradient.
Jet—High Velocity flow through an orifice, often referring to the flow exiting a pipe.
Momentum—The form of energy combining the flow rate (Q), the fluids density (p), and the fluids velocity (V) as defined in Newton's Second Law (F=ma). This law states that a force is required to change the momentum of an object or fluid.
Non-Dimensional Length—The non-dimensional length (N/R 1 ) relates the diffuser length (N or L) to the pipe radius (R 1 ) or box culvert width (W). Non-dimensional length allows comparison of diffusers of different sizes based on geometric relationships. See Miller, 1990 p. 68 for further discussion.
Separated Flow—The condition that exists when the boundary layer separates from the wall of a pipe or diffuser. Streamlines of the fluid move away from the wall and allow eddies and reversing flow to occupy the separated zone. The strong adverse pressure gradient in diffuser outlets is closely associated with flow separation. Separation frequently occurs in diffusers with wide flare angles and also with non-symmetric inlet flows. Separated flow is able to oscillate in the diffuser cone, which results in large pressure fluctuations, loss of the diffuser inlet vacuum, little decrease in outlet velocity, and little increase in flow rate. This is associated with a large increase in outlet losses and a high outlet loss coefficient relative to stable diffusers.
Siphon outlets—See diffusers. This is the name Hinds (1927) used for diffusers.
Symmetric Flow—Flow that is uniformly distributed across the pipe or diffuser cross-section.
Throat—The transition from the pipe to the diffuser.
Transitions—A change in area either at an inlet or at an outlet of a fluid passage is referred to as a transition. In inlet transitions, pressure drives the flow and smooth curved surfaces are required to prevent flow separation. In properly designed outlet transitions, the geometry of the transition reflects the momentum of the fluid. For example, a well-designed outlet diffuser reflects the natural expansion of the water leaving the pipe, and mechanically confines it to prevent separation. Transitions in horizontally expanding channels and diffusers have an optimum total divergence angle of about 12°. The loss coefficient at an inlet or an outlet is directly related to the effectiveness of the flow transition.
Vacuum—A condition where pressure falls below atmospheric pressure. In this report, the reduced pressure at the diffuser inlet is referred to as the vacuum pressure even if it does not fall below atmospheric pressure, because it is significantly lower than the pressure at the outlet of the diffuser. The diffuser vacuum pressure could be above atmospheric pressure if the diffuser outlet is significantly submerged. However, the hydraulic gradient and flow rate will still be increased in proportion to the effective head, the difference between the inlet pressure and the vacuum pressure at the diffuser inlet.
DETAILED DESCRIPTION OF INVENTION
The present invention comprises a culvert diffuser 100 configured to be used as part of a culvert 1 installation. Such culverts 1 are configured to have an inlet 10 , an outlet 20 , an inside diameter 30 , a cross-sectional area 40 , and a longitudinal axis 50 . Typically, culverts 1 are formed as straight pipes having cylindrical cross-sections, but they may also have rectangular or square cross-sections (these are known as box culverts). Culverts 1 are typically made of corrugated metal, cast iron, vitrified clay, fiberglass, polyvinyl chloride, or other composite materials.
The diffuser 100 of the present invention is designed to alter the geometry of the outlet 20 of the culvert 1 . It comprises a body member 101 , with the body member 101 having a continuous sidewall 160 , a proximate end 110 , a distal end 120 , a proximate opening 130 at its proximate end 110 , and an outlet opening 150 at its distal end 120 . The proximate opening 130 of the body member 101 of the diffuser 100 has an inside diameter 140 which is substantially the same as the inside diameter 30 of the culvert 1 . This allows for the proximate end 110 of the body member 101 of the diffuser 100 to be connected to the outlet 20 of the culvert 1 without gapping, providing a water-tight connection. The diffuser 100 can be made of any suitable material, with the preferred material being fiberglass.
The sidewall 160 of the body member 101 of the diffuser 100 angles outward from the longitudinal axis 50 of the culvert 1 . This results in the outlet opening 150 of the body member 101 of the diffuser 100 having a cross-sectional area 152 which is greater than the cross-sectional area 40 of the culvert 1 . In some embodiments the cross-sectional area 152 of the outlet opening 150 of the diffuser 100 is between two and three times the cross-sectional area 40 of the culvert 1 . In the preferred embodiment the cross-sectional area 152 of the outlet opening 150 of the diffuser 100 is two times the cross-sectional area 40 of the culvert 1 . The outlet opening 150 of the body member 101 can have any suitable shape; for example, a conical sidewall 160 results in the outlet opening 150 having a substantially circular shape, while a boxed sidewall 160 results in the outlet opening 150 having a substantially rectangular shape. In the preferred embodiment, the sidewall 160 flares only laterally, providing for the outlet opening 150 having a substantially oval shape.
In one embodiment of the present invention, the sidewall 160 of the body member 101 of the diffuser 100 is formed of a first lateral portion 162 , a second lateral portion 164 , an upper portion 166 , and a lower portion 168 . The first lateral portion 162 of the sidewall 160 angles outwardly at a first flare angle 172 from the longitudinal axis 50 of the culvert 1 . Likewise, the second lateral portion 164 of the sidewall 160 angles outwardly at a second flare angle 174 from the longitudinal axis 50 of the culvert 1 , with the first and second flare angles 172 , 174 being substantially the same. The upper portion 166 of the sidewall 160 extends outward substantially parallel to the longitudinal axis 50 of the culvert 1 , as does the lower portion 168 of the sidewall 160 . Differently sized flare angles 172 , 174 may be used. In the preferred embodiments the first flare angle 172 is between five and seven degrees and the second flare angle 174 is between five and seven degrees. In the most preferred embodiments the first flare angle 172 and the second flare angle 174 are each about six degrees. This maximizes attachment of the water flow through the diffuser 100 . A first distance 182 is measured from the upper portion 166 of the sidewall 160 at the outlet opening 150 to the lower portion 168 of the sidewall 160 at the outlet opening 150 ; this first distance 182 is substantially the same as the inside diameter 30 of the culvert 1 . A second distance 184 is measured from the first lateral portion 162 of the sidewall 160 at the outlet opening 150 to the second lateral portion 164 of the sidewall 160 at the outlet opening 150 ; this second distance 184 is substantially twice the inside diameter 30 of the culvert 1 .
The combination of the sizes of the first and second flare angles 172 , 174 and the cross-sectional area 152 of the outlet opening 150 of the diffuser dictate the overall length of the diffuser. In the preferred embodiment, where the first and second flare angles 172 , 174 are about six degrees each, and the cross-sectional area 152 of the outlet opening 150 of the diffuser is about twice the cross-sectional area 30 of the culvert, the overall length of the diffuser 100 is about five times the cross-sectional area 30 of the culvert.
In another embodiment of the present invention, a culvert diffuser system 200 is presented. The culvert diffuser system 200 comprises a culvert pipe 201 , a culvert diffuser 300 , a culvert inlet 400 , and an outlet weir 500 . The culvert pipe 201 has an inlet end 210 , an outlet end 220 , an inside diameter, a cross-sectional area, and a longitudinal axis, and is substantially cylindrical and open at its inlet end 210 and its outlet end 220 . The culvert diffuser 300 is configured as described above, with a substantially oval opening at its distal end 320 . The proximate end 310 of the culvert diffuser 300 has an inside diameter substantially the same as the inside diameter of the culvert pipe 201 , so that the proximate end 310 of the culvert diffuser 300 is in water-tight connection with the outlet end 220 of the culvert pipe 201 . The culvert inlet 400 has a proximate end 410 and a distal end 420 , with the proximate end 410 and the distal end 420 both being opened and the proximate end 410 of the culvert inlet 400 having a greater cross-sectional area than the distal end 420 of the culvert inlet 400 . The distal end 420 of the culvert inlet 400 has an inside diameter substantially the same as the inside diameter of the culvert pipe 201 , so that the distal end 420 of the culvert inlet 400 is in water-tight connection with the inlet end 210 of the culvert pipe 201 . Finally, the outlet weir 500 is an independent structure located some distance from the outlet end 320 of the culvert diffuser 300 . The outlet weir 500 has a main body that is capable of substantially diverting the flow of water 700 . It is positioned such that its top portion 510 is located higher than the upper portion of the sidewall of the culvert diffuser 300 . This allows water 700 to pond up between the outlet weir 500 and the distal end 320 of the culvert diffuser 300 , keeping the outlet end 320 of the culvert diffuser 300 fully submerged during high water flows. In the preferred configuration of this embodiment, the outlet weir 500 is located at least 1.5 times the length of the culvert diffuser 300 from the distal end 320 of the culvert diffuser 300 .
In this embodiment, the culvert pipe 201 of the culvert diffuser system 200 may be configured to fit within an existing highway culvert 600 . This allows for simple and inexpensive repairs to existing highway culverts 600 . Though the culvert pipe 201 reduces the inside diameter of the original highway culvert 600 , the operation of the culvert diffuser 300 and the culvert inlet 400 allow for greater capacity of water flow through the culvert pipe 201 as a function of cross-sectional area, thereby maintaining or even improving the overall rate of water flow capacity through the culvert diffuser system 200 .
Modifications and variations can be made to the disclosed embodiments of the present invention without departing from the subject or spirit of the invention as defined in the following claims.
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The present invention embodies a diffuser extending from the outlet end of a highway culvert, whereby the diffuser flares outwardly to provide a larger area cross-section at the outlet of the culvert in order to increase the capacity of the culvert and to reduce the effects of erosion from the outflow of water from the culvert outlet.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vane type vacuum pump to be mounted on diesel engine automobiles and the like, and more specifically, to a vane type vacuum pump which enhances a volume efficiency as well as realizes miniaturization and reduction of weight by improving the coupling structure of an input shaft with a rotor.
2. Description of the Related Art
In general, although automobile brakes use a negative pressure to obtain an auxiliary force, since diesel engine automobiles cannot obtain the negative pressure directly from an engine, they obtain the negative pressure by driving a vacuum pump by the rotational torque of the engine.
FIG. 10 is a side cross sectional view showing a vane type vacuum pump employing a conventional gear drive system and FIG. 11 is a cross sectional view taken along the line D--D of FIG. 10.
In the respective drawings, the input shaft 1 of the vane type vacuum pump has a gear la securely fixed to the outer periphery of one end thereof projecting to the outside by force-fit (or shrinkage-fit) and the vacuum pump is driven in rotation by an engine side drive gear (not shown) engaged with the gear 1a.
The end of the input shaft 1 on the gear la side is journaled on a bearing 2a disposed to a front bracket 2 and the other end of the input shaft 1 is journaled on a sleeve bearing 3a disposed to a rear bracket 3. The front bracket 2 and the rear bracket 3 are composed of aluminum alloy for the reduction of weight thereof.
The front bracket 2 and the rear bracket 3 constitute a cylindrical pump chamber P which is hermetically sealed through an O ring 4 and the central axis of the pump chamber P is offset from the center of rotation of the input shaft 1.
In this case, the rear bracket 3 has a housing shape for constituting the pump chamber P and is securely fixed to the front bracket 2 by three bolts Q (see FIG. 11.)
A spline-coupling portion 1b is formed to the middle of the input shaft 1 in the pump chamber P and a rotor 5 is engaged with the input shaft 1 through the spline-coupling portion 1b. A similar spline-coupling portion is also formed to the inner periphery of the rotor 5 so that it is coupled with the spline-coupling portion 1b.
The rotor 5 is held unmovable in a rotational direction and movable in an axial direction by being spline coupled to the input shaft 1.
The input shaft 1 and the rotor 5 are composed of alloy steel or a sintered iron (Fe) material to secure strength at the spline-coupling portion.
A plurality of grooves 5a (three in the case of FIG. 11) are formed to the outer periphery of the rotor 5 and vanes 6 are accommodated in the respective grooves 5a so as to be radially movable.
As shown in FIG. 11, one end of the rotor 5 comes into intimate contact with the inner wall of the rear bracket 3 through an oil film of several microns thick and the vanes 6 are completely accommodated in the grooves 5a at the position. Further, a space is formed by offset between each the grooves 5a and the inner wall of the rear bracket 3 so that the vane 6 can sufficiently fly out from the groove 5a.
A lubrication passage 3b and a suction port 3c are formed to the rear bracket 3 and an exhaust port 2b communicating with the lubrication passage 3b is formed to the front bracket 2. A lubricant supplied from the lubrication passage 3b acts to seal the pump chamber P as well as cool the vacuum pump and is exhausted from the exhaust port 2b passing through the sleeve bearing 3a and the spline-coupling portion 1b.
A tank (not shown) which is required to be evacuated to vacuum is connected to the suction port 3c and air sucked from the suction port 3c (see an arrow) is exhausted from the exhaust port 2b disposed at a confronting position.
Next, operation of the conventional vane type vacuum pump shown in FIG. 10 and FIG. 11 will be described.
First, the input shaft 1 journaled on the bearing 2a and the sleeve bearing 3a is driven in rotation through the gear la engaged with the engine side drive gear.
The rotational torque of the input shaft 1 is transmitted to the rotor 5 through the spline-coupling portion 1b and rotates the vanes 6 disposed in the outer peripheral grooves 5a of the rotor 5 clockwise in FIG. 11.
With this operation, the vanes 6 are flown out radially from the grooves 5a by a centrifugal force and rotated while being pressed against the inner wall of the rear bracket 3 of the pump chamber P under pressure as well as sliding through the oil film.
At the time, since the center of rotation of the rotor 5 is offset from the central axis of the pump chamber P, air is sucked from the suction port 3c side and sequentially exhausted from the exhaust port 2b side as the vanes 6 are rotated to thereby make the tank connected to the suction port 3c to a negative pressure.
Incidentally, the volume efficiency of the vacuum pump depends upon the amount of offset of the center of rotation the rotor 5 with respect to the pump chamber P (the amount of flying out of the vanes 6), that is, the depth of the outer peripheral grooves 5a of the rotor 5. However, since the depth of the grooves 5a is regulated by the outside diameter of the spline-coupling portion 1b and further the outside diameter of the spline-coupling portion 1b cannot be reduced to secure mechanical strength, it is difficult to set the volume efficiency depending upon the pump chamber P and the vanes 6 to a large value.
Since the rotor 5 which is engaged through the spline-coupling portion 1b in the vicinity of the center of the input shaft 1 is composed of the sintered Fe material to secure the mechanical strength such as wear resistance and the like taking transmission torque into consideration, it is difficult to reduce the weight thereof.
Further, since the coefficient of thermal expansion of the rotor 5 composed of the sintered Fe material is different from that of the front bracket 2 and the rear bracket 3 composed of the aluminum alloy, it is difficult to secure gastightness in the pump chamber P of high temperature, thus sufficient vacuum characteristics cannot be obtained at high temperature.
As described above, the conventional vane type vacuum pump transmits the rotational torque of the input shaft 1 to the rotor 5 by the engagement of the spline-coupling portion 1b formed to the outer periphery of the input shaft 1 with the spline-coupling portion formed to the inner periphery of the rotor 5. Thus, there is a problem that the volume efficiency cannot be sufficiently secured by the vanes 6 in the pump chamber P because the depth of the grooves 5a are regulated.
Since the rotor 5 which is rotated through the spline-coupling portion 1b is composed of the sintered Fe material, there is a problem that the weight of the rotor 5 cannot be reduced.
Further, since the coefficient of thermal expansion of the rotor 5 (sintered Fe material) is different from that of the front bracket 2 and the rear bracket 3 (aluminum alloy), there is a problem that it is very difficult to secure gastightness between the rotor 5 and the pump chamber P in a temperature range to be used.
An object of the present invention made to solve the above problems is to provide a vane type vacuum pump which enhances a volume efficiency as well as realizes miniaturization and reduction of weight.
Another object of the present invention is to provide a vane type vacuum pump which realizes reduction of weight as well as secures stable gastightness in a wide temperature range by composing a rotor of aluminum alloy.
SUMMARY OF THE INVENTION
A vane type vacuum pump according to the present invention comprises a cylindrical pump chamber of hermetically sealed structure having a suction port and an exhaust port, a rotor disposed in the pump chamber and having a rotary shaft offset with respect to a central axis of the pump chamber, a plurality of grooves disposed to the outer periphery of the rotor, vanes radially movably disposed in the grooves and sliding in intimate contact with the inner wall of the pump chamber when the rotor rotates, an input shaft having a rotary shaft coaxial with the rotor for rotating the rotor, and torque transmission means for transmitting the rotational torque of the input shaft to the rotor, wherein the torque transmission means comprises a carrier disposed to the outer periphery of the input shaft integrally therewith, a flange unit formed to the end surface of the carrier so as to confront the end surface of the rotor, a plurality of recessed portions formed to the respective end surfaces of the rotor and the flange unit, and a plurality of pins for coupling the rotor with the flange unit through the respective recessed portions with the respective pins extending in the direction of the rotary shafts of the rotor and the input shaft and inserted into the respective recessed portions.
A vane type vacuum pump according to the present invention is arranged such that the respective pins are disposed concentrically with the center of rotation of the rotor and the input shaft.
A vane type vacuum pump according to the present invention is arranged such that the respective pins are securely fixed to the recessed portions on the end surface of the rotor by force-fit or shrinkage-fit as well as axially movably held by the recessed portions on the end surface of the flange unit.
A vane type vacuum pump according to the present invention is arranged such that the recessed portions on the end surface of the flange unit extends in a radial direction and is formed to a U-shape on a plane.
A vane type vacuum pump according to the present invention is arranged such that the recessed portions on the end surface of the flange unit have an inside diameter slightly larger than the outside diameter of the pins and are formed to a circular shape on a plane.
A vane type vacuum pump according to the present invention is arranged such that the respective pins are securely fixed to the recessed portions on the end surface of the flange unit by force-fit or shrinkage-fit as well as axially movably held by the recessed portions on the end surface of the rotor.
A vane type vacuum pump according to the present invention is arranged such that the recessed portions on the end surface of the rotor have an inside diameter slightly larger than the outside diameter of the pins and are formed to a circular shape on a plane.
A vane type vacuum pump according to the present invention is arranged such that the carrier is securely fixed to the input shaft by force-fit or shrinkage-fit.
A vane type vacuum pump according to the present invention is arranged such that the carrier is formed to the outer periphery of the input shaft integrally therewith.
A vane type vacuum pump according to the present invention is arranged such that the rotor has a through hole with an inside diameter slightly larger than the outside diameter of the input shaft and the input shaft is inserted into the through hole and journals the rotor so that it is movable in the direction of the rotary shaft thereof.
A vane type vacuum pump according to the present invention is arranged such that the rotor has a through hole with an inside diameter slightly smaller than the outside diameter of the input shaft and the input shaft supports the rotor by being force fit into the through hole.
A vane type vacuum pump according to the present invention is arranged such that the pump chamber is composed of a front bracket and a rear bracket each composed of aluminum alloy and the rotor is composed of aluminum alloy.
A vane type vacuum pump according to the present invention is arranged such that the rear bracket has an opening and one end of the input shaft is journaled by the opening.
A vane type vacuum pump according to the present invention is arranged such that the input shaft is journaled through the outer periphery of the carrier.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side cross sectional view showing an embodiment 1 of the present invention;
FIG. 2 is a cross sectional view taken along the line A--A of FIG. 1;
FIG. 3 is a cross sectional view taken along the line B--B of FIG. 1;
FIG. 4 is a side cross sectional view showing an embodiment 2 of the present invention;
FIG. 5 is a cross sectional view taken along the line C--C of FIG. 4;
FIG. 6 is a side cross sectional view showing an embodiment 6 of the present invention;
FIG. 7 is a side cross sectional view showing an embodiment 7 of the present invention;
FIG. 8 is a side cross sectional view showing an embodiment 8 of the present invention;
FIG. 9 is a side cross sectional view showing an embodiment 9 of the present invention;
FIG. 10 is a side cross sectional view showing a conventional vane type vacuum pump.
FIG. 11 is a cross sectional view taken along line D--D of the vacuum pump shown in FIG.
FIG. 12 is a side cross sectional view showing an aspect of the invention where an input shaft and a carrier are formed as a unit.
FIG. 13 is a side cross sectional view showing an aspect of the invention where there is no gap between the input shaft and the rotor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
An embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a side cross sectional view showing an embodiment 1 of the present invention, FIG. 2 is a cross sectional view taken along the line A--A of FIG. 1 and FIG. 3 is a cross sectional view taken along the line B--B of FIG. 1. Arrangements similar to those mentioned above are denoted by the same numerals and the description thereof is omitted.
In this case, torque transmission means for transmitting the rotational torque of an input shaft 1 to a rotor 5 includes a carrier 7 disposed to the outer periphery of the input shaft 1 integrally therewith, a flange unit 7a formed to the end surface of the carrier 7 in confrontation with the end surface of the rotor 5, a plurality of recessed portions 5b and 7b formed to the respective end surfaces of the rotor 5 and the flange unit 7a and a plurality of pins 8 for coupling the rotor 5 and the flange unit 7a through the respective recessed portions 5b, 7b in place of the aforesaid spline-coupling portion 1b.
The respective pins 8 extends in the rotational axis direction of the rotor 5 and the input shaft 1 and are inserted into the respective recessed portions 5b and 7b. Further, the respective pins 8 are disposed concentrically with the center of rotation of the rotor 5 and the input shaft 1 and located on the outer peripheral side of the rotor 5.
The respective pins 8 are securely fixed to the recessed portions 5b on the end surface of the rotor 5 by force-fit or shrinkage-fit as well as held by the recessed portions 7b on the end surface of the flange unit 7a so as to be movable in an axial direction.
Further, the recessed portions 7b on the flange unit 7a are formed by being extended in a radial direction and have a U-shape on a plane as shown in FIG. 2.
The carrier 7 is securely fixed to the input shaft 1 integrally therewith by force-fit or shrinkage-fit.
The rotor 5 has a through hole 5c whose inside diameter is slightly larger than the outside diameter of the input shaft 1 and the input shaft 1 is inserted into the through hole 5c and journals the rotor 5 so that it is movable in the rotational axis direction.
The bearing 2a in a front bracket 2 journals the outer periphery of the carrier 7 and one end of the input shaft 1 on the gear 1 side is journaled through the carrier 7.
Further, the rotor 5 is composed of aluminum alloy which is the same material as that of the front bracket 2 and the rear bracket 3 (aluminum alloy) constituting the pump chamber P.
In this case, the front bracket 2 has a housing shape for constituting the pump chamber P and is securely fixed by bolts Q on the rear bracket 3 side through an O ring 4.
With this arrangement, the thickness of the front bracket 2 is reduced on the bearing 2a side to thereby realize miniaturization.
Next, operation of the embodiment 1 of the present invention shown in FIG. 1 to FIG. 3 will be described. Note, as apparent from the positional relationship between a suction port 3c and an exhaust port 2b (see FIG. 3), FIG. 1 to FIG. 3 show a case that the input shaft 1 and the rotor 5 rotate counterclockwise.
First, the recessed portions 5b having an inside diameter slightly smaller than the outside diameter of the pins 8 are formed to the end surface of the rotor 5 when the rotor 5 is made and the plurality of pins 8 are securely fixed in the recessed portions 5b concentrically with the center of the rotation of the rotor 5 by force-fitting (or shrinkage-fitting).
The carrier 7 having the flange unit 7a is securely fixed on the input shaft 1 by force-fitting (or shrinkage-fitting) as well as the recessed portions 7b having an inside diameter greater than the outside diameter of the pins 8 disposed on the recessed portion 7b in correspondence to the pins 8 on the rotor 5.
Then, the rotational torque of the input shaft 1 is transmitted to the rotor 5 through the pins 8 by inserting the pins 8 disposed on the rotor 5 into the recessed portions 7b on the flange unit 7a as shown in FIG. 1 and FIG. 2.
On the other hand, the through hole 5c which has the diameter permitting the input shaft 1 to pass therethrough is defined to the center of the of the rotor 5, the input shaft 1 is inserted into the through hole 5c while leaving a gap therebetween and the rotor 5 is journaled therein so that it can slide in the axial direction.
The rotor 5 is coupled with the input shaft 1 through the carrier 7 and the pins 8 which act as the torque transmission means and driven in rotation together with the input shaft 1.
Therefore, the rotational torque transmitted from an external engine (not shown) to the input shaft 1 through the gear 1a is transmitted to the carrier 7 arranged integrally with the input shaft 1 and to the rotor 5 from the pins 8 inserted into the recessed portions 7b on the flange unit 7a of the carrier 7 to thereby rotate the rotor 5 and vanes 6 about the input shaft 1.
Since the spline-coupling portion 1b (see FIG. 10) used as the torque transmission means for transmitting the rotational torque from the input shaft 1 to the rotor 5 is replaced with the pins 8 as described above, the torque transmission means can be disposed at a position apart from the center of rotation of the input shaft 1 in an outer peripheral direction.
A tangential force imposed on the pins 8 can be reduced by increasing the radius of transmission of the rotational torque as described above, whereby the rotor 5 can be composed of the aluminum alloy to realize reduction of weight.
Since the spline-coupling portion 1b is not necessary, the inside diameter of the rotor 5 can be reduced and the grooves 5a used for inserting the vanes 6 into the rotor 5 can be formed deeply in the direction of the center axis of rotation. Therefore, the amount of flying-out of the vanes 6 can be set to a large value, whereby the volume efficiency can be enhanced. Further, the coaxial accuracy between the input shaft 1 and the rotor 5 is enhanced as compared with the case in which the spline-coupling portion 1b is used, whereby a vacuum accuracy is enhanced.
In addition, since the adverse affect caused by the difference of coefficients of thermal expansion can be avoided by composing the rotor 5, the front bracket 2 and the rear bracket 3 of the same material by composing the rotor 5 of the aluminum alloy, a specification of characteristics to a change of temperature is stabilized so that the coaxial accuracy between the rotor 5 and the input shaft 1 is enhanced, whereby the accuracy of the vacuum pump can be enhanced.
Since the pins 8 constituting the torque transmission means are supported in the recessed portions 7b formed to the U-shape on the plane only in a rotational direction, they have flexibility in the axial direction and the radial direction, so that structural restriction is reduced as well as an assembling property can be enhanced. In addition, the formation of the recessed portions 7b to the U-shape permits the weight of the flange unit 7a of the carrier 7 to be reduced to thereby accelerate the weight reduction.
Note, although the pins 8 are disposed concentrically with the center of rotation of the input shaft 1 in the embodiment 1, it is needless to say that the pins 8 may be disposed at any arbitrary position where the end surface of the rotor 5 confronts the end surface of the flange unit 7a.
Further, although the rotor 5 is composed of the aluminum alloy, it may be composed of any arbitrary material having a coefficient of thermal expansion similar to that of the aluminum alloy. When the front bracket 2 and the rear bracket 3 are composed of other material, it suffices only to compose the rotor 5 of the other material likewise.
Although the bearing 2a is disposed to the outer periphery of the carrier 7 for the purpose of miniaturization in the axial direction, when the miniaturization is not particularly needed, the bearing 2a may be moved in the axial direction of the input shaft 1 and journal the input shaft 1 at any arbitrary position.
Further, although the rear bracket 3 side is formed to the housing shape for the purpose of the miniaturization in the axial direction, when the miniaturization is not particularly needed, the front bracket 2 side may be formed to the housing shape likewise the above-mentioned.
Embodiment 2
Although the recessed portions 7b for supporting the pins 8 in the rotational direction are formed to the U-shape on the plane in the embodiment 1, they may be formed to a circular shape.
FIG. 4 is a side cross sectional view showing an embodiment 2 of the present invention in which the recessed portions 7b are formed to a circular shape and FIG. 5 is a cross sectional view taken along the line C--C of FIG. 4, wherein arrangements similar to those mentioned above are denoted by the same numerals and the description thereof is omitted.
In this case, the circular recessed portions 7b formed to the flange unit 7a have an inside diameter slightly larger than the outside diameter of the pins 8 and support the pins 8 so that they are movable in an axial direction.
With this arrangement, the rotational torque of the input shaft 1 can be transmitted to the rotor 5 through the pins 8 likewise the above arrangement, although structural flexibility and assembling property are slightly restricted.
Embodiment 3
Although the pins 8 are securely fixed to the recessed portions 5b on the rotor 5 side, they may be securely fixed to the recessed portions 7b on the carrier 7 side. In this case, the respective pins 8 are securely fixed to the recessed portions 7b on the flange unit 7a by force-fit or shrinkage-fit as well as they are axially movably held by the recessed portions 5b on the rotor 5.
Note, the recessed portions 5b on the rotor 5 may be formed to a circular shape on a plane likewise the above arrangement.
Embodiment 4
Although the carrier 7 is securely fixed to the outer periphery of the input shaft 1 by force-fit (or shrinkage-fit), the carrier 7 may be formed integrally with the input shaft 1 on the outer periphery thereof in the process for manufacturing the input shaft 1.
In this case, since the number of parts can be reduced, a cost can be further lowered.
Embodiment 5
Although the input shaft 1 is inserted into the large through hole 5c defined to the rotor 5 and the rotor 5 is journaled on the input shaft 1 so as to be movable in the axial direction, the inside diameter of the through hole 5c may be formed slightly smaller than the outside diameter of the input shaft 1 and the input shaft 1 may be inserted into the small through hole 5d by force-fit, as shown in FIG. 13
In this case, since the input shaft 1 force fit into the through hole 5d supports the rotor 5 also in the rotational direction, the tangential force imposed on the pins 8 can be further reduced, whereby the strength of the rotor 5 can be reduced.
Embodiment 6
Although the extreme end of the input shaft 1 is journaled by the sleeve bearing 3a provided with the rear bracket 3 in the above respective embodiments, when the rear bracket 3 is composed of the aluminum alloy, the input shaft 1 may be directly journaled at the opening of the rear bracket 3.
FIG. 6 is a side cross sectional view showing an embodiment 6 of the present invention in which the input shaft 1 is directly journaled by the rear bracket 3, wherein the arrangements similar to those mentioned above are denoted by the same numerals and the description thereof is omitted.
In this case, since an opening 3d is formed to the rear bracket 3 and the extreme end of the input shaft 1 is directly journaled by the opening 3d, the metal sleeve bearing 3a (see FIG. 1) can be omitted.
With this arrangement, the weight can be further reduced as well as since the bearing unit is composed of the aluminum alloy likewise the rear bracket 3, the structural accuracy to the change of temperature can be further stabilized.
Note, over-crystallized aluminum alloy containing silicon (Si) monocrystal and the like are used as the aluminum alloy functioning as the bearing.
Embodiment 7
Although the gear 1a is disposed to the one end of the input shaft 1 on the front side as the engaging unit for the drive source on the external engine side in the above respective embodiments, it is needless to say that any arbitrary engaging unit may be used.
FIG. 7 is a side cross sectional view showing an embodiment 7 of the present invention in which a sprocket 1c is applied as the engaging unit for the engine side drive source (not shown), wherein arrangements similar to those mentioned above are denoted by the same numerals and the description thereof is omitted.
In this case, the sprocket 1c is securely fixed to a chain drive input shaft 1 integrally therewith on one side thereof on a front side and the input shaft 1 is coupled with the engine side drive source through a chain engaged with the sprocket 1c.
Embodiment 8
FIG. 8 is a side cross sectional view showing an embodiment 8 of the present invention in which a V-pulley 1d is applied as the engaging unit with the engine side drive source, wherein arrangements similar to those mentioned above are denoted by the same numerals and the description thereof is omitted.
In this case, the V-pulley 1d is securely fixed to a pulley-drive type input shaft 1 integrally therewith on one side thereof on the front side and the input shaft 1 is coupled with the engine side drive source through a belt (not shown) trained around the V-pulley 1d.
Embodiment 9
FIG. 9 is a side cross sectional view showing an embodiment 9 of the present invention in which a coupling 10 is applied as the engaging unit with the engine side drive source, wherein arrangements similar to those mentioned above are denoted by the same numerals and the description thereof is omitted.
In this case, the cylindrical coupling 10 is mounted to the coupling-drive type input shaft 1 on one end thereof on the front side and the input shaft 1 is coupled with the engine side drive source through a projecting part (not shown) to be engaged with the recess 10a formed at the extreme end of the coupling 10.
The coupling 10 has an inside diameter slightly larger than the outside diameter of the input shaft 1 and a hole 1b which passes through both the sides thereof at its central portion in a diametrical direction.
Further, the input shaft 1 has a through hole 1e in a metrical direction formed to one end thereof on the front side which corresponds to the hole 10b of the coupling 10.
A locking pin 11 inserted into the hole 10b and the through hole 1e holds the input shaft 1 and the coupling 10 so that they are not relatively rotated.
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In a vane type vacuum pump comprising a rotor 5 having a rotary shaft offset in a pump chamber P of hermetically sealed structure, grooves 5a disposed on the outer periphery of the rotor, vanes 6 disposed in the grooves and sliding while in intimate contact with the inner wall of the pump chamber, an input shaft 1 having a rotary shaft coaxial with the rotor, and torque transmission means for transmitting the rotational torque of the input shaft to the rotor, the torque transmission means includes a carrier 7 disposed to the outer periphery of the input shaft integrally therewith, a flange unit 7a formed to the end surface of the carrier so as to confront the end surface of the rotor, recessed portions 5b, 7b formed to the respective end surfaces of the rotor and the flange unit, and pins 8 for coupling the rotor with the flange unit through the respective recessed portions, and the pins extending in the direction of the rotary shafts of the rotor and the input shaft are inserted into the respective recessed portions. With this arrangement, the vane type pump chamber can enhance a volume efficiency and realize miniaturization and reduction of weight.
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BACKGROUND OF THE INVENTION
This application is a continuation-in-part application of Application Ser. No. 398,593, filed Sept. 19, 1973 now abandoned.
This invention relates to a means and method for checking telephone service lines or other electrical service lines, particularly for low voltage service, to determine the operability thereof, and also for detecting the presence of any telephones, or other electrical devices or equipment, authorized or unauthorized, connected to a service line, or for detecting the removal from the line of electrical equipment, such as a speaker and the like.
In the past, telephone companies, in particular, have lost a great amount of money due to the use by subscribers of one or more unauthorized telephone sets at a service installation. For exammple, a subscriber may subscribe to and pay for one telephone set and then the subscriber may obtain one or more sets from a source independent of the telephone company and attach these sets to his service line without the authorization or knowledge of the telephone company and without paying any service charges thereon. Thus, the telephone company receives reimbursement for service of only one telephone while the subscriber benefits from the use of two or more telephones. There is no satisfactory means known in the prior art by which the telephone company may determine by a routine check from a remote location or checking station whether or not a subscriber has connected an unauthorized telephone set or sets to the service line, if the subscriber has disconnected the bell in the unauthorized telephones. This is due to the fact that at the present time the bell ringing circuit in a telephone imposes a predetermined impedance or resistance in the line. The telephone service company regularly performs a routine check, in which it sends a signal through the line to the service installation and into the telephone and thus senses or measures the impedance or resistance in the line to determine the presence of the telephone connected to the line. Accordingly, if the subscriber disconnects the bell ringing circuit from the telephone, there is no way in which the telephone service company can obtain an indication or reading of any resistance in the line indicating the presence of the telephone. Of course, the telephone company could send servicemen or company representatives to various service installations to personally check to determine the number of telephones present at that service installation, but this would be prohibitively expensive and would involve other problems.
Moreover, in recent years the use of telephone jacks has become widespread, and a subscriber may subscribe to one or more telephones and may simply plug the telephone or telephones into a desired jack in a desired location at the service installation. This situation increases the problem of the use of unauthorized telephone sets, since the subscriber can merely plug an unauthorized telephone set into a jack at a desired location.
Another problem of a serious nature is the fact that when a residence is equipped with telephone jacks, as aforedescribed, the subscriber at the residence may disconnect all of his telephones in order not to be bothered or disturbed by the ring of the telephone, and when the telephone or telephones are thus disconnected, there is no way in which the telephone company can determine whether or not the service line to the residence is operable without sending a serviceman to the residence, and this involves a substantial cost to the telephone company.
With the present invention, the telephone company is enabled to quickly and easily determine both the operability of the service line to a service installation, even though there is no telephone set connected to the service line at the service installation, and to determine the presence and number of unauthorized telephone sets connected to the line at the service installation. This checking is accomplished from a test station, such as a main checking station remote from the service installation, and merely involves the transmittal of a signal, as heretofore done, over the line to the service installation and measuring the amount of deviation in the signal produced by the invention at the service installation.
Further, valuable equipment or devices, such as amplifiers, loud speakers, microphones, radios, and the like often must be left connected to electrical service lines, and are thus susceptible to being stolen or detached by accident or inadvertance, and the removal of such equipment from the line may not be detected promptly. The present invention enables the line and equipment connected thereto to be monitored and inspected from a remote checking station, even miles away, and an alarm system can be connected therewith to alert personnel to the condition of the line, or removal of equipment therefrom, even though the equipment may be switched off, or not actuated.
More particularly, the invention comprises an electrical device which is connected to the line at the service installation and which enables a first signal to be obtained when no telephone set or other electrical equipment is connected to the service installation and, further, to modify the signal when a telephone set or other electrical equipment is connected thereto to indicate the presence of the telephone or other electrical equipment.
In a preferred form of the invention, the electrical device comprises a simple resistance element or capacitor or the like which imposes a predetermined impedance on the service line, which is measurable by the person making the routine check of the line in order to determine both the condition of the line and the presence of any authorized and/or unauthorized telephone sets or other electrical equipment on the line.
OBJECTS OF THE INVENTION
It is an object of this invention to provide a means for determining from a remote test or checking station the condition of an electrical service line between the checking station and a service installation for electrical equipment, even when no electrical equipment is connected to the line at the service installation.
Another object of this invention is to provide a means for determining from a remote test or checking station the presence of any authorized and/or unauthorized telephone sets or other electrical equipment connected to a service line at a service installation.
A further object of this invention is to provide a means for determining from a remote test or checking station both the operability of a service line between the checking station and a service installation and the presence of any authorized and/or unauthorized electrical equipment, such as telephone sets, connected to the line at the service installation.
A still further object is to provide a means for determining from a remote location whether electrical equipment has been removed from an electric service line.
A still further object of the invention is to provide a method of accomplishing each of the above objects.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view in section of a telephone jack and plug embodying the present invention.
FIG. 2 is a view taken along line 2--2 in FIG. 1.
FIG. 3 is a sectional view of the jack and plug of FIG. 1 showing the jack and plug coupled together.
FIG. 4 is a diagrammatic, perspective, fragmentary view of a system embodying the present invention.
FIG. 5 is a view similar to FIG. 1 of a modified telephone jack and plug incorporating the present invention.
FIG. 6 is a view taken along line 6--6 in FIG. 5.
FIG. 7 is a view of the jack and plug of FIG. 5 shown in coupled relationship.
FIG. 8 is a view similar to FIG. 7 of a modified form of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In the drawings, wherein like reference numerals indicate like parts throughout the several views, a telephone coupler or jack and plug of substantially conventional construction are indicated generally at 10 in FIG. 1 and comprise a plug 11, comprising a suitable electrical insulating material and with a substantially flat, smooth front face 12 and a handle or grip means 13 on the rear face thereof. A plurality of electrical contacts or prongs 14 project forwardly from the body at the front face 12 thereof, and the prongs are connected through a pair of wires or electrical leads 15 and 16 and an electrical cable C to a suitable telephone set or instrument (not shown).
A female half or jack 17 of the coupler 10 is affixed to a wall W or the like by means of a plurality of suitable fasteners, such as screws 18 or the like, extended through the jack 17 into the wall W. The jack or female coupling half 17 also comprises a body of suitable electrical insulating material and has a substantially flat, planar front face 19 with a plurality of contact receptive sockets 20 and 21 therein, in which are disposed spring type contacts 22 and 23, respectively, for engagement by the prongs 14 on the male coupling half or plug 11 to establish electrical connection between the halves when they are coupled together. The spring contacts 22 and 23 are connected to a pair of wires 24 and 25, respectively, leading to a source of energy or service line for the telephone installation.
A device 26, in accordance with the invention, is connected across the wires 24 and 25 in parallel with the contacts 22 and 23 to enable a telephone service company to readily ascertain the operability of the service line, even when the male coupling half 11 is disconnected from the female coupling half 17, and also enables the telephone service company to readily ascertain or determine the presence of any telephone sets connected to the service line, whether they are authorized or unauthorized, and whether the bells are connected or disconnected in the telephone sets. The device 26 includes a suitable impedance means, such as resistance element or capacitor or the like 27 for imposing a predetermined impedance on the service line, and a switch 28 for selectively connecting and disconnecting the resistance or impedance or the like from the service line. The switch 28 includes a contact base plate 29 connected to the capacitor or resistance element or the like 27 and a contact point 30 affixed to one end of the plate 29. A similar contact point 31 is affixed to one end of a leaf spring member 32, which is fixed at its other end 33 to the female coupling half 17 and is normally urged into the closed position with contact points 30 and 31 in electrically conducting engagement, as shown in FIG. 1. A suitable electrical insulating pad 34 of a material such as felt or the like is affixed to the leaf spring 32 intermediate its ends and in registry with the socket 20 through the female coupling half in a position to be engaged by one of the contact prongs 14 on the male coupling half when the coupling halves are joined together, as in FIG. 3, to disengage the contact points 30 and 31 and thus disconnect the resistor or capacitor or the like 27 from the service line.
The capacitor or resistance element or the like 27 is selected to have a value such as to impose a predetermined impedance of any suitable value to obtain an indication of the presence of a telephone on the service line and the operability of the service line as aforesaid. Preferably, the impedance is either above or below that of the telephone set, and it may include a fractional impedance to render it more difficult to circumvent.
Thus, with the device as described above, and with the jack disconnected, as in FIG. 1, the resistor or capacitor or like 27 imposes a predetermined impedance on the service line and the service company or telephone company is enabled to make a routine check of the service line merely by transmitting a signal over the service line and to the device 26. The switch 28 being closed results in the impedance of the capacitor or resistor or the like being imposed on the line and thus this impedance is indicated at the checking station and it can be determined from the value of the impedance measured at the checking station whether the service line is operable or not.
Further, if the jack is connected, as in FIG. 3, to connect a telephone set to the service line, the switch 28 is opened, thus removing the resistor or capacitor or the like 27 from the line, and if the bell in the telephone connected thereto is not disconnected, then the resistance or impedance offered by the bell is measured at the checking station to indicate the presence of a telephone, and if the bell is disconnected, then the removal of the resistor or capacitor or the like 27 from the line is registered at the checking station to give an indication of a change in the impedance in the line, and thus to indicate that a telephone set has been connected to the service line.
In FIG. 4, for example, a service line L extends from a checking station CS to a suitable service installation or residence R, where three couplers or jacks 10a, 10b and 10c are provided, and where only one authorized telephone T1 is connected via cord C to jack 10a. Assume that the value of the capacitor or resistor or the like 27 in each jack imposes an impedance of 11/2 ohms on the service line and that the bell in telephone T1 imposes or has an impedance of 2 ohms, then with no telephone connected to any of the jacks 10a, 10b or 10c, a total impedance of 41/2 ohms would be measured at the checking station CS. If telephone T1 is now connected to jack 10a, then the switch 28 is opened and the 11/2 ohm resistance is removed and the 2 ohm resistance of the ringing circuit in the telephone T1 is imposed on the line, thus resulting in a total resistance or impedance reading at checking station CS of 5 ohms. Thus, for one authorized telephone at the installation R either one of two readings should be obtained at the checking station, i.e. 41/2 ohms when no telephone set is connected and 5 ohms when one telephone set is connected. If the subscriber at service installation R decides to purchase an unauthorized telephone T2 and to connect it to the service line without knowledge of the telephone company in an attempt to avoid payment of the service charge on the telephone T2, then ordinarily the subscriber would disconnect the bell in telephone T2 and merely connect it to the service line. With the present invention, however, as soon as the cord C of telephone T2 is connected to jack 10c or 10b, a prong 14 of the plug opens the switch 28 in that jack and removes or open-circuits the 11/2 ohm resistance or impedance connected across that service line, thus changing the signal measured at checking station CS by that amount, so that if the service line is checked to service installation R and one legal telephone T1 and one unauthorized telephone T2 are connected to the service line, as indicated in FIG. 4, a reading of 31/2 ohms will be obtained, indicating the presence of the unauthorized telephone T2.
In FIGS. 5-7 a modified telephone coupler 35, embodying a device 26 in accordance with the invention, is illustrated and comprises a male coupling half or plug 11' having a substantially flat, planar front face 12' and a handle means 13' on the rear face thereof. However, rather than the plurality of forwardly axially projecting contact prongs 14, as in the FIG. 1 embodiment, a pair of annular, concentric contact rings 36 and 37 project forwardly from the front face 12' and the rings 36 and 37 are connected by means of a pair of wires 16' and 15', respectively, to a cord or the like C which leads to a telephone (not shown).
Also disposed in the front face 12' of male coupling half 11' is a magnet 38 having a conically shaped projection 40 projecting forwardly from face 12' in concentric relationship with contacts 36 and 37.
A female coupling half or jack 17' is suitably secured to a wall or the like W by means of a plurality or fastening means, such as screws 18, extended through the female coupling half into the wall and the coupling half 17' has a substantially flat, planar front face 19', in the center of which is secured a magnet means 41 having a conically shaped recess 42 extended therethrough. Also, a pair of annular, concentric, radially spaced apart grooves or channels 43 are disposed in concentric relationship to the magnet 41 and a pair of annular, ring-shaped floating electrical contacts 44 and 45 are disposed in the channels 43 for reception of the ring-shaped contacts 36 and 37 on the male coupling half or plug 11'. The rear face of female coupling half or jack 17' is recessed at 46 and the conical recess 42 in the magnet 41 extends and continues through the female coupling half 17' into the recess 46 at the rear thereof. Wires 24 and 25 are connected with the contacts 43, and a device 26, in accordance with the invention, and comprising a suitable resistor or capacitor or the like 27 and a switch 28, as aforedescribed, is connected between the wires 24 and 25, as before.
The use and operation of this form of the invention are substantially identical with the form of the invention illustrated in FIGS. 1-4, except that the coupling halves 11' and 17' may be coupled together in any relative rotational position therebetween because of the concentric annular relationship of the electrical contacts and of the magnet means for holding the coupling halves together.
In FIG. 8 a still further form of the invention is illustrated, and in this form of the invention, a suitable light emitting means 47, such as a light emitting diode, is substituted for the capacitor or resistor or the like 27 in the device 26'. In addition to providing a predetermined impedance in the service line connecteed with the coupler 35' of FIG. 8, the light emitting diode 47 provides a visual indication through the conical recess 42 opening into the recess 46 behind the female coupling half or jack 17' of the condition of the service line connected to the jack.
In other words, if the service line is operable and the coupling halves are disconnected, then the switch 28 is closed and the light emitting diode 47 is energized, thus projecting light through the conical recess 42.
The light emitting diode 47 could be used in conjunction with a suitable resistor or capacitor or the like 27, if desired, rather than used in lieu of the resistor or capacitor or the like.
Other types of telephone connectors than that described and illustrated herein may be utilized with the present invention, and other types of devices may be used to modify the signal transmitted to the service installation, rather than the particular resistance or capacitance elements described herein.
Further, while only three jacks have been illustrated in FIG. 4, it is to be understood that any number of jacks may be provided and the present invention will still provide an indication of the operability of the service line and of the presence of any unauthorized telephone on the service line.
Moreover, as noted previously, the present invention can equally as well be used to determine the operability of electric service lines to which loudspeakers, microphones, radios, or other electrical equipment is connected, and to determine whether any such electrical equipment has been disconnected or removed from the service line. For such electrical equipment, the signal imposed on the line would be selected so as to be compatible with the signal used in conjunction with operation of the particular electrical equipment, i.e. so as not to interfere with normal audio functions, or suitable filtering devices could be used. Additionally, more than one capacitor and the like could be used at the service installation.
As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is, therefore, illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims or that form their functional as well as conjointly cooperative equivalents are, therefore, intended to be embraced by those claims.
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Apparatus, method and system to check the operability of an electrical service line, such as a telephone service line or other low voltage service line, between a test station and a telephone service installation or other electrical equipment connected to the line, even in the absence of any telephone set or other electrical equipment connected to the line at the service installation, including an electrical device connected to the line at the service installation to receive a signal transmitted thereto from the test station and to modify the signal returned to the test station to indicate the operability of the line and to modify the signal to indicate the presence or removal of any telephone set or other electrical equipment connected to the line at the service installation.
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FIELD OF THE INVENTION
This invention relates generally to communication networks, and in particular to a wireless communication system basestation based on a generic cell site architecture providing support to multiple air interface standards such as CDMA (code division multiplex access), TDMA (time division multiplex access) and GSM (groupe special mobile).
BACKGROUND ART
Historically, basestations used for wireless communications were designed to support a single air interface standard, for example AMPS (advanced mobile phone service), as the limited selection of air interface standards available in the cellular communications industry did not necessitate the use of more versatile basestations. More recently however, the emergence of several new air interface standards such as CDMA, TDMA and GSM made it desirable for a basestation to provide support to multiple air interface standards. To do this, the conventional approach consisted of providing designated signal processing equipment for each air interface standard to be serviced. The variety of signal processing functionality requirements of current cellular installations such as those used for PCS (personal communication system) operations which address a variety of air interface protocols do not permit a cost-effective and efficient allocation of the resources present at the basestation. Concurrent support of several air interfaces requires the duplication of wideband digital receivers and transmitters, A-D (analog-to-digital) and D-A (digital-to-analog) converters and signal processing equipment for each air standard serviced. The accommodation of several air interface standards necessitates replicating some of the apparatus used in both the receive and transmit directions for each additional air interface protocol sought to be supported by the basestation. The equipment unique to each protocol typically includes two sets of DSP (digital signal processing) units, an RX (receive) channelizer bank, a TX (transmit) channelizer bank, an RF front end which has a wideband receiver, a wideband transmitter and a pair of A-D (analog-to-digital) and D-A (digital-to-analog) converters as is well known in the art. However, duplicating this equipment for each air interface standard and more particularly the RF front end may very rapidly prove to have a major impact on the overall cost of the transceiver.
In addition to the need to reduce the cost of the transceiver, it would also be desirable to make the RF front end simple and more portable. This is due to the fact that some wireless service providers require the RF equipment to be remotely mounted on the antenna tower used for transmission with the remainder of the basestation installed on the ground so as to minimize losses between the antenna and the RF equipment.
In view of the possible remoteness of the RF front end section from the remainder of the basestation, the RF front end should be designed in a portable fashion to eliminate the need to install additional or different expensive and bulky RF equipment when different types of wireless signalling must be accommodated.
The need to address the multiple signalling protocols defined by the various air interface standards has also triggered the emergence of what is now known in the wireless industry as the software radio. A software radio is a highly desirable GCS (generic cell site) architecture for use in PCS installations. It consists of a single configurable basestation hardware design with signal processing equipment that can address several air interface standards. The particular features of interest of a software radio include software configurable wideband reception and transmission capabilities. These characteristics enable the software radio to handle multiple channels from various air interface standards. However, this software configurability does not allow multiple standards to be serviced simultaneously, instead allowing them to be serviced only in sequence.
U.S. Pat. No. 5,537,435 which issued Jul. 16, 1996 to Carney et al. and entitled “Transceiver Apparatus Employing Wideband FFT Channelizer With Output Sample Timing Adjustment And Inverse FFT Combiner For Multichannel Communication Network” discloses a multichannel wireless communication transceiver architecture for wideband signal processing. This patent discloses, among other things, the use of rational rate conversion techniques in an FFT-based wideband channelizer to provide optimum sampling of each digital channel signal output fed to the processing units. The transceiver architecture described in this patent uses a pair of oscillators from which a unique sampling rate for the A-D converter is selected according to the sampling requirements of the particular air interface standard serviced by the transceiver. In particular, the oscillators are provided to respectively accommodate TDMA or CDMA signal processing but the disclosure makes it clear that these two air interface protocols cannot be serviced simultaneously. The oscillators are merely provided to make the basestation more versatile in that it can selectively be configured to either process TDMA or CDMA signals.
U.S. Pat. No. 5,592,480 which issued Jan. 7, 1997 also to Carney and al. and entitled “Wideband Wireless Basestation Making Use of Time Division Multiple-Access Bus Having Selectable Number of Time Slots and Frame Synchronization to Support Different Modulation Standards” partially addresses the redundancy problem outlined above by the use of a TDM (time division multiplexing) bus for providing digital samples of a number of wireless communication channels. This TDM bus is claimed to efficiently service TDMA and CDMA standards simultaneously with a dynamic allocation of signal processing resources therefore eliminating the need to designate or install additional processing units for each air interface standard serviced. However, there is no solution provided for the increase in complexity in the RF front end (see FIG. 9 for example). Separate wideband digital tuners and exciters are required for each different air interface standard supported by the basestation.
Accordingly, there is a need for a cost-effective, simpler and more portable RF front end that can simultaneously service multiple air interface standards.
SUMMARY OF THE INVENTION
It is an object of the present invention to obviate or mitigate one or more of the above- identified disadvantages.
According to a first broad aspect, this invention provides a receive section for a multichannel wireless communication system for processing a composite RF (radio frequency) signal containing RF signals each having an RF bandwidth associated with a respective air interface standard, the receive section comprising a first antenna for receiving the composite RF signal, a wideband receiver connected to the first antenna for down-converting the composite RF signal to produce a down-converted signal, an A-D (analog-to-digital) converter connected to the wideband receiver for performing an analog-to-digital conversion on the down-converted signal to produce a first composite digital signal at a common digitizing rate, for each particular air interface standard: a) an associated RX (receive) channelizer bank connected to receive the first composite digital signal from the A-D converter for adjusting the first composite digital signal data rate to a corresponding standard DSP (digital signal processing) data rate specified by the associated air interface standard to produce a respective adjusted composite digital signal and for extracting from the respective adjusted composite digital signal a respective set of channelized digital signals and b) a first set of DSP units connected to the RX channelizer bank for digitally processing and demodulating the corresponding set of channelized digital signals to produce a first set of digital channel signals each having an associated channel bandwidth corresponding to the particular air interface standard.
According to a second broad aspect, the invention provides a transmit section for a multichannel wireless communication system for processing multiple sets of digital channel signals, each set of digital channel signals being associated with a respective air interface standard, the transmit section comprising, for each particular air interface standard: a) a set of DSP units each connected to receive the corresponding set of digital channel signals for providing a respective set of digitally processed and modulated channel signals, b)an associated TX (transmit) channelizer bank connected to receive the corresponding set of digitally processed and modulated channel signals, the TX channelizer banks being respectively operative to adjust the data rate of each digitally processed and modulated channel signal received to the common digitizing rate for collectively producing a composite digital signal at the common digitizing rate which is representative of the digitally processed and modulated channel signals, a D-A (digital-to-analog) converter connected to receive the composite digital signal for performing a digital-to-analog conversion on the composite digital signal at the common digitizing rate to produce a composite analog signal, the transmit section further comprising a wideband transmitter connected to the D-A converter for up-converting the composite analog signal to produce an up-converted signal and an antenna for transmitting the up-converted signal.
In particular, the invention provides a basestation transceiver which simultaneously addresses multiple air interface standards with cost-effective and efficient allocation of the resources present at the transceiver and significantly reduces redundancy in the RF equipment used.
The RF front end includes RF transmit and receive sections. The receive section designed in accordance with this invention is configured to over-sample a selected band of RF energy large enough to contain the contents of the signals employed in any of the air interface standards supported in the band. A preferred embodiment of the present invention supports J-STD-008 CDMA, IS-136A TDMA and J-STD-007A GSM standards which necessitates the sampling of a 15 MHz band located in the 1850 MHz to 1910 MHz frequency spectrum allocated for US PCS (United States Personal Communication System) uplink operations. The receive section includes a receive antenna, a single wideband receiver coupled to a single A-D converter with a common digitizing rate calculated to simultaneously accommodate all of the air interface protocols serviced. The A-D converter is coupled to a plurality of RX channelizer banks with a high speed optical link. A plurality of rate adjustment components selected from the group of decimators, rational rate converters and interpolators is used in each RX channelizer bank to convert the incoming digitized signal generated by the A-D converter at the common digitizing rate into a digitized signal having the appropriate rate for a particular air interface standard. Each RX channelizer bank is responsible for tuning the digitized signal to be located in the frequency band specified by a particular air interface protocol, separating the digitized signal into the channel bandwidths specified by the same air interface protocol and suppling the channelized digital signals to a set of baseband DSP units for further processing and demodulation to produce a respective set of digital channel signals in a form suited for distribution to the remainder of the telephony network, which may for example include a PSTN (public switching telephone network).
On the transmit side, baseband DSP units are designated to modulate and process digital channel signals received from the telephony network. The baseband DSP units used in association with each air interface protocol are coupled to a corresponding TX channelizer bank which functions to filter and tune the frequency spectrum of the digitally processed and modulated channel signals received in the frequency band used for transmit operations and also operates to adjust their respective data rate to the common digitizing rate. The TX channelizer banks are interconnected in cascade for combining the digitally processed and modulated channel signals into a composite digital signal. This composite digital signal is routed via a high speed optical link to the transmit section of the RF front end which includes a single D-A converter and a single wideband transmitter coupled to a transmit antenna. The D-A converter and the wideband transmitter operate to convert the composite digital signal received from the TX channelizer banks into an analog form and upconvert the resulting signal to the desired radio frequency range before transmitting them via the transmit antenna. A preferred embodiment of the present invention adjusts and combines CDMA, TDMA and GSM digital channel signals in respective CDMA, TDMA and GSM TX channelizer banks, upconverts and transmits these signals in the form of a composite signal in a 5 MHz band located in the 1930 MHz to 1990 MHz frequency range allocated for US PCS downlink operations.
The use of a common digitizing rate in the transceiver eliminates the current practice of duplicating the equipment used in the radio frequency front end section of a transceiver for each air interface protocol serviced. As a result, a transceiver of the present invention provides efficient and cost-effective simultaneous support to a variety of air interface standards.
Yet another advantage of this invention is the resulting reduction in complexity in the RF front end. This makes it portable enough to be conveniently installed at a remote location such as, for example, an RF tower while the remaining portion of the transceiver apparatus is kept on the ground.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be described with reference to the attached drawings in which:
FIG. 1 is a block diagram of a transceiver portion of a conventional basestation which can support multiple air interface standards;
FIG. 2 is a block diagram of a transceiver portion which supports multiple air interface standards according to an embodiment of the invention;
FIG. 3 is a block diagram of the RF front end receive section of the transceiver portion illustrated in FIG. 2;
FIG. 4 is a block diagram of the signal converter of the RF front end receive section of FIG. 3;
FIG. 5 is a block diagram of the reference clock generator of the transceiver portion of FIG. 2;
FIG. 6 is a block diagram of an example of a CDMA RX (receive) channelizer bank for use in the transceiver portion of FIG. 2;
FIG. 7 is a block diagram of an example of a TDMA RX channelizer bank for use in the transceiver portion of FIG. 2;
FIG. 8 is a block diagram of an example of a GSM RX channelizer bank for use in the transceiver portion of FIG. 2;
FIG. 9 is a block diagram of an example of a CDMA TX (transmit) channelizer bank for use in the transceiver portion of FIG. 2;
FIG. 10 is a block diagram of an example of a TDMA TX channelizer bank for use in the transceiver portion of FIG. 2;
FIG. 11 is a block diagram of an example of a GSM TX channelizer bank for use in the transceiver portion of FIG. 2; and
FIG. 12 is a block diagram of the RF front end transmit section of the transceiver portion illustrated in FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring firstly to FIG. 1, a conventional transceiver portion of a basestation that can service multiple air interface standards such as CDMA, TDMA and GSM comprises a receive section generally indicated by 2 and a transmit section generally indicated by 1. The receive section 2 has a receive antenna 3 coupled to a CDMA wideband receiver 4 , a TDMA wideband receiver 5 and a GSM wideband receiver 6 which are, in turn, respectively coupled to A-D converters 10 , 11 , 12 . Wideband receivers 4 , 5 , 6 and A-D converters 10 , 11 , 12 form the RF front end receive section generally indicated by 30. The A-D converters 10 , 11 , 12 are respectively connected to a CDMA RX (receive) channelizer bank 7 , a TDMA RX channelizer bank 8 and a GSM RX channelizer bank 9 . Each RX channelizer bank 7 , 8 , 9 produces a plurality N of channelized digital signals and is coupled to a corresponding set of baseband DSP units 13 , 14 , 15 .
In operation, the wideband receivers 4 , 5 , 6 of the RF front end receive section 30 all function in a similar fashion, respectively downconverting a selected band of the RF energy collected by the receive antenna 3 . Next, the wideband receivers 4 , 5 , 6 forward the downconverted signals to respective CDMA, TDMA and GSM RX channelizer banks 7 , 8 , 9 through the corresponding A-D converters 10 , 11 , 12 , each with a sampling rate clock signal of a sufficiently high frequency to accommodate the total bandwidth associated with their respective air interface standard. RX channelizer banks 7 , 8 , 9 are all configured to separate the received digital signal into a plurality N of channelized digital signals, each respectively with, for example, a channel bandwidth of 1.25 MHz for CDMA, 30 kHz for TDMA and 200 KHz for GSM. The channelized data respectively generated by each RX channelizer bank 7 , 8 , 9 is then routed to the corresponding set of baseband DSP units 13 , 14 , 15 for further processing and demodulation to produce a respective set of digital channel signals in a form suited for further processing and distribution to the PSTN by the basestation.
Similarly, the transmit section 1 of the conventional transceiver illustrated in FIG. 1 has a plurality of sets of baseband DSP units 20 , 21 , 22 , with each DSP unit coupled to the telephony network to receive ones of a plurality of digital channel signals. These sets of DSP units 20 , 21 , 22 are connected to a respective CDMA, TDMA and GSM TX (transmit) channelizer bank 23 , 24 , 25 , followed by a D-A converter 26 , 27 , 28 . The D-A converters 26 , 27 , 28 are respectively coupled to corresponding wideband CDMA, TMDA and GSM transmitters 16 , 17 , 18 which are connected to an RF combiner 105 to form the RF front end transmit section generally indicated by 29. The RF combiner 105 is coupled to a transmit antenna 19 .
In function, the sets of baseband DSP units 20 , 21 , 22 are coupled to receive from the telephony network respective ones of a plurality of digital channel signals to be modulated over different narrowband frequency channels and processed in accordance with the characteristics of the particular air interface standard used by each multichannel network. The TX channelizer banks 23 , 24 , 25 each receive the digitally processed and modulated digital channel signals associated with each particular air interface, be it CDMA, TDMA or GSM, from the corresponding set of baseband DSP units 20 , 21 , 22 and respectively combine these digital signals into a composite digital signal which is, in turn, supplied to a corresponding D-A converter 26 , 27 , 28 to be converted to an analog form. D-A converters 26 , 27 , 28 are coupled to corresponding wideband transmitters 16 , 17 , 18 to upconvert the composite analog signals to the appropriate RF frequency band. These composite analog signals are combined in the RF combiner 105 and supplied to the transmit antenna 19 for transmission.
Referring now to FIG. 2, a basestation transceiver, according to an embodiment of the invention which services CDMA, TDMA and GSM air interface standards and more particularly J-STD-008 CDMA, IS-136A TDMA and J-STD-007A GSM (thereafter simply referred to as CDMA, TDMA and GSM) at 1900 MHz has a receive section generally indicated by 2 and a transmit section generally indicated by 1. The receive section 2 has a receive antenna 3 , an RF front end receive section 30 , multiple RX channelizer banks 7 , 8 , 9 which are coupled to baseband DSP units 13 , 14 , 15 in a manner identical to that described above in reference to FIG. 1 . The receive section 2 also has a reference clock generator 106 coupled between the RF front end receive section 30 and the baseband DSP units 13 , 14 , 15 .
Preferably, the RF front end receive section 30 is installed on or near the receive antenna 3 with a high speed optical link 104 connecting it to the remainder of the receive section 2 which would be typically installed on the ground near the base of the antenna tower. The RF front end receive section 30 is comprised of a single wideband receiver 40 and a single A-D converter 41 and will now be described in further detail with reference to FIG. 3 .
The wideband receiver 40 is connected to the A-D converter 41 and has an RF analog receiver and downconverter unit generally indicated by 32 for connection to the receive antenna of FIG. 2 . The RF analog receiver and downconverter unit 32 has a low noise amplifier 39 coupled to a first band pass filter 42 which is, in turn, coupled to an RF-IF (radio frequency-to-intermediate frequency) mixer 46 . The RF-IF mixer 46 has an associated RF local oscillator signal 87 derived from a common reference clock signal, Fref, which is generated by the reference clock generator 106 of FIG. 2 . More specifically, the RF local oscillator signal 87 is obtained via a narrow loop bandwidth PLL (phase-locked loop) generally indicated by 36 as having a phase detector 31 , a loop filter 35 , a crystal VCO (voltage controlled oscillator) 44 and a frequency divider 49 . The PLL 36 is connected in series with a signal converter 109 (further detailed later in reference to FIG. 4) which is external to the RF analog receiver and downconverter unit 32 and is connected to receive the common reference clock signal Fref from the reference clock generator 106 .
The RF analog receiver and downconverter unit 32 further has a second band pass filter 48 coupled internally to the output of RF-IF mixer 46 and externally to the input of an AGC (automatic gain control) actuator 33 . The output of the AGC actuator 33 is, in turn, coupled to an IF (intermediate frequency) downconverter generally indicated by 34 which includes an IF mixer 47 and a band pass filter 51 . The IF mixer 47 has an associated IF local oscillator signal 88 also derived from Fref through the signal converter 109 .
The IF downconverter 34 is coupled to the A-D converter 41 which receives a high frequency digitizing clock signal (hereinafter referred to as the common digitizing clock signal) 89 derived from Fref also through the signal converter 109 . The A-D converter 41 is connected to a P-S (parallel-to-serial) converter 66 which, in turn, is coupled to the RX channelizer banks 7 , 8 , 9 via the high speed optical link 104 (see FIG. 2) and also back to the AGC actuator 33 through an AGC controller unit 37 to form an AGC feedback loop. The AGC controller unit 37 is also coupled to the RX channelizer banks 7 , 8 , 9 , and is connected to receive AGC loop control signals from a micro-processor 52 which has its input coupled to an EEPROM (electrically erasable programmable read-only memory) unit 45 .
In operation, the RF front end receive section 30 obtains RF energy collected by the receive antenna 3 and couples it to the RF analog receiver and downconverter unit 32 which uses the band pass filter 42 to select a band of RF energy from the incoming signal pre-amplified in the low noise amplifier 39 . The RF band must be large enough to contain the contents of the signals employing any one of the air interface standards supported. To service CDMA, TDMA and GSM channel signals for example, the RF analog receiver and downconverter unit 32 (which can be for example an off-shelf part such as the SR1019 dual channel down receiver manufactured by Watkins-Johnson) selects a 15 MHz frequency band from the frequency spectrum allocated for US PCS (United States Personal Communication System) operations. In this embodiment, the RF analog receiver and downconverter unit 32 selects the 15 MHz band extending from 1850 MHz to 1865 MHz. The pre-amplified RF band thus selected is downconverted to a first IF band by the combined operation of RF-IF mixer 46 and band pass filter 48 . As an example, the RF analog receiver and downconverter unit 32 of FIG. 3 may downconvert the 15 MHz RF band centered at 1857.5 MHz to a first IF band centered at 108 MHz using the RF local oscillator signal 87 with a frequency of 1749.8112 MHz and supply the downconverted signal to the AGC actuator 33 . The 1749.8112 MHz RF local oscillator signal 87 is derived from the common reference signal, Fref, through the signal converter 109 and the PLL 36 . In order to generate this RF local oscillator signal 87 , the signal converter 109 (further detailed below in reference to FIG. 4) functions to receive Fref which is assumed to be 2.4576 MHz for reasons explained below and produce an output signal 90 with a frequency of 1.2288 MHz. This output signal 90 is coupled to the PLL 36 which operates to generate the desired 1749.8112 MHz RF local oscillator signal 87 with a 1/1424 frequency divider 49 .
The AGC actuator 33 is also described below in greater detail but may be now briefly described as adjusting the gain of the incoming downconverted signal according to the AGC control parameters it receives from the AGC controller unit 37 . The IF downconverter 34 uses mixer 47 and band pass filter 51 to downconvert the output of the AGC actuator 33 to a second IF band, preferably extending from 3 MHz to 18 MHz and centered at 10.5 MHz. This downconversion example is effected by the use of the IF local oscillator signal 88 operating at a frequency of 117.9648 MHz directly obtained and derived from the 2.4576 MHz Fref through the signal converter 109 .
The output of band-pass filter 51 is a down-converted, multichannel signal with a frequency content located in the 3 MHz to 18 MHz range. This signal holds the contents of the 1.25 MHz, 30 KHz and 200 KHz voice/data channels available in the communication systems of interest and is digitized in the A-D converter 41 (which may be, for example, the high speed 12 bit AD9042 manufactured by Analog Devices). As noted above, the A-D converter 41 uses the common digitizing clock signal 89 which is derived from Fref through the signal converter 109 . The digitizing rate of the A-D converter 41 preferably set for this example to 63.8976 MHz is carefully selected, as described in detail below, to eliminate the need for additional expensive and complex signal filtering and shielding that would otherwise be required in the RX channelizer banks 7 , 8 , 9 for simultaneously processing the digitized signal received by the A-D converter 41 at the common digitizing rate based on their respective CDMA, TDMA and GSM requirements.
The following section will now describe in detail and with reference to FIG. 4 the signal converter 109 through which the RF local oscillator signal 87 (see FIG. 3 ), the IF local oscillator signal 88 and the common digitizing clock signal 89 are derived from Fref. This will be followed by a complete description of the method used to generate Fref for a basestation supporting CDMA, TDMA and GSM air interface standards and with reference to the clock generator 106 illustrated in FIG. 5 .
Referring firstly to FIG. 4, the signal converter 109 functions to receive the 2.4576 MHz Fref from the reference clock generator 106 for providing the RF analog receiver and downconverter unit 32 , the IF downconverter 34 and the A-D converter 41 with respective output signal 90 , IF local oscillator signal 88 and common digitizing clock signal 89 .
More specifically, the signal converter 109 has a frequency divider 85 coupled to the reference clock generator 106 for receiving the Fref signal. This frequency divider 85 is connected to a narrow loop bandwidth PLL generally indicated by 54 which supplies the common digitizing clock signal 89 to the A-D converter 41 . The PLL 54 has a phase detector 57 , a loop filter 62 , a crystal VCO 84 and a frequency divider 86 . The output of the PLL 54 is also coupled externally to a pair of frequency dividers 110 , 111 to produce the output signal 90 for the RF analog receiver and downconverter unit 32 This output signal 90 is also fed internally to a PLL 38 for producing the IF local oscillator signal 88 to the IF downconverter 34 . Similarly to the PLL 54 , the PLL 38 has a phase detector 50 , a loop filter 53 , a crystal VCO 55 and a frequency divider 56 . It is to be noted however that as the phase noise has been virtually eliminated by the PLL 54 , the lock-acquisition time of subsequent PLLs 36 and 38 is preferably improved by operating therein a loop bandwidth wider than that of the PLL 54 .
In operation, the signal converter 109 functions to receive the 2.4576 MHz Fref signal from the reference clock generator 106 for providing the RF analog receiver and downconverter unit 32 , the IF downconverter 34 and the A-D converter 41 with respective output signal 90 , IF local oscillator signal 88 and common digitizing clock signal 89 . More specifically, the output signal 90 supplied to the RF analog receiver and downconverter unit 32 is obtained from Fref through the frequency dividers 85 , 110 , 111 and PLL 54 . The IF local oscillator signal 88 supplied to the IF downconverter 34 is produced with PLLs 54 , 38 and frequency dividers 85 , 110 and 111 while the common digitizing clock signal 89 is obtained from Fref through the frequency divider 85 and PLL 54 .
In this example, the frequency of signal Fref=2.4576 MHz is initially divided by 16 in the frequency divider 85 and subsequently multiplied by a factor of 416 by the PLL 54 with a 1/416 frequency divider 86 to produce the 63.8976 MHz digitizing clock signal required for the A-D converter 41 (the selection of this particular frequency is further discussed below). The output of PLL 54 is consecutively divided further in the frequency dividers 110 , 111 by respective factors of 4 and 13 to produce the 1.2288 MHz output clock signal 90 which is supplied to the RF analog receiver and downconverter unit 32 . The 1.2288 MHz signal is also applied to PLL 38 for producing the 117.9648 MHz IF local oscillator signal 88 required by the IF downconverter 34 with a frequency divider 56 which has a divider of 1/96.
Referring to FIG. 5, the method used to select, generate and obtain the common reference signal, Fref, for a basestation supporting CDMA, TDMA and GSM air interface standards will now be described in relation to the reference clock generator 106 .
The reference clock generator 106 operates to receive the CDMA, TDMA and GSM system clocks from respective sets of baseband DSP units 13 , 14 , 15 for producing Fref, and supplying it to the signal converter 109 . The reference clock generator 106 is preferably located near the baseband DSP units 13 , 14 , 15 , 20 , 21 , 22 and has a programmable divider 112 connected to receive the CDMA, TDMA and GSM system clocks. The programmable divider 112 supplies its output signal 156 to a PLL generally indicated by 113 which has a phase detector 114 , a loop filter 115 , a crystal VCO 116 and a programmable frequency divider 117 . The PLL 113 is externally coupled to the basebands DSP units 20 , 21 , 22 , to the TX channelizer banks 23 , 24 , 25 and is also coupled to the signal converter 109 (see FIG. 4) through a programmable counter 118 .
In operation, the reference clock generator 106 functions to supply the common reference clock signal, Fref, to the signal converter 109 for deriving the RF and IF local oscillator signals and the common digitizing clock signal described above in reference to FIG. 3 . Fref is generated from any of the CDMA, TDMA and GSM system clocks received from respective baseband DSP units 13 , 14 and 15 . As these system clock signals are derived from the baseband DSP units 13 , 14 and 15 , their respective frequency is dependent upon the corresponding baseband DSP signalling rate. As a result, Fref is selected to be derivable from any multiple of the system clocks. As an example, the systems clock signals of the preferred embodiment respectively operate at the following frequencies:
CDMA system clock: 19 660 800 Hz
TDMA system clock: 6 220 800 Hz
GSM system clock : 26 000 000 Hz
The common reference clock signal, Fref, is selected to be easily derivable from any of the above system clocks. As such, these systems clocks are applied to the programmable divider 112 which selects one system clock and divides it down to a frequency suited for the PLL 113 . The programmable divider 112 of a basestation which supports CDMA, TDMA and GSM air interface standards may, for example, divide the associated system clocks as follows:
CDMA system clock: 19 660 800/512=38 400 Hz
TDMA system clock: 6 220 800/162=38 400 Hz
GSM system clock : 26 000 000/625=41 600 Hz
The programmable divider 112 supplies its output signal 156 to the PLL 113 which has a mode of operation similar to that of PLLs 38 and 54 described above in reference to FIG. 4 and accordingly functions to receive the system clock initially selected and divided down in the above-described manner by the programmable divider 112 and produce the output signal 157 . The loop bandwidth of the PLL 113 is such that the output signal 157 can be generated from any of the divided-down versions of the system clocks. Further, the frequency of the output signal 157 is dictated by the dividing factor, 1/i, programmed into the programmable frequency divider 117 which is preferably set such that the output signal 157 generated operates at the common digizing rate of 63.8976 MHz (the selection of which is further detailed below) independent of the frequency of the programmable divider output signal 156 . Generating the output signal 157 at the common digitizing rate of 63.8976 MHz in close proximity of the baseband DSP units is particularly useful because it is used locally for signal synchronization in the transmit section 1 of FIG. 2 and more particularly in the baseband DSP units 20 , 21 and 22 and TX channelizer banks 23 , 24 , 25 .
The PLL output signal 157 is fed into the programmable counter 118 which functions to produce Fref with a frequency high enough to be easily handled by currently available PLLs. In this particular example, Fref is selected to be 2.4576 MHz as this frequency is well suited for the PLLs 36 , 38 , 54 located in the RF front end receive section 30 of FIG. 3 . The 2.4576 MHz Fref signal is obtained with the programmable counter 118 by dividing the 63.8976 MHz clock signal 157 by a factor of 26.
Referring back to FIG. 3, the output of A-D converter 41 consists of a composite digital signal comprised of a plurality of parallel streams of digital pulses. This plurality of parallel streams of digital pulses is generated at the common digitizing rate and is coupled to a P-S (parallel-to-serial) converter 66 to be combined into a single stream of digital pulses for transmission to the RX channelizer banks 7 , 8 , 9 via a high speed optical link where the composite digital signal comprising a single stream of digital pulses is applied to an S-P (serial-to-parallel) converter 59 (further described in reference to FIG. 6) to be converted back into a plurality of parallel streams of digital pulses and subsequently applied to the RX channelizer banks 7 , 8 , 9 . The operation of the S-P converter 59 and RX channelizer banks 7 , 8 , 9 is further detailed below with reference to FIGS. 6, 7 and 8 .
The A-D converter 41 is also coupled to the AGC actuator 33 through the AGC controller unit 37 to form an AGC feedback loop so as to prevent clipping of the A-D converter 41 for high received mobile signal strengths. The AGC controller unit 37 ensures that the A-D converter 41 is, to the extent possible, operating within its dynamic range by continuously monitoring the digital samples it generates as they are generated by the A-D converter 41 . The gain adjustment to be inserted by the AGC actuator 33 in the analog signal path is proportional to the average error between each digital sample with an amplitude greater than the A-D converter detection threshold and the detection threshold itself. The average error is calculated for a specified number of digital samples defining a sample window and is used to determine the gain attenuation to be inserted by the AGC actuator 33 for the duration of the next window of digital samples generated by the A-D converter 41 . In other words, a new attenuation factor is calculated in the AGC controller 37 and effected in the AGC actuator 33 for each new sample window based on the average error observed in the previous sample window. The attenuation applied in the AGC actuator 33 of the RF front end receive section 30 is also signalled to the RX channelizer banks 7 , 8 , 9 or the baseband DSP units 13 , 14 , 15 and may consequently be un-applied therein by a corresponding digital compensation such that the channelized digital signals processed and demodulated by the baseband DSP units 13 , 14 , 15 are within a constant amplitude range independent of the AGC controller settings.
The serial digitized signal generated by the P-S converter 66 and comprised of a single stream of digital pulses is transmitted via the high speed optical link 104 (see FIG. 2) and received by an S-P (serial-to-parallel) converter 59 (described below with reference to FIG. 6) connected to the RX channelizer banks 7 , 8 , 9 . The RX channelizer banks 7 , 8 , 9 are designed to tune and filter the S-P converter 59 output signal and adjust its sample rate to the DSP data rate specified by their corresponding air interface standard with a plurality of rate adjustment components which may be for example decimators, rational rate converters and interpolators. This sample rate adjustment enables each RX channelizer bank 7 , 8 , 9 to extract the plurality N of channelized digital signals from the received signal, all respectively with, for example, a 1.25 MHz bandwidth as specified by CDMA, a 30 KHz bandwidth as specified by TDMA and a 200 KHz bandwidth as specified by GSM.
This section will now describe in detail and with reference to FIGS. 6, 7 and 8 , the architecture of CDMA, TDMA and GSM RX channelizer banks 7 , 8 , 9 in accordance with the embodiment of the present invention. To begin, however, the method used to generate and obtain the above-referenced common digitizing rate of 63.8976 MHz for a basestation supporting CDMA, TDMA and GSM air interface standards is detailed, as this is required for an understanding of the description of the RX channelizer banks 7 , 8 , 9 .
The common digitizing rate employed by A-D converter 41 is first selected in conformance to the Nyquist theorem fundamental sampling rule: 2*Fmax where Fmax=18 MHz is the upper frequency limit of the 15 MHz composite signal. The common digitizing rate must therefore be at least 36 MHz. Secondly, the common digitizing rate must be selected according to clock requirements specific to each air interface standard supported by the basestation which are, in this example, CDMA, TDMA and GSM air interface standards.
The following table contains in the first column all relevant air interface standards to be considered in the selection of the common digitizing rate for this embodiment. For this example, the corresponding DSP system rates are shown in their standard form in the second column and given in their prime factors in the third column:
TABLE 1
System DSP rates
Standard
(Hz)
Prime factors
CDMA
chip rate(fc):
(2 14 ) * (3) * (5 2 )
1228800
system clock:
(2 18 ) * (3) * (5 2 )
19660800
TDMA - D-AMPS
symbol rate:
(2 2 ) * (3 5 ) * (5 2 )
24300
symbol rate
multiple:
(2 3 ) * (3 5 ) * (5 2 )
48600
system clock:
(2 10 ) * (3 5 ) * (5 2 )
6220800
GSM
symbol rate:
(2 7 ) * (5 6 ) * 13
270833.3
System clock:
(2 5 ) * (5 6 ) * 13
26000000
intermediate:
6500000
Concurrent processing by respective CDMA, TDMA and GSM multichannel networks of a digitized signal operating at a common digitizing rate necessitates some sample rate adjustment in the corresponding RX channelizer banks 7 , 8 , 9 . The complexity and cost of such adjustment is proportional to the processing requirements of each RX channelizer bank 7 , 8 , 9 . In any combination of air interface standards, one of the standards will require the most processing to convert the data rate of the incoming digitized signal to the desired DSP data rate and extract from this digitized signal the plurality N of channelized digital signals as specified by that particular air interface standard. This high processing demand has a direct bearing on the hardware complexity and cost of the corresponding RX channelizer bank. In order to reduce the overall hardware complexity and implementational costs associated with using a common digitizing rate, a third step consists of selecting a set of prime factors according to the figures contained in TABLE 1, for which the most processing intensive of the CDMA, TDMA and GSM multichannel networks can most easily be filtered and adjust its channelizer input data rate to meet its DSP data rate standard. This is preferably carried out by selecting all of the prime factors of the most processing intensive air interface standard to reduce the cost increase of the associated RX channelizer bank and therefore minimize the overall cost of the transceiver. If necessary, further factors may be successively added from other standards to ensure compliance with the Nyquist condition. However, the selection of such factors must also be carried out in consideration of the cost-related issues mentioned above.
In this example, analysis found that CDMA requires the most complex processing among the particular combination of CDMA TDMA and GSM air interface standards for similar filtering requirements as its associated channel bandwidth is greater than that of the TDMA and GSM air interface standards. Accordingly, all of its prime factors are selected. The CDMA prime factors (2 14 )*(3)*(52) found in TABLE 1 above yield a digitizing rate of 1.2288 MHz. However, according to the Nyquist minimum sample rate of 36 MHz calculated above, this frequency is too low. To satisfy the Nyquist condition, an additional factor is selected from other standards. By inspection of the values contained in TABLE 1, 13 is the most appropriate factor to select among the TDMA and GSM prime factors, as the resulting rate adjustment to be implemented in the CDMA and TDMA RX channelizer banks 7 , 8 is comparatively more cost-effective than the rate adjustment required if prime factors other than 13 are used. This factor of 13 from GSM is added to produce a common digitizing rate of 15974400 Hz which is also, according to the Nyquist criterion, too low. A further cost-effective factor of (2 2 ) may be added to the factors in consideration to yield a sample rate of 63897600 Hz which amply satisfies the Nyquist condition. This digitizing rate is given in terms of its prime factors as (2 16 )*(3)* (5 2 )*13 or can be expressed as a function of the CDMA chip rate, fc=1.2288 MHz as follows:
Common digitizing rate=52*fc
Therefore, a basestation which simultaneously supports CDMA, TDMA and GSM air interface standards in accordance with this example may use an A-D converter 41 with digitizing capabilities of 52*1.2288 MHz=63.8976 MHz.
As noted above, generating a digitized signal at the common digitizing rate of 52*fc requires some sample rate adjustment in the RX channelizer banks 7 , 8 , 9 for simultaneously processing the incoming digitized signal based on their respective CDMA, TDMA and GSM requirements. The input rate changes to effect for obtaining the desired DSP data rate expected by each RX channelizer bank 7 , 8 , 9 (see TABLE 1) are determined from the CDMA-based common digitizing rate (selected in the manner described above) by dividing it separately with the CDMA, TDMA and GSM clock rates in their prime number form. This operation is described below for each of the CDMA, TDMA and GSM air interface standards with reference to corresponding FIGS. 6, 7 and 8 , and is followed, in each case, by a complete description of the associated CDMA, TDMA and GSM RX channelizer bank architecture.
Referring firstly to FIG. 6, the input rate change to be effected in the CDMA RX channelizer bank 7 to adjust the rate of the incoming digitized signal from 63.8976 MHz to the CDMA DSP receive data rate of (8*fc) or (8*1.2288 MHz) is determined by dividing the common digitizing rate with the CDMA DSP receive data rate in their prime number form as follows:
common digitizing rate (52 * fc):
(2 16 ) * (3) * (5 2 ) * 13
CDMA DSP receive data rate (8 * fc):
(2 17 ) * (3) * (5 2 )
CDMA rate adjustment (dividend):
13/2
According to these figures, the CDMA input rate change is obtained by first decimating the incoming signal received at a rate of 52*fc by a factor of 13 and then interpolating it by a factor of 2. However, in order to reduce the number of digital operations to be performed therein and therefore obtain a more cost-effective implementation of the input rate change the incoming digitized signal received is preferably decimated further (provided this does not result in loss of signal information) before it is further processed in the CDMA RX channelizer bank 7 . This additional decimation of the incoming digitized signal is compensated for by a corresponding interpolation to produce the required DSP data rate. As an example, the incoming signal received in the CDMA RX channelizer bank 7 is further decimated by a factor of 2 (in addition to the decimation of 13 calculated above) followed by an interpolation of 4 which results in an overal decimation of (13*2) followed by an interpolation of 4. This input rate change enables the CDMA RX channelizer bank 7 to take the composite signal obtained from the RF front end receive section 30 at the common digitizing rate of (52*fc) or 63.8976 MHz through the S-P converter 59 and extract from it a series of digital I (in-phase) and Q (quadrature) channel signals having the CDMA based sample rate of (8*fc). The CDMA RX channelizer bank 7 further operates to supply the I/Q channelized digital signals generated therein to the corresponding set of baseband DSP units 13 for further processing and demodulation.
More specifically, the CDMA RX channelizer bank 7 has a plurality, N, of CDMA RX channelizers (only three shown) generally indicated by 92 , 94 , 95 . The CDMA RX channelizers 92 , 94 , 95 are each coupled externally to the output of the S-P converter 59 . The CDMA RX channelizers 92 , 94 , 95 have an identical architecture and mode of operation and will now be described below with reference to a single CDMA RX channelizer 92 .
The CDMA RX channelizer 92 of this example is coupled to receive the incoming digitized signal from the RF front end receive section 30 of FIG. 2 through the S-P converter 59 . More specifically, the incoming digitized signal generated by the RF front end receive section 30 of FIG. 2 as a single stream of digital pulses is converted back into a plurality of streams of digital pulses. The CDMA RX channelizer 92 has a coarse-tune NCO (numerically controlled oscillator) unit 60 with an input coupled externally to the output of S-P converter 59 and with I/Q outputs supplied to a CIC (cascaded integrator comb) filter 63 . The CDMA RX channelizer 92 also has a fine-tune NCO unit 67 where the respective I/Q outputs of the CIC filter 63 are coupled thereto. The fine-tune NCO 67 is, in turn, connected to a CSD FIR (canonic signed digit finite impulse response) filter 64 . The CSD FIR filter 64 is coupled to a pair of digital compensators generally indicated by 61 . The digital compensators 61 are coupled to an adder 157 which is also coupled to receive the AGC compensation signals from the RF front end receive section 30 for supplying a composite AGC signal 158 to the corresponding baseband DSP units 13 . The outputs of digital compensators 61 are coupled to an interpolator unit 65 to produce a digital channel I/Q signal with the required CDMA DSP receive rate for further processing by the corresponding set of baseband DSP units 13 .
In operation, the CDMA RX channelizer 92 is responsible for filtering and tuning the incoming digitized signal and adjusting its sample rate to meet the CDMA based sample rate of (8*fc) for extracting a single channelized digital signal in accordance with the CDMA air interface standard requirements.
More specifically, the incoming digitized signal is applied to the coarse-tune NCO unit 60 where it is initially separated into its I/Q signal components and coarsely tuned so as to align the desired signal's centre frequency to the CIC filter 63 for high rate decimation filtering. Fine tuning of the frequency of the incoming digitized signal is obtained with the fine-tune NCO unit 67 which operates to finely shift the spectrum of the digitized signal in frequency so as to match its associated centre frequency to that of the CSD FIR filter 64 for low rate decimation filtering. The CSD FIR filter 64 also operates to extract a single CDMA digital channel I/Q signal from the incoming digitized signal in accordance with the CDMA air interface standard and supply its respective I and Q components to the corresponding digital compensators 61 . The digital compensators 61 respectively scale the I and Q signal components to 4 bits each as is required by the baseband DSP units 13 . The scaling factor applied therein is combined in the adder 157 to the AGC compensation signals received from the RF front end receive section 30 of FIG. 2 for producing, the AGC composite signal 158 . This AGC composite signal 158 is supplied to the corresponding set of baseband DSP units 13 for system level metrics and in particular, for cell breathing.
The sample rate of the CDMA digital channel 4 bit I/Q signal is further adjusted to obtain the desired CDMA DSP receive data rate of 8*fc by coupling the rescaled I/Q signals to the interpolation filter 65 . For this example, the 52*fc digitized signal is processed through NCO units 60 , 67 and decimated in CIC filter 63 and CSD FIR filter 64 with respective decimation factors of 13 and 2 calculated above for the CDMA air interface standard. The individual digital channel I/Q signal is extracted from the digitized signal according to the CDMA air interface standard and obtained via the output of the interpolation filter 65 where it is supplied therefrom to the corresponding set of baseband DSP units 13 for demodulation and further processing.
Referring now to FIG. 7, the TDMA input rate change is also determined by dividing the CDMA-based common digitizing rate of (52*fc) with the 48.6 KHz TDMA DSP rate expressed in their prime number form. The division is carried out as follows:
common digitizing rate (52 * fc):
(2 16 ) * (3) * (5 2 ) * 13
TDMA DSP data rate (48.6KHz):
(2 3 ) * (3 5 ) * (5 2 )
TDMA rate adjustment (dividend):
26 * 8 *256/81 * 2
According to the above dividend, the TDMA rate change is obtained by decimating the incoming composite signal received from the RF front end receive section 30 at the common digitizing rate of (52*fc) or 63.8976 MHz by a factor of (26* 8*2) followed by a rational rate conversion of (81/256). This allows the TDMA RX channelizer bank 8 to receive the composite signal obtained at the common digitizing rate through the S-P converter 59 described above with reference to FIG. 4 and extract from it a series of digital I (in-phase) and Q (quadrature) channel signals having the TDMA DSP rate of 48.6 KHz. The I/Q channelized digital signals generated therein are supplied to the corresponding set of baseband DSP units 14 for further processing and demodulation. More specifically, the TDMA RX channelizer bank 8 has a plurality N of architecturally identical TDMA RX channelizers (only three shown) generally indicated by 97 , 98 , 99 which are coupled externally to the S-P converter 59 . The TDMA RX channelizer bank 8 will now be described in relation to a single TDMA RX channelizer 97 in a manner similar to that used for describing the CDMA RX channelizer bank 7 above with reference to FIG. 6 .
The TDMA RX channelizer 97 of this example has a coarse-tune NCO unit 68 , a CIC filter 70 and a fine-tune NCO unit 69 connected together in sequence. In addition, the TDMA RX channelizer 97 has the fine-tune NCO unit 69 coupled to a pair of digital compensators generally indicated by 79 which are, in turn, coupled to receive the AGC compensation signals from the receive section of the front end 30 through a logarithmic decoder 58 . The digital compensators 79 are coupled to a second CIC filter 71 which is, in turn, coupled an RRC (rational rate conversion) FIR filter 72 . The TDMA RX channelizer 97 also has the RRC FIR filter 72 coupled to an RC (rate change) FIR filter 73 which is externally coupled to the corresponding set of baseband DSP units 14 .
In operation, the TDMA RX channelizer 97 is responsible for responsible for filtering and tuning the incoming digitized signal and adjusting its sample rate to meet the TDMA DSP data rate of 48.6 KHz for extracting a single channelized digital signal in accordance with the TDMA air interface standard requirements.
More specifically, the desired frequency shift and TDMA DSP data rate of 48.6 KHz are obtained by first processing the incoming digitized signal through NCO units 68 , 69 and CIC filters 70 , 71 in a manner similar to that described above with reference to the CDMA RX channelizer 92 of FIG. 6 . For this example, the 52*fc digitized signal is decimated in the CIC filters 70 , 71 to respectively decimate by a high rate decimation factor of 26 and low rate decimation factor of 8 as calculated above for the TDMA air interface standard. The digitized signal is gain compensated with AGC compensation signals obtained from the received section of the RF front end 30 through the logarithmic decoder 58 and applied in the digital compensators 79 . The digital compensation factor applied therein is selected to cancel out the attenuation inserted in the RF front end receive section 30 (which is described above in reference to FIG. 3) so as to make the attenuation transparent to the corresponding set of baseband DSP units 14 . According to the decimation factors calculated above with reference to the TDMA air interface standard, the digitized signal is decimated further in the RRC FIR filter 72 with a rational rate conversion of (81/256) and also in the RC FIR filter 73 to operate the final decimation of 2 required to obtain the desired 48.6 KHz TDMA DSP data rate. The TDMA digital channel I/Q signal is extracted from the digitized signal according to the TDMA air interface standard and obtained via the output of the channel compensation FIR filter 73 to be supplied to the corresponding set of baseband DSP units 14 for further processing and demodulation.
Referring now to FIG. 8, the input rate change to be effected in the GSM RX channelizer bank 9 to adjust the rate of the incoming composite signal from 63.8976 MHz to the GSM DSP data rate of 541 . 666 KHz is determined by dividing the CDMA-based common digitizing rate of (52*fc) with the 541.666 KHz GSM DSP rate expressed in their prime number form as follows:
common digitizing rate (52 * fc):
(2 16 ) * (3) * (5 2 ) * 13
GSM DSP data rate (541.666KHz):
(2 2 ) * (5 6 )/3 * 13
GSM rate adjustment (dividend):
16 * 2 * 12/5 * 192/125 * 2
According to the above dividend, the GSM rate change is obtained by first decimating the incoming composite signal by a factor of (16*2) followed by two rational rate conversions, namely (5/12) and (125/192). This rate change enables the GSM RX channelizer bank 9 to take the composite signal obtained from the RF front end receive section 30 at the common digitizing rate of (52*fc) or 63.8976 MHz through the S-P converter 59 and extract from it a series of digital I (in-phase) and Q (quadrature) channel signals having the GSM DSP rate of 541.666 KHz. The I/Q channelized digital signals generated therein are supplied to the corresponding set of baseband DSP units 15 for further processing and demodulation. More specifically, the GSM RX channelizer bank 8 has a plurality N of architecturally identical GSM RX channelizers (only three shown) generally indicated by 101 , 102 , 103 and coupled externally to the S-P converter 59 . The GSM RX channelizer bank 9 will now be described in relation to a single GSM RX channelizer 101 in a manner similar to that used for describing the TDMA RX channelizer bank 8 above with reference to FIG. 7 .
The GSM RX channelizer 101 of this example has a coarse-tune NCO unit 74 , a first CIC filter 76 , a fine-tune NCO unit 75 , digital compensators generally indicated by 81 , a second CIC filter 77 , a logarithmic decoder 83 and a first RRC FIR filter 82 all interconnected identically to the NCO units 68 , 69 , CIC filters 70 , 71 , digital compensators 79 , the logarithmic decoder 58 and the RRC FIR filter 72 of the TDMA RX channelizer 97 described above with reference to FIG. 7 . However, the GSM RX channelizer architecture differs from that of the TDMA RX channelizer 97 in that the GSM RX channelizer 101 has its first RRC FIR filter 82 coupled to a second RRC FIR filter 80 . The RRC FIR filter 80 is, in turn, coupled to a droop compensator filter 78 which is connected externally to the corresponding set of baseband DSP units 15 .
In operation, the GSM RX channelizer 101 of this example functions similarly to the TDMA RX channelizer 8 described above with reference to FIG. 7 . In particular, the GSM RX channelizer 101 is also responsible for filtering and tuning the incoming digitized signal and adjusting its sample rate to meet the GSM DSP data rate of 541.666 KHz for extracting a channelized digital signal in accordance with the GSM air interface standard requirements. The GSM RX channelizer processes the (52*fc) digitized signal in NCO units 74 , 75 , CIC filters 76 , 77 to respectively effect a high rate decimation filtering by a factor of 16 and a low rate decimation filtering by a factor of 2. The digitized signal is gain compensated with AGC compensation signals obtained from the RF front end receive section 30 through the logarithmic decoder 83 in a manner similar to that described above with reference to the TDMA RX channelizer 97 of FIG. 7 . The desired GSM DSP data rate is obtained by further decimating the received signal with RRC FIR filters 82 and 80 by respective factors of (5/12) and (125/192) (see the decimation factors calculated above for the GSM air interface standard). The GSM digital channel I/Q signal is extracted from the digitized signal according to the GSM air interface standard and obtained via the output of the RRC FIR filter 80 . The GSM digital channel I/Q signal is then droop compensated in the droop compensator filter 78 before being supplied to the corresponding set of baseband DSP units 15 for demodulation and further processing.
Referring now back to FIG. 2, the transmit section 1 of the basestation transceiver designed according to this invention has a plurality of sets of baseband DSP units 20 , 21 , 22 with each DSP unit coupled to the telephony network to receive one of a plurality of digital channel signals. These sets of DSP units 20 , 21 , 22 digitally process and modulate the digital channel signals received and are connected to respective CDMA, TDMA and GSM TX channelizer banks 23 , 24 , 25 which are connected in series to an RF front end transmit section generally indicated by 29 for producing a composite digital signal representative of the content of the digitally processed and modulated channel signals which can also be referred to as the CDMA digital channel signals, the TDMA digital channel signals and the GSM digital channel signals. The RF front end transmit section 29 has a single D-A converter 108 coupled to a single wideband transmitter 107 which is connected to a transmit antenna 19 . The RF front end transmit section 29 is preferably installed on or near the transmit antenna 19 with a high speed optical link 130 connecting it with the remainder of the basestation to receive the composite signal and converting it into an analog form at a specified common D-A rate. This common D-A rate is selected to be the common digitizing rate of (52*fc) for reasons which are explained below. The resulting composite analog signal is then upconverted by the wideband transmitter 107 to the desired RF range before being transmitted via the transmit antenna 19 .
The composite digital signal supplied to the D-A converter 108 is obtained by combining the CDMA, TDMA and GSM digital channel signals respectively processed by the CDMA TX channelizer bank 23 , the TDMA TX channelizer bank 24 and the GSM TX channelizer bank 25 . In order to combine these digital channel signals and simultaneously convert them to an analog form, their respective data rate must be converted to a common D-A rate. However, this requires sample rate adjustment in the TX channelizer banks 23 , 24 25 and give rise to a number of considerations which must be taken into account in selecting a suitable common D-A rate. These considerations are the same as those discussed above in relation to the selection of a common digitizing rate and the method described thereafter is applicable here. As such, the common D-A rate is preferably selected to be equal to the common digitizing rate of (52*fc). Consequently, the CDMA, TDMA and GSM rate adjustment factors calculated above for converting the RX channelizer banks input rate of (52*fc) to the desired CDMA, TDMA and GSM DSP data rates can be used for determining the rate adjustment factors required for performing the reverse operation which consists of converting the rate of the CDMA, TDMA and GSM digital channel signals from their respective DSP data rate to the common digitizing rate of (52*fc). This approach is further described below for each of the CDMA, TDMA and GSM TX channelizer banks 23 , 24 , 25 with reference to FIGS. 9, 10 and 11 .
Referring firstly to FIG. 9, the rate change to be effected in the CDMA TX channelizer bank 23 to adjust the rate of the CDMA digital channel signals received from the corresponding baseband DSP units 20 at the CDMA DSP transmit data rate of (2*fc) to the common digitizing rate of (52*fc) is determined in relation to the rate adjustment factors calculated above for converting the CDMA RX channelizer bank input data rate from (52*fc) to (8*fc). In particular, for reducing the input data rate from (52*fc) to (2*fc), it can be observed that the CDMA RX channelizer bank 7 operates a decimation of (2*13). Based on this, the rate of the CDMA digital channel signals can be adjusted from (2*fc) to (52*fc) by interpolating each CDMA digital channel signal by a factor of 26 or (2*13). This enables the CDMA TX channelizer bank 23 to produce the CDMA digital channel signals at the (52*fc) rate and combine them with the TDMA and GSM digital channel signals also produced at the (52*fc) rate by respective TDMA and GSM combiners 24 , 25 (further detailed below with reference to FIGS. 10 and 11) for generating the composite digital signal at the (52*fc) common digitizing rate.
More specifically, the CDMA TX channelizer bank 23 has a plurality, N, of CDMA TX channelizers (only three shown) generally indicated by 119 , 120 , 121 each coupled externally to one of the DSP units 20 to receive a CDMA digital channel signal for locating its respective frequency spectrum in the frequency band used for CDMA transmit operations and adjusting its data rate from the CDMA DSP transmit rate of (2*fc) to the common digitizing rate of (52*fc). The CDMA TX channelizers 119 , 120 , 121 are interconnected in a cascaded chain arrangement to digitally combine the adjusted CDMA digital channel signals 159 , 160 , 161 in cascade. To properly operate this cascaded digital channel combining, the CDMA TX channelizers 119 , 120 , 121 are synchronized to account for the propagation delay incurred by each CDMA digital channel signal 159 , 160 , 161 and in particular to account for the cumulative propagation delay experienced by the CDMA digital channel signals 159 , 160 , 161 as they are passed through successive adders on their way to the D-A converter 108 . More particularly, the CDMA digital channel signals 159 , 160 , 161 generated by the CDMA TX channelizers 119 , 120 , 121 are combined in time synchronization with the CDMA digital channel signal 159 delayed more than the CDMA digital channel signal 160 which is itself delayed more than the CDMA digital channel signal 161 .
The CDMA TX channelizers 119 , 120 , 121 are also cascaded with the TDMA TX channelizer bank 24 for combining the CDMA digital channel signals 159 , 160 , 161 with the TDMA and GSM digital channel signals respectively produced by the TDMA and GSM TX channelizer banks 24 , 25 and received via the output signal 143 . More specifically, this output signal 143 is representative of the content of the TDMA and GSM digital channel signals respectively produced by the TDMA and the GSM TX channelizer banks 24 , 25 as the TDMA TX channelizer bank 24 itself is cascaded with the GSM TX channelizer bank 25 (this is further explained below in reference to FIGS. 10 and 11 ). The TDMA TX channelizer bank output signal 143 is received in the CDMA TX channelizer 121 last in the CDMA chain for producing, in the CDMA TX channelizer 119 first in the CDMA chain, and through the P-S converter 168 , the composite digital signal 130 which is representative of the content of the CDMA, TDMA and GSM digital channel signals.
The CDMA TX channelizers 119 , 120 , 121 have an identical architecture and similar mode of operation for each producing a CDMA digital channel signal at the common digitizing rate of (52*fc) and combining it with other CDMA, TDMA and GSM digital channel signals in the manner describe above. As such, only the CDMA TX channelizer 119 will now be described.
The CDMA TX channelizer 119 has an IIR (infinite impulse response) filter 122 coupled to receive a CDMA digital channel I/Q signal from the corresponding baseband DSP units 20 . The I/Q outputs of the IIR filter 122 are coupled to a CSD FIR filter 123 which is coupled to a fine-tune NCO unit 124 . The fine-tune NCO unit 124 supplies its I/Q outputs to a VCCI (variable cascaded comb integrator) 125 which is connected to a coarse-tune NCO 126 . The CDMA TX channelizer 119 also has a programmable delay 128 coupled to receive the real output of the coarse-tune NCO 126 through a variable gain unit 127 for producing the CDMA digital channel signal 159 having the common digitizing rate of 52*fc. The CDMA digital channel signal 159 is fed into a channel adder 129 where it is combined with a dither signal and the output signal of the preceding CDMA TX channelizer 120 to produce the composite digital signal 130 for the D-A converter 108 through a P-S converter 168 .
In operation, the CDMA TX channelizer 119 of this example receives the CDMA digital channel I/Q signal from the corresponding baseband DSP units 20 and functions to filter and shift its respective frequency spectrum into the frequency band specified for CDMA transmit operations and adjust its data rate from the CDMA DSP transmit rate of (2*fc) to the common digitizing rate of (52*fc). The CDMA TX channelizer 119 also operates to delay the CDMA digital channel signal 159 thus produced to synchronously combine it with the CDMA digital channel signals 160 , 161 such that the CDMA propagation delays are equalized. The CDMA digital channel signals 159 , 160 , 161 are also combined with the TDMA and GSM digital channel signals respectively produced by the TDMA TX channelizer bank 24 and the GSM TX channelizer bank 25 of the cascaded chain arrangement for generating the composite digital signal 130 .
More specifically, the CDMA digital channel I/Q signal received is initially applied to the I/Q inputs of the IIR filter 122 to be phase equalized. The CDMA digital channel I/Q signal is then processed in the CSD FIR filter 123 to be interpolated by a factor of 2 and have out of band suppression applied. This is followed in the fine-tune NCO unit 124 by a fine frequency shift of the frequency spectrum occupied by the CDMA digital channel I/Q signal. The CDMA digital channel I/Q signal is further interpolated in the VCCI 125 by a factor of 13 to effect the required interpolation of 26 . The frequency shift required to locate the CDMA digital channel I/Q signal in the frequency band used for CDMA transmit operations is completed with a wideband frequency shift operated by the coarse-tune NCO unit 126 for coarsely shifting the frequency spectrum of the CDMA digital I/Q signal. The coarse-tune NCO unit 126 also operates to digitally combine the I and Q signal components together and supply the resulting real signal to the variable gain unit 127 which is used to control the transmit power of its output signal. This output signal is then time delayed by the programmable delay 128 for aligning the CDMA digital channel signal 159 produced with the output signal of the preceding CDMA TX channelizer 120 . These two signals are then digitally combined in the digital adder 129 at the common digitizing rate together with the dither signal which is used to improve the performance of the D-A converter 108 (further described below in reference to FIG. 12) by randomizing the quantization errors introduced therein. Typically, only one dither signal needs to be on in the CDMA TX channelizer bank 23 and is added out of band so as to prevent degradation of the desired signals. The digital adder 129 produces, through the P-S converter 168 , the composite digital signal 130 which is representative of the content of the CDMA, TDMA and GSM digital channel signals.
Referring now to FIG. 10, the TDMA rate change to be effected in the TDMA TX channelizer bank 24 to adjust the rate of the TDMA digital channel signals received from the corresponding baseband DSP units 21 at the TDMA DSP data rate of 48.6 KHz to the common digitizing rate of (52*fc) is based on the rate adjustment factors calculated above for converting the TDMA RX channelizer bank input data rate from (52*fc) to 48.6 KHz. As noted before, this rate change is obtained by adjusting the TDMA RX channelizer bank input signal rate by (26*8*2*(81/256)) which corresponds to decimating the TDMA RX channelizer bank input signal by a factor of (26*8*2) or (16*26) followed by a rational rate conversion of (81/256). Based on this, the rate of the TDMA digital channel signals is adjusted in this example from 48.6 KHz to (52*fc) by interpolating each TDMA digital channel signal by a factor of (16*4*26) and operating a rational rate conversion of (64/81). This enables the TDMA TX channelizer bank 24 to produce the TDMA digital channel signals at the (52*fc) rate and combine them with the GSM digital channel signals received in the GSM TX channelizer bank 25 and also produced at the (52*fc) rate (further details below) for generating an output signal 143 having the (52*fc) common digitizing rate and representative of the content of the TDMA and GSM digital channel signals.
More particularly, the TDMA TX channelizer bank 24 has a plurality, N, of TDMA TX channelizers (only three shown) generally indicated by 131 , 132 , 133 each coupled externally to one of the DSP units 21 to receive a TDMA digital channel signal for locating its respective frequency spectrum in the frequency band used for TDMA transmit operations and adjusting its data rate from the TDMA DSP rate of 48.6 KHz to the common digitizing rate of (52*fc). The TDMA TX channelizers 131 , 132 , 133 are in time synchronization and are interconnected in a cascaded chain arrangement in a manner similar to that described above in relation with the CDMA TX channelizers 119 , 120 , 121 of FIG. 9, to digitally combine the adjusted TDMA digital channel signals 162 , 163 , 164 in cascade.
The TDMA TX channelizers 131 , 132 , 133 are also cascaded with the GSM TX channelizer bank 25 for combining the TDMA digital channel signals 162 , 163 , 164 with the GSM digital channel signals produced therein. More particularly, the GSM TX channelizer bank 25 generates an output signal 169 which is received in the TDMA TX channelizer 133 last in the TDMA chain for producing, in the TDMA TX channelizer 131 first in the TDMA chain, the output signal 143 representative of the content of the TDMA and GSM digital channel signals.
The TDMA TX channelizers 131 , 132 , 133 have an identical architecture and similar mode of operation for each producing a TDMA digital channel signal at the common digitizing rate of (52*fc) and combining it with other TDMA, CDMA, GSM digital channel signals in the manner describe above. As such, the TDMA TX channelizer bank 24 will now be described in relation to a single TDMA TX channelizer 131 in a manner similar to that used for describing the CDMA TX channelizer bank 23 with reference to FIG. 9 .
The TDMA TX channelizer 131 has an FIR filter 134 coupled to receive a TDMA digital channel I/Q signal from the corresponding baseband DSP units 21 . The I/Q outputs of the FIR filter 134 are coupled to an RCF (rate change filter) 135 which is coupled to a FCCI (fixed cascaded comb integrator) 136 . The I/Q outputs of the FCCI 136 are supplied to a fine-tune NCO unit 137 which is followed by a VCCI 138 , a coarse-tune NCO unit 139 , a variable gain unit 140 and a programmable delay 141 connected together in sequence to produce the TDMA digital channel signal 162 . The TDMA digital channel signal 162 is fed into a channel adder 142 where it is combined with a dither signal and the output signal of the preceding TDMA TX channelizer 132 to produce the output signal 143 for the CDMA TX channelizer bank 23 .
In operation, the TDMA TX channelizer 131 of this example receives the TDMA digital channel I/Q signal from the corresponding baseband DSP units 21 and functions to filter and shift its respective frequency spectrum into the frequency band specified for TDMA transmit operations and adjust its data rate from the TDMA DSP transmit rate of 48.6 KHz to the common digitizing rate of (52*fc). The TDMA TX channelizer 131 also operates to delay the TDMA digital channel signal 162 to remain in time synchronization with the TDMA TX channelizers 132 , 133 . As noted above, this is required for synchronously combining the TDMA digital channel signals 162 , 163 , 164 such that the TDMA propagation delays are equalized. The TDMA digital channel signals 162 , 163 , 164 are also combined with the CDMA and GSM digital channel signals to produce, in the CDMA TX channelizer bank 23 , the composite digital signal 130 .
More specifically, the TDMA digital channel signal received is initially applied to the I/Q inputs of the FIR filter 134 to be interpolated by a factor of 16. The TDMA digital channel I/Q signal is then processed in the RCF 135 with a rational rate conversion of (64/81) and interpolated further in the FCCI 136 by a factor of 4. The frequency shift required to locate the TDMA digital channel I/Q signal in the frequency band used for TDMA transmit operations is finely and coarsely effected by respective fine-tune NCO unit 137 and coarse-tune NCO unit 139 . The TDMA digital channel I/Q signal is further interpolated in the VCCI 138 by a factor of 26 to finalize the required TDMA rate change of (16*4*(64/81)*26) and obtain the desired (52*fc) data rate. The TDMA digital channel real signal is processed further in the variable gain unit 140 and the programmable delay 141 in a manner identical to that described above with respect to the CDMA TX channelizer 119 to adjust its transmit power and align the TDMA digital channel signal 162 produced with the output signal of the preceding TDMA TX channelizer 132 . These signals are then digitally combined in the digital adder 129 at the common digitizing rate together with the dither signal for producing the output signal 143 which is representative of the content of the TDMA and GSM digital channel signals.
Referring now to FIG. 11, the GSM rate change to be effected in the GSM TX channelizer bank 25 to adjust the rate of the GSM digital channel signals received from the corresponding baseband DSP units 22 at the GSM DSP data rate of 541.666 KHz to the common digitizing rate of (52*fc) is based on the rate adjustment factors calculated above for converting the GSM RX channelizer bank input data rate from (52*fc) to 541.666 KHz. As noted before, this rate change is obtained by adjusting the GSM RX channelizer bank input signal rate by (16*2*(5/12)*(125/192)) which corresponds to decimating the GSM RX channelizer bank input signal by a factor of (16*2) followed by two rational rate conversions, namely (5/12) and (125/192). Based on this, the rate of the GSM digital channel signals is adjusted in this example from 541.666 KHz to (52*fc) by interpolating each GSM digital channel signal by a factor of (2*16) and operating two rational rate conversions of (12/5) and (192/125). This enables the GSM TX channelizer bank 25 to produce the GSM digital channel signals at the (52*fc) rate for generating the output signal 169 having the (52*fc) common digitizing rate and representative of the content of the GSM digital channel signals.
More particularly, the GSM TX channelizer bank 25 has a plurality, N, of GSM TX channelizers (only three shown) generally indicated by 144 , 145 , 146 each coupled externally to one of the DSP units 22 to receive a GSM digital channel signal for locating its respective frequency spectrum in the frequency band used for GSM transmit operations and adjusting its data rate from the GSM DSP rate of 541.666 KHz to the common digitizing rate of (52*fc). The GSM TX channelizers 144 , 145 , 146 are in time synchronization and are interconnected in a cascaded chain arrangement in a manner similar to that described above in relation with the TDMA TX channelizers 131 , 132 , 133 of FIG. 10, to digitally combine the GSM digital channel signals 165 , 166 , 167 in cascade.
The GSM TX channelizers 144 , 145 , 146 have an identical architecture and similar mode of operation for each producing a GSM digital channel signal at the common digitizing rate of (52*fc) and combining it with other CDMA, TDMA and GSM digital channel signals in the manner described above. As such, the GSM TX channelizer bank 24 will now be described in relation to a single GSM TX channelizer 144 in a manner similar to that used for describing the TDMA TX channelizer bank 23 with reference to FIG. 10 .
The GSM TX channelizer 144 has an FIR filter 147 coupled to receive a GSM digital channel I/Q signal from the corresponding DSP units 22 . The I/Q outputs of the FIR 147 are coupled to a first RCF 148 which is coupled to a second RCF 149 . The GSM TX channelizer 144 also has a fine-tune NCO unit 150 , a VCCI 151 , a coarse-tune NCO unit 152 , a variable gain unit 153 , and a programmable delay 154 all interconnected identically to the NCO units 137 , 139 , the VCCI 138 , the variable gain unit 140 and the programmable delay 141 of the TDMA TX channelizer 131 described above with reference to FIG. 10 for producing the output signal 169 to the TDMA TX channelizer bank 24 .
In operation, the GSM TX channelizer 144 of this example receives the GSM digital channel I/Q signal from the corresponding baseband DSP unit 22 and functions to filter and shift its respective frequency spectrum into the frequency band specified for GSM transmit operations and adjust its data rate from the GSM DSP transmit rate of 541.666 KHz to the common digitizing rate of (52*fc). The GSM TX channelizer 144 also operates to delay the GSM digital channel signal 165 to remain in time synchronization with the GSM TX channelizers 145 , 146 . As noted above, this is required for synchronously combining the GSM digital channel signals 165 , 166 , 167 such that the GSM propagation delays are equalized. The GSM digital channel signals 165 , 166 , 167 are also combined with the CDMA and TDMA digital channel signals to produce, in the CDMA TX channelizer bank 23 , the composite digital signal 130 .
More particularly the GSM digital channel signal received is initially applied to the I/Q inputs of the FIR filter 147 to be interpolated by a factor of 2. The rational rate conversions of (12/5) and (192/125) are respectively operated in the first and second RCFs 148 , 149 . The GSM digital channel I/Q signal is further interpolated in the VCCI 151 by a factor of 16 to finalize the required GSM rate change of (2*16*(12/5)*(192/125)) and obtain the desired (52*fc) data rate. The frequency shift required to locate the GSM digital channel I/Q signal in the frequency band used for GSM transmit operations is finely and coarsely effected by respective fine-tune NCO unit 150 and coarse-tune NCO unit 152 . The GSM digital channel I/Q signal is processed in the variable gain unit 153 and the programmable delay 154 in a manner identical to that described above with respect to the TDMA TX channelizer 131 for producing the GSM digital channel signal 165 with its transmit power adjusted and in digital alignment with the output signal of the preceding GSM TX channelizer 145 . These two signals are then digitally added in the digital adder 145 at the common digitizing rate together with the dither signal for producing the output signal 169 representative of the content of the GSM digital channel signals.
Referring now to FIG. 12, the RF front end transmit section 1 receives the composite digital signal 130 generated by the TX channelizer banks 23 , 24 , 25 , converts it in the D-A converter 108 to an analog form and upconverts in the wideband transmitter 107 the resulting composite analog signal to the desired radio frequency range before transmitting it via the transmit antenna 19 . More specifically, the D-A converter 108 is coupled to receive the composite digital signal 130 through the S-P converter 170 . The output of the D-A converter 108 is supplied to an IF upconverter generally indicated by 179 which includes an IF mixer 171 and a band pass filter 172 . The IF upconverter 179 is connected to an RF upconverter and analog transmitter generally indicated by 180 for connection to the transmit antenna 19 of FIG. 2 . The RF upconverter and analog transmitter 180 has an IF-RF mixer 173 coupled to a band pass filter 174 which is connected to an amplifier 175 .
The D-A converter 108 , IF upconverter 179 and RF upconverter and analog transmitter 180 respectively derive their clock signal from the composite digital signal 130 . More specifically, the D-A clock signal 181 is obtained via a PLL 176 . The IF upconverter has an associated IF local oscillator signal 182 also derived through the PLL 176 and obtained with another PLL 177 connected in series with the PLL 176 . The RF upconverter and analog transmitter 180 receives its associated RF local oscillator signal with a PLL 178 connected in series with the PLL 176 .
In operation, the RF front end transmit section 1 receives the composite digital signal 130 generated by the TX channelizer banks 23 , 24 , 25 , converts it in the D-A converter 108 at the common digitizing rate of (52*fc) to an analog form and upconverts in the wideband transmitter 107 the resulting composite analog signal to the RF band located in the 1930 MHz to 1990 MHz frequency range allocated for US PCS for downlink operations. The composite analog signal thus converted is then transmitted via the transmit antenna 19 .
More particularly, the D-A converter 108 receives the composite digital signal 130 generated by the CDMA, TDMA and GSM TX channelizer banks 23 , 24 , 25 at the common digitizing rate of (52*fc) via the high speed optical link 104 (see FIG. 2) and through the S-P converter 170 . The D-A converter 108 converts the composite digital signal 130 with the D-A clock signal 181 operating at the common digitizing rate of (52*fc) and derived through the PLL 176 which operates in a manner similar to the PLLs described above in reference to FIG. 4 . The resulting composite analog signal has a bandwidth of 5 MHz and is fed to the IF upconverter 179 where it is upconverted to a first IF band extending from 110 MHz to 115 MHz with the IF local oscillator signal 182 set at 103.2192 MHz and also derived from the composite digital signal. The composite analog signal is further upconverted and amplified in the RF upconverter and analog transmitter 180 to the RF range allocated for US PCS downlink operations and extending from 1930 MHz to 1990 MHz. This upconversion is operated with the RF local oscillator signal 183 set to be in the 2040 MHz to 2105 MHz frequency range. The RF signal thus obtained is then supplied to the transmit antenna 19 for transmission.
While the common digitizing rate used by basestations of the present invention has been described above with reference to a particular set of air interface standards, further modifications and improvements to curtail the support to a subset of the air interface standards discussed above or to provide support for additional or different air interface standards which will occur to those skilled in the art, may be made within the purview of the appended claims, without departing from the scope of the invention in its broader aspect.
In particular, the common digitizing rate of the present invention has been selected in a manner described above to simultaneously support the CDMA, TDMA and GSM air interface standards. Furthermore, it is to be understood that a common digitizing rate other than 63.8976 MHz may be used to simultaneously handle CDMA, TDMA and GSM. As it becomes desirable to have more or different air interface standards simultaneously supported by basestations in accordance with this invention, it can be appreciated that a new digitizing rate will have to be calculated according to the method described therein.
Advantageously, the operational range of currently commercially available A-D and D-A converters such as the ones referenced above in relation to the RF front end receive and transmit sections are sufficient to handle the digitizing rate required to simultaneously accommodate CDMA, TDMA and GSM air interface standards. It can be further appreciated that a new common digitizing rate designated to support a particular set of air interface standards will have to be selected according to the present invention so as to be within the operational range of the A-D and D-A converters.
The selection of a new common digitizing rate will necessitate modifications in each RX channelizer bank which can be implemented in the manner prescribed therein to respectively adjust the data rate of the digitized signal received from the RF front end receive section at the new common digitizing rate to the DSP data rate standard specified by the corresponding air interface standard for extracting the channelized digital signals in accordance to each particular standard. It is to be understood that once a common digitizing rate is selected, the manner in which it is converted back to the proper rate for each standard is not unique. An example for CDMA, TDMA and GSM has been given, but different techniques may be employed.
Similarly, the TX channelizer banks will also have to be modified in the manner prescribed therein to respectively adjust the data rate of the digitally processed and modulated digital channel signals received from each set of baseband DSP units at the DSP data rate standard specified by the corresponding air interface standard to the new common digitizing rate for supplying the digital channel signals combined into a composite digital signal to the D-A converter at the new common digitizing rate. It is also to be understood that once a common digitizing rate is selected, the manner in which each rate is converted to the common digitizing rate is not unique. An example for CDMA, TDMA and GSM has been given, but different techniques may be employed. It can also be further appreciated that the new common digitizing rate designated to support a particular set of air interface standards will have to be selected in the manner prescribed therein so as to avoid any unnecessary complexity increase in the corresponding RX and TX channelizer banks.
Advantageously, the receive and transmit architectures of the basestation transceiver described above allow the support of diversity. Although the specific manner in which this can be implemented is beyond the scope of this invention, it can be appreciated that diversity can be achieved by simply replicating the entire signal path from the antenna to the DSP resources.
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A basestation transceiver simultaneously addressing multiple air interface standards with cost-effective and efficient allocation of the resources available at the transceiver. The invention significantly reduces the redundancy of the radio frequency equipment used in the transceiver by the use of a common digitizing rate selected to simultaneously accomodate all of the air interface protocols serviced.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to tufting machines and more particularly to a tufting machine wherein the needles are selectively engageable and are carried in needle modules characterized by opposing pairs of needle holders which retain needles in an in-line, or linear arrangement.
[0002] Tufting machines which produce carpet typically include a large frame having a head within which a rotatable mainshaft is mounted and from which needle driving structure is supported for reciprocation of a multiplicity of needles. The frame also includes a bed within which oscillating loopers or hooks are mounted for cooperating with the needles to form loops of yarn, knives being used in conjunction with the hooks to cut the loops in many tufting machines.
[0003] As the tufting art has developed, there have been a substantial number of innovations to obtain unique patterning effects. One such innovation has been to shift the needles laterally in accordance with a pattern. Another innovation has been to provide each needle with a sew/no-sew capability by mounting the needles on individual needle holders which are reciprocated selectively by either being latched to or disengaged from a reciprocating latch bar, the latter being reciprocably driven continuously from mechanism driven by the rotating mainshaft. When latched to the latch bar, the needle reciprocates into cooperation with the hook to form a loop. The latching occurs by means of latch pins on pneumatic cylinders driven in accordance with a pattern. Machines of this type are known as controlled needle machines, and when each needle is individually controlled in this manner, it is known as an individually controlled needle machine.
[0004] A significant development in the tufting art was to combine the individual controlled needle machine concept with the shifting needle concept, and to feed the backing material intermittently. This provides a tufting machine wherein the needles may be threaded with a number of different yarns, e.g., yams of different colors, and a needle having a yarn of a particular color may be inserted into the backing at any of a selected number of locations so that precise multi-color patterns may be produced similar to the fine woven carpets produced by looms. A machine of this type is illustrated in Bardsley, U.S. Pat. No. 5,653,184.
[0005] Over the years, a number of improvements have been made to this design. Specifically, Bardsley, U.S. Pat. No. 5,974,991 provided an improvement to tufting machines to provide needle holders which are individually latched to a reciprocating drive bar and include externally mounted springs, each spring biasing a ratchet clamp which provides for sew/no-sew capability for respective needles
[0006] Other tufting machine designs apart from individually controlled needle machines have employed opposing pairs of needle holders including Bardsley, U.S. Pat. No. 4,790,252 and Price, U.S. Pat. No. 4,815,402. The '252 patent allowed for only one, or the other, of the needle holders to be operated at by a particular push rod. This allowed for opposing needles to have different type yarns to create unique patterning effects. However, it was not possible to operate both pairs of opposing needle holders at the same time.
[0007] The '402 patent discloses that opposing pairs of needles may be moved simultaneously, but does not teach the orientation of opposing pairs of needles in a single linear relationship. Furthermore, the '402 patent does not contemplate opposing needle holders to be constructed in an easily replaceable needle module or modules.
[0008] Along with efforts to create unique patterning effects, an increase in detail has been desired. One way to increase the detail of the patterning effects is to decrease the gauge, i.e., the average distance between needle centerlines across the tufting machine. Although it appears that one would only need to reduce the diameter of the needles themselves and/or the thickness of the needle holders to decrease the gauge, this unfortunately weakens these components and increases their failure rate.
[0009] The '402 patent teaches one way of decreasing the gauge of tufting machines, but improvements to this basic design are necessary in many applications. For instance, the '402 patent contemplates two parallel and spaced apart rows of needles. The gauge on either of the two rows is half the gauge of the asserted gauge of the machine. The finer gauge is achieved as a result of staggered needles, not a single row of needles. While staggered needles may be satisfactory for some applications, tails of yarn formed by start up of needles in front row of needles are sewn through by rear needles. This is not desirable.
SUMMARY OF THE INVENTION
[0010] Consequently, it is a primary object of the present invention to provide a tufting machine having opposing needle modules providing a single row of needles arranged in a linear relationship.
[0011] It is another object of the invention to provide a needle module having two or more needle holders connected by guide plates to a mounting block adapted to be secured within a tufting machine.
[0012] It is a further object of the present invention to provide a needle module which supports two or more needle holders and a mounting block adapted to be secured within a tufting machine.
[0013] It is still a further object of the invention to provide a tufting machine with roughly half the gauge of adjacent needle holders.
[0014] Accordingly, the present invention provides a tufting machine having opposing sets of needle holders connected together in the form of needle modules. This configuration provides increased rigidity to the needle holders and is believed to speed the replacement of spent parts. The needle holders are preferably offset one from the other so that the gauge of the needle module may be half the gauge of either of the sets of opposing needle holders. Furthermore the needles from the opposing sets of needle holders are preferably arranged in a single linear relationship relative to one another.
[0015] Not only do needle holders gain stability from being connected to opposing needle holders, but the mounting block preferably connects the needle module to a post for lateral stability of the needle module. The connection to the post may allow for up and down adjustment of the needle module, while retaining the mounting block in a fixed position during operation of any of the individual needle holders.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings in which:
[0017] [0017]FIG. 1 is a fragmentary vertical cross section view taken substantially through a tufting machine constructed in accordance with the principles of the present invention;
[0018] [0018]FIG. 2 is a fragmentary vertical cross section view taken substantially through a needle module shown in the tufting machine of FIG. 1;
[0019] [0019]FIG. 3 is a top view of a portion of the needle module shown in FIG. 2, namely the mounting block connected to guide plates, the needle holders and spring rods have been removed; and
[0020] [0020]FIG. 4 is an elevational perspective view of the needle module shown in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] In most senses, the tufting machine to which the present invention is applicable has a conventional construction. Thus, a detailed explanation of the workings of the machine will not be provided here.
[0022] The tufting machine 10 has a head 12 within which is mounted a conventional drive mechanism for reciprocably driving a plurality of laterally spaced push rods 14 , one of which is illustrated in FIG. 1. The lateral direction is defined as transverse relative to the longitudinal direction in which a base material is being fed through the machine from the front to the rear thereof, as hereinafter described. The details of the drive mechanism within the head are not required for a disclosure of the present invention, but may be obtained from the disclosure in U.S. Pat. No. 3,882,432 among others.
[0023] Adjacent the lower end of each push rod 14 is a yoke 18 somewhat similar to the yoke utilized in U.S. Pat. No. 4,815,402. The yoke 18 has a spanning member 20 secured to the push rod 14 , and a pair of downwardly depending limbs 22 , 24 spaced apart in the direction from front to rear of the machine. A laterally elongated latch carrying bar 26 having a substantially L-shaped cross section configuration is connected to the lower end of the limb or limbs 22 while a similar latch carrying bar 28 is connected to the lower end of the limb or limbs 24 . The latch carrying bars 26 , 28 have latch pins 30 , 32 which may be extended from within the latch carrying bars 26 , 28 as shown in FIG. 1 in a similar manner as described in the '402 patent to selectively move individual needle holders 42 , 44 up and down as described in further detail below.
[0024] The needle module 40 is shown in FIG. 2. The needle module 40 is comprised of at least two, and preferably more needle holders 42 , 44 which are on opposing sides of tufting axis 46 . FIG. 1 shows at least three needle holders 42 , 44 , 48 while FIG. 3 contemplates each needle module 40 having thirty five needle holders 42 , 44 disposed one per slot 50 or slot 52 in the guide plates 54 , 66 . Needle holder 42 is one of a set that opposes needle holder 44 , 48 about the tufting axis 46 .
[0025] [0025]FIG. 2 shows the needle module 40 comprised of a plurality of needle holders 42 , 44 which are connected to needles 58 . Tufting axis 46 is perpendicular to the tufting row 60 , shown in FIG. 4, to create a tufting plane wherein the needles 58 are substantially co-linear. As can be seen in FIG. 4, opposing needle holders 42 , 44 are constructed to overlap along base portions 62 , 64 so that the needles 58 may be arranged in a co-linear relationship.
[0026] Referring back to FIG. 2, one or more guide plates 54 , 66 are utilized to provide lateral support to the needle holders 42 , 44 while allowing the needle holders to move up and down within slots 50 , 52 in the guide plate.
[0027] The guide plates 54 , 66 shown in FIG. 3 are configured to work adjacent to one another such as containing a plurality of needle holders 42 and 44 . The guide plates have interfitting edges 68 , 70 which cooperate with one another to allow there to be no decrease in gauge where the adjacent guide plates 54 , 66 contact one another. The guide plates 54 , 66 are also preferably machined so that slots 50 substantially surround at least three sides of a needle module, while slots 52 may or may not be as encompassing as slots 50 are illustrated.
[0028] In order to assemble a needle module 40 , the needle holders 42 , 44 , are fitted with needles 58 and placed in the slots 50 , 52 of the guide plates 54 , 66 . Rods 72 , 74 are then placed through bores 76 , 78 in the base 62 , 64 of the needle holder. The rods 72 , 74 have compression spring members 80 , 82 . The compression spring members 80 , 82 allow for the spring members 80 , 82 and/or rods 72 , 74 to connect into caps 84 , 86 on the needle holder 42 , 44 by compressing the members 80 , 82 and inserting the rods 72 , 74 . The caps 84 , 86 have bores 88 , 90 which receive one of the spring members 80 , 82 or rods 72 , 74 . The caps 84 , 86 may be integral to the needle holder 42 or 44 or may connected thereto. The caps 84 , 86 or other portion of needle holder 42 or 44 may have ledges 92 , 94 which limit the travel of the needle holder 42 or 44 relative to the latch carrying bars 26 , 28 illustrated in FIG. 1 or other portions of the limbs 22 , 24 in a vertical direction. These ledges 92 , 94 may also assist in returning the needle holders 46 , 48 to top on release of latch pin 30 , 32 .
[0029] The guide plates 54 , 66 are connected to a mounting bar 96 such as with bolts 98 , 100 or otherwise. The mounting block arrangement provides horizontal stability to the needle holders 42 , 44 and thus to the needles 58 during tufting operation.
[0030] In prior art constructions, such as illustrated in FIG. 1 of U.S. Pat. No. 5,974,991, the only additional horizontal stability was provided by arm 26 . While this improvement is also present as arm 110 , it has been found that horizontal stability closer to the needles 58 is also advantageous. Guide 112 may also provide some horizontal stability for needle modules 42 and thus for the needle module 40 .
[0031] [0031]FIG. 3 show detail concerning the mounting block 96 and top plate 114 which is held by bolt 98 into mounting block 96 . Bottom plate 116 is utilized in a similar manner with bolt 100 to secure the guide plates 54 , 66 there between. The guide plates 54 , 66 are substantially parallel to one another and connected at spaced apart portions on the mounting block 96 .
[0032] [0032]FIG. 1 illustrates the operation of the tufting machine 10 . During operation the push rod 14 reciprocates up and down, thereby driving yoke 18 and limbs 22 , 24 up and down. The plurality of latch pins 30 , 32 are preferably individually controlled in order to tuft a desired pattern onto the backing 106 . When the latch pins 30 , 32 are extended into receivers, illustrated as channels 115 , of the needle holders 42 , 44 the needles 58 connected to the latched needle holders 42 , 44 are driven through the backing with yarn 118 , 120 .
[0033] If a particular needle holder 48 is not latched in its respective channel 115 during the downward stroke of the push rod 14 , the respective needle 58 carried by the needle holder 48 is not driven through the backing 106 for that particular stroke of the push rod 14 . Needle holders 42 , 44 have been latched, needle holder 48 has not been latched.
[0034] The mechanics of the needle module 40 during operation may be better understood by examining the enlarged illustrations in FIGS. 2 and 4. FIG. 2 shows needle holders 42 , 44 in a down position relative to the guide plates 54 , 66 , as well as the mounting bar 96 . The compression member 80 , 82 are at least partially compressed and the position would result in the needles 58 being driven through the backing (not shown in this Figure); this is an engaged position since the spring members 80 , 82 would be more compressed than when disengaged as shown by needle holder 48 in FIG. 1. FIG. 4 shows needle modules 42 , 44 in an up position relative to the guide plates 54 , 66 , and the mounting bar 96 . The spring members 80 , 82 are not as compressed in FIG. 4 as they are in FIG. 2. Note how the mounting bar 96 and guide plates 54 , 66 are lower in FIG. 4 than in FIG. 2. The spring members 80 , 82 in FIG. 4 preferably are still under some compression so that the rods 72 , 74 are retained relative to the needle holders 42 , 44 since the rods 72 , 74 assist in maintaining the needle holders 42 , 44 in position relative to the guide plates 54 , 66 and thus the mounting block 96 .
[0035] As specific needle holders 42 , 44 are latched and driven to tuft, these particular needle holders 42 , 44 are driven downwardly while the guide plates 54 , 66 , the mounting bar 96 , and the needle holders 48 not latched remain stationary. In the latched needle holders 42 , 44 , the spring members 80 , 82 are compressed and the needle holders 42 , 44 continue through the downward stroke of the push rod 14 . On the upward stroke of the push rod 14 , the needle holders 42 , 44 may be unlatched or continue to be latched for another stitch. A bridge plate 122 may add to the stability of the guide plates 54 , 66 and thus to the needle module 40 .
[0036] Numerous alternations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.
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A tufting machine configured to provide needles co-linearly along a tufting plane from opposing needle holders provided in a needle module. The needle holders may be selectively latched with latch pins connected to limbs extending from a yoke connected to the push rod of the tufting machine. The needle holders are biased in a dis-engaged position with compression springs which extend between caps on the needle holders and a guide plate which locates the needle holders laterally while spacing the opposed needle holders from one another.
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This is a divisional of copending application Ser. No. 08/010,932, filed on Jan. 29, 1993, now U.S. Pat. No. 5,340,797.
BACKGROUND OF THE INVENTION
This invention was developed at least in part under U.S. Air Force Contract F19628-91-C-0082, and the U.S. government has certain rights in this invention pursuant to this contract.
The present invention relates generally to a superconductor material. More particularly, the invention relates to a textured, high temperature superconductor ceramic ("HTSC") material and a method of producing this material at low temperatures.
High temperature superconducting ceramics (HTSC) are intrinsically weak and brittle materials. In addition, conventional ceramic processing of these materials produces polycrystalline bodies which have low critical current densities (j c , in DC measurements) and high surface resistivities (R S , in RF measurements). Commercial applications of these materials require components that exhibit high j c and/or low R s values as well as the capability of producing mechanically strong and easy to manufacture components. Due to the materials' low mechanical strength, commercially useful structures cannot be produced without the use of a substrate to impart strength and toughness to the superconductor. This is especially true for lower frequency RF devices that will require the superconductor to be formed into relatively large, complex shapes. HTSC thin films have been shown to have high current densities and low R s values. However, these films are not useful for low frequency RF applications because they require expensive single crystal substrates (typically, LaAlO 4 or SrTiO 4 ) and can only be formed into planar structures with dimensions under a few inches.
Bulk HTSC materials with highly textured microstructures can exhibit the level of electrical performance required for commercial applications. For YBa 2 Cu 3 O 7-x , such textured microstructures are produced using a method called peritectic recrystallization or, more commonly, "melt-texturing". In this process, "textured" YBa 2 Cu 3 O 7-x is produced by crystallizing this compound out of its peritectic mixture of Y 2 BaCuO 5 plus a Ba/Cu-rich liquid. Many variations of this technique have been described, and it is commonly practiced in laboratories throughout the world. However, the process remains essentially the same as that originally developed in 1988.
The melt-tearing process typically involves heating a sample above the peritectic temperature (1015° C. in air) to decompose the YBa 2 Cu 3 O 7-x into Y 2 BaCuO 5 plus liquid. This mixture is cooled slowly through the peritectic temperature allowing YBa 2 Cu 3 O 7-x to crystallize. When this cooling is performed in the presence of a thermal gradient, the YBa 2 Cu 3 O 7-x grains preferentially grow parallel to the gradient and a "teared" microstructure results. The slow cooling keeps the nucleation rate of YBa 2 Cu 3 O 7-x low, resulting in the formation of a small number of nuclei. As a result, the YBa 2 Cu 3 O 7-x grains can grow to very large sizes before impingement; and if the cooling is performed in a thermal gradient, the grains will be highly aligned. In the originally developed process samples were measured to have critical currents of up to 17,000 A/cm 2 in self-field with only a small magnetic field dependence. Improvements to this process (which have included the production of continuous lengths of melt-textured filaments) have resulted in measured current densities as high as 140,000 A/cm 2 in self field and 44,000 A/cm 2 in a 1 Tesla field at 77K.
While the melt-texturing process has proven to be very effective in the fabrication of bulk YBa 2 Cu 3 O 7-x having properties approaching those of thin film materials, it has substantial drawbacks. First, melt-texturing is essentially a crystal growth process in which the rate of material production is controlled by the velocity of the crystallization front. In the case of YBa 2 Cu 3 O 7-x crystallizing out of its peritectic mixture, the crystallization rate is extremely sluggish. Even in extremely large thermal gradients (10 7 K/m) growth rates of only 1.2 cm/hr have been achieved. A second problem, of particular importance to texturing thick film structures, is the fact that the melt-texturing process requires processing at temperatures above 1000° C. in the presence of the extremely reactive peritectic liquid. This severely limits the choice of substrate materials that can be used without reacting with the superconductor. To date, only zirconia and magnesia have been used with any degree of success, and these ceramics are expensive and difficult to process.
It is therefore an object of the invention to provide an improved method of producing a high temperature superconductor (HTSC) material.
It is a further object of the invention to provide a novel method of producing an HTSC material at relatively low temperatures with very high rate of production.
It is another object of the invention to provide an improved method of producing HTSC structures on relatively inexpensive substrates.
It is yet a further object of the invention to provide a novel HTSC article of manufacture.
It is still an additional object of the invention to provide an improved method of manufacturing HTSC material and an article of manufacture having relatively intricate patterns formed directly from the process.
It is still another object of the invention to provide a novel HTSC article of manufacture of an intermediate phase state having minimal liquid involved in its manufacture.
Further objects and advantages of the present invention, together with the organization and manner of operation thereof; will become apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings, wherein like elements have like numerals throughout the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a 40X magnification microstructure of reactively textured YBa 2 Cu 3 O 7-X on silver buffered stainless steel;
FIG. 2 shows a reactively textured YBa 2 Cu 3 O 7-x on a silver substrate at 40X magnification;
FIG. 3 illustrates a conventional peritectic recrystallized thick film microstructure on a zirconia substrate;
FIG. 4A illustrates an exemplary rocking angle X-ray diffraction curve showing the highly textured nature of an HTSC material prepared by one of the methods of the invention; and FIG. 4B shows X-ray diffraction patterns for three crystalline YBa 2 Cu 3 O 7-x samples;
FIG. 5 illsutrates a pseudobinary phase diagram of YBa 2 Cu 3 O 7-x and 3BaO0.5CuO; and
FIG. 6 shows surface RF resistivity extrapolated to 1 GHz for YBa 2 Cu 3 O 7-x specimens of the invention, a prior art sintered YBa 2 Cu 3 O 7-x and Cu.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A process in accordance with one form of the invention involves the crystallization of YBa 2 Cu 3 O 7-x out of a metastable liquid formed by rapidly introducing a non-equilibrium mixture of Y-, Ba-and Cu-compounds (mixed in the appropriate stoichiometry) into a combination of temperature and a gas atmosphere in which YBa 2 Cu 3 O 7-x is the thermodynamically stable phase. Two general variations of this process have been successfully demonstrated. In the first general method of preparation, Y 2 O 3 , CuO, and BaCO 3 powders are mixed in a molar ratio of 0.5:3.0:2.0 and are heated in a CO 2 rich atmosphere to approximately 850° C. to 890° C. The atmosphere is then changed to 2 tort of pure oxygen. The use of a CO 2 -rich atmosphere during heating suppresses the decomposition of BaCO 3 and consequently prevents YBa 2 Cu 3 O 7-x from forming prematurely. When the atmosphere is rapidly changed to a reduced pressure oxygen environment, the reaction mixture begins to decompose to a partially molten state out of which YBa.sub. 2 Cu 3 O 7-x crystallizes.
In a second general method of preparation, a prereacted, phase-pure YBa 2 Cu 3 O 7-x powder is heated to approximately 850° C. to 890° C., also in a CO2-rich atmosphere. Without limiting the scope of the invention, it is believed the presence of the CO 2 causes the YBa 2 Cu 3 O 7-x to decompose into a complex mixture of oxides and oxycarbonates. As for the first general method, the atmosphere is changed at temperature to a reduced pressure oxygen containing atmosphere, which causes this mixture to decompose into the partially molten state from which YBa 2 Cu 3 O 7-x can crystallize.
In accordance with one form of the invention, this `reactive texturing` process is preferably carried out on either a silver foil or a base metal, such as a stainless steel, which has been electroplated with either silver or silver with a nickel intermediate layer. In this embodiment the silver or silver/nickel buffer layers are necessary since YBa 2 Cu 3 O 7-x and its precursors are relatively active compounds which react strongly with most base metals. Silver is relatively inert with respect to YBa 2 Cu 3 O 7-x . This silver or silver/nickel buffer layer is preferably at least 0.002" thick to protect the superconductor. Base metals which have proven satisfactory include stainless steels, such as 302 stainless steel, 304 stainless steel, 316 stainless steel and also Inconel 600. The process has been practiced on a variety of shapes, including discs, tubes, wires and coils. Copper can also be used in this temperature range. The successful use of copper as a substrate requires use of an appropriate intermediate metal which will prevent interdiffusion of copper, silver and oxygen.
The substrate can be coated with the precursor slurry of appropriate stoichiometry using either painting, dipping, spraying, or any other technique currently used to apply thick film coatings or patterns. It has been determined that the preferred thickness of this applied coating is about 0.002" to 0.008". The preferred thermal processing has three steps:
1. Binder/organic removal. Heating of the coating is preferably carried out in a reduced total pressure oxygen environment (e.g., 2 torr of oxygen) heated at a rate of between 30° C./hr and 300° C./hr from room temperature to a temperature between 350° C. and 500° C. which is sufficient to removal the volatile components of the precursor paint.
2. Reaction suppression/precursor formation. Heating of the coating is preferably performed at a rate of about 300° C./hr. in a nitrogen atmosphere containing between at least about 0.8% and 2.8% CO 2 . One can use higher pressures of CO 2 , but such higher pressures are more than needed to suppress the decomposition of BaCO 3 or initiate the decomposition of YBa 2 Cu 3 O 7-x . The CO 2 can be mixed with any inert gas, such as N 2 , argon or helium. The temperature is preferably between the temperature of the binder removal stage and the temperature of the crystallization stage. These temperatures are sufficient to suppress the formation of YBa 2 Cu 3 O 7-x in the case of an oxide/carbonate precursor or decompose the YBa 2 Cu 3 O 7-x precursor to an appropriate mixture of oxides and oxycarbonates.
3. Crystallization. A preferred window for crystallization of YBa 2 Cu 3 O 7-x exists between about 850° C. and 900° C. in an atmosphere of about 1 to 3 torr of oxygen, although the oxygen pressure can range up to one atmosphere pressure. Below about 850° C., the grain sizes are greatly reduced in size. It should also be noted that at higher oxygen partial pressures, the process temperature increases such that at 0.21 atm. oxygen the temperature of treatment would be about 975° C. Preferably the process temperature is maintained below the melting point of the silver containing substrate. Most preferably, therefore, the pressure of oxygen is kept below about 50 torr to operate at a temperature below 925° C. (the melting point of silver at 50 torr). One can choose to perform the process by slowly increasing the temperature within this window during the crystallization process as opposed to using a simple isothermal hold. Either procedure is acceptable.
In the above described preferred process an intermediate product, or article of manufacture, is obtained. In the conventional melt texturing process the peritectic zone (region P in FIG. 5) encompasses the region of the phase diagram involved in producing the desired YBa 2 Cu 3 O 7-x . In this conventional method the amount of liquid present is quite large throughout the processing temperature range (about 1015° C. then cooled slowly through the peritectic temperature of 1013° C.). On the other hand in the instant invention, rather than having an intermediate product of solid material and a substantial percentage of peritectic liquid, the intermediate product is primarily a solid and a small fraction of a eutectic liquid (not a peritectic liquid). Since the reactants are metastable, the liquid that forms is the lowest melting liquid in the Y-Ba-Cu-O system, that is, the ternary eutectic. Substantial advantages result from being able to prepare textured YBa 2 Cu 3 O 7-x without excess liquid present. One such advantage is the ability to cast well defined solid patterns without need of liquid barriers in place. A desired pattern can be disposed on a substrate, such as by applying a thick film slurry in a desired pattern; and then the YBa 2 Cu 3 O 7-x can be formed by the method of the invention without substantial liquid flowage causing loss of the shape of the desired pattern. Thus, the intermediate product of the invention formed at about 850°-900° C. does not have the undesirable large liquid component present in the conventional intermediate product formed in the peritectic region.
A process has been described herein which produces textured YBa 2 Cu 3 O 7-x microstructures, as in the peritectic recrystallization method. However, unlike peritectic recrystallization, the instant method produces these microstructures at low temperatures (less than about 900° C.) and in relatively short times (less than about 1 hr compared to 10-15 hours for conventional melt texturing). This combination of low temperatures and short times enables the use of relatively inexpensive and easy to form base metal substrates that substantially reduce the potential cost of the component. This cost reduction makes this process much more attractive for the commercial application of HTSC components. This process is especially attractive for the fabrication of three dimensional RF resonant structures which are the fundamental components of numerous RF devices such as filters, oscillators and combiners. As can be seen in FIG. 6, the resulting YBa 2 Cu 3 O 7-x exhibits a substantially improved RF resistivity over both conventional copper and over a prior art YBa 2 Cu 3 O 7-x prepared by sintering and disposed on a silver substrate.
The following are nonlimiting examples of methods of preparing HTSC materials.
EXAMPLE 1
A mixture of Y 2 O 3 , CuO, and BaCO 3 was mixed in turn with an acrylic binder, a sorbitan trioleate dispersant, and an n-butanol/xylene solvent to make precursor `paint`. Other suitable carrier formulations can also be used as understood in the art. This paint was then applied to a silver foil using a paint brush. The resultant dried coating was 0.008" thick. This sample was then placed in a controlled atmosphere furnace, heated in 2 torr of oxygen at 60° C./hr to 350° C. to insure adequate removal of the organic components of the paint. The atmosphere of the furnace was then changed to 0.9% CO 2 in nitrogen, and the sample was heated to 900° C. at a rate of about 300° C./hr. The atmosphere of the furnace was again changed to 2 torr of oxygen, and the sample was held at temperature for 1 hour. This treatment resulted in a textured, crystallized YBa 2 Cu 3 O 7-x microstructure.
EXAMPLE 2
A commercial YBa 2 Cu 3 O 7-x powder was mixed with an acrylic binder, a sorbitan trioleate dispersant, and an n-butanol/xylene solvent to make a precursor `paint`. This paint was applied to a 304 stainless steel disc, a 316 stainless steel disc, and an Inconel 600 disc (all 1.125" diameter and previously electroplated with 0.002" of silver) with a paint brush. The resultant dried coating was, in all cases, about 0.004 to 0.005" thick. All three samples were then placed in a controlled atmosphere furnace, and heated in 2 torr of oxygen at 60° C./hr to 350° C. to insure proper removal of the organic components of the paint. The atmosphere of the furnace was then changed to 1.1% CO 2 in nitrogen, and the sample was heated to 880° C. at a rate of 300° C./hr. The atmosphere of the furnace was again changed to 2 torr of oxygen, and the furnace temperature was slowly increased at a rate of 25° C./hr to 900° C. This treatment resulted in a textured, crystallized YBa 2 Cu 3 O 7-x microstructure for all samples.
EXAMPLE 3
A variety of starting materials different from those used in Examples 1 and 2 also proved satisfactory. These starting materials included: (1) phase pure YBa 2 Cu 3 O 7-x with 22% Y 2 BaCuO 5 , (2) YBaSrCu 3 O 7-x with 22% Y 2 BaCuO 5 , (3) a CuO rich commercially available YBa 2 Cu 3 O 7-x and stoichiometric YBa 2 Cu 3 O 7-x . All of these starting materials were used successfully in implementing the methods described in Examples 1 and 2.
EXAMPLE 4
Any one of the above example procedures was followed and the pattern of the original starting material remained substantially the same after preparing YBa 2 Cu 3 O 7-x . This was compared to conventionally prepared YBa 2 Cu 3 O 7-x (peritectic processing) which showed substantial liquid flowage and loss of the spatial pattern of the original starting material.
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A high temperature superconductor and composite structure. A superconductor is disposed on a silver substrate without interdiffusion. The superconductor is formed by heating to a temperature not exceeding the peritectic point of the superconductor material, providing an oxidizing atmosphere while not exceeding the melting point of silver and disposing the superconductor on the silver substrate.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to arrangements for controlling access by one person to a page of the World Wide Web provided by a second person.
[0003] 2. Summary of the Prior Art
[0004] When someone attempts to access a Web site provided on an appropriate server, arrangements are already known in which there is some control over the access permitted. Although many Web-sites permit people accessing those sites to view any page of the site, it is also known to provide more limited access arrangements. For example, access to the Web-site or a part of it may be permitted only on input of a suitable password. In general, however, such known systems of access control have been limited. It is also known to permit access based on the source from which access is requested. The computer from which a person is seeking access has an appropriate unique identifier (such as its IP number) and access is permitted when that identifier corresponds to one for which the server has already been set to identify. In each case, the access control is determined by an input (password or computer identity) from the person seeking access. These systems do not permit a third party to control the access.
[0005] Once a person has accessed a Web-site, normal arrangements permit that person to access pages of the Web-site in a way determined by the person accessing the Web-site. There may be arrangements for permitting the order in which pages can be looked at, but the choice of when to change from one page to another is, in existing systems, either pre-programmed or under the control of the person accessing the Web-site. Thus, if a third party provides that Web-site, the third party cannot control, which Web page is being looked at, and thus what the person is seeing. This can be a problem in situations where the third party is in contact with the person accessing the Web-site via some other route, e.g. by telephone, and is discussing the Web-site with the person accessing it. The third party cannot be sure that the person accessing the Web-site is looking at the right pages. There are arrangements to permit a third party to track the activity of a person accessing a Web-site, i.e. to be told which part of the Web-site the person has accessed, after they have accessed it, these arrangements do not permit the third party of influence the person except passively.
[0006] This problem may be further compounded by the fact that Web pages take time to down-load from the Web-site to the computer of the person seeking access, and thus again the third party does not know whether the person accessing the Web-site can see relevant information on a particular Web page, or not.
[0007] It is known to provide Web-sites in which Web pages advance themselves to change the displayed content. There are three known ways of doing this. The first one is known as HTTP Meta-refresh but has the disadvantage that the time of successive page advancements is fixed. A similar disadvantage is obtained with the second method for advancing Web pages, known as JavaScript (ECMAscript). It is also known to use Applets, but the use of applets decrease the system security, and are therefore often disabled.
SUMMARY OF THE INVENTION
[0008] The present invention seeks to develop arrangements for controlling access of a person to a Web-site, and in particular to permit a third party to control that access. The present invention has several aspects, concerned with different features of such control.
[0009] For the ease of subsequent description, a person connecting to a Web server to retrieve information for a Web-site will be referred to as a “client”. A person connecting to the Web server to control access of a client to the Web server will be referred to as a “agent”. In commercial situations, agents may be members of an “agent group”, being a group of agents from the same organisation or company. Furthermore, although references shall be made herein to “Web pages” accessible at a server, it is to be understood that this terminology is intended to include any form of information (such as multi-media information) accessible from a Web site and viewable on a browser. The term “Web page” is not intended to be limited to information embedded in a Web page.
[0010] The first aspect of the invention is concerned with permitting an agent to regulate, in real time or as nearly so as the Internet permits, the degree of access of a client to a Web-site or sites. At its most general, this aspect proposes that the agent is presented with information identifying the client and can vary the degree of access in a freely selectable way. At any time, the agent can vary the degree of access permitted. Thus, when the client seeks to access the Web-site they are required to communicate information by which they can be identified, and then the agent is presented with the identifying information to permit the agent to determine whether or not that client should access the Web-site, the agent determines the degree of access and is able at any time to vary that access.
[0011] The communication of information from the client may occur in one of two ways. It is possible for the client to input the information and for the information then to be transmitted to the agent. Alternatively, where the client and agent are in contact via some other route, for example by telephone, data may be presented to the client which is then communicated to the agent via that other route. The information is not a password, in the sense of a predetermined item which, if correctly input, determines the permitted degree of access. The information itself does not determine the degree of access but instead provides a way for the agent to identify the client i.e. to distinguish one client from another. The degree of access is determined by the agent and thus, unlike a password arrangement, the degree of access can vary with time as the agent chooses.
[0012] Since the aim of this aspect of the present invention is to permit the client to access an appropriate Web site, or selected pages thereof, there is not a direct link via the Internet between the client and agent, but instead both are in communication with a common server. That server may contain a database identifying clients, and be under the control of the agent. That server may also communicate with a secure data storage, and the server may then retrieve data from that storage only when the client's information matches that stored in the database, and the agent has authorised such access. Thus the client information stored is accessible by the agent and the agent controls the server to determine the degree of access. The agent may at any time vary the degree of access and the server can determine that the correct client is given that degree of access because of the identification of the client which is present on the server.
[0013] Thus, the database may be considered as storing a plurality of client sessions, and the agent is presented with a list of such sessions and can select and deselect any or all sessions, and can vary the degree of access for any or all sessions.
[0014] The database may comprise one or more memory locations for short-term data storage, such as a state register or the like, and/or one or more memory locations for long-term data storage (e.g. archiving).
[0015] The next aspect of the invention proposes that the agent is able to change the Web page which the client is accessing without requiring the client to trigger that intervention. It would be possible for the agent to change the Web page which the client is accessing by means of software downloaded on to the client's computer but this has security implications for the client, and is therefore undesirable. Instead, this aspect of the invention proposes that the client and agent each access a common server, and instructions from the agent to that server then control which Web pages the client sees. This obviates the need for the client computer to employ specialist software other than that employed in standard HTML compliant browsers, since it is the common server that is controlled by the agent and not the client computer.
[0016] Normal Web browsers only permit requests to be transmitted from the client's computer to a server to which that computer is connected, and therefore it is not normally possible for the agent directly to control what is requested by the client. However, in this aspect, the client controls the content of the Web page which is sent to the client in response to a request from the client, thereby permitting the agent to control the Web page seen by the client without the agent controlling the client's computer. Requests are repeatedly and regularly transmitted from the client's computer to the server, and the agent controls how the server responds to such requests. The request may simply cause the current information to be resent, but this can cause a flickering of the client's screen.
[0017] Therefore, it is preferable that Web pages are provided to the client which contain at least two frames, one of which contains the information that the client is to see and the other (which is not normally visible or is of insignificant size e.g. less than ten pixels in extent along its minimum dimension, such as its height, or width) is a refresh instruction. After a suitable delay, e.g. Is, that refresh instruction is transmitted back to the server as a request to re-transmit the corresponding pair of frames. When the agent does not want to change the Web page seen by the client, only one of the pair of frames (the one containing the refresh instruction) is transmitted to the client in response to the request from the client so the information which the client sees does not change. However, since that refresh instruction is a request to retrieve data from a particular site, if the agent changes the site corresponding to that refresh instruction, the client will be presented with a different Web page at the next refresh operation. The refresh instruction will then cycle, refreshing only the frame with the refresh instruction until the agent again changes the data to which the refresh operation is directed. Thus, the client is repeatedly sending requests to the server, but only the frame containing the refresh instruction (which is not visible or is insignificant) is updated, eliminating screen flicker, unless the agents decides to change what the client sees.
[0018] This aspect of the present invention is not limited to the transmission of two frames, and additional frames may be transmitted in each step of the refresh cycle to permit the agent to have further control operations or to provide additional information to the client.
[0019] It should be noted that, in practice, where the agent changes the data to which the refresh instruction is directed, thereby changing the content of the frame to be seen by the client, the refresh instruction may also changed, so that the whole page is re-loaded into the client's computer, rather than having the same refresh frame.
[0020] As has previously been mentioned, it is desirable that the agent knows that the client is viewing a particular Web page. Since downloading of the Web page to the client's computer takes time, and that time is dependant on factors out of control of both the client and agent, it is already known for a server to record in a text log file information about access to it, including the fact that the page has successfully been downloaded. In another aspect of the invention, it is proposed that that information is passed to the agent in real time, so that the agent knows when the page has been downloaded, and so knows that the client can view the information on that page.
[0021] It is possible for the server to signal to the agent when it has completed its transmission to the client. However, use of the Internet means that there may be proxy servers between the client and the server controlled by the agent. Normally, such proxy servers can be ignored when considering Internet transmissions, but they introduce delays in transmission of data from the server controlled by the agent to the client. Thus, if an agent relied on signals from the server indicating that the server had completed its transmission, that would not necessarily correspond to the information having been loaded onto the client's computer.
[0022] It is already known that when a Web page is downloaded from a server to a client, the client's computer generates a signal when the page has been downloaded. This is known as an “onload” event, and usually results in a signal within the client's computer such as a “done” signal visible to the client. However, it is now proposed that the Web browser at the client's computer signals the onload event to the agent indicating the occurrence of the onload event. More generally, it is proposed that any signal which is generated by the client's computer in response to the successful downloading and display, at the client's computer, of information from a Web site may be used to indicate an onload event. The signal may be sent directly to the agent or to the server, and the server interprets that event, and generates a signal to the agent. Thus, the agent knows when the download of a Web page is complete. As has previously been mentioned, normal Web browsers only permit requests to be sent from client's computer to the server, but the use of multiple frames as previously described means that information in the form of a request can be transmitted to the server which information represents the occurrence of an onload event indicating that the download of the Web page has been completed, but which information is in the form of a request to the server. In this aspect, the request merely affects a frame which is not visible or is insignificant to the client, but the server may signal to the agent using that request as a trigger.
[0023] The World Wide Web uses a system of storing Web pages to reduce the overall Web bandwith on the Internet. This arrangement is usually referred to as caching. However, Web pages that change their content regularly can be disadvantageously affected by this. Although there is a known method of disabling caching, this does not always work because some arrangements ignore the header parameters which disable page caching.
[0024] Another aspect of the present invention is concerned with providing an alternative way of disabling caching, and proposes that each request is uniquely different, such as by incorporating data representing the time (a time stamp) or a randomly generated number.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] An embodiment of the present invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which:
[0026] [0026]FIG. 1 is a schematic block diagram of a network in which the present invention may be embodied;
[0027] [0027]FIG. 2( a ) illustrates and arrangement in which an agent is connected by the Internet to a single client;
[0028] [0028]FIG. 2( b ) shows and arrangement in which an agent is connected via the Internet to multiple clients;
[0029] [0029]FIG. 3 is a flow chart showing the operations required in an embodiment of the invention which a client logs on to a server controlled by an agent;
[0030] [0030]FIG. 4 is a flow chart showing the operations carried out when an agent logs on to a server to which the client will access;
[0031] [0031]FIG. 5 is a flow chart showing the operations carried out in an embodiment of the invention to enable an agent to authorise a client to access appropriate information;
[0032] [0032]FIG. 6 is a flow chart showing the operations carried out when a client requests information;
[0033] [0033]FIG. 7 is a flow chart showing how the agent may send information to client, and FIG. 8 shows how the information in FIG. 7 is then delivered to the client; and
[0034] [0034]FIG. 9 is an example of a session table used in the embodiment of the present invention.
DETAILED DESCRIPTION
[0035] [0035]FIG. 1 illustrates an architecture-level block diagram of a network as an example of the network in use for this invention. The network 1 includes one or more client network access devices 3 . Each client network access device can comprise a microcomputer including a central processing unit, memory and a network adaptor for communication, all linked by a bus. Each client network access device 3 is contains a client browser application 2 that provides a user interface allowing data to be viewed, and any necessary instructions to be transmitted. This client network access device typically includes a screen, and may also include a keyboard and screen cursor manipulator such as a mouse, a remote control or voice recognition. The client network access device is linked to the network to which the Web host 9 is also connected. This network would typically be, as illustrated in FIG. 1, the Internet 6 , a large number of independent nodes and routers that enable the transfer of TCP/IP formatted data packets to and from a large number of remote sites. The connection may be indirect as shown in FIG. 1. The client network access device 3 can be linked to an intranet 4 , and the connection from the intranet 4 to the Internet 6 may be through a proxy cache server 5 . Within the route taken by the data from the web host 9 over the internet, there may be additional proxy cache servers 12 operated by Internet Service Providers for the purpose of reducing traffic data volumes or otherwise.
[0036] For this invention, the controlling Web host 9 , contains three core elements. These are an Hypertext transfer protocol (HTTP) server 13 , comprising software for responding to requests for data and returning any legitimately requested material to the client or agent network access devices, for example the Apache Web server software. There is also a database server 11 , for storing both short and long term data about accounts and account activity, containing software such as the RDBMS package MySQL. Thirdly, the web host contains storage 10 for contents for the Web-site. These elements of the web host may be running on one or more computers, each also containing a CPU, memory and network adaptor linked to a common bus. Where more than one computer is used, these may be connected either via the Internet, or preferably via a local area network (LAN) 14 .
[0037] An unlimited number of clients may be connected, via the Internet 6 . For this invention, these would be grouped into sessions, in which one client would play the role of agent. Sessions with 1 agent and 1 client, or 1 agent and 3 clients, are shown if FIG. 2( a ) and FIG. 2( b ) respectively.
[0038] A TCP/IP connection is established between the client browser application 2 and the Web host 9 . Establishment of a TCP/IP connection entails the prior configuration of various IP addresses, usually represented in a dotted decimal notation or dotted hexadecimal notation in each of the computers, routers, management stations and workstations currently resident on the network. Certain IP network numbers are reserved for use by particular aspect of TCP/IP communication. The address is provided as a header to a data packet sent between a sender and a recipient. Router functions within the network strip the header and delivered associated data within the packet (e.g., instructions and information) to the designated addressee/recipient. The recipient provides a TCP header for additional reliability. TCP headers, in combination with application layer data are usually termed a segment. The segment can include a variety of data that are returned to the sender to ensure that the original IP message was properly received.
[0039] Consider now the case where an agent is to control which clients may access which pages of the Web-site. In this embodiment, it is assumed that the agent has some form of communication with the client, such as by being in contact with them by telephone, as it should be noted that the present invention is not limited to the case where the agent has such contact with the client.
[0040] There are several operations that must occur before the agent can control the Web pages that the client sees. The first stage is that the client must go through an appropriate log-in operation to ensure that appropriate Web pages are displayed only to identified clients. Similarly, the agent must carry out a log-in operation to permit the agent to have the right to control what the client sees. Next, an agent which has validly logged-in must then authorise a validly logged-in client to access the information, and the client's browser application must then make the appropriate request. The agent may control the Web pages that the client sees (agent push) and that pushed information must be delivered to the client with the agent being able to determine when the client has received the appropriate information. Each of these stages will now be described in more detail.
[0041] Each agent or agent group is allocated a unique identifying number (OGID).
[0042] A database is created that contains details of all agents and agent groups. In particular, it contains session tables for monitoring when clients are in, or attempting to enter, a communications session with an agent. Each of these session tables will have name that is made unique through the addition of the OGID. For example, cstb — 123456 may be the session table for the agent group with OGID 123456. An example of such a table is given in FIG. 9. As is seen, there are fields to contain the client session ID number, the identifying personal information of the client the IP address sent by the client network access device as part of the TCP/IP packet header, the status of the client (ie if they have been selected by an agent) and an agent ID number if they have been selected. Other information may also be stored in this table.
[0043] The client commands the client network access device to request access to a particular Internet Web-site address (client log-in) by issuing a Hypertext Transfer Protocol (HTTP) request through the client browser application. The request is provided in a format recognizable as an Internet Web-site address, for example. “http://www.claripoint.com”. This type of address is referred to as a Uniform Resource Locator (URL).
[0044] In this example, the client would add OGID to the Internet Web-site address. This is illustrated at step 100 in FIG. 3. For example, http://www.claripoint.com/123456. This OGID number identifies the group to which the client's agent belongs, and hence means that the agent can be notified of the presence of the client visiting the Website. To make it easier for the client, the complete URL including the OGID can be hidden as a hyperlink from the agent's own Web-site, or a more memorable name can be used instead of the OGID and aliasing or other known means used on the http server to redirect the URL with the name to the URL with the OGID. The http server first separates the OGID from the URL (step 101 in FIG. 3), and responds to the requested URL by displaying a display presentation, such as a form, to the client in which the client may enter some personnel identifying information, for example name and telephone number (step 102 in FIG. 3). Alternatively, the page returned may have other unique information generated by the server, such as a simple number, word or picture that may be simply described to the agent by the client and hence allow the agent to identify the computer connection that the client is making. In both these cases, the http server embeds a hidden field (within a standard. HTML form using the <input type=“hidden”> notion) containing the OGID of the agent group, or otherwise adds the OGID to the reply so that the next client request also contains the OGID.
[0045] The second request from the client to the http server will then contain the OGID, as well as the information from which the agent can uniquely identify the client. This could for example be the client's name and telephone number.
[0046] When the client completes the form (Step 103 ) the http server adds an IP address (step 104 ) and the http server communicates with the database server to establish a new session for the client, and record its details within the session table for the agent's agent group (step 105 ). First, a check is made for any pre-existing data in the table that matches the personal customer information and the IP address from the TCP/IP data packets from the client network access device. (http servers typically make this address available as the environment variable REMOTE_ADDR). If the personal details match, but the IP address is different, this could simply be a co-incidence (for example if the agent has only requested a first name, and two clients with the same first name have logged on). Equally if the IP numbers are also identical a proxy server acting as a firewall could have caused this. However, a matching set of data could also indicate an attempt is being made by a third party to masquerade as the client. In this case, seeing only identical personal information, the agent would be unable to select the correct client. With this uncertainty, the http server will deliver a new form to the client network access device asking that a change is made to the data, for example to add an extra number to the client name (step 107 ). When re-submitted (step 108 ), this should provide a unique data set but if not, steps 107 and 108 may be repeated until a unique identification is possible. When a unique set of personal identifying information has been thus obtained, it is written to the agent group session table (step 109 ). The database server is responsible for generating a unique client session ID number that is added to this record in the database as the record is created.
[0047] Before responding to the client, the server creates a temporary key (step 110 ), which is a unique pseudo-random number. This key is recorded in the database (step 111 ).
[0048] The http server generates the response to the client network access device. All URLs contained within the response HTML page, whether static links or included in JavaScript or meta tags, will have the OGID, client session ID number and additionally a time stamp appending to the URL in the standard GT format of attaching variables to URLs, for example, http://www.asite.com/page.htm?variable1=value1&variable2=value2.
[0049] This will be repeated to ensure that every request made by the client identifies that client with the OGID, client session ID number and last temporary key issued (step 600 in FIG. 6) such that the client status and validity of the request can be checked against the database. This process is illustrated further in FIG. 6 and described below.
[0050] The http server is able to use the OGID to select the appropriate table within the database (step 601 ). The database will first check that the client, as identified by the session ID, remains authorised by the agent to view the material specified by the URL address (step 602 ). As a security check, the database will then check that the temporary key supplied by the client matches that previously issued to the client (step 603 ). If the client request passes both steps 602 and 603 , the http server is told to authorise access (step 604 ), otherwise access is denied (step 611 ) and an appropriate warning page is returned to the client (step 612 ). If access has been authorised, a new temporary key is generated (step 605 ) and recorded in the database (step 606 ). Information to be displayed would normally be held on a secure http server, requiring user identification and password to access the said information. However, this procedure may also be used to authenticate a request for non-secure information. The http server can be told of which of these modes to operate by a field set by the agent within the database (step 607 ). If the information to be displayed is held within a secure space within the storage, the http server may retrieve this information itself, using its own name and password, on behalf of the client (step 608 ). The http server may then create the page containing the requested information, and again append the OGID, client session ID and the new temporary key to any URLs included (step 609 ).
[0051] If it is known that the client browser application is programmed to accept cookies, then these may be used to provide the numbers required for client authentication, instead of the GET method.
[0052] To logout the client can be provided with a hyperlink that causes the http server to request that the database server removes the client's details from the relevant agent group client session table. Alternatively, a regular routine on the database server will detect and delete clients who have not accessed the server within a fixed time period.
[0053] For the above to function, the agent must also be logged into the same Web host. This is illustrated in FIG. 4. The agent may have their access controlled by a standard and well-known means of username and password control or otherwise. Having entered his username and password into a log-in page on the Web-site (step 200 in FIG. 4), these values are tested (step 201 ) against those stored in the database (step 202 ). If authorised, the agent is assigned a temporary session ID key that is checked on each request that they make to the server (step 203 ).
[0054] Key data from the agent's agent group session table is extracted and displayed to the agent within the browser application of their client network access device (step 204 ). As the information will change when new clients login and logout, it is important that this information is refreshed regularly. In this embodiment this is achieved by a Java applet running in the Web browser of the agent, although simple HTML pages using META-REFRESH to refresh themselves or other means could be used.
[0055] The agent's Java applet directly requests the information from the http server using the standard HTTP protocol (steps 205 to 207 ). The information that is returned (steps 208 and 209 ) includes the identifying information entered by the client for each of the clients that are logged into the http server for the agents agent group, except those who are currently selected by other agents within the agent group.
[0056] Further security checks are performed by the Java applet on the agent's client network access device communicating with an ‘alive’ signal every second to the http server. Again, a sequence of unique temporary keys, cookies or other means may be used to authenticate the requests from the agent and to ensure that session security is not compromised by duplicated requests from a third party. A separate process is run on the http server to ensure that all agents remain connected. If contact with an agent is lost, caused for example by him logging off or his connection to the Internet failing, then the http server will detect this, and send an instruction to the database server to de-select all of the clients whom the agent had selected within that agents agent group client session table. Thus, in FIG. 4, steps 205 to 209 are repeated with a short, say 1 second, delay 210 .
[0057] The agent is able to select which client(s) he wishes to authorise from the interface of the Java applet (step 500 ). After the agent has made this selection, the applet sends the request to the http server (step 501 ). This request is sent as a POST request, containing an instruction to the server as to the change or action required, the details to identify the appropriate clients, and the necessary information to identify and authorise the agent.
[0058] As the status of the client could have changed even in the very short time since the agent was last presented with the status information, the http server first retrieves new information from the agent group client session table to check that the client is still logged on, and that the client has not been selected by another agent in the group (step 503 ). Provided these are both true, the http server will send a request to the database server to update the agent group session table with the information that the chosen client is now selected, and the agent ID of the agent who has made the selection (step 504 ).
[0059] Having described how the client and agent both log on, how the agent may select a client, and how the client's browser application requests can be checked for authorisation by the agent, the method by which the agent can specify the information to be displayed in the client's browser application will now be described.
[0060] First, the agent must specify the material that he wishes his selected client(s) to see, a process illustrated in FIG. 7. He specifies this as a URL (step 700 ), being the correct form to address information for retrieval over the Internet by a client browser application.
[0061] Having made his selection, which may be by means of an activeX control or Java applet or otherwise to provide him with an easy interface, this URL is passed from the agent's browser application to the web host (step 701 ). This is again in the form of GET/POST request containing the instruction, the URL and the necessary information to identify and authenticate the agent.
[0062] The http server instructs the agent group client session database to record the new requested URL in each of the rows of data representing the clients currently selected by that agent. The database will contain for each client both the URL requested to be displayed, and the last URL displayed by the client (FIG. 9).
[0063] The ‘push’ of information to the client is created by a regular request for information by the client, a process illustrated in FIG. 8.
[0064] The http server generates and delivers a page containing 2 or more frames to the client network access device (step 800 ). The first of these frames is made almost invisible but limiting its height to just one pixel high, and removing all borders and scroll bars.
[0065] The URL for the contents of the first frame (step 801 ) is a page generated by the http server. It is a very simple page, normally containing all of the elements described above for the authentication of the client requests as well as a <meta http-equiv=“refresh” content=“1”>. This causes this scarcely visible page to request a new copy of itself every second (steps 803-804). Because each request has a new temporary key, the full URL is different for each and every request, even from the same client. (This further ensures that proxy cache servers reliably pass the request to the web host, as it has been found that some of the available proxy cache servers do not correctly implement the no-cache pragma.)
[0066] One receiving the request, the http server will establish if the agent requires new material to be shown to the client. It does this by comparing the contents of the fields for the requested URL and the last displayed URL in the database (step 805 ). If these fields are the same, the server simply issues a new simple page with a new temporary key and another 1 second refresh (steps 806 - 807 ). Until the agent changes the field for the requested URL as described above (step 702 ), steps 802807 repeat.
[0067] However, if the material to be shown by the agent to client has changed, when detected in step 805 the http server will instead create (step 808 ) and deliver (step 809 ) a page to frame 1 containing an instruction (in JavaScript or another language understood by the client browser application), requesting that the full frameset be reloaded (step 800 ).
[0068] The second frame that is generated within the full frameset is the frame in which the requested material is displayed. This is accompanied by a short JavaScript that is triggered by the client's browser application ‘onLoad’ event when the information is fully displayed (step 810 ). This may request a new URL from the http server, and the receipt of the URL request (step 811 ) signals that the information has been fully downloaded. This provides a more reliable feedback mechanism than relying on the server log to establish when the material has been delivered, as again the presence of proxy servers between the web host and the client can mean that the information has left the web host well before it arrives at the client.
[0069] The http server requests the database to update the latest URL displayed by the client (step 812 ). Finally, as the http server must respond to the request sent by the client browser application, even though in this instance no request is desired, the response is a blank page shown in another almost invisible frame (steps 813 / 814 ).
[0070] Having allowed the agent to specify the information to be displayed to the client, this embodiment also allows the agent to receive feedback of when that information is displayed to the client. This happens in the following manner. It has already been described how by comparing the requested URL field and the last displayed URL field, it is possible to identify if the information is downloaded, as is done in step 805 . It has further been described how the agent regularly requests information from the same agent group client session table in the database (steps 205 - 210 ). The status of whether or not the client has successfully completed the download of the last requested information can be added to the information collected by the agent in this sequence, and appropriately displayed to the agent.
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In a network accessed by a client access device ( 3 ) and an agent access device ( 8 ), there is disclosed a method and apparatus for the regulation by the agent of the degree of access available to the client ( 3 ) to Web pages at a Web host ( 9 ) in common communication the client ( 3 ) and agent ( 8 ) via the internet ( 6 ). The degree of access is determined after the client ( 3 ) has supplied identifying information to the agent ( 8 ), the agent being in control of the Web host ( 9 ) so as to variably determine what degree of access the identified client should have to Web pages provided by the Web host. Methods and apparatus are disclosed for the control of the Web host ( 9 ) by the agent ( 8 ) so as to regulate which Web pages the client views via the Web host ( 9 ), in what order they are viewed, and when. A method and apparatus for signalling to the agent, via the Web host ( 9 ), when a Web page is onloaded at the clients browser application ( 2 ) is disclosed, as is a method of disabling caching of data transmitted between the client ( 8 ) and the host ( 9 ).
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FIELD OF THE INVENTION
The present invention relates generally to information processing systems and more particularly to a system and methodology for enabling automatic calling of participants for scheduled conference calls.
BACKGROUND OF THE INVENTION
Because the workday is often hectic, people rush from one activity to another. Consequently, they are often late dialing into teleconferences or “telecons”. This problem is aggravated when they need to find the phone number within a calendar entry for the telecon to dial in. In their haste, it is not unusual for simple mistakes to be made, such as looking at the wrong calendar entry, mis-dialing the phone number, neglecting to dial a leading digit for external calls, misreading and entering the wrong passcode, etc.
These types of problems can exist no matter what type of communications devices are being utilized. For example, even utilizing a combination of teleconferencing and Instant Messaging through Voice over Internet Protocol or “VoIP”, teleconference participants will continue to experience the difficulties described above.
Thus, there is a need for an improved teleconferencing system and methodology for enabling automatic set-up of teleconference calls to participants in scheduled teleconferences.
SUMMARY OF THE INVENTION
A method and system are provided in which teleconference calls are scheduled in advance and, at an appropriate predetermined time, calls are automatically made to the designated participants of the conference calls thereby avoiding the need for the participants to call into a teleconference center. In a preferred embodiment, when teconferences are scheduled, telecon participants are designated and their phone numbers are input or otherwise determined, for example, through access to a centralized database. A calendar is monitored and at a predetermined time relative to the scheduled start of the telecon, a server system application initiates the calling of the participants for connection to the telecon. The status of the called participants is determined and displayed on individual display devices of the other participants in the telecon. In one example, designated participants are called back at selected intervals if the initial automated call is unanswered.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention can be obtained when the following detailed description of a preferred embodiment is considered in conjunction with the following drawings, in which:
FIG. 1 is an overall system schematic illustrating an exemplary arrangement in which the present invention may be implemented;
FIG. 2 is a schematic block diagram of several of the components of a user terminal device which may be used by a participant;
FIG. 3 is an example of an input display screen which may be used in scheduling teleconferences in accordance with the present invention;
FIG. 4 is an example of a status display screen which may be used in association with the present invention; and
FIG. 5 is a flow chart illustrating an exemplary functional sequence in one implementation of the present invention.
DETAILED DESCRIPTION
It is noted that circuits and devices which are shown in block form in the drawings are generally known to those skilled in the art, and are not specified to any greater extent than that considered necessary as illustrated, for the understanding and appreciation of the underlying concepts of the present invention and in order not to obfuscate or distract from the teachings of the present invention.
As herein disclosed, the present invention enables users to configure their VoIP support to provide automated ‘dialing’ to connect all participants to a telecon. VoIP support would connect to all participants based on information contained in an application calendar entry and the connection number information contained in centralized profiles, for example. The task of dialing into a telecon would be relegated to a centralized dial-in system. This functions by having the central system attempt to connect to all users rather than have the users dial in to a central number. This will not only be a valuable usability aid, it will also reduce the chance of user error. The person who schedules the VoIP teleconference would setup and send the meeting notice. In the meeting notice would be the names of the participants and a central number (e.g., 1-877-IBM-CONF) that continues to act as the focal point to the meeting. Normally, each user dials into a telecon by initially dialing into the telecon number and giving a passcode. The invention would move the tasks of dialing into a VoIP telecon away from each user and have the system call out to participants. Instead of each VoIP telecon participant manually dialing into the telecon, the system would use individual profiles of participants from one or more central directories or databases to determine or confirm the connection number of each participant and initiate a call to each participant. In an exemplary implementation, when the system first initiates the telecon call-out procedure, a popup would appear listing the names of each of the invited participants in a ‘gray-out’ format. As participants answered the call, their popup entry would changed from grayed to black (or some other configurable color) for a quick indication of their connected status. The status of those who have not answered (still grayed out) would be available in more detail by right clicking over the invitee's name. Doing so would present more detailed information concerning the called participant's status.
The system can be configured to continue attempting to connect. For example, retries can be configured to repeat continuously until the meeting is scheduled to end, retry 5 (more or less) times, retry every 6 minutes for 3 additional attempts, etc. Participants that could not respond at their profiled number could still call-in themselves using conventional methods. Passcodes could still be used to verify the identity of respondents.
With specific reference to the drawings, FIG. 1 illustrates a system in which the present invention may be implemented. As shown, a teleconference server or call center 101 is arranged to include or have access to a conference calendar application 115 which, in turn, is designed to receive and store input regarding a scheduled telecon and to initiate the conference call to the designated participants at the scheduled time. The server 101 also has access to one or more databases 113 for retrieving and/or confirming information, including phone numbers, of the designated participants. As is hereinafter explained in greater detail, the conference server is enabled to initiate a scheduled conference call to designated participants through an interconnection network 103 such as, for example, the Internet. In accordance with the present invention, calls are automatically placed to participants A 105 , B 107 , C 109 and D 111 in the illustration. The devices used to participate in the teleconference may be personal computers, cell phones or any other device which has voice capabilities and is VoIP enabled. In one embodiment of the present invention, display capabilities are also utilized to enhance the functional features of the teleconferencing system disclosed herein.
As shown in FIG. 2 , an exemplary user teleconferencing device, e.g. 105 , includes, inter alia, a processor 201 which is coupled to a main bus 203 . Other components that are connected to the main bus 203 include a cache memory 205 , and a system memory 207 which may be implemented with flash memory. The system also may include a CD drive 209 for example in a PC embodiment, and a modem or wireless communication system 210 capable of connecting to the conference server 101 through the interconnection network 103 . The user device 105 also includes an input interface 211 for enabling user input from a keyboard or keypad 213 , a mouse or pointer device 215 and/or a voice system 216 including a microphone for receiving voice input from the user. A network interface 217 is also connected to the main bus 203 along with a storage device 218 a sound subsystem 224 and a video subsystem 225 and associated display device 226 . Other components and/or subsystems may also be connected to the main bus 203 as indicated by the extended bus sections.
In FIG. 3 , there is shown an exemplary input display screen by which a user may schedule a teleconference to be set-up at the conference server 101 . As shown, a display screen 301 is presented to a user and the user is enabled to input the date 303 of the proposed teleconference, the time 305 of the telecon, as well as the names of the participants 307 whom the user wishes to have participate in the scheduled telecon. The user is enabled to input specific names 309 as well as the participant's phone number 311 . If a phone number is not known to the user or scheduler, the input line is left blank 313 and the system will access an appropriate database with the input name to determine the appropriate phone number and fill-in the phone number. The system may also be configured to present as a pop-up window on the scheduling screen, a listing of individuals names and numbers if the database check determines that there are more than one person with the input name, in order to enable the scheduler to positively select the desired participant. Also presented on the scheduling screen is the conference number 315 to be known by the designated participants. In one example, a password feature may also be included. With the password feature, the system will dial and connect to the participants, but will not allow a voice connection until the correct password is entered and verified. The conference number should be known to the participants in case they will not be at their designated phone at the time of the scheduled call. Participant call-back options 319 are also presented to the scheduler for use in designating further actions in the event the designated participant does not respond to the automated teleconference set-up call. The scheduler may point-and-click 317 on the CALL BACK OPTIONS text 319 to have a pop-up window 321 appear. The scheduler may then select from several options which may be presented including an option 323 to continuously call back a designated participant for the full duration of the scheduled conference call if the scheduled participant does not respond to the conference set-up call from the server 101 . Another option 325 would designate that the un-responding participant is to be called-back every 5 minutes for three times, for example. When the scheduler has made his selections, an ENTER button 327 will input the call-back selections made by the scheduler. A subsequent selection of an ENTER text 329 will enter all of the information input by the scheduler for subsequent automatic implementation at the time the conference call is to occur. The system may be configured to begin to make the conference call connections a certain number of minutes prior to the scheduled time of the conference so that all of the participants will be on line or connected when the telecon is to begin.
At the designated date 303 and time 305 , the server is programmed to make the calls to the designated teleconference participants 309 . At that time, a status screen 401 , as shown in FIG. 4 , is displayed to all connected participants as they are connected to the call. The status screen 401 , in the example, includes the date 403 , time 405 and designated participants 407 to the call in name, number and status columns 409 , 411 and 413 . As shown, the missing phone number 313 in the set-screen 301 has been located in the database 113 by the program and filled-into the status screen 412 . In the FIG. 4 example, Galvin 415 and James 417 are not yet connected and their names are displayed in light text as well as being noted as “NOT CONNECTED” 419 and 421 , respectively. Also in the example, since Jones and Smith have been connected, the status column corresponding to their names shows a “CONNECTED” status and their names are emboldened on the status screen. A user is enable to point-and-click 423 on the “NON-CONNECTED” text 421 in order to have a pop-up screen 425 appear to present more information regarding the reason for the unconnected status of the designated participant. As shown, possible reasons include that there was no answer 427 , or the line was busy 429 or that the call was connected but later dropped for some reason 431 . The connected participants are also enabled to change the call back options 433 from the status screen by pointing-and-clicking on the CALL BACK OPTIONS text 433 as discussed in connection with FIG. 3 . Once a designated participant has been connected, the corresponding light text will become emboldened to visually indicate the connected status of the participant.
A functional sequence of the methodology of an exemplary embodiment of the present invention is shown in FIG. 5 . As shown, when it is determined by the conference server 101 and conference calendar application 115 that a scheduled teleconference is to begin 501 , the server 101 retrieves the conference information 503 and initiates calls 505 to the designated participants. If a called participant does not connect 507 , the reason for the non-connect is determined and saved 509 and all active status displays are updated 511 to indicate that a connection has not been made. The next uncalled participant is then called 505 . When a participant is connected 507 , the status information is updated 513 and if the participant has a display, the updated status information screen 401 is displayed on the connected participant's display screen. If there are more uncalled participants 515 the next participant is called 505 by the server 101 until all of the designated participants have been called. When there are no more uncalled designated participants 515 , the process goes to implement the input call-back programming 517 as determined by default or by the scheduler, e.g. 321 .
The method and apparatus of the present invention has been described in connection with a preferred embodiment as disclosed herein. The disclosed methodology may be implemented in a wide range of sequences, menus and screen designs to accomplish the desired results as herein illustrated. Although an embodiment of the present invention has been shown and described in detail herein, along with certain variants thereof, many other varied embodiments that incorporate the teachings of the invention may be easily constructed by those skilled in the art, and even included or integrated into a processor or CPU or other larger system integrated circuit or chip. The disclosed methodology may also be implemented solely or partially in program code stored on a CD, disk or diskette (portable or fixed), memory stick or other memory device, from which it may be loaded into memory and executed to achieve the beneficial results as described herein. Accordingly, the present invention is not intended to be limited to the specific form set forth herein, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents, as can be reasonably included within the spirit and scope of the invention.
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A method and system are provided in which teleconference calls are scheduled in advance and, at an appropriate predetermined time, calls are automatically made to the designated participants of the conference calls thereby avoiding the need for the participants to call into a teleconference center. In a preferred embodiment, when teconferences are scheduled, the telecon participants are designated and their phone numbers are input or otherwise determined, for example, through access to a centralized database. A calendar is monitored and at a predetermined time relative to the scheduled start of the telecon, a server system application initiates the calling of the participants for connection to the telecon. The system may be configured to require participants to enter a password before the connection is completed. The status of the called participants is determined and displayed on individual display devices of the other participants in the telecon. In one example, designated participants are called back at selected intervals if the initial automated call is unanswered.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority from the following copending patent applications: application Ser. No. 09/915,226, filed Jul. 23, 2001; application Ser. No. 09/638,805, filed Aug. 12, 2000; application Ser. No. 09/562,599, filed Apr. 29, 2000; provisional application Ser. No. 60/255,635, filed Dec. 13, 2000; application Ser. No. 09/851,400, filed May 7, 2001; provisional application Ser. No. 60/323,923, filed Sep. 15, 2001 and PCT application no. PCT/US01/25197 filed Aug. 10, 2001. The entire disclosure of each of the above-referenced patent applications is expressly incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to forming anastomoses between two hollow bodies, and more specifically, using magnetic force to form such anastomoses.
[0004] 2. Description of Related Art
[0005] Various non-suture based anastomotic systems have been proposed in the art, however, none has performed well enough to receive any significant level of acceptance in the field. Many of the proposed couplings fail to remain sufficiently patent, either acutely or chronically. Another technical challenge is to create an anastomosis that produces a fluid-tight seal between the hollow bodies. This is due in large part to the difficulty in securing an anastomotic component without overly traumatizing the tissue and without placing too much foreign material in the vessel lumen.
SUMMARY OF THE INVENTION
[0006] One embodiment of the invention provides an anastomotic component that is coupled or attached to the wall of a vessel without protruding into the lumen of the vessel or penetrating the vessel wall. That is, substantially none of the anastomotic component or assembly is located within the vessel lumen (i.e., after the anastomosis has been formed). As a result, there is preferably no foreign structure or material disposed within the target vessel lumen after creating the anastomosis.
[0007] The specific manner in which the anastomotic component is secured to the vessel may vary according to the invention. In one embodiment biocompatible adhesive is used to secure a component to the exterior of the target vessel wall without extending into the lumen. This component is coupled to a magnetic or ferromagnetic assembly carried on a graft vessel. Another embodiment uses adhesive to secure the anastomotic components to both vessels.
[0008] According to further embodiments magnetic force is used in combination with an additional locking force, for example, a mechanical connection, to maintain the vessels in proper position and provide heightened resistance to pressure fluctuations that might occur post-formation of the anastomosis. Alternative constructions for the anastomotic components are disclosed, as are various delivery devices and methods for deploying the components.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0009] Other features, benefits and advantages of the present invention will be apparent from the following detailed description of preferred embodiments thereof taken in conjunction with the accompanying drawing figures, wherein:
[0010] FIGS. 1A and 1B are, respectively, plan and elevation views of a magnetic anastomotic component constructed according to one embodiment of the invention;
[0011] FIG. 1C is an elevation view of a magnetic anastomotic component constructed according to an alternative embodiment of the invention;
[0012] FIGS. 2A and 2B are, respectively, perspective and elevation views of a magnetic anastomotic component constructed according to another embodiment of the invention;
[0013] FIGS. 3A and 3B are, respectively, perspective and elevation views of a magnetic anastomotic component constructed according to yet another embodiment of the invention;
[0014] FIG. 4 is a perspective view showing the anastomotic component of FIGS. 3A and 3B attached to a vessel;
[0015] FIGS. 5A and 5B are perspective views showing an anastomotic component being secured to a vessel according to another embodiment of the invention;
[0016] FIGS. 6A-6C are elevation views showing anastomotic components constructed according to different embodiments of the invention being used to form an anastomosis between two vessels;
[0017] FIGS. 7A-7C are elevation views showing an anastomotic component being secured to a vessel according to another embodiment of the invention;
[0018] FIG. 7D is an elevation view showing the component of FIGS. 7A-7C being secured to an end of a vessel;
[0019] FIGS. 8A and 8B are perspective views of magnetic anastomotic components provided with tissue anchoring elements according to another embodiment of the invention;
[0020] FIGS. 9A-9C are elevation views, in section, showing magnetic anastomotic components provided with tissue traction-enhancing structure according to another embodiment of the invention;
[0021] FIGS. 10A-10C are, respectively, perspective views and a sectional view of one of the magnetic anastomotic components shown in FIG. 9C ;
[0022] FIGS. 11A and 11B are, respectively, plan and sectional views of a magnetic anastomotic component provided with tissue gripping structure according to another embodiment of the invention;
[0023] FIG. 11C is a sectional view of an anastomotic component having an alternative tissue gripping structure;
[0024] FIGS. 12A-12D are, respectively, perspective, side elevation, end elevation and plan views of a magnetic anastomotic component constructed according to another embodiment of the invention;
[0025] FIGS. 13A-13C are, respectively, perspective, side elevation and end elevation views of an anastomosis formed by a pair of magnetic anastomotic components constructed according to another embodiment of the invention;
[0026] FIGS. 14A-14D are, respectively, plan, perspective, end elevation and side elevation views of a magnetic anastomotic component constructed according to another embodiment of the invention;
[0027] FIGS. 15A-15D are, respectively, plan, perspective, end elevation and side elevation views of a magnetic anastomotic component having a similar construction as the component shown in FIGS. 14A-14D ;
[0028] FIGS. 16A-16B perspective views showing an anastomotic component being mounted to the exterior surface of a hollow body according to one embodiment of the invention;
[0029] FIGS. 16C-16D perspective views showing an anastomotic component being mounted to the exterior surface of a hollow body according to one embodiment of the invention;
[0030] FIGS. 17A and 17B are, respectively, perspective and end elevation views of an extravascular anastomosis created according to one embodiment of the invention;
[0031] FIGS. 18A-18D are perspective views showing an anastomotic component being mounted to the exterior surface of a hollow body according to another embodiment of the invention; and
[0032] FIG. 19 is an end elevation view of a magnetic anastomotic component mounted to the exterior of a vessel according to one embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] FIGS. 1A and 1B show a first embodiment of a magnetic anastomotic component 10 having a ring-shaped body 12 and an opening 14 . As shown in FIG. 1B the component body 12 is generally flat. However, as shown in FIG. 1C , the body 12 may be curved, for example, to match the curvature of a vessel to which it is secured.
[0034] FIG. 2A shows a magnetic anastomotic component 16 with an opening 18 . The body of the component 16 has an oval or elliptical shape with leading edges 20 for facilitating atraumatic introduction into a vessel. As shown in FIG. 2B , the component 16 is flat. As in the above embodiment, however, the component 16 could be curved instead, for example, in a manner similar to the curvature of the anastomotic component 22 shown in FIGS. 3A-3B . Also, the curvature may extend over all or a portion of the length (or width) of the component.
[0035] FIG. 4 shows the anastomotic component 22 of FIGS. 3A and 3B mounted on the side wall of a vessel V. According to the preferred embodiments, the component is secured to the vessel without projecting into the vessel lumen, thereby avoiding potential problems associated with foreign material located in the vessel lumen. The component may be secured to the exterior of the vessel by suitable means, for example, adhesive, mechanical fasteners, or both.
[0036] FIGS. 5A and 5B show the anastomotic component 16 of FIGS. 2A and 2B mounted on a side wall of a vessel V. FIG. 5B shows mechanical fastening means, the illustrated means being in the form of sutures S, which are used to attach the component 16 to the vessel V. While sutures S are shown, it will be recognized that any suitable mechanical fastener may be used, e.g., clips, stents, barbs, hooks, wires, etc.
[0037] In the embodiments of FIG. 4 and FIGS. 5A-5B , the anastomotic component is secured to the exterior of the vessel wall by suitable means. FIGS. 6A and 6B show anastomoses between two vessels V 1 and V 2 . In FIG. 6A , the vessels have mounted thereto, respectively, magnetically attracted anastomotic components 24 , 26 . (For clarity, the components are shown slightly separated.) The components 24 , 26 are rectangular in cross-section. In FIG. 6B the vessels V 1 , V 2 have mounted thereto, respectively, components 28 , 30 . The components 28 , 30 are provided with a curved exterior surface that generally corresponds to the curvature of the walls of vessels V 1 and V 2 .
[0038] The anastomoses shown in FIGS. 6A and 6B are created without placing any component portion in the vessel lumen. FIG. 6C shows an embodiment wherein a vessel V 1 has an anastomotic component 32 secured thereto, while a vessel V 2 has an anastomotic component comprising portions 34 A and 34 B secured thereto. Unlike the embodiments of FIGS. 6A and 6B , thought, the portion 34 B of the one component is disposed within the lumen of vessel V 2 .
[0039] FIG. 7A shows a vessel V prior to forming an opening in the wall thereof. FIG. 7B shows the vessel V after an opening O has been formed therein. FIG. 7C shows an anastomotic component 36 positioned around the outside of the opening in the vessel V. An internal locking member 38 , which may be in the form of a snap ring, is positioned within the vessel lumen and cooperates with a groove in component 36 to secure the vessel and component together. FIG. 7D shows an anastomotic component 40 positioned around the end of a vessel V. The internal locking component 38 cooperates with a groove in the component 40 to secure the component to the end of the vessel (as opposed to the side wall of the vessel, as in the previous embodiments).
[0040] FIG. 8A shows a magnetic anastomotic component 42 having an opening 44 and a pair of attachment tabs 46 with openings 48 . The component 42 is mounted to the exterior of a vessel (not shown), for example, by passing a fastener (also not shown) through each opening 48 into engagement with the vessel tissue. Alternatively, the tabs 46 and openings 48 may be used as secondary securing means, for example, if the component 42 is secured to the vessel by other means, e.g., adhesive.
[0041] FIG. 8B shows a magnetic anastomotic component 50 having an opening 52 and attachment structure 54 to facilitate securing the component to a vessel (not shown). As above, the structure 54 may be used alone or in combination with other means for securing the component to the vessel. In the illustrated embodiment, the attachment structure 54 is affixed to the component 50 to define a plurality of openings 56 which may be use to receive sutures, clips, clamps, pins, barbs, or other securing or fastening means.
[0042] One benefit of the embodiments of FIGS. 8A-8B and 9 A- 9 B is that the attachment structure is disposed away from (or below) the magnetic coupling surface of the component. That is, the exposed surface of the first component is free to mate with the exposed surface of the second component without interference from the attachment structure. As a result, one or both components can be firmly affixed to its vessel without adversely affecting the anastomosis.
[0043] FIGS. 9A-9C show three embodiments of magnetic anastomotic components that are provided with structure for increasing the traction or gripping force between the components and a vessel to which they are secured. In FIG. 9A , anastomotic component portions 58 A, 58 B sandwich a vessel wall W and are preferably provided with a layer of material to enhance engagement with the tissue. FIG. 9B shows component portions 60 A and 60 B, each of which includes a projection 62 at the end thereof which grabs the tissue of the vessel wall W, thereby enhancing securement. FIG. 9C shows anastomotic component portions 64 A and 64 B, each of which is provided with a series of grooves or annulations 66 that grippingly engage the tissue of the vessel wall W.
[0044] FIGS. 10A-10C show an anastomotic component 68 with an opening 70 and a plurality of grooves or bumps 72 . The grooves or bumps 72 , which may also be in the forms of ridges, serrations, sharp or dull edges, etc., grab the tissue of the vessel to which the component is secured, which provides additional attachment force. FIG. 10C shows the ridges 72 having sharp points 74 to further enhance engagement with the tissue.
[0045] FIGS. 11A-11C show a magnetic anastomotic component 74 with an opening 76 and a peripheral edge 76 that defines a sharp point 78 . As shown in FIG. 11B , a second anastomotic component 80 may be used with the component 74 , the component 80 having a complimentary-shaped edge 82 which cooperates with the edge 76 to sealingly and grippingly grab tissue of a vessel to which the components are secured. FIG. 11C shows a variation of the component 74 wherein a plurality of edges 74 ′ and 76 ′ are provided. A modified second component 80 ′ has a plurality of complimentary edges 82 ′ that mate with the edges 76 ′ of component 74 ′. In each of these embodiments the force-increasing structure is shown running along the entire length of the component. It will be appreciated that such structure may be extend along all or any portion of the component, and could extend across the width or longitudinal axis of the component, rather than along the axis, as in FIGS. 10A-10C .
[0046] The attachment force-increasing embodiments of FIGS. 9A-9C , 10 A- 10 C and 11 A- 11 C provide several benefits. In addition to enhancing attachment of the component to the vessel, the resulting anastomosis may have higher resistance to bursting under high pressures, e.g., acute pressure increases. For example, placing a rough or bumpy parylene coating on the surface of a magnetic component produces higher burst pressure resistance than using a smooth surface. It is desirable to increase pressure resistance, preferably without increasing the risk of occlusion.
[0047] According to the invention, the components described above may be secured to the vessel by various means. For example, the component may be adhesively attached to the exertion of the vessel so that the lumen of the vessel is free of any component portion. In addition to the adhesive securement of the component, any of the above-described traction or tissue-gripping structure may be used as well. Additionally, the component may be provided with tabs or other attachment structure as described above.
[0048] FIGS. 12A-12D show a magnetic anastomotic component 84 having a rounded configuration designed to mate with the curvature of a vessel, and an opening 86 adapted to communicate with the vessel lumen. The thickness of the component 84 is tapered across its width ( FIG. 12C ) and may be tapered more or less from the specific configuration shown.
[0049] FIGS. 13A-13C show an anastomosis created according to another embodiment of the invention. A first vessel V 1 and a second vessel V 2 are provided with respective magnetically-attracted components 88 , 90 . The component 88 has an intravascular portion 92 and an extravascular portion 94 , while the component 90 has an intravascular portion 96 and an extravascular portion 98 as shown best in FIGS. 13A and 13C . The extravascular portions 94 , 98 of the respective components are flat and provide a flat engagement to enhance the magnetic force holding the components together.
[0050] FIGS. 14A-14D show a magnetic anastomotic component 100 having a luminal opening 102 and a plurality of slots 104 . The slots 104 serve any of several purposes including allowing tissue ingrowth to promote attachment to the vessel, enhance traction between the component 100 and the vessel to which it is attached, etc.
[0051] FIGS. 15A-15D show a magnetic anastomotic component 106 with a luminal opening 108 and a plurality of apertures 110 disposed around its perimeter. The apertures 110 give the component 106 a frame-like structure and may serve any of the purposes described above with respect to the previous embodiment. It will be noted that the components 106 and 100 , while illustrated as being curved to match the curvature of a vessel or mating component (not shown), they may instead be flat or otherwise configured.
[0052] FIGS. 16A and 16B show a magnetic anastomotic component 112 being attached to a vessel V according to one embodiment of the inventions. An opening O is formed in an opening of a side wall of the vessel V and a magnetic anastomotic component 112 is moved into position such that the luminal 114 of the component is aligned with the opening O ( FIG. 16B ).
[0053] FIGS. 16C and 16D show a magnetic anastomotic component 116 being secured to a vessel V according to another embodiment of the invention. In this embodiment, the component 116 is lowered against and secured to the vessel wall as in the above embodiment. However, an opening is formed in the vessel after placing the component in this embodiment. As shown in FIG. 17B , a suitable instrument is used to remove the tissue circumscribed by the opening 116 of the component 116 . The components 112 and 116 may be secured to the exterior of the wall of vessel V by any suitable means disclosed herein.
[0054] FIG. 17A shows an anastomosis between first and second vessels V 1 and V 2 which are provided, respectively, with magnetically attracted components 120 , 122 . As shown in FIG. 17B , of the components 120 , 122 have mating surfaces which are positioned against each other and held by magnetism to create the anastomosis.
[0055] FIGS. 18A-18D show a magnetic anastomotic component being secured to the exterior of a vessel wall according to still another embodiment of the invention. Delivery device D includes an internal placement member 130 which is used to place a magnetic anastomotic component 132 . The placement member 130 is positioned within the lumen of the vessel through an incision in the wall, and the anastomotic component 132 is slid down against the exterior of the vessel. Magnetic attraction holds the component 132 in position around the incision.
[0056] It should be noted that in positioning the placement member within the lumen of the vessel v, the delivery device is manipulated, typically by pulling up to tension the vessel wall, and the edges of the incision are positioned around a portion 134 of the delivery device D so as to make the incision the desired size. When the edges of the incision are so positioned, the anastomotic component 132 is slid down and the magnetic attraction captures the edges of the incision, thereby maintaining a suitable size opening.
[0057] Next, the delivery device D is removed as shown in FIG. 18C . Finally, as shown in FIG. 18D , the internal placement member 130 is pushed distally and rotated and then removed (for example, by wires W) through the incision in the vessel V. The magnetic anastomotic component 132 is preferably provided with adhesive to secure the component to the vessel. Alternatively, adhesive may be applied around the incision on the vessel and the component 132 moved into contact therewith.
[0058] FIG. 19 shows an embodiment of the invention where a magnetic anastomotic component 136 is secured to an intermediate member 138 , for example a dacron blanket, which itself is secured to the wall of a vessel V. These embodiments may be practiced by forming a blanket or surface of adhesive on the vessel exterior, and then forming the incision through the adhesive (which may be less difficult than incising the vessel wall directly).
[0059] The invention may be practiced using any suitable biocompatible adhesives. In general, fibrin sealants and cyanoacrylate esters are the two types of adhesives widely used for biological bonding. Gelatin-resorcinol-formaldehyde glues have limited use as well. Other possible bioadhesives include gelatin-resorcinol-formaldehyde glue, bovine albumin, glutaraldehyde, marine organism (mussel) based, collagen and thrombin.
[0060] Fibrin sealants are biodegradable, adhere well to connective tissue, promote wound healing, and generally have less bond strength than cyanoacrylate esters. A two-part system may be used to apply the sealant, or a one-part, ready-to-use formulation may be used instead. The adhesives used may have or not have antifibrinolytic agents (e.g., aprotinin, etc.)
[0061] Those skilled in the art will recognize that many modifications, alterations and variations of the illustrated embodiments may be made without departing from the scope and spirit of the invention as defined by the appended claims. For example, while the embodiments are described in connection with magnetic anastomotic components, it will be appreciated that various features of the invention may be practiced in conjunction with non-magnetic anastomotic components. Further, it will be appreciated that, independent of the specific illustrated embodiments, the components disclosed herein may be used to create end-to-end, end-to-side or side-to-side anastomoses, between blood vessels or any hollow anatomical structures.
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Methods and devices using magnetic force to form an anastomosis between hollow bodies. End-to-side, side-to-side and end-to-end anastomoses can be created without using suture or any other type of mechanical fasteners, although such attachment means may be used in practicing some aspects of the invention. Magnetic anastomotic components may be attached to the exterior of a vessel, e.g., by adhesive, without extending into the vessel lumen. Various magnetic component configurations are provided and may have different characteristics, for example, the ability to match the vessel curvature or to frictionally engage the vessel.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of the filing dates of U.S. Provisional Patent Application Ser. No. 60/930,837 filed May 18, 2007 and GB Application No. 0709604.3 filed May 18, 2007, the disclosure of each of which is incorporated by reference herein.
FIELD OF THE INVENTION
The present invention generally relates to a method and system for allocating resources for accessing data within a public network and is particularly, but not exclusively, suited to providing access to data when the delivery of data is metered, such as when data are delivered to terminals connected to mobile networks.
BACKGROUND OF THE INVENTION
As is well known, the Internet provides access to huge numbers of web pages; increasingly the web pages include nested links and objects, the delivery of which can require what is sometimes a non-trivial amount of bandwidth. This is typically not a problem for requests received from terminals that are fixedly connected to the Internet (either directly, or via one of several network portions), and of course the transmission of data within the Internet—on a per request basis—is free. However, with the advent of widespread deployment of 3G networks, requests are increasingly being received from terminals connected to wireless networks. Unlike the transmission of data within fixed-line networks, the transmission of data within mobile networks is typically metered on a per transmission basis. As a result, mobile terminals are faced with hitherto unseen costs for accessing web sites.
SUMMARY
In accordance with aspects of the present invention, there is provided methods and systems according to the appended claims.
In some arrangements embodiments provide a method of recording allocation of resources in response to a request, the method comprising:
receiving a request for a data item to be transmitted to a device in the network, the request comprising data indicative of one or more requested items;
accessing a storage system so as to identify data listings having items generating a match with the requested data item;
retrieving data indicative of a network location corresponding to the or each matched data item, the network location providing access to a set of data corresponding to the matched data item;
retrieving data indicative of an amount of data and a resource allocation associated with the set of data accessible via the network location;
on the basis of a network subscription associated with device and the amount of data, evaluating actual usage of network resources when accessing the set of data;
in the event that the set of data are accessed from the network location, offsetting said evaluated actual usage against the resource allocation so as to identify an amount of usage of network resources to be charged to the network subscription; and
updating a record associated with said data listing so as to log said resource allocation event.
These embodiments of the invention therefore provide a means of offsetting access to data from a given web site on the basis of a resource allocation associated with the network location, for example a web site. This can be pre-specified by the information provider associated with the web site. Preferably the data are transmitted to, and the evaluation is performed by, the device from which the request is received, such as a mobile device. However, in other arrangements the amount of data, the resource allocation and the corresponding network location are transmitted to a device other than the mobile device. The requested items can be key words making up a search request or can be web site names indicating web sites of interest to a user associated with the mobile device.
In either arrangement, data indicative of transport costs associated with the network subscription are retrieved and, when the device performing the evaluation is the mobile device associated with the network subscription, the transport costs can be retrieved from a removable storage device associated therewith, or from data provided by the corresponding network operator or input manually.
In the event that one or more data elements from the set are retrieved by the mobile device, data indicative of the actual usage of network resources is transmitted to a billing system maintained by the network operator associated with the network subscription. The actual usage can be used in decrementing an account balance, or, in the event that the resource allocation is accounted for after accessing the data, the actual usage of network resources can be used to increment the account balance associated with the network subscription.
In some embodiments the resource allocation can be weighted according to the size of one or more data element accessible from the network location, the number of nested links, and/or rating data associated with the network location whereby to evaluate said actual usage.
The mobile device can be arranged to display the data listings as a list of selectable links, which are ordered in dependence on the amount of usage of network resources to be charged to the network subscription. The links can be classified on the basis of the amount of usage of network resources to be charged to the network subscription; examples of such classifications include fully subsidised, partially subsidised and non-subsidised.
Embodiments of the invention can also comprise sending information about the network location to the mobile device prior to retrieving the data indicative of an amount of data and the resource allocation associated with the set of data accessible via the network location; typically this involves transmitting the set of data accessible via the network location to the device and receiving data indicative of selected elements from the set of data. These selected elements can then be used to adjust the amount of data (and thence the evaluated usage) associated with the set of data. Typically selection of a given element indicates that the element should be excluded from the download of data from the network location, and so effectively reduces the amount of data to be factored into the evaluation. The selection process can be dependent upon the amount of data to be downloaded, the number of nested links, ratings applied to the data, and other such characteristics.
According to another aspect of the present invention there is provided a mobile terminal configured to evaluate resource requirements in relation to data access from a given network location.
The embodiments are particularly well suited to use in the context of providing search results to a mobile terminal, because the transmission of data over wireless networks is chargeable.
Embodiments of the invention are particularly convenient for use in transmitting search results to a terminal connected to a mobile communications network.
According to a further aspect of the invention there is provided a method of identifying a characteristic of a set of data accessible via a link specifying a network location; the characteristics include size of elements of the set of data rating applied to the set of data, amount of resource that has been allocated in relation to elements of the set of data etc. and the method comprises:
receiving a request for a said characteristic to be transmitted to a device in the network, the request comprising data indicative of a said link;
identifying a link listing generating a match with the requested link, said link listing being identifiable from a list comprising a plurality of link listings;
retrieving data indicative of a set of data accessible from the identified link listing;
identifying a said characteristic from the retrieved set of data on the basis of predefined characteristic request criteria; and
transmitting data indicative of the identified characteristic to the device.
According to a yet further aspect of the present invention there is provided a user interface for a mobile device, the user interface being for use in designating an element of data as having a type of downloadable status (such as “not downloadable” or “downloadable”). The user interface preferably comprises display means arranged to display the set of data in conjunction with a plurality of selectable display objects, each being assigned to a given element of the set of data. The display means is responsive to selection of a given said display object so as to designate the element of data corresponding thereto as having a first type of downloadable status, and the mobile station is arranged to transmit data indicative of elements having said first type of downloadable status to a network node for use in controlling data subsequently transmitted to the mobile station.
This therefore provides a means of explicitly selecting or deselecting individual elements from transmission to the mobile station.
In accordance with further aspects of the invention there is provided a distributed system and apparatus for carrying out the method steps described above.
Further features and advantages of the invention will become apparent from the following description of preferred embodiments of the aspects of the invention, given by way of example only, which is made with reference to the accompanying drawings. It is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope and spirit of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram showing a distributed information system within which embodiments of the invention can operate;
FIG. 2 is a schematic diagram showing fields of several records stored within the search database shown in FIG. 1 ;
FIG. 3 is a schematic block diagram showing components of the search engine shown in FIG. 1 ;
FIG. 4 is a schematic block diagram showing components of a mobile terminal configured according to embodiments of the invention;
FIG. 5 is a timing diagram showing data flows between components of the distributed information system of FIG. 1 when operating according to a process of an embodiment of the present invention;
FIGS. 6 a and 6 b are schematic diagrams showing an example web page output from the search engine during the process shown in FIG. 5 ;
FIG. 7 is a schematic diagram showing an alternative distributed information system within which embodiments of the invention can operate;
FIG. 8 is a timing diagram showing data flows between components of the distributed information system of FIG. 7 when operating according to a process of an embodiment of the present invention; and
FIG. 9 is a schematic flow diagram showing further steps associated with the embodiment shown in FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
As described above, embodiments of the present invention are generally concerned with allocating resources for providing providers and/or end users with access to publicly accessible material via devices such as mobile terminals. The nature of the process for quantifying the resource allocation and the criteria relating thereto is described in detail below, but first a description of the infrastructure needed to support some embodiments of the invention will be presented with reference to FIG. 1 , which shows an example of a distributed information system 1 . The current embodiment relates to servicing of search requests—i.e. requests for content corresponding to keywords; however, as will be appreciated from a full reading of the specification the invention applies to servicing a range of types of requests and accordingly is not to be limited to the realm of search engine technologies.
In the current embodiment the distributed information system 1 comprises a plurality of information providers 6 a , 6 b , 6 c , at least some of which are arranged to store content and information, and a search engine 10 , all of which are connected to a network 12 either directly or indirectly (e.g. via the Internet, local area networks (LANs), other wide area networks (WANs), and regional networks accessed over telephone lines, such as commercial information services). Mobile terminals 2 , 4 are adapted to communicate with the various information providers 6 a , 6 b , 6 c via mobile network 14 and an appropriate gateway GW, as shown; the terminals 2 , 4 can be mobile telephones or PDAs, lap top computers and the like, and the mobile network 14 can comprise a licensed network portion (such as is provided by cellular networks using e.g. Global System for Mobile Communications (GSM) technology, Wideband Code Division Multiplex Access (WCDMA); Code Division Multiplex Access (CDMA), WiMax) and/or unlicensed network portions (such as is provided by Wireless LANs and Bluetooth technologies). The gateway GW can be a GPRS support node (GGSN) forming part of the mobile network 14 .
The mobile terminals 2 , 4 comprise browser programs adapted to locate, and access data from, web sites corresponding to the or each information provider 6 a , 6 b , 6 c . The browser programs allow users of the terminals 2 , 4 to enter addresses of specific web sites, typically in the form of Uniform Resource Locators, or URLs, and are typically adapted to receive and display web and WAP pages; in the event that a given terminal 2 is only capable of processing and displaying WAP pages, translation of a web page can be performed by a device in the network or by suitable translation software running on the device 2 . As is known in the art, any given web page can include links nested therein, which, when selected, can provide access to other pages or data such as plain textual information, or digitally encoded multimedia content, such as software programs, audio signals, videos graphics, etc. Accordingly selection of such links results in transmission of further data to the terminals 2 , 4 .
In accordance with conventional systems, the search engine 10 is operable to receive keywords of interest to the users of terminals 2 , 4 , and, by accessing data stored in the search database 20 , to generate search results relating thereto. The search results are organised into a list of hypertext links to content that contain information relevant to these search terms; each link generally corresponds to a network location corresponding to a given information provider 6 a , 6 b , 6 c.
As described above, embodiments of the invention are concerned with allocating resources for providing access to publicly accessible material via devices such as mobile terminals, and provide a mechanism for evaluating delivery costs to be borne by the subscriber and presenting the results in conjunction with these costs; this might be different to the actual delivery costs, since information providers can allocate resources for use in offsetting the actual delivery costs.
For each information provider 6 a , 6 b , 6 c , the search database 20 can hold allocation records comprising data indicative of an allocation of resource for use in offsetting delivery costs associated with providing access to their content. The allocation records can comprise parameters specifying an allocation in absolute terms or in relative terms (e.g. as a percentage of the overall delivery costs), together with parameters specifying temporal data and location data that control applicability of the allocations. Furthermore the search database 20 can hold rating records comprising rating data gathered from third parties and recipients that have already accessed the content. These rating data preferably relate to usability of a given web site from the point of view of a user of a mobile device, and can be collected automatically or manually. The search database 20 can additionally hold resource requirement records, which specify data such as the size of the web page accessible via the URL associated with the information provider 6 a , 6 b , 6 c , links that are nested within the web page, and objects accessible via the web site.
Rather than being stored within the search database 20 , one or more of the allocation, storage and/or rating records can alternatively be held in a database (not shown) maintained by (a) third party/parties, in which case the search engine 10 can query the third party database in order to retrieve this information at the time of collating the search results.
These allocation and resource requirement data can be specified by a given information provider 6 a , 6 b , 6 c via a form or similar (not shown), and in the case of the resource requirements data, software components associated with the search database 20 can be arranged to download the web page so as to verify, or correct, the submitted data. Once the data have been verified, the search database 20 stores the same in a database record corresponding to the information provider 6 a ; an example of a suitable schema is shown in FIG. 2 . As can be seen, in this representation, any given record R comprises a plurality of fields: the URL corresponding to the information provider is stored in field 201 , the keywords in field 203 , the resource allocation amounts in field 205 , site ratings in field 207 , and resource requirements in field 209 . It will be appreciated that FIG. 2 is highly schematic and that for example in the case of field 207 , there the schema will most likely include subfields corresponding to respective elements thereof; for example, there could be a subfield corresponding to automatically generated rankings, manually generated rankings, and ratings specified by other users. Any given record can also include other fields such as an account balance for the information provider (as described in more detail below); conversely any given record can comprise a subset of the fields shown in FIG. 2 .
The processes involved in collating the search results will now be described with reference to FIG. 3 , which shows components of the search engine 10 . The search engine 10 is preferably embodied as a web server, and comprises standard operating system, storage, processor, input/output interfaces, together with includes various bespoke software components 301 , 303 , 305 . These software components are arranged, respectively, to receive a search request, identify keywords within the request (request receiving software component 301 ), to query the search database 20 on the basis of the keywords and generate corresponding search listings (database querying software component 303 ); the search listings are preferably accompanied by the resource allocation data 205 , rating data 207 , resource requirements data 209 in the search database 20 as described above. The request receiving software component 301 is also arranged to identify the terminal 2 to which the search listings are to be transmitted, so that the search results collating software component 305 can deliver the results and accompanying data to this terminal 2 in the form of a results message M 1 . Whilst shown as single units in FIG. 1 , it will be appreciated that the search engine 10 and database 20 can comprise a plurality of units distributed in the Internet 12 .
It will thus be appreciated that in at least some embodiments the data returned to the mobile terminal 2 include, for any given search listing and thus information provider 6 a identified to have content relating to the keywords submitted from the mobile terminal 2 , data indicative of the amount of data retrievable from the information provider 6 a , data indicative of the amount of resources that have been allocated by the information provider 6 a to offset the costs of the mobile terminal 2 accessing the content, and data indicative of ratings applied to the content of the information provider 6 a . Accordingly the mobile terminal 2 includes bespoke software processing components arranged to process these data in order to organise the results into various categories such as “free to access”, “access subsidised”, “fully chargeable”. These software components will now be described with reference to FIG. 4 , which shows components of the mobile terminal 2 .
The mobile terminal 2 has an antenna 401 for communicating across the network 14 in known manner and provides a user interface, having a keypad 403 and display screen 405 , a loudspeaker 407 and a microphone 409 ; alternatively the user interface could comprise components such as touch screens, touch pads and the like. The handset also comprises a processor 411 , an operating environment 413 and various standard software applications such as a browser (as described above); the mobile terminal 2 is also provided with a smart card reader 417 of known type for interacting with a removable or non-removable SIM or a UICC 419 , which may be provided with a processor, operating environment, and software applications. In order to process data according to embodiments of the invention, the mobile terminal 2 includes a search results processing software component 415 , which can be embedded within the browser or can be a separate application running on the mobile terminal 2 . It will be appreciated that the results processing component 415 could comprise means for sending the search request in the first instance, and thus be configured to monitor for the search results message M 1 in response to the query in accordance with standard methods.
Operation of the various components of the distributed information system 1 when servicing a search request will now be described with reference to FIG. 5 , which is a timing diagram showing the various messages and data transmission between components 2 , 10 , 20 , 6 a and 16 . At step S 5 . 1 , the mobile terminal 2 sends a search request to the search engine 10 using the browser application of the terminal 2 , the search request comprising one or more keywords of interest. In addition terminal related information such as data identifying the subscriber and the terminal used by the subscriber associated with the terminal 2 can be sent to the search engine 10 (or a different network component, which is in operative communication with the search engine 10 ); these identifying data are preferably encrypted and can include the International Mobile Subscription Identifier (IMSI), Mobile Station ISDN Number (MSISDN), International Mobile Equipment Identifier (IMEI), terminal type, memory configuration, software configuration, browser type and other identifiers available from the SIM 419 or the terminal 2 or a database in the terminal 2 .
The search request is received by the search engine 10 , having been routed via the mobile network 14 , gateway GW and other network portions, and the request receiving component 301 extracts the keywords from the search request, formulating a query based thereon and sending same to the search database 20 (step S 5 . 3 ). The search database 20 performs a lookup in respect of the keywords and retrieves data indicative of network location and other data stored within fields 201 , 203 , 205 , 207 etc., and creates a message M 1 as described above. The message M 1 is then sent to the mobile terminal 2 (step S 5 . 5 ).
Once the message M 1 has been received, the search results processing software component 415 is arranged to identify the respective search listings therein, which is to say data specifying URL, resource allocation, rating, and resource requirement corresponding to information providers 6 a . . . 6 c identified as having content relevant to the keywords contained within the search request. These data are then processed by the results processing component 415 using various algorithms in order to identify which of the information providers' content can be accessed for free or at a subsidised rate, and optionally, to identify ratings applicable to the content (step S 5 . 7 ).
For example, assuming information provider 6 a has a resource requirement of 3 MB (2 MB+5 click-through links), and that the provider 6 a has specified an allocation of 1 to offset the costs of accessing its content then the results processing software component 415 evaluates a subsidy per KB of content of 1 /3 MB=0.0003 /kbyte. As described above, this effectively represents an amount that the sponsor is willing to subsidise for the mobile terminal 2 to receive data from its network location. Assuming information provider 6 b has a resource requirement of 20 kbyte and has specified that it will pay 0.2 to offset the costs of accessing its content, then the amount of subsidy for accessing the network location corresponding to provider 6 b is 0.2/20=0.01 /kbyte; further, assuming information provider 6 c has an overall resource requirement of 120 kbyte (100 kbyte+2 objects) and has specified “100% sponsorship” for accessing its content, then the entire cost of accessing the content will be offset by the information provider 6 c.
These amounts are then compared against the actual transport costs associated with delivering data from the various network locations to the terminal 2 : this information can be derived from delivery plan data stored either on the SIM 419 , or delivered, upon request, to the terminal, from the operator in respect of which the terminal 2 is a subscriber, or can be entered manually. For example, assuming the costs of transport to terminal 2 are P=0.007 /kbyte, then the costs of accessing data from information providers 6 a , 6 b , 6 c are as follows:
Information provider 6 a : 1 /2 MB=0.0003 /kbyte, which is less than the transport costs, so that, whilst the data is subsidised, it will nevertheless be delivered at a cost. Information provider 6 b : 0.2/20 kbyte=0.01 /kbyte, which is greater than the transport costs, so that data will be delivered at no cost. Information provider 6 c : 0.3/120 kbyte=0.0025 /kbyte, which is less than the transport costs; in any event, the information provider 6 c has indicated that it will cover all of the transport costs, so that the data will be delivered at no cost.
The foregoing passages assume that all of the information providers listed in the search database 20 have submitted a non-zero allocation of resources for use in offsetting the costs of accessing their content. However, the search database 20 will also hold entries corresponding to information providers that are not interested in subsidising access to their content. Since the query performed by the database querying software component 303 will return all data corresponding to all information providers having entries in the database 20 associated with to the keywords specified in the search request, the message M 1 will include entries corresponding to non-paying and paying information providers.
The search listings could be assigned one of the above-mentioned access categories (“free to access”, “access subsidised”, “fully chargeable”), and be presented to the recipient in the form of a URL link together with an indication of the assigned category. The rating data can additionally be presented in conjunction with the category, thereby providing an indication to the recipient of a generally accepted value of the content accessible from respective information providers 6 a , 6 b , 6 c . Examples of possible graphical representations of this information are shown in FIGS. 6 a and 6 b , which show various forms of a results page WI that can be output from the results processing software component 415 . It will be appreciated that these are examples of possible ways of representing the output and that combinations of the various representations are possible.
When a link within the search listings is selected, this causes the terminal 2 to send an account identifier and URL corresponding to the selected listing to the search engine 10 ; the search engine 10 , more specifically the account updating software component 307 thereof, is then responsible for updating the respective account together with providing a means of re-directing the request to the URL of the selected listing. Typically the account identifier is embedded as a parameter in the URL, but it could be embedded within a cookie that is transmitted to, and maintained at, the terminal 2 along with the results message M 1 .
Assuming the user to select one of the links appearing within the subsidised portion (e.g. information provider 6 a ), message M 2 comprising account identification and/or the selected URL is transmitted to the search engine 10 (step S 5 . 9 ). When received, the account updating component 307 sends a standard HTTP retrieval request to the URL listed within message M 2 , the request having, as source address, a network identifier corresponding to the terminal 2 (step S 5 . 1 ).
Alternatively the search engine 10 returns information such a redirecting URL to the browser running on the mobile terminal 2 . As an example, message M 2 can comprise the following data:
http://www.search service.com/url?sa=L=0wSrvIS3D QoAgBUN z-&q=http://www.infoprovider6a.com/p=leuro sponsor sKpNrit4Aw”.
The message M 2 will be analysed by the search engine 10 , causing a redirection message to http://www.inforpovider6a.com to be returned to the terminal 2 .
Data are then transmitted to the terminal 2 under control of the information provider 6 a corresponding to the selected URL in response to the re-directed access request transmitted from the search engine 10 at step S 5 . 11 . It is to be noted that the data can be modified and/or selected based on the capabilities of the terminal 2 , these being requested from the terminal 2 or derivable by the information source 6 a on the basis of information held by the search engine 10 (e.g. based on the information transmitted from the terminal at steps S 5 . 1 or S 5 . 9 ).
Whilst this is shown in FIG. 5 (step S 5 . 13 ), it will be appreciated that transmission of data from the network location occurs independently of the components of data information system 1 , and is shown for completeness only.
The account updating software component 307 accesses the search database 20 on the basis of account identifier retrieved from message M 2 , and at step S 5 . 15 indicates that data have been accessed from this information provider 6 a.
In one arrangement step S 5 . 9 can additionally involve the mobile terminal 2 transmitting a further message M 3 to the search engine 10 , which includes data identifying the cost of accessing data from the information provider 6 a (as identified by the results processing software component 415 at step S 5 . 7 ). The message can include data identifying the subscriber associated with the terminal 2 (preferably encrypted); these identifying data preferably correspond to those data sent at step S 5 . 1 and can include the International Mobile Subscription Identifier (IMSI), Mobile Station ISDN Number (MSISDN), International Mobile Equipment Identifier (IMEI), memory configuration, software configuration, browser type and other identifiers available from the SIM 419 or the terminal 2 or a database in the terminal 2 . In response to receipt of message M 3 the account updating software component 307 can then update the account balance to account for the transport costs associated with delivering the content to the terminal 2 . In such arrangements—those in which the transport costs are accounted for in real time—the search engine 10 can then send a message M 4 to the billing system 16 associated with the mobile network portion 14 shown in FIG. 1 . This message M 4 includes data identifying the subscriber associated with the mobile terminal 2 , derived from the message M 3 sent at step S 5 . 9 , and again preferably formatted in encrypted form. Returning to FIG. 5 , data indicative of the actual cost to the subscriber to receive data from the selected information provider 6 a are thus transmitted to the billing system 16 at step S 5 . 17 , for use in incrementing the subscriber's balance to as to account for the fact that delivery of the content has been sponsored by the information provider 6 a.
In a particularly advantageous arrangement these data are transmitted to the billing system at the same time as, or before, the request for content is transmitted to the information provider 6 a at step S 5 . 11 , thereby ensuring that the subscriber's balance is “topped up” to include the subsidised costs or to ensure that data connection is allowed.
As an alternative to the mobile terminal 2 transmitting the evaluated transport costs to the search engine 10 at step S 5 . 9 , the account updating software component 307 can independently evaluate the transport costs on the basis of whichever data plan is associated with the network operator of the mobile terminal 2 , this having been sourced from the various network operators by virtue of an agreement between the network operator and the search provider. In such arrangements the message M 3 would simply include data identifying the subscriber of the mobile terminal 2 so that the account updating software component 307 can identify the transport costs applicable to delivery of data to this subscriber.
In the above embodiments the mobile terminal 2 is described as sending queries for web pages and documents accessible via the web relating to keywords of interest to the user, and there being a search engine 10 arranged to broker, coordinate and account for user access to such content. However, embodiments of the invention could also be applied to arrangements such as that shown in FIG. 7 , in which there is a service 12 that can simply provide access to a list of web sites. The service 12 is connected to service database 24 , which is arranged to hold records corresponding to those shown in FIG. 2 , with or without the inclusion of keywords characterising data accessible from the web sites. In such arrangements the mobile terminal 2 would additionally be equipped with an application (not shown) for accessing the service 12 and requesting information about the various site, in particular links and objects that are accessible from a given site. In view of the fact that access to data and objects in a given site incurs transport costs, the application would be capable of receiving input from the user identifying those parts of the web site that the user does not want to be receive at the mobile terminal (typically resource intensive links or objects). This process is shown in FIG. 8 , and largely mirrors the steps described above in relation to FIG. 5 : the notable differences to the first embodiment lie in the content sent in message M 5 at step S 8 . 5 : this includes details of the objects and links that are accessible via the URL listed as a web site accessible via service 12 . In addition, step S 8 . 7 involves running an application that allows the user to select objects and links that it does not wish, or wishes to receive from the web site, while message M 6 transmitted at step S 8 . 9 additionally includes details of the selected objects and links. As a result, the service 12 acts as a filter in relation to the content accessible from the information provider 6 a : as shown in FIG. 8 , the service 12 requests data from the website to be transmitted thereto (step S 8 . 11 ), thereby enabling the service 12 to remove those objects and links specified by the contained within message M 6 . Accordingly the data that are transmitted to the mobile station 2 at step S 8 . 17 is a subset of the data accessible from the information provider 6 a . Clearly, in view of the fact that the resource requirements etc. associated with links and objects are specified in the data transmitted in the message M 5 transmitted at step S 8 . 5 , the transport costs can be evaluated based on this selected subset of data.
Thus this embodiment of the invention involves the mobile terminal 2 including an application with a user interface that displays data accessible from a specified web site to the user and enables the user to select therefrom. Alternatively the browser or application running on the terminal 2 can be configured so as to automatically request specific types of objects and elements; such a request can be formulated on the basis of selection rules stored by the terminal 2 , these rules specifying object size (including resolution in the case of images and file size in relation to file types generally), delivery costs, data plan associated with the terminal 2 etc.
As an alternative, the mobile terminal 2 could be equipped with an application that enables the user to enter data indicative of a web site for which transport costs etc. associated with links accessible via the web site are required (i.e. those links for which clicking on the link would lead to the transmission of further data to the mobile terminal); in such arrangements the content of the web site corresponding to the URL entered by the user is downloaded to the mobile terminal, and then forwarded from the mobile terminal to the service 12 . This process flow is illustrated in FIG. 9 , and receipt of the content from the information provider 6 a triggers step S 8 . 1 shown in FIG. 8 . Subsequent forwarding of the content to the service 12 can occur with or without manual intervention on the part of the user; in the case of manual intervention, the user can specify those particular parts of the web site that are to be filtered from the web site. In cases involving automatic forwarding of the data to the service 12 , the application can be configured with access to rules that automatically trigger step S 8 . 1 in response to detection of certain data within the data downloaded from the information source 6 a.
Additional Details and Modifications
The embodiments described in relation to FIG. 8 describe the mobile terminal 2 being configured with a user interface that enables the user to select items from a web site that are to be included/excluded as accessible to the user. The user interface can additionally include means for the user to transmit data indicative of a ranking applied by the user to the content associated with any given information provider 6 a , 6 b , 6 c ; this ranking data can be transmitted to the search database 20 (or database 24 ) or a third party responsible for maintaining the ranking data (which feeds the ranking data into the databases 20 , 24 in the manner described above).
The requests submitted at step S 5 . 1 can be submitted from a terminal other than the one to which the search results are to be delivered; for example, requests could be submitted as part of an automated process, which includes, as one of the input fields, an identifier corresponding to the terminal 2 destined to receive the search results. In addition, search requests could be typed in or entered via speech recognition software.
Each record R i in the search database 20 corresponding to an information provider can additionally comprise a field relating to an account balance for the information provider. The balance is quantified in terms of resources, which can be money or usage of different types of communications services. The latter type of resource are particularly convenient for embodiments of the invention, since communications resources could be directly traded rather than being translated into and out of financial amounts.
Whilst in the above embodiment the results message M 1 is delivered directly to the mobile terminal 2 , the search results could alternatively be transmitted to a search results service, for further processing of the results or delivery thereof to the mobile device.
The term “sponsored link” is to be understood as subsidizing access to content associated with any of the links listed in the message M 1 .
By way of clarification, the term “non-sponsored link” is to be understood as including (but not limited to) a link to a network location associated with an information source whose presence in a list of results is defined purely on the relevance of the content of the data items associated with the web page to the request and is unrelated to any subsidy that might be applied to effect delivery thereof.
Additionally, when the terminal 2 requests data from a service such as information provider 6 a , the browser or application 415 running on the terminal 2 can be configured to request associated ranking and other related information e.g. nested links associated with the information provider 6 a from the service 12 . The information from service 12 can be used by an application or browser in the terminal 2 to inform the user about certain characteristics of links via the user interface. The requested information can include rating information, mobile friendliness, feasibility of the content behind the link for the target terminal, size of the content, price of the delivery etc., and this information enables the user to decide whether or not to access data from the information provider 6 a . The user interface can block or hide some of the links on the basis of predefined screening rules held by the mobile terminal 2 . These screening rules can include rules relating to e.g. feasibility of accessing a link and content type and can be manually configured by the user of the terminal or automatically set by other authorised users such as parents or employers. Such screening rules can be automatically set on the basis of information uploaded to the service 12 by the authorised users, and then downloaded to the mobile terminal 2 for use in controlling access thereto.
The above embodiments are to be understood as illustrative examples of the invention. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.
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A method of recording allocation of resources in response to a request for a data item to be transmitted to a device in the network where the request comprises data indicative of one or more requested items. The device is typically a mobile device and the requested items can be key words making up a search request or can be web site names indicating web sites of interest to the user. In response to the request, data listings having items generating a match with the requested data item are identified and data indicative of a network location corresponding to the or each matched data item are retrieved. In addition data indicative of an amount of data and a resource allocation associated with the set of data accessible via the network location are retrieved and these data, together with a network subscription associated with device and the amount of data, are used to evaluate actual usage of network resources when accessing the set of data. If data are subsequently requested from the network location the evaluated actual usage is offset against the resource allocation so as to identify an amount of usage of network resources to be charged to the network subscription, and a record associated with said data listing is updated so as to log said resource allocation event.
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FIELD OF THE INVENTION
The present invention relates to novel, fluorosilicone fluids, and more particularly, to fluorosilicone fluids useful as high-density fluid ocular tamponades, methods of producing the fluorosilicone fluids and methods of using the fluorosilicone fluids in vitreoretinal surgical procedures.
BACKGROUND OF THE INVENTION
Ocular tamponades are vitreous substitutes that are used to reposition the retina of an eye in instances where a reattachment is not achievable by natural healing or by laser coagulation. The purpose of a vitreous substitute is to provide long-term tamponade of the retina, i.e., exhibit an ideal tamponade pressure (force/area) to position and maintain the retina in place while not damaging the retina. The tamponade pressure is a function of the density of the tamponade polymer and the volume occupied thereby in the vitreous. The ideal tamponade is non-toxic, chemically inert and highly transparent. Current commercially used tamponades include perfluorocarbon-liquids, balanced salt solutions, silicone oil or fluid and gases, such as air, sulfur hexafluoride (SF 6 ) and perfluorocarbons (PFCs). The type of tamponade used depends on the severity of the retinal detachment. The addition of a PFC fluid that has a high specific gravity of approximately 1.7 to 2.0 g/cm 3 expulses the subretinal fluid into the vitreous cavity and pushes the retina into place. Such fluids reposition the detached retina very effectively, but can only be used for short-term application because with long term PFC fluid use, retinal necrosis occurs. This is believed to be due to a combination of the high solubility of oxygen in the PFC fluids and the high density of the PFC fluids. Silicone oil is the preferred tamponade in cases of severe detachment, where the tamponade will be used six months or longer. Silicone oil, however, has a density of less than 1 (0.98 g/cm 3 ) and is therefore only useful for retinal detachment of the superior portion of the eye. The silicone oil in the vitreous will migrate to the upper position of the vitreous only and is unacceptable in cases of lower retinal detachments or where there may be a risk of vitreoretinopathy in the lower position of the vitreous. Further, for the aphakic eye, the silicone oil will tend to move to the anterior chamber of the eye during sleep and come in contact with the corneal endothelium, creating a number of serious ocular defects.
Because of the noted shortcomings of current, commercially available ocular tamponades, there is a need for ocular tamponades that are relatively easy to synthesize and purify and that both the viscosity and density can be controlled.
SUMMARY OF THE INVENTION
The present invention is a novel high-density vitreoretinal fluid tamponade that is based on a fluorosilicone fluid. Preferred fluorosilicone fluids of the present invention have the general structure illustrated in Formula 1 below:
wherein x is an integer less than 500; y is an integer less than 500; x+y is equal to an integer greater than 1 and less than 1000; z is an integer less than 100; and R is selected from the group consisting of hydrogen and fluorine.
The high-density fluorosilicone fluid vitreoretinal tamponades of the present invention are relatively easy to synthesize and purify. Likewise, both the viscosity and density can be controlled through the respective degree of polymerization and degree of fluoro side-chain substitution.
Accordingly, it is an object of the present invention to provide a high-density vitreoretinal tamponade.
Another object of the present invention is to provide a process for the manufacture of a high-density vitreoretinal tamponade.
Another object of the present invention is to provide a process for using a high-density vitreoretinal tamponade in a surgical procedure.
Another object of the present invention is to provide a process for manufacturing vitreoretinal tamponades that allows for control of the density and viscosity of the vitreoretinal tamponade .
Still another object of the present invention is to provide a vitreoretinal tamponade suitable for relatively long term use in an eye.
A further object of the present invention is to provide a process for manufacturing and using a vitreoretinal tamponade suitable for relatively long term use in an eye.
These and other objectives and advantages of the present invention, some of which are specifically described and others that are not, will become apparent from the detailed description and claims that follow.
DETAILED DESCRIPTION OF THE INVENTION
The subject invention is a high-density vitreoretinal fluid tamponade based on a fluorosilicone fluid. The preferred fluorosilicone fluids of the present invention have the general structure illustrated in Formula 1 below:
wherein x is an integer less than 500; y is an integer less than 500; x+y is equal to an integer greater than 1 and less than 1000; z is an integer less than 100; and R is selected from the group consisting of hydrogen and fluorine.
The high-density fluorosilicone fluid vitreoretinal tamponades of the present invention are relatively easy to synthesize and purify. Synthesis of the fluorosilicone fluid vitreoretinal tamponades of the present invention is accomplished by either a one-step ring opening polymerization process or a two-step ring opening/hydrosilation process as illustrated in Scheme 1 below.
During synthesis of the subject fluorosilicone fluid, both viscosity and density can be controlled through the respective degree of polymerization and degree of fluoro side-chain substitution. For example, should increased density and/or viscosity be desired, the same is achieved by increasing the siloxane chain length and increasing the fluoro side-chain substitution. Likewise, should decreased density and/or viscosity be desired, the same is achieved by decreasing the siloxane chain length and decreasing the fluoro side-chain substitution.
Once synthesized, the subject fluorosilicone fluid is then purified by supercritical fluid extraction, solvent extraction or high vacuum devolatilization as known by those skilled in the art of purification.
The fluorosilicone fluid vitreoretinal tamponades of the present invention are described in still greater detail in the examples that follow. It should be noted that the procedure set forth in the following examples represents only one of many possible procedures useful in the preparation of the subject fluoro functionalized siloxanes.
EXAMPLE 1
Ring-opening/Hydrosilation Procedure
Synthesis of Trimethylsilyl-Capped Poly (25 mole % methyl siloxane)-co-(75 mole % dimethylsiloxane)(T 2 D 75 D 25 H)
To a 1000 mL round bottom flask under dry nitrogen was added octamethylcyclotetrasiloxane (D 4 (371.9 g, 1.25 mole)), tetramethylcyclotetrasiloxane (D 4 H (100.4 g, 0.42 mole)) and hexamethyldisiloxane (T 2 (0.7 mole)). Trifluoromethane sulfonic acid (0.25%, 1.25 g, 8.3 mmole) was added as initiator. The reaction mixture was stirred 24 hours with vigorous stirring at room temperature. Sodium bicarbonate (10 g, 0.119 mole) was then added and the reaction mixture was again stirred for 24 hours. The resultant solution was filtered through a 0.3μ teflon® (E. I. DuPont de Nemours and Company, Wilmington, Del.) filter. The filtered solution was vacuum stripped and placed under vacuum (>0.1 mm Hg) at 50° C. to remove the unreacted silicone cyclics. The resulting silicone hydride functionalized siloxane was a viscous, clear fluid. (Yield 70%; SEC: Mn=7,500, Mw/Mn=2.2.)
EXAMPLE 2
General Procedure for the Synthesis of the Fluoro Side Chain Siloxanes
Synthesis of Methacrylate End-Capped Poly (25 mole% (3-(2,2,3,3,4,4,5,5-octafluoropentoxy)propyl methyl siloxane)-co-(75 mole% dimethylsiloxane)(Scheme 2)
To a 500 mL round bottom flask equipped with a magnetic stirrer and water condenser was added T 2 D 75 D 25 H (0.002 mole), allyloxyoctafluoropentane (27.2 g, 0.1 mole), tetramethyldisiloxane platinum complex (2.5 mL of a 10% solution in xylenes), 75 mL of dioxane and 150 mL of anhydrous tetrahydrofuran under a nitrogen blanket. The reaction mixture was heated to 75° C. and the reaction was monitored by IR and 1 H-NMR spectroscopy for loss of silicone hydride. The reaction was complete in 4 to 5 hours of reflux. The resulting solution was placed on a rotoevaporator to remove tetrahydrofuran and dioxane. The resultant crude product was diluted with 300 mL of a 20% methylene chloride in pentane solution and passed through a 15 gram column of silica gel using a 50% solution of methylene chloride in pentane as eluant. The collected solution was again placed on the rotoevaporator to remove solvent and the resultant clear oil was placed under vacuum (>0.1 mm Hg) at 50° C. for four hours. The resulting octafluoro functionalized side-chain siloxane was a viscous, clear fluid. (Yield 65%; SEC: Mn=17535, Mw/Mn=1.7 (see attached table.))
The chemical properties of the fluorosilicone fluid vitreoretinal tamponades of the present invention are described in detail in Table 1 below.
TABLE 1
Chemical Properties of Perfluorosilicone
Fluids for Retinal Tamponade Application
Refractive
Surface
Interfacial
Com-
Viscosity
Index
Density
Tension
Tension
pound
(cps)
(25° C.)
(g/cm 3 )
(mN/m)
(mN/m)
1*
9300
1.3914
1.115
25.5
30.4
2**
2150
1.3837
1.254
27.1
31.9
3***
1120
1.3860
1.212
26.1
27.0
4****
130
1.3964
1.032
24.1
39.0
5*****
185
1.3823
1.144
23.2
32.1
6******
980
1.3668
1.248
23.9
33.1
7*******
9300
1.3860
1.124
27.2
31.8
Commercial
variable
1.4040
0.962
24.2
N.A.
Silicone Oil
Tamponade
100-6000
1.30-1.40
1.0-1.6
20-30
25-50
Material
Require-
ments
*x = 75, y = 25, z = 4, R = H
**x = 13, y = 37, z = 4, R = H
***x = 25, y = 25, z = 4, R = H
****x = 45, y = 5, z = 4, R = H
*****x = 45, y = 5, z = 8, R = F
******x = 75, y = 25, z = 8, R = F
*******x = 100, y = 100, z = 8, R = F
Fluorosilicone fluid tamponades synthesized and purified using the processes of the present invention are used as customary in the field of ophthalmology. For example, in a surgical vitreoretinal procedure, the fluorosilicone fluid tamponade synthesized and purified in accordance with the processes of the present invention is placed and maintained in the posterior segment of the eye for the desired period of time prior to the removal thereof.
While there is shown and described herein a process for the synthesis and purification of fluorosilicone fluids for use as ocular tamponades, it will be manifest to those skilled in the art that various modifications may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to particular processes herein described except insofar as indicated by the scope of the appended claims.
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Fluorosilicone fluids useful as high-density fluid ocular tamponades and methods of producing, purifying and using the fluorosilicone fluids in an ocular surgical procedure for retinal treatment.
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FIELD OF THE INVENTION
[0001] This invention relates to power amplifiers and, more specifically, to a circuit and method for adjusting the voltage at the commonly connected ballasted ends of a plurality of base ballasted HBTs forming a power amplifier when the voltage appearing at one of the bases of the plurality of HBTs drops below a threshold.
BACKGROUND OF THE INVENTION
[0002] Hetero-junction bipolar transistor (HBT) power amplifiers are becoming the standard for cellular applications due to their high power density and reduction in die size. HBT's can draw substantial base current during high power operation. Since multi-finger power devices suffer from thermally related current collapse they cannot be operated without ballast resistors on either the emitter or base. Emitter ballasting is not practical for power amplifiers because of the high emitter currents and small resistor values, so base ballasting must be used. Because an individual HBT is a very small device, it is required to be paralleled with multiple HBTs to achieve high power operation required for most power amplifier applications.
[0003] Accordingly, HBT power amplifiers such as those used in radio frequency (RF) applications employ multiple small devices connected in parallel. As noted above, each of these small HBT devices require a ballast resistor to be connected to its base before being connected to the other HBTs forming the power amplifier (PA). The resistive ballasting of individual cells keeps parallel HBT fingers from entering thermal collapse. Additionally, a capacitor may be used to bypass the base resistor to preserve high frequency gain or the RF signal may be fed to the base connections through a separate capacitor. For purposes of illustration, the figures contained herein will illustrate the principal using capacitor bypassed ballast resistors although those skilled in the art will realize that this embodiment of the invention will work the same regardless of the connection of the RF capacitors feeding the base connection.
[0004] [0004]FIG. 1 shows a typical multi-fingered base ballasted Power Amplifier (PA) circuit. A plurality of HBTs 110 , each ballasted with a resistor 130 /capacitor 120 are connected in parallel. For each small HBT device, first ends 130 a , 120 a of a resistor 130 and a capacitor 120 are connected to the base 185 of the individual HBT devices and the other ends 130 b , 120 b of the resistor and the capacitor become the input 180 of each base ballasted HBT device 190 . For purposes of simplicity, when two or more base ballasted HBT devices 190 are “connected in parallel”, their collectors 160 share a first common node, their emitters 170 share a second common node connected to ground, and the inputs 180 share a third common node. A radio frequency signal is received at the input 140 and connected to the commonly connected inputs 180 of the base ballasted HBT devices 190 . The commonly connected collectors 160 that are connected to a voltage source 155 produce an amplified RF output 150 .
[0005] Due to the base current requirements, a biasing circuit 195 is usually included. Typical biasing circuits with RF decoupling components neglected for simplicity are shown in FIGS. 2 and 3. FIG. 2 shows a diode biasing circuit 200 . The base of an HBT device 210 is connected to the collector and the collective inputs 180 of the of the base ballasted HBT devices 190 of FIG. 1. The emitter is connected to ground. The first end 220 b of a reference resistor 220 is connected to the collector and base while the second end 220 a of the reference resistor 220 is connected to a reference voltage 230 .
[0006] [0006]FIG. 3 shows a preferred current mirror biasing circuit 300 . A current mirror is formed by HBT devices 310 and 320 . The collector of the first HBT device 310 is connected to a voltage source 350 , its emitter is connected to the base of the second HBT device 320 and its base is connected to the collector of the second HBT device 320 . The emitter of the second device is connected to ground. And finally, the first end 330 b of a reference resistor 330 is connected to the base of the first HBT device 310 and the collector of the second HBT device 320 while the second end 330 a of the reference resistor is connected to a reference voltage 340 .
[0007] Although not exhaustive, these biasing circuits are typical of those employed in the industry although other types of biasing circuits are contemplated and may be used with the invention. The biasing circuits try to keep the current through the power device constant with variations in temperature and reference voltages. Although either of these biasing circuits or others could be used, current mirror biasing is typically preferred and will be used in the discussion.
[0008] Using the current mirror of FIG. 3 as the Bias of FIG. 1, the reference voltage 340 and the reference resistor 330 form a constant current source which is mirrored by the first HBT device 310 and the second HBT device 320 . If no ballast resistors 130 were required, the current mirror would be adequate up to the limits of the HBT devices 310 and 320 . However, with ballast resistors and during high power operation, the current mirror is unable to keep the voltage on the bases 185 of the individual HBT power device cells 110 constant because of the drop on the ballast resistor. In power operation when more HBTs are connected in parallel, increased base current is required from the current mirror. This strain on the current mirror results in increased voltage drops across the ballasting resistors 130 resulting in the voltage at the base of the individual HBT devices 110 to droop, limiting linearity and maximum output power.
[0009] What is required is an improved HBT power amplifier circuit that doesn't effect the quiescent point at lower output powers, but comes into play when higher powers are being generated that effectively prevents this drooping from occurring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a simplified electrical schematic of a prior art base ballasted HBT power amplifier;
[0011] [0011]FIG. 2 is a simplified electrical schematic of a diode bias circuit occasionally used in HBT power amplifiers;
[0012] [0012]FIG. 3 is a simplified electrical schematic of a current mirror bias circuit typically used in HBT power amplifiers;
[0013] [0013]FIG. 4 are a simplified electrical schematic of a base ballasted HBT power amplifier including an HBT linearizer and power booster according to one embodiment of the invention; and
[0014] [0014]FIG. 5 is a flow chart demonstrating a method of increasing linearity and boosting power of an HBT power amplifier according to one embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] Referring to FIG. 4, one model of an embodiment of a base ballasted HBT power amplifier with an HBT linearizer and Power Booster is shown. Similar reference numerals are used throughout the figures to represent similar features when possible.
[0016] A plurality of base ballasted HBT devices 190 are connected in parallel. Each of the ballasted HBT devices 190 have a ballast resistor 130 connected at one end to the base of the HBT cell 110 and the other producing an input 180 of the base ballasted HBT device 190 . A ballast capacitor 120 may be connected across the ballast resistor as shown. Although the embodiment shown includes a resistor biasing scheme with a bypassing capacitor, other ballasting schemes are possible such as bringing in the RF signal to each base node through an individual capacitor, often called split ballasting. As split ballasting is well know in the industry, a detailed description is not included for simplicity. A plurality of base ballasted HBT devices 190 are connected in parallel such that their inputs 180 share a common node and receive an RF input signal, their collectors 160 are connected to a voltage source 155 and produce an RF output signal 150 , and their emitters 170 share a node and are connected to ground.
[0017] At least one base 185 a of one of the HBT devices is connected through a resistor 430 to a base 412 of an HBT transistor 410 . The emitter 411 of this HBT transistor 410 is connected to ground 360 while the collector 413 is connected to a base 422 of another HBT transistor 420 . The emitter 421 of the HBT transistor 420 is connected to the commonly connected inputs 180 of the base ballasted HBT devices 190 while the collector is connected to a voltage source 350 . A resistor 450 is connected such that one end connects with the base 422 of HBT transistor 420 and collector 413 of HBT transistor 410 and the end of the resistor connects to the voltage source 350 . A capacitor 440 is connected between the base 412 of the HBT transistor 410 and ground 360 such that resistor 430 and capacitor 440 form a low pass filter for the signal detected from at least one base 185 a of one of the HBT devices 110 forming the power amplifier.
[0018] A bias circuit 195 of the current mirror type is connected such that the collector of the first HBT device 310 is connected to a voltage source 350 , its emitter is connected to the base of the second HBT device 320 and its base is connected to the collector of the second HBT device 320 . The emitter of the second device is connected to ground 360 . And finally, the first end 330 b of a reference resistor 330 is connected to the base of the first HBT device 310 and the collector of the second HBT device 320 while the second end 330 a of the reference resistor is connected to a reference voltage 340 .
[0019] In operation, the HBT device 410 senses the voltage appearing on one of the bases 185 a of at least one of the HBT device cells 110 through the low pass filter formed by resistor 430 and capacitor 440 . Resistor 450 is set such that at quiescent or low power operation, HBT device 420 supplies negligible current to the commonly connected inputs 180 of the base ballasted HBT devices 190 allowing the power device to be entirely controlled by the current mirror bias formed by HBT devices 310 and 320 .
[0020] During high power operation, if the voltage on the base of the power HBT device cell 100 sags, it is detected across the low pass filter by HBT device 410 , which begins to turn off. As HBT device 410 begins to turn off it caused the base voltage appearing on the base 422 of HBT transistor 420 to increase. An increase voltage at the base 422 of HBT transistor 420 causes an increased voltage to appear on the emitter of HBT transistor 420 which drives the commonly connected inputs 180 of the base ballasted HBT devices 190 . Thus, at high power operation, the voltage boost circuit created by HBT devices 410 and 420 takes over the power amplifier from the normal current mirror biasing circuit. Since this added circuitry supplies a higher voltage supply than the current mirror alone, it keeps the base bias at needed values further into compression and improves linearity and boosts power.
[0021] [0021]FIG. 5 is a flowchart demonstrating a method of linearizing the HBT power amplifier and boosting power during drooping of high power operations according to one embodiment of the invention. When the circuit is on, in step 520 , the power booster and linearizer constantly monitors the voltage appearing directly at the base of one of a plurality of base ballasted HBT devices connected in parallel where the base ballast of the individual HBT devices may cause a voltage difference to occur between the input to the plurality of base ballasted devices and the bases of the HBT cells. If the voltage appearing directly at the base of at least one of the HBT cells begins to droop in step 530 , the circuit provides supplemental power to the plurality of parallel connected base ballasted HBT devices in step 540 , otherwise, the circuit passively provides negligible quiescent current to the plurality of base ballasted HBT devices. This allows the circuit to predictably run according to any well known bias that has been implemented to control the power amplifier.
[0022] While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.
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A power amplifier incorporates base ballasted hetero-junction bipolar transistors (HBTs) in parallel. A transistor pair adjusts the voltage applied to the base ballast if it senses that the voltage appearing between one of the HBT transistors and its base ballast is drooping to a level not strong enough to keep the HBTs active.
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RELATED APPLICATIONS
This application claims priority to U.S. Provisional Patent Application No. 61/202,363, filed on Feb. 23, 2009, the entire content of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a wall fixture, and more particularly to a wall fixture for furring a solid wall.
SUMMARY
With recent developments in building codes, exterior walls including basement walls, must meet R-15 or better insulation values. This has led to the development of Insulated Concrete Forms (ICFs), the use of Z-furring with foam panels, and other methods of insulating solid walls in general and in concrete, masonry, and block walls in particular. All of these methods of insulating solid walls have limitations, particularly with respect to secondary operations such as installing pipes, wires, plumbing, and other conduits. Other limitations include thermal bridging, porous construction, and outdoor exterior surfaces that do not provide adequate protection from the elements.
In some embodiments, the present invention provides a wall fixture positionable between an interior wall and an exterior wall of a structure, the interior wall being positionable substantially parallel to and spaced a distance from the exterior wall, each of the interior and exterior walls extending between a floor and a ceiling of the structure. The wall fixture includes a web defining multiple apertures extending through the web between opposite sides of the web and sized to receive at least one of plumbing, conduit, and wires, a first flange extending outwardly from a first end of the web and being engageable with one of the interior wall and the exterior wall, the first flange including multiple mounting locations spaced along a length of the first flange for supporting fasteners securable at multiple locations spaced along a height of the one of the interior wall and the exterior wall, and a second flange extending from a second end of the web opposite the first end of the web and being engageable with the other of the interior wall and the exterior wall. The second flange is pivotally connected to the web for movement relative to the web between a first orientation, in which the second flange is substantially parallel to the web, and a second orientation, in which the second flange is non-parallel to the web. The second flange includes multiple mounting locations spaced along a length of the second flange for supporting fasteners securable at multiple locations spaced along a height of the other of the interior wall and the exterior wall.
In some embodiments, the present invention provides, a wall fixture positionable between an interior wall and an exterior wall of a structure, the interior wall being spaced a distance from the exterior wall, each of the interior and exterior walls extending between a floor and a ceiling of the structure. The wall fixture includes a first member having a flange extending from a web, the flange including multiple mounting locations spaced along a length of the flange for supporting fasteners securable at multiple locations spaced along a height of one of the interior wall and the exterior wall, and a second member having a flange extending from a web, the second member adjustably securable to the first member such that a distance between exterior sides of the flanges is variable, the flange of the second member including multiple mounting locations spaced along a length of the flange for supporting fasteners securable at multiple locations spaced along a height of an other of the interior wall and the exterior wall, the web of one of the first member and the second member defining multiple apertures extending through the web between opposite sides of the web and sized to receive at least one of plumbing, conduit and wires. A stop is positioned on one of the first member and the second member to limit relative movement between the first and second members and to prevent movement of the other of the first member and the second member across the apertures.
The present invention also provides a wall mounting system including an interior wall and an exterior wall of a structure, the interior wall being spaced a distance from the exterior wall, each of the interior and exterior walls extending between a floor and a ceiling of the structure, and a wall fixture positionable between the interior wall and the exterior wall. The wall fixture includes a first member having a flange extending from a web, the flange including multiple mounting locations spaced along a length of the flange for supporting fasteners securable at multiple locations spaced along a height of the interior wall, a second member having a flange extending from a web, the second member adjustably securable to the first member such that a distance between exterior sides of the flanges is variable, the flange of the second member including multiple mounting locations spaced along a length of the flange for supporting fasteners securable at multiple locations spaced along a height of the exterior wall. The web of one of the first member and the second member defines multiple apertures extending through the web between opposite sides of the web and sized to receive at least one of plumbing, conduit and wires. The web of the first member includes a channel having multiple indentations spaced along a length of the channel. The web of the second member includes multiple protrusions spaced along a length of the web, the web of the second member being insertable into the channel of the first member in a direction substantially parallel to the length of the web of the second member such that the protrusions engage the indentations to adjustably secure the first member to the second member and vary the distance between the flanges.
Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a wall fixture according to one embodiment of the invention.
FIG. 2 is another cross-sectional view of the wall fixture of FIG. 1 .
FIG. 3 is an enlarged view of a portion of the wall fixture of FIG. 1 .
FIG. 4 is a partial perspective view of the wall fixture of FIG. 2 .
FIG. 5 is an exploded cross-sectional view of a wall fixture according to another embodiment of the invention.
FIG. 6 is a cross-sectional view of the wall fixture of FIG. 5 .
FIG. 7 is another cross-sectional view of the wall fixture of FIG. 5 .
FIG. 8 is a top view of a portion of the wall fixture of FIG. 5 .
FIG. 9 is a bottom view of a portion of the wall fixture of FIG. 5 .
FIG. 10 is a side view of the wall fixture of FIG. 5 .
FIG. 11 is a front view of a wall mounting system constructed from the wall fixture of FIG. 5 .
FIG. 12 is a cross-sectional side view of a portion of the wall mounting system of FIG. 11 .
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
DETAILED DESCRIPTION
FIGS. 1-4 illustrate a wall fixture 10 according to some embodiments of the invention. As shown in FIG. 1 , the wall fixture 10 includes a web 15 , a first flange 20 , and a second flange 25 . The first flange 20 extends substantially perpendicularly from one end of the web 15 and the second flange 25 extends substantially perpendicularly from the opposite end of the web 15 . A latch 30 extends from the web 15 . A protrusion 35 extending from the second flange 25 defines a recess 37 for receiving the latch 30 . The second flange 25 is pivotally coupled to the web 15 by a hinge 40 .
As shown in FIG. 3 , a stop 42 is provided near the hinge 40 . The wall fixture 10 can be made of plastic, including recycled plastic. The wall fixture 10 can be formed by extrusion. The hinge 40 can be a living hinge. In some embodiments, the latch 30 is received by a recess 37 defined by the second flange 25 . The stop 42 can be supported by either the web 15 or the second flange 25 . In some embodiments, both of the web 15 and the second flange 25 support a stop 42 .
FIG. 1 shows the wall fixture 10 in a first orientation. In the first orientation, the second flange 25 is substantially parallel to the web 15 . As shown by the arrow in FIG. 1 , the second flange 25 can be pivoted about the hinge 40 to a second orientation.
FIG. 2 shows the wall fixture 10 in the second orientation. In the second orientation, the second flange 25 is non-parallel to the web 15 . In the illustrated embodiment, the second flange 25 is substantially perpendicular to the web 15 . The latch 30 engages the recess 37 in the second protrusion 35 such that the second flange 25 is releasably secured in the second orientation. The stop 42 limits the movement of the second flange 25 relative to the web 15 .
FIG. 4 shows mounting locations 45 through the first flange 20 and the second flange 25 and apertures 50 through the web 15 . The mounting locations 45 are spaced along a length of the first flange 20 and along a length of the second flange 25 . The mounting locations 45 are sized to receive fasteners, such as, for example, threaded fasteners, nails, cohesive bonding materials, glue, adhesive, pins, clips, clamps, inter-engaging elements, and any combination of such fasteners. The apertures 50 are spaced along a length of the web 15 and allow plumbing, conduit, wire, pipe, or other such construction components to pass through the web 15 .
In use, the wall fixture 10 is attached to an exterior wall, such as a concrete exterior basement wall. The wall fixture 10 in the first orientation is placed against the wall with the first flange 20 extending away from the wall. The second flange 25 is fastened to the wall by fasteners applied to the mounting locations 45 . After the second flange 25 has been fastened to the wall, the wall fixture 10 is rotated to the second orientation and secured by the latch 30 . A bonding material, such as closed cell foam, can be applied to the wall fixture 10 . The bonding material flows through the apertures 45 thereby increasing bond strength between the wall fixture 10 and the wall, increasing the structural integrity of the wall fixture 10 , and providing insulation value. An interior wall is fastened to the first flange 20 by fasteners applied to the mounting locations 45 .
FIGS. 5-10 illustrate a wall fixture 65 according to other embodiments of the invention. As show in FIG. 5 , the wall fixture 65 includes a first member 70 and a second member 75 . The first member 70 includes a web 80 and a flange 85 extending substantially perpendicularly from the web 80 . The web 80 defines a channel 90 that extends into the web 80 . The channel 90 includes a series of indentations 95 defined between opposed rows of protrusions 97 . A stop 99 is positioned at the bottom of the channel 90 . In some embodiments, the flange 85 extends from the web 80 at an oblique angle.
The second member 75 includes a web 100 and a flange 105 extending substantially perpendicularly from the web 100 . The flange 105 includes a hook-shaped end 110 . A portion of the web 100 includes a series of protrusions 115 . The protrusions 115 are sized and shaped to be received by the indentations 95 and to engage the indentations 95 and the protrusions 97 . In some embodiments, the flange 105 extends from the web 100 at an oblique angle. In some embodiments, the flange 105 does not include the hook-shaped end 110 .
FIG. 6 shows a portion of the web 100 of the second member 75 inserted into the channel 90 of the first member 70 . The protrusions 115 engage the indentations 95 thereby adjustably securing the first member 70 to the second member 75 . The leading pair of protrusions 120 can be selectively inserted to multiple pairs of indentations. As shown in FIG. 6 , the leading pair of protrusions 120 is inserted to a first position at a first pair of indentations 125 , thereby spacing the flange 105 at a first distance from the flange 85 . As shown in FIG. 7 , the leading pair of protrusions 120 is inserted to a second position at a second pair of indentations 130 , thereby spacing the flange 105 at a second distance from the flange 85 . The distance between the flange 85 of the first member 70 and the flange 105 of the second member 75 varies depending on the selective insertion of the web 100 into the channel 90 such that the leading pair of protrusions 120 engages a selected pair of indentations 125 .
FIG. 8 shows mounting locations 135 through the flange 105 of the second member 75 . The mounting locations 135 are spaced along a length of the second member 75 and are sized to receive fasteners, such as, for example, threaded fasteners, nails, cohesive bonding materials, glue, adhesive, pins, clips, clamps, inter-engaging elements, and any combination of such fasteners.
FIG. 9 shows mounting locations 135 through the flange 85 of the first member 70 . The mounting locations 135 are spaced along a length of the first member 70 and are sized to receive fasteners, such as, for example, threaded fasteners, nails, cohesive bonding materials, glue, adhesive, pins, clips, clamps, inter-engaging elements, and any combination of such fasteners.
FIG. 10 shows apertures 137 through the web 100 of the second member 75 . The apertures 137 are spaced along the length of the second member 75 . The apertures 137 allow plumbing, conduit, wire, pipe, or other construction components to pass through the web 100 .
In use, the wall fixture 65 is attached to an exterior wall 140 , such as a concrete basement wall, as shown in FIG. 11 . The exterior wall 140 extends between a floor 145 and a ceiling 150 . The first member 70 is placed against the wall 140 with the web 80 extending away from the wall 140 . The flange 85 of the first member 70 is fastened to the wall 140 by fasteners applied to the mounting locations 135 . After the flange 85 has been fastened to the wall 140 , the second member 75 is inserted into the first member 70 in a direction substantially parallel to the length of the web 100 . The second member 75 is inserted to a selected position. The protrusions 115 of the web 100 engage the indentations 95 in the channel 90 thereby adjustably securing the second member 75 to the first member 70 . The second member 75 can be moved between possible positions along the web 80 of the first member 70 without the use of a tool. As shown in FIG. 6 , the stop 99 limits relative movement between the first member 70 and the second member 75 . The stop 99 prevents movement of the first member 70 across the apertures 95 such that the apertures 95 are not covered by the web 80 of the first member 70 .
FIG. 11 illustrates a wall mounting system 155 including multiple wall fixtures 65 . As described above, the wall fixtures 65 are fastened to the exterior wall 140 . The wall fixtures 65 are fastened to each other using fasteners, such as, for example, threaded fasteners, nails, cohesive bonding materials, glue, adhesive, pins, clips, clamps, inter-engaging elements, and any combination of such fasteners. In use, the wall fixtures 65 allow a user to create a flat mounting surface even when the wall fixtures 65 are fastened to an exterior wall 140 that is not itself flat. The user adjusts the distance between the flanges 105 and the flanges 85 such that the flanges 105 are parallel and coplanar to each other to create the flat mounting surface.
As shown in FIG. 12 , an interior wall 160 is fastened to the wall fixture 65 . The interior wall 160 extends between the floor 145 and ceiling 150 and can be constructed from, for example, foam panels, drywall, or other wall components. The flange 105 of the second member 75 is fastened to the interior wall 160 by fasteners applied to the mounting locations 135 .
Various alternatives to the certain features and elements of the present invention are described with reference to specific embodiments of the present invention. With the exception of features, elements, and manners of operation that are mutually exclusive of or are inconsistent with each embodiment described above, it should be noted that the alternative features, elements, and manners of operation described with reference to one particular embodiment are applicable to the other embodiments.
The embodiments described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention.
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A wall fixture positionable between interior and exterior walls of a structure and including a first member having a flange extending from a web, the flange including mounting locations spaced along a length of the flange for supporting fasteners securable at a plurality of locations spaced along the interior wall and a second member having a flange extending from a web. The second member can be adjustably securable to the first member such that a distance between exterior sides of the flanges is variable. The flange of the second member can include mounting locations spaced along the flange for supporting fasteners securable at a plurality of locations spaced along the exterior wall. The web of one of the first and second members can define apertures sized to receive at least one of plumbing, conduit and wires.
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BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
Specifically, though not exclusively, the device of the invention is usefully employed in the conserves industry for separating juice or pulp of fruit or vegetables from their skins, seeds and other waste.
The device comprises a tubular strain, provided with an inlet for the produce to be treated, and a discharge outlet for the refuse generated during treatment, at the centre of which, extending from the inlet to the discharge outlet, is situated a rotatable shaft which can be rotated on command. The shaft radially bears a plurality of spatulas, each of which terminates very close to the surface of the strain and moves the produce to be treated centrifugally, pressing it against the strain; the refuse is also nudged towards the discharge outlet. The device also comprises a cover, surrounding the discharge shaft, which is provided with an outlet mouth for the extracted juice or pulp.
2. Prior Art
The prior art teaches devices of this type; an example is described in Italian patent application no. 67132A/77.
One of the disadvantages of known devices is that between strain and spatulas there exists a danger of crushing seeds and skins of produce, resulting in a freeing of bitter tastes which can affect the quality of the finished product.
A further drawback is reduced productivity, that is, a reduced quantity of extracted product per unit of time in relation to power utilized and size of the device used.
A further drawback is that the spatulas wear out quickly and have therefore to be frequently substituted.
A still further drawback in known devices is that the strain, which is fine and slim, cannot be very long as it would deform, which leads to limited potential production of the device.
A still further drawback in known devices is represented by the fact that the strain is subjected to considerable mechanical stress due to the large mass of produce rotating at high speed.
SUMMARY OF THE INVENTION
The main aim of the present invention is to obviate the above-mentioned drawbacks in the known art by providing a device, constructionally simple and economical, which improves the quality of the extracted product, which is highly productive and which is subject, in relation to the quantity of produce treated, to only modest mechanical stress. An advantage of the invention is that it reduces costs and inoperative times for the substitution of the spatulas.
A further advantage is that it eliminates the risk of crushing seeds and skins.
A still further advantage is that it reduces mechanical stress, especially on the spatulas and the strain.
A still further advantage of the invention is that the strains can be easily and rapidly dismounted from the device.
A still further advantage of the invention is that differentiated peripheral velocities of treatment can be achieved, without changing the spatulas.
These aims and advantages and others besides are all attained by the device in question, as it is set out in the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of the present invention will better emerge from the detailed description that follows, of some embodiments of the invention, illustrated in the form of non-limiting examples in the accompanying drawings, in which:
FIG. 1 is a partially sectioned vertical elevation of a first embodiment of the invention;
FIG. 2 is a lateral view from the right of FIG. 1, with some parts removed better to evidence others;
FIG. 3 is a detail of FIG. 1 in enlarged scale;
FIG. 4 is an enlarged scale illustration of section according to line IV--IV of FIG. 3;
FIG. 5 is a partially-sectioned vertical elevation of a second embodiment of the device;
FIG. 6 is a partially-sectioned vertical elevation of a third embodiment of the device;
FIG. 7 is an enlarged scale view of a detail of FIG. 6;
FIG. 8 is an enlarge scale view of a section of a detail of FIG. 7, according to line VIII--VIII.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the figures of the drawings, 1 denotes in its entirety a device for extracting juice or pulp from food produce which, in all embodiments, comprises a tubular strain 2 2' 2" provided with an inlet 3 for the produce to be treated and a discharge outlet 4 for the refuse produced during treatment.
A casing 7 surrounds the strain 2 and is provided with an outlet 8 for the extracted product.
A rotatable shaft 5 is situated between the inlet 3 and the discharge outlet 4, which shaft 5 bears a plurality of radial spatulas 6.
As shown in FIG. 4, each of the spatulas 6 is mounted on the shaft 5 by means of a cylindrical joint 14 which allows the spatulas 6 to oscillate up to a predetermined degree with respect to the rotatable shaft 5. Each of the spatulas 6 terminates very close to the surface of the tubular strain 2 2' 2", and has a free zone 9 between the front face 6a of the spatula (with reference to the rotation direction thereof, indicated by an arrow 15 in the figures) and the peripheral extremity 6b.
The free zone 9 is delimited, in the example, by a first surface 9a and a second surface 9b, said first surface 9a extending in breadth radially and said second surface 9b extending circumferentially.
Each of the spatulas 6 comprises a main body 61, affording a slot 62, housing a plate 100 made of hard resistent material, such as tungsten carbide, high-speed steel or the like, which projects radially from the peripheral extremity of the main body 61.
Each plate 100 is fixed to the main body 61, for example by means of rivets or welding.
The plate 100 constitutes the peripheral extremity 6b of the spatula 6 and said first surface 9a; the peripheral extremity 6b of the spatula 6 also exhibits a posterior surface 110 inclined with respect to the strain. The peripheral extremity 6b of each of the spatulas 6 therefore is corner-shaped, formed by the first radial surface 9a and the inclined posterior surface 110; the angle of inclination alpha of the posterior surface 110 with respect to the strain is about 10 degrees. The device further comprises a radial shield 20 arranged immediately downstream of the inlet 3. The radial shield 20 is provided with peripheral blades 21, is solidly constrained to the rotatable shaft B and affords an annular peripheral passage zone 22 for the produce.
Thus the produce can transit towards the spatulas 6 only through the passage zone 22.
The strain exhibits holes 12, 12', 12" and 13, 13', 13" of progressively decreasing diameter going from the inlet 3 to the discharge outlet 4.
A single strain 2 can be provided, in which a first portion 2a, close to the inlet 3, is provided with holes 12 having a greater diameter with respect to holes 13 of a second portion of the same strain 2, close to the discharge outlet 4.
In this case, a scraper knife 23 is provided, arranged on the external surface of the strain and rotatable with respect thereto.
The scraper knife 23 is supported by a pair of cogrings 24 set in rotation by means of pinions 26 and a small rotating shaft 26.
The cogrings 24 are held in position by pivots 28 disposed parallel to an axis of rotation of said cogrings 24, and by idle pinions 29 arranged externally of the cogrings 24. One of the pivots 28 bears the scraper knife 23. This embodiment is not specifically illustrated but can easily be deduced from FIG. 1 (conserving the numbers of the various elements) by imagining portions 2a and 2b to be united to make a single strain 2 and the portions of the scraper knife 23 to be united to make a single scraper knife 23.
In the first embodiment, illustrated in FIGS. 1, 2, 3 and 4, the tubular strain 2 is divided into two portions, 2a and 2b; the first portion 2a, close to the inlet 3, affords holes 12 having a greater diameter than the holes 13 of the second portion 2b, close to the discharge outlet 4. In this embodiment, the scraper knife 23 is divided into two portions and the pivot 28 supporting the scraper knife 23 can be rotated about its axis to bring the scraper knife 23 into a diametrically opposite position to the one illustrated, thus enabling the strain to be dismounted from the posterior portion (right) of the device.
In a third embodiment, illustrated in FIGS. 6, 7, 8, the strain 2", is divided into two coaxial portions 2a", 2b", of a same diameter and connected to each other by means of a radial flange 18".
A fixed annular support 10" surrounds the strain 2" externally in the conjunction zone of the portions 2a" and 2b", that is at the flange 18' and coaxially thereto. The annular support 10" is solidly constrained to the casing 7 by means of tie bars 19". Also in this embodiment the strain 2" exhibits holes 12", 13", which progressively decrease or decrease step-by-step in diameter in a direction going from the inlet 3 to the discharge outlet 4.
Two scraper knives 23", 23a", are alignedly arranged on the external surface of the strain 2", separated by the flange 18" and the annular support 10", and rotate with respect to the strain.
The scraper knives 23" and 23a" are supported, each by an extremity, by a ring of a pair of cogrings 24" set in rotation, by means of pinions 25", by a single shaft 26".
The cogs of the cogrings 24" are crossed by an annular discharge channel 40"; in this way the cogged couplings can be automatically and continuously cleaned.
The annular support 10" is provided with a recess 11' which allows passage of said shaft 26".
An idle support roller 30", 30a", is connected to the free end of each of the scraper knives 23", 23a".
A notch 31" is made in the flange 18", which notch 31" extends radially from the external surface of the strain to a height which is slightly greater than the height of the scraper knife 23a", enabling easy withdrawal of the portion 2a" of the strain.
In this embodiment too the strain could consist of a single part. In this case the two scraper knives 23" and 23a" are supported by the annular support encircling the strain and not by the flange, which obviously is no longer present.
Several annular supports might be provided, coaxial and appropriately distanced one from a next.
In a second embodiment, illustrated in FIG. 5, the strain 2' is divided into two coaxial parts 2a' and 2b', connected one to the other by means of a radial flange 18'. In the device illustrated in FIG. 5, the connection between the parts of the strain is achieved simply by pressing the relative flanges made on the two parts thereof one against the other.
In this embodiment part 2b', which is arranged at the discharge outlet 4 end of the device, has a greater diameter than part 2a', which is arranged towards the inlet 3 end of the device. Evidently in this embodiment the spatulas 6 provided on part 2b' will be longer than the spatulas 6 on part 2a', in order that their extremities which are unconnected to the rotatable shaft 5 remain very close to the internal surface of the strain.
In the interest of keeping all the spatulas 6 identical, with evident constructional and maintenance advantages, the greater height as mentioned above can be obtained by adjusting the distance of the fulcrum of the spatulas 6 with respect to the rotatable shaft 5 axis.
In this embodiment too a fixed annular support 10' externally surrounds the strain 2' in the connection zone between its two parts 2a' and 2b', that is, at the flange 18' and coaxially thereto. The annular support is solidly constrained to the casing 7 by means of tie bars 19'.
In this embodiment too the strain exhibits holes 12', 13', which are of progressively or step-by-step decreasing diameter, going from the inlet 3 to the discharge outlet 4. The holes of part 2a' have a greater diameter with respect to the holes of part 2b'.
Two scraper knives 23' and 23a', are arranged on the external surface of the strain 2', separate from the flange 18' and the annular support 10' and rotating with respect to the strain.
The scraper knives 23' and 23a', are supported, each by an extremity, by a ring of a pair of cogrings 24' rotated by means of pinions 25' by a single shaft 26'.
In this embodiment too, the cogs of the cogrings 24' are crossed by an annular discharge channel 40'.
The annular support 10' is provided with a recess 11' which affords passage of said shaft 26'.
An idle support roller 30, 30a, is connected to the free end of each of the scraper knives 23', 23a'.
This second embodiment of the device exhibits the further considerable advantage of imparting a greater peripheral velocity on the produce at the second portion of the strain.
In this zone the produce is lighter and more fibrous and its mass is smaller as a large portion of the liquid has already exited through the holes of the first portion of the strain. In this way greater device productivity is obtained, thanks to the greater peripheral velocity impressed on the "lighter" part of the produce, while mechanical stress on the strain is not increased, as the "liquid and heavy" part of the produce, which is more easily expelled from the strain as it is full of liquids, rotates at a slower peripheral speed. The functioning of the device, similar to that of known devices, is as follows: the shaft is rotated so that the spatulas 6 rotate the produce imparting thereof a centrifugal effect, pressing it against the strain, causing it to exit through the holes; at the same time the motion of the spatulas 6 pushes the waste material towards the discharge outlet 4.
The special characteristics of the extremities of the spatulas 6 improve the quality of the extracted product and favour optimal passage of the juice and pulp through the holes of the strain. Risk of strain blockage is considerably reduced, as the is risk of crushing seeds and skin. Tests have revealed that the load bearing on the spatulas 6 and the strain are also reduced. The above advantages are especially obtained where the angle of inclination alpha is comprised between 8 and 15 degrees.
The use of a plate made of hard and resistant material means that the machine can be used at optimum productivity speed for a considerable length of time, independently of the shape of the plate itself.
The presence of the radial shield 20, which forces the product to enter a circular peripheral crown whereat the centrifugal force imparted by the motion of the blades increases, so does the productivity of the device since the action of the blades is utilized over the entire circumference.
The characteristics of the strain holes, apart from leading to an improvement in the final extracted product, contribute to high machine productivity as the product, in the zone where the holes have a greater diameter, exits more easily and with smaller energy expenditure without leading to a drop in product quality, since said zone is arranged near the inlet 3 of the device where the produce is more fluid.
In tomato working, the presence of small holes in the terminal zone of the strain, where the product is dryer, considerably diminishes the risk of the peel and the seeds being crushed and passing through the strain; in this way the bitter-tasting substance, contained in the peel and seeds, does not pass through the strain and lower the quality of the product,
The presence of the annular support 1 ends greater strength to the device as well as rendering it scarcely deformable. In particular, a strain of considerable length can be used, which will also be of a sufficient flexional resistance. This considerably improves the productivity of the device.
The device can be simply and rapidly dismounted. It is especially easy to substitute the strain, an operation which occurs quite frequently during functioning of the device. The operation takes place with the device at a high temperature. In the third embodiment the scraper knives are first brought to the position of the notch 31" before the strain is removed (with movement from left to right, with reference to FIG. 7), passing it over the knives 23a" through the notch 31". Thanks to this procedure, the flange does not obstruct the removal of the strain. If the strain is made of more than one portion, only the portion near the discharge outlet 4 need be frequently substituted, as it is the portion most susceptible to blocking; thus maintenance times can be cut to a minimum.
In the second embodiment the device is dismounted simply and quickly, especially portion 2b' of the strain, which is the portion which gets obstructed more easily and therefore has to be substituted more often. To dismount portion 2a' of the strain, which needs to be dismounted less frequently, a part of the rotor has to be dismounted.
It is evident that the various characteristics described can be used as a group or in part, and can be variously combined according to the type of product being worked or the work performance required of the device.
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The invention relates to a device for extracting juice or pulp from food produce. It is particularly useful in the food conserves industry for separating the juice or pulp of fruit and vegetables from the skins and seeds. A tubular strain, provided with an inlet and a discharge outlet for refuse by-products, has at its centre a shaft bearing a plurality of spatulas, each of which has an extremity set very close to a surface of the strain; each of the spatulas bears at its peripheral end a plate made of a hard material, which projects radially from the main body and delimit a free zone between the front face and the peripheral extremity of the spatula. The tubular strain exhibits holes which are of progressively or step-by-step diminishing diameter, going from the inlet to the discharge outlet, and also exhibits an annular support which surrounds the strain.
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BACKGROUND OF THE INVENTION
The invention relates to chromoionophore comprising an chromophore and an ionophore capable of selectively binding sodium ions for determining sodium ion in a sample. The present invention also relates to a method of determining the concentration of sodium ions in a sample wherein the chromoionophore is contacted with sodium ion in a sample, wherein the intensity of at least one absorption maximum in the visible region changes and the concentration of sodium ion is calculated based on the change in the intensity of the absorption maximum.
The accurate measurement of physiologic cations, such as sodium, potassium, lithium, calcium, and magnesium, is essential in clinical diagnosis. Traditionally, these ions were determined in plasma or serum using ion-selective electrodes (ISE), which are very cumbersome to use and costly to maintain. Serious drawbacks of electrochemical measuring arrangements are the requirement of a reference element, sensitivity towards electrical potentials and electromagnetic interference.
An alternative enzymatic method is based on the activation of β-Galactosidase by cations (Berry et al., Clin. Chem., 34/11, 1988 2295-2298). The high cost and poor stability of the enzyme preclude its extensive application in clinical laboratories. Therefore, the development of practical and inexpensive calorimetric reagents for the clinical determination of these ions in biological fluids remains an important area of research.
U.S. Pat. No. 4,367,072 describes a process for the determination of metal ions using simple crown ethers as ion-binding units. However, the binding is too weak to be useful for many practical applications, such as clinical applications, in which the indicator has to discriminate between ions with very similar properties, e.g., sodium versus potassium or magnesium versus calcium.
U.S. Pat. No. 5,011,924 and U.S. Pat. No. 4,994,395 describe cryptands (or cryptohemispherands) linked with an ionizable chromophore, which changes its color upon binding of ions based on charge interaction between the bound cation and the anion of chromophore. Although all nitrogen atoms in these cryptands are aliphatic, and not electronically conjugated with the chromophore, the results of measurement of serum samples using these chromoionophores are impressive and promising (Helgeson et. al. J. Am. Chem. Soc ., vol. 111, 1989, 6339-6350). However, the syntheses of these cryptands, especially of those cryptohemispherands, are lengthy and tedious. Consequently, the manufacturing cost of these reagents remains prohibitively high even in the decades following their discovery. The cost factor could be a reason why these reagents have not replaced those ISE modules in most large clinical analyzers, in which the ISE methods are still dominating (see Burtis et. al. ed. “Tietz Textbook of Clinical chemistry and Molecular Diagnostics” Elsevier Sauders, St. Louis, Mo., USA 2006, page 986).
U.S. Pat. No. 5,952,491 report sodium ionophore, which has π-electron conjugated nitrogen and is coupled to a fluorophore to make luminophore-ionophore sensors where the respective ions are detected by measuring luminescence emission. All three ionophores has been proven to be very effective in determination of sodium in whole blood in which sodium is the major cation. (see He et. al. Anal. Chem . Vol. 75, 2003, 449-555), thus showing that the ionophore is effective under physiological conditions.
By coupling to a chromophoric moiety, the ionophore can be converted into colorimetric sensors. The chromophoric moieties can be a nitro-substituted styryl or phenylazo, substituted thiazolevinyl or thiazoleazo, substituted naphthothiazolevinyl or naphthothiazoleazo, substituted naphthylvinyl or naphthylazo, substituted quinolinovinyl or quinolinoazo and their quartemized salts. To date, there has been no systematic investigation of these types of colorimetric reagents. Gunnlaugsson et al. ( J. Chem Soc., Perkin Trans. 2, 2002, 141-150) describe use of a sodium ionophore with a nitrophenylazo chromophore. The water solubility of this dye is so poor that one has to use organic solvent to solubilize it. The water solubility can be improved dramatically if a charge is introduced into the dye molecules. The absorption wavelength can be red-shifted by replacing the nitrophenyl with a nitrothiazole or larger chromophore-generating substituent.
The present invention provides sodium chromoionophores that are water soluble and can be reliably used for detection of ions in samples that absorb at wavelengths longer than about 400 nm. Examples of such samples are biological fluids including plasma, serum and urine.
For the chromoionophores of the present invention, the amount of ion present is determined by measuring changes in the intensity of at least one absorption maximum of the chromoionophore upon contacting the chromoionophore with an ion. The measurements are done by using standard centralized instruments, such as ultraviolet-visible spectrometers. A calibration curve for an ion is generated from a series of empirically determined absorption spectra. A calibration curve is useful for at-once determining the concentration of ion in a sample from the measured absorbance.
The chromoionophores of this invention absorb visible light (about 400 nm or greater) with reasonable extinction coefficient, thus avoiding those practical problems associated with variable background absorption from optical components, cuvette polymer materials, and biological samples. Further, the invention is well suited for practice in the determination of sodium ion in the presence of physiological concentrations of other alkali ions.
SUMMARY OF THE INVENTION
In brief, the present invention relates to novel chromoionophores, comprising a chromophoric moiety and an ionophoric moiety. The invention further relates to a method of determining sodium ions in a sample, wherein the ions are contacted with a compound having chromophoric moiety and an ionophoric moiety, where the ionophoric moiety interacts with the sodium ions present in the sample, resulting in the chromophoric moiety changing its radiation absorption properties in the ultraviolet and visible regions of the spectrum. In one embodiment, a change in an intensity of an absorption maximum is measured and the ion concentration is determined accordingly.
In one embodiment, the chromoionophores of the invention comprise an ionophore having one or more chelating moieties that is capable of selectively binding sodium ions and a chromophore having a plurality of conjugated unsaturated bonds. The chromoionophore exhibits at least one absorption maximum having a wavelength in the visible region having a first intensity and wherein the absorption maximum has a second intensity that is different from the first intensity in an amount that is by proportional to the concentration of sodium ion present in a mixture comprising sodium ions and the chromoionophore.
In other embodiments, the chromoionophores of the invention are compounds having the Formula (I)
wherein, r and s independently are selected from the group consisting of 0, 1 or 2, and L is a chromophoric moiety. It should be understood that compounds wherein r is 1 and s is 0, and L is
are excluded from the scope of this invention.
The invention further provides a method of determining the concentration of potassium ions in a sample comprising
(a) measuring the intensity of at least one absorption maximum of a solution of a chromoionophore sensitive to the presence of sodium ions in solution to obtain a first intensity; wherein the concentration of the chromoionophore in solution is known; and
wherein said at least one absorption maximum has a wavelength in the visible region;
(b) contacting the solution of the chromoionophore with the sample; whereby the first intensity changes;
(c) measuring the intensity of at least one absorption maximum to obtain a second intensity;
(d) deriving the concentration of sodium ion in the sample based, in part, on the difference between the first and second intensities.
In one embodiment, at least one absorption maximum occurs at a wavelength that is in the visible region.
In another embodiment, the difference between the first and second intensities results in a colorimetric change in the solution sample comprising the chromoionophore and sodium ions.
In another embodiment, at least one absorption maximum occurs at a wavelength of about 400 nm or greater.
In another embodiment, at least one absorption maximum occurs at a wavelength between about 400 nm and about 800 nm.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of synthetic pathway to sodium calorimetric indicator.
FIG. 2 is a graph illustrating the absorbance of a sodium colorimetric indicator in accordance with the invention versus sodium concentration in serum sample.
FIG. 3 is a graph illustrating a calibration curve a sodium calorimetric indicator in accordance with the invention versus sodium concentration in serum sample.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the terms have the following meanings:
The term “alkyl” as used herein refers to a straight or branched chain, saturated hydrocarbon having the indicated number of carbon atoms. For example, (C 1 -C 6 ) alkyl is meant to include, but is not limited to methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, isohexyl, and neohexyl. An alkyl group can be unsubstituted or optionally substituted with one or more substituents.
The term “alkylene” refers to a divalent alkyl group (e.g., an alkyl group attached to two other moieties, typically as a linking group). Examples of a (C 1 -C 7 ) alkylene include —CH 2 —, —CH 2 CH 2 —, —CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 —, and —CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 —, as well as branched versions thereof. An alkylene group can be unsubstituted or optionally substituted with one or more substituents.
The term “alkoxy” as used herein refers to an —O-alkyl group having the indicated number of carbon atoms. For example, a (C 1 -C 6 ) alkoxy group includes —O-methyl, —O-ethyl, —O-propyl, —O-iospropyl, —O-butyl, —O-sec-butyl, —O-tert-butyl, —O-pentyl, —O-isopentyl, —O-neopentyl, —O-hexyl, —O-isohexyl, and —O-neohexyl.
The term “alkenyl” as used herein refers to a straight or branched chain unsaturated hydrocarbon having the indicated number of carbon atoms and at least one double bond. Examples of a (C 2 -C 8 ) alkenyl group include, but are not limited to, ethylene, propylene, 1-butylene, 2-butylene, isobutylene, sec-butylene, 1-pentene, 2-pentene, isopentene, 1-hexene, 2-hexene, 3-hexene, isohexene, 1-heptene, 2-heptene, 3-heptene, isoheptene, 1-octene, 2-octene, 3-octene, 4-octene, and isooctene. An alkenyl group can be unsubstituted or optionally substituted with one or more substituents.
The term “Ar” as used herein refers to an aromatic or heteroaromatic moiety. An “aromatic” moiety refers to a 6- to 14-membered monocyclic, bicyclic or tricyclic aromatic hydrocarbon ring system. Examples of an aromatic group include phenyl and naphthyl. An aromatic group can be unsubstituted or optionally substituted with one or more substituents. The term “heteroaromatic” as used herein refers to an aromatic heterocycle ring of 5 to 14 members and having at least one heteroatom selected from nitrogen, oxygen and sulfur, and containing at least 1 carbon atom, including monocyclic, bicyclic, and tricyclic ring systems. Representative heteroaromatics are triazolyl, tetrazolyl, oxadiazolyl, pyridyl, furyl, benzofuranyl, thiophenyl, benzothiophenyl, quinolinyl, pyrrolyl, indolyl, oxazolyl, benzoxazolyl, imidazolyl, benzimidazolyl, thiazolyl, benzothiazolyl, isoxazolyl, pyrazolyl, isothiazolyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, cinnolinyl, phthalazinyl, quinazolinyl, pyrimidyl, azepinyl, oxepinyl, naphthothiazolyl, quinoxalinyl. A heteroaromatic group can be unsubstituted or optionally substituted with one or more substituents.
The term “halogen” as used herein refers to —F, —Cl, —Br or —I.
As used herein, the term “heteroatom” is meant to include oxygen (O), nitrogen (N), and sulfur (S).
The term “chromoionophore” as used herein refers to a compound comprising at least one ionophore and at least one chromophore.
The following abbreviations are used herein and have the indicated definitions: LAH is lithium aluminum hydride; DMF is dimethylformamide; NMR is nuclear magnetic resonance; THF is tetrahydrofuran.
Compounds of the Invention
The present invention provides compounds of Formula (I) referred to as “chromoionophores”
wherein r and s are as defined above.
In one embodiment, the chromophoric moiety L is selected from the group consisting of —NO 2 , Formula (II) and (III),
wherein, Ar is a (C 6 -C 10 ) aromatic moiety or a (C 5 -C 14 ) heteroaromatic moiety containing one or more heteroatoms selected from N, O, and S, and wherein Ar is substituted with one or more substituents selected from the group consisting of hydrogen, —NO 2 , —NO, —CN, (C 1 -C 8 ) straight chain or branched alkyl, (C 2 -C 8 ) alkenyl, halogen, —SO 3 H, —W—COOH, —W—N(R 1 ) 3 , —C(O)OR 1 , —C(O)R 1 ; W is (C 1 -C 8 ) alkylene; and R 1 is selected from the group consisting of hydrogen and (C 1 -C 8 ) straight chain or branched alkyl.
In another embodiment, Ar is selected from the group consisting of Formula (IV), (V), (VI), and (VII)
wherein X is O or S, and Y is N or C;
R 2 , at each occurrence, is independently selected from the group consisting of hydrogen, —NO 2 , —NO, —CN, C 1 -C 8 straight chain or branched alkyl, (C 2 -C 8 ) alkenyl, halogen, —SO 3 H, -Q-COOH, -Q-N(R 4 ) 3 , —C(O)OR 4 , —C(O)R 4 .
R 3 is -Q-SO 3 − or -Q-COO − .
Q is (C 1 -C 8 ) alkylene.
R 4 is selected from the group consisting of hydrogen and (C 1 -C 8 ) straight chain or branched alkyl;
Variable l is an integer selected from 1 to 3; m is an integer selected from 1 to 7; n is an integer selected from 1 to 5; and p is an integer selected from 1 to 6.
Specific examples of compounds of Formula I are provided below:
The invention further provides methods of determining sodium ion in a sample comprising a chromoionophore according to Formula (I) and sodium ions, where the chromoionophore has the general Formula (I)
wherein r and s are as defined above.
The invention further provides methods of determining sodium ion in a sample comprising a chromoionophore according to Formula (I) and sodium ions, where the chromophoric moiety L is selected from the group consisting of —NO 2 , Formula (II) and (III),
wherein, Ar is a (C 6 -C 10 ) aromatic moiety or a (C 5 -C 14 ) heteroaromatic moiety containing one or more heteroatoms selected from N, O, and S, and wherein Ar is substituted with one or more substituents selected from the group consisting of hydrogen, —NO 2 , —NO, —CN, (C 1 -C 8 ) straight chain or branched alkyl, (C 2 -C 8 ) alkenyl, halogen, —SO 3 H, —W—COOH, —W—N(R 1 ) 3 , —C(O)OR 1 , —C(O)R 1 ; W is (C 1 -C 8 ) alkylene; and R 1 is selected from the group consisting of hydrogen and (C 1 -C 8 ) straight chain or branched alkyl.
The invention further provides methods of determining sodium ion in a sample comprising a chromoionophore according to Formula (I) and sodium ions, where Ar is selected from the group consisting of Formula (IV), (V), (VI), and (VII)
wherein X is O or S, and Y is N or C;
R 2 , at each occurrence, is independently selected from the group consisting of hydrogen, —NO 2 , —NO, —CN, C 1 -C 8 straight chain or branched alkyl, (C 2 -C 8 ) alkenyl, halogen, —SO 3 H, -Q-COOH, -Q-N(R 4 ) 3 , —C(O)OR 4 , —C(O)R 4 .
R 3 is -Q-SO 3 − or -Q-COO − .
Q is (C 3 -C 8 ) alkylene.
R 4 is selected from the group consisting of hydrogen and (C 1 -C 8 ) straight chain or branched alkyl.
Variable l is an integer selected from 1 to 3; m is an integer selected from 1 to 7; n is an integer selected from 1 to 5; and p is an integer selected from 1 to 6.
The invention further provides methods of determining sodium ion in a sample comprising a chromoionophore according to Formula (I) and sodium ions, where the sample is a biological fluid. Examples of biological fluids are whole blood, plasma, serum, and urine.
The invention further provides methods of determining sodium ion in a sample comprising a chromoionophore according to Formula (I) and sodium ions, where the sample has a pH of 6.5 or above.
Preparation of the Compounds of Formula (I)
Those skilled in the art will recognize that there are a variety of methods available to synthesize molecules described herein. The synthesis of the chromoionophore (Na6) and (Na12) from commercially available compounds is illustrated in FIG. 1 . o-Anisidine (Na1) was di-alkylated with 2-chloroethanol then reacted with bis[(2-chloro-ethoxy)]ethane. The resultant phenylazacrown ether (Na3) was coupled with diazonium (Na5) to afford chromoionophore (Na6). Na3 was also converted to (Na12).
Example 1
N,N-Bis(2-hydroxylethyl)-2-methoxyaniline (Na2). Na1 (452 g, 4 mol) was dissolved in 2-chloroethanol (1,932 g, 24 mol) and heated to 80° C. for 15 min. K 2 CO 3 (608 g, 4.4 mol) was slowly added such that the temperature of this exothermic reaction was kept below 110° C. The mixture was heated at 95° C. for 22 h., cooled and approximately 800 mL of unreacted 2-chloroethanol was removed under vacuum. The residue was diluted with water (1 L) and extracted with CHCl 3 (2×1 L). The CHCl 3 solutions were back-washed with water (5×1.5 L), dried over K 2 CO 3 and the solvent evaporated to afford 404 g (48%) of a light brown oil. 1 H NMR (CDCl 3 ): δ=3.18 (t, 4H), 3.50 (t, 4H), 3.60 (m, 2H), 3.82 (s, 3H), 6.90 (m, 2H), 7.10 (m, 1H), 7.19 (m, 1H). Anal. Calcd. for C 11 H 17 NO 3 : C, 62.54; H, 8.11; N, 6.63. Found: C, 61.33; H, 8.28; N, 6.43.
Example 2
2-Methoxyphenylaza-15-crown-5 (Na3). Na2 (403 g, 1.91 mol) was dissolved in dioxane (2.21 L) and heated at 80° C. for 20 min. Powdered NaOH (168 g, 4.20 mol) was added slowly within about 3 h. The temperature was then increased to 95° C., bis(2-chloroethanoxyethane) (300 mL, 1.93 mol) added in one portion and the mixture kept at 95° C. for 30 h. The suspension was then filtered hot, the solvent evaporated, and the residue treated with a solution of NaClO 4 (234 g, 1.91 mol) in methanol (640 mL). The mixture was stirred at 60° C. for 30 min and concentrated to about 300 mL. Ethyl acetate (860 mL) was added, the mixture stirred at room temperature for 20 min then allowed to stand at room temperature for 2 h. The resulted precipitate was filtered, washed with ethyl acetate (2×200 mL) and dried at room temperature for 30 min to give 199 g of azacrown-sodium perchlorate complex as a soft white powder. This powder was dissolved in a mixture of CH 2 Cl 2 (600 mL) and water (600 mL), the layers separated and the aqueous phase was extracted with CH 2 Cl 2 (400 mL). The organic solutions were combined, washed with water (8×600 mL), dried over Na 2 SO 4 then evaporated to afford 100.4 g (16%) of pale yellow oil. 1 NMR (CDCl 3 ) δ=3.49 (t, 4H), 3.68 (t, 16H), 3.82 (s, 3H), 6.88 (m, 3H), 7.12 (m, 1H). Anal. Calcd for C 17 H 27 NO 5 : C, 62.70; H, 8.36; N, 4.30. Found: C, 61.63; H, 8.44; N, 4.26.
Example 3
4-(2′,4′-Dinitrophenylazo)-2-methoxyphenylaza-15-crown-5 (Na6, R═NO 2 ). Na3 (1.62 g, 5 mmol) was dissolved in 50 mL tetrahydrofuran and the resulting solution was diluted with 50 mL methanol. To this solution 2.54 g (10 mmol) 2,4-dinitrophenyldiazonium tetrafluoroborate was added in three portions. The suspension was stirred at room temperature for 2 hours. When TLC showed that Na3 was gone, the solvent was evaporated and the residue was dissolved in 500 mL chloroform, washed 500 mL water. The solvent was evaporated to get about 3.32 g oily gum. This crude product was purified with a short column, packed with 25 g silica gel, eluted with chloroform to remove front impurities, then using chloroform/methanol (99/1, v/v) to get 0.84 g dark red gum product. 1 H NMR (CDCl 3 ) 3.60 (t, 16H), δ=3.70 (t, 4H), 3.82 (s, 3H), 6.78 (d, 1H), 7.36 (d, 1H), 7.52 (m, 1H), 8.22 (d, 2H), 8.80 (s, 1H).
Example 4
Synthesis of Na8 (R═CH 2 COOEt). Under the cooling of ice-water bath, sodium nitride 1.39 g (20 mmol) was added to 16 g (40.8 mmol) concentrated sulfuric acid and stood for five minutes, then warmed to 60° C., the solution became clear. The solution was cooled to under 0° C. with ice-salt bath; then 3.72 g (20 mmol) ethyl 2-aminothiazole-4-acetate was added in one portion. The solution was kept at under 0° C. and stirred for two hours. KI-starch paper monitored the free nitrous acid until reaction completed. Used immediately for next step.
Example 5
Synthesis of Na9 (R═CH 2 COOEt). Under the cooling of ice-water, the solution of Na8 was slowly transferred into the solution of Na3 (4.87 g (3 mmol) and sodium acetate 8.10 g (82 mmol) in 50 mL acetic acid. The resulting suspension mixture was stirred overnight and poured into stirring 400 mL DI water, extracted with 200 mL chloroform. The organic layer was washed with 200 mL sat. sodium carbonate, 200 mL DI water, dried over anhydrous sodium sulfate. The solvent was evaporated and the residue was further purified with 10 g silica gel 60 using chloroform:methanol 9:1 (v/v) as elution to afford 2.53 g dark red product. 1 H NMR (CDCl 3 ) 1.25 (t, 3H), 3.60 (t, 16H), δ=3.70 (t, 4H), 3.82 (s, 3H), 4.20 (q, 2H), 6.75 (d, 1H), 7.35 (d, 1H), 7.48 (m, 1H), 8.20 (s, 1H).
Example 6
Synthesis of Na10 (R═CH 2 COOH). To a solution of 2.50 g Na9 in 50 mL methanol was added 10 mL water and 10 mL 1 N KOH. The resulting solution was warmed to 60° C. and let it cooled to room temperature for 1 h. The solvent was evaporated and the residue was dissolved in 5 mL methanol. This solution was directly used as stock solution.
Example 7
Synthesis of Na11. Na3 (100 g, 308 mmol) was dissolved in DMF (145 mL, 1850 mmol) in a 500 mL three-neck flask and cooled to −5° C. POCl 3 (57.4 mL, 616 mmol) was added dropwise via an addition funnel such that the solution temperature did not exceed 5° C. After stirring at room temperature for 16 h, the solution was heated to 60° C. for 1 h, cooled, poured into 500 g ice, the flask rinsed flask with 70 mL water, and the combined aqueous solutions adjusted to pH 7 (by pH paper) with saturated K 2 CO 3 . The solution was extracted with CHCl 3 (2×500 mL), the CHCl 3 phase washed with water (2×500 mL) then dried over MgSO 4 (100 g) for 1 h. Evaporation of the solvent afforded 85 g light yellow oil that crystallized upon standing overnight. Re-crystallization from ethyl acetate/hexane (1:4) afforded 56 g (51%) light orange crystals. 1 H NMR (CDCl 3 ) δ=3.68 (t, 16H), 3.78 (t, 4H), 3.82 (s, 3H), 7.05 (m, 1H), 7.28 (m, 2H), 9.78 (s, 1H). Anal. Calcd for C 18 H 27 NO 6 : C, 61.17; H, 7.70; N, 3.96. Found: C, 61.05; H, 8.01; N, 4.04.
Example 8
Synthesis of Na12. Na11 (0.35 g, 1 mmol) was dissolved in 10 mL 10 mL ethanol. To this solution 0.35 g (1.1 mmol) 2-methyl-1-(3-sulfopropyl)naphtho[1,2-d]thiazolium inner salts and 0.11 g (1.1 mmol) triethylamine were added. The resulting solution was stirred under reflux for 18 h. after cooling. The solvent was evaporated and the residue was purified by a silica gel column with CHCl3/methanol (99/1,v/v) as eluent to give 0.48 g dark brown powder. 1 H NMR (CDCl 3 ) δ=2.1 (m, 2H), 3.45 (m, 4H) 3.68 (t, 16H), 3.78 (t, 4H), 3.82 (s, 3H), 6.9-8.3 (m, 9H).
Example 9
Method of Determining Sodium Ions: Solvents and reagents are purchased from Aldrich (Milwaukee, Wis.) and used without further purification. Analytical grade buffer and inorganic salts are purchased from either Fluka AG (Buchs, Switzerland) or Sigma Co. (St. Louis, Mo.). Absorption measurements are performed with a Shimadzu UV2101PC spectrophotometer equipped with a jacketed cuvette holder for controlling of temperature. Titration of a chromoinophore is carried out in the following manner: A methanolic solution of a chromoionophore is diluted with buffer, deionized water or deionized water with organic co-solvent in a volumetric flask to make about 30 μM final solution, the required amount of solid salt is added and the solution's absorption spectrum is measured. The typical titration spectra are shown in FIG. 2 .
A sodium colorimetric reagent used for FIG. 3 is formulated as follows: a methanolic solution containing of about 2.3 mg of calorimetric sodium indicator Na10 (R═CH 2 COOH) is mixed with 0.905 g tetramethylammonium hydroxide pentahydrate and 0.0292 g ethylenediaminetetraacetic acid. The resulting mixture is dissolved in methanol and bring the total volume to 100 ml. 2.7 ml of this solution is mixed with 0.3 ml serum or aqueous sample, incubated at 37° C. for 5 min. The absorption values are recorded at wavelength of 486 nm, and are used to plot the chart shown in FIG. 3 .
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The invention relates to methods of determining sodium ions in a sample, wherein the ions are contacted with a compound having chromophoric moiety and an ionophoric moiety, where the ionophoric moiety interacts with the sodium ions present in the sample, resulting in the chromophoric moiety changing its radiation absorption properties in the ultraviolet and visible regions of the spectrum. For example, a change in an intensity of an absorption maximum is measured and the ion concentration is determined accordingly.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application claims priority to and the benefit of Korean Patent Application No. 10-2015-0078003 filed on Jun. 2, 2015, the entire contents of which is incorporated herein for all purposes by this reference.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to an automatic transmission for a vehicle. More particularly, the present invention relates to a planetary gear train of an automatic transmission of a vehicle improves power delivery performance and reduces fuel consumption by achieving nine forward speed stages and widening gear ratio span using a minimum number of constituent elements and securing linearity of step ratios.
Description of Related Art
In recent years, a rise in oil price causes dashing into unlimited competition for enhancing fuel efficiency.
As a result, researches into reduction of a weight and the enhancement of the fuel efficiency through down sizing are conducted in the case of an engine and researches for simultaneously securing operability and fuel efficiency competitiveness through multiple speed stages are conducted in the case of an automatic transmission.
However, in the automatic transmission, as the number of speed stages increase, the number of internal components increase, and as a result, mountability, cost, weight, transmission efficiency, and the like may still deteriorate.
Accordingly, development of a planetary gear train which may bring about maximum efficiency with a small number of components may be important in order to increase a fuel efficiency enhancement effect through the multistages.
In this aspect, in recent years, 8-speed automatic transmissions tend to be implemented and the research and development of a planetary gear train capable of implementing more speed stages has also been actively conducted.
However, since a conventional 8-speed automatic transmission has gear ratio span of 6.5-7.5, improvement of fuel economy may not be great.
In addition, if 8-speed automatic transmission has gear ratio span larger than 9.0, it is hard to secure linearity of step ratios. Therefore, driving efficiency of an engine and drivability of a vehicle may be deteriorated, and thus, development of high efficiency automatic transmissions which achieve at least nine forward speed stages is necessary.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
BRIEF SUMMARY
Various aspects of the present invention are directed to providing a planetary gear train of an automatic transmission for a vehicle having advantages of improving power delivery performance and fuel economy by achieving nine forward speed stages and one reverse speed stage and widening gear ratio span and of securing linearity of step ratios.
A planetary gear train of an automatic transmission for a vehicle according to an exemplary embodiment of the present invention may include: an input shaft receiving torque of an engine; an output shaft outputting changed torque; a first planetary gear set including first, second, and third rotation elements; a second planetary gear set including fourth, fifth, and sixth rotation elements; a third planetary gear set including seventh, eighth, and ninth rotation elements; and a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements, wherein the input shaft is directly connected to the fourth rotation element and is selectively connected to the eleventh rotation element, the output shaft is directly connected to the eighth rotation element and the twelfth rotation element, the third rotation element is directly connected to the tenth rotation element, the ninth rotation element is directly connected to the eleventh rotation element, the second rotation element is selectively connected to the sixth rotation element, the first rotation element is directly connected to a transmission housing, the third rotation element is selectively connected to the fifth rotation element, the second rotation element is selectively connected to the sixth rotation element, the fifth rotation element is selectively connected to the transmission housing, the seventh rotation element is selectively connected to the transmission housing, and at least two rotation elements among the fourth, fifth, and sixth rotation elements of the second planetary gear set are selectively connected to each other.
The first, second, and third rotation elements of the first planetary gear set may be a first sun gear, a first planet carrier, and a first ring gear, the fourth, fifth, and sixth rotation elements of the second planetary gear set may be a second sun gear, a second planet carrier, and a second ring gear, the seventh, eighth, and ninth rotation elements of the third planetary gear set may be a third sun gear, a third planet carrier, and a third ring gear, and the tenth, eleventh, and twelfth rotation elements of the fourth planetary gear set may be a fourth sun gear, a fourth planet carrier, and a fourth ring gear.
Each of the first, second, third, and fourth planetary gear sets may be a single pinion planetary gear set.
The second planetary gear set may be selectively locked-up by selective connection of the fourth rotation element and the fifth rotation element.
The planetary gear train may further include: a first clutch selectively connecting the eleventh rotation element to the input shaft; a second clutch selectively connecting the fourth rotation element to the fifth rotation element; a third clutch selectively connecting the third rotation element to the fifth rotation element; a fourth clutch selectively connecting the second rotation element to the sixth rotation element; a first brake selectively connecting the fifth rotation element to the transmission housing; and a second brake selectively connecting the seventh rotation element to the transmission housing.
A planetary gear train of an automatic transmission for a vehicle according to another exemplary embodiment of the present invention may include: an input shaft receiving torque of an engine; an output shaft outputting changed torque; a first planetary gear set including first, second, and third rotation elements; a second planetary gear set including fourth, fifth, and sixth rotation elements; a third planetary gear set including seventh, eighth, and ninth rotation elements; a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements; a first rotation shaft connected to the first rotation element and directly connected to a transmission housing; a second rotation shaft connected to the second rotation element; a third rotation shaft connecting the third rotation element to the tenth rotation element; a fourth rotation shaft connected to the fourth rotation element and directly connected to the input shaft; a fifth rotation shaft connected to the fifth rotation element, selectively connected respectively to the third rotation shaft and the fourth rotation shaft, and selectively connected to the transmission housing; a sixth rotation shaft connected to the sixth rotation element and selectively connected to the second rotation shaft; a seventh rotation shaft connected to the seventh rotation element and selectively connected to the transmission housing; an eighth rotation shaft connecting the eighth rotation element to the twelfth rotation element and directly connected to the output shaft so as to be operated as an output element; and a ninth rotation shaft connecting the ninth rotation element to the eleventh rotation element and selectively connected to the input shaft.
The first planetary gear set may be a single pinion planetary gear set and may include a first sun gear as the first rotation element, a first planet carrier as the second rotation element, and a first ring gear as the third rotation element. The second planetary gear set may be a single pinion planetary gear set and may include a second sun gear as the fourth rotation element, a second planet carrier as the fifth rotation element, and a second ring gear as the sixth rotation element. The third planetary gear set may be a single pinion planetary gear set and may include a third sun gear as the seventh rotation element, a third planet carrier as the eighth rotation element, and a third ring gear as the ninth rotation element. The fourth planetary gear set may be a single pinion planetary gear set and may include a fourth sun gear as the tenth rotation element, a fourth planet carrier as the eleventh rotation element, and a fourth ring gear as the twelfth rotation element.
The planetary gear train may further include: a first clutch selectively connecting the input shaft to the ninth rotation shaft; a second clutch selectively connecting the fourth rotation shaft to the fifth rotation shaft; a third clutch selectively connecting the third rotation shaft to the fifth rotation shaft; a fourth clutch selectively connecting the second rotation shaft to the sixth rotation shaft; a first brake selectively connecting the fifth rotation shaft to the transmission housing; and a second brake selectively connecting the seventh rotation shaft to the transmission housing.
In one aspect, the first clutch may be disposed at a rear of the fourth planetary gear set, the second clutch and the first brake may be disposed in front of the first planetary gear set, the fourth clutch may be disposed between the first planetary gear set and the second planetary gear set, and the third clutch and the second brake may be disposed between the second planetary gear set and the third planetary gear set.
In another aspect, the first clutch may be disposed at a rear of the fourth planetary gear set, the first brake may be disposed in front of the first planetary gear set, the fourth clutch may be disposed between the first planetary gear set and the second planetary gear set, and the second and third clutches and the second brake may be disposed between the second planetary gear set and the third planetary gear set.
The third and fourth clutches and the second brake may be operated at a first forward speed stage, the second and third clutches and the second brake may be operated at a second forward speed stage, the second and fourth clutches and the second brake may be operated at a third forward speed stage, the first and second clutches and the second brake or the first and fourth clutches and the second brake may be operated at a fourth forward speed stage, the first, second, and fourth clutches may be operated at a fifth forward speed stage, the first, second, and third clutches may be operated at a sixth forward speed stage, the first, third, and fourth clutches may be operated at a seventh forward speed stage, the first and third clutches and the first brake may be operated at an eighth forward speed stage, the first and fourth clutches and the first brake may be operated at a ninth forward speed stage, and the fourth clutch and the first and second brakes may be operated at a reverse speed stage.
An exemplary embodiment of the present invention may achieve nine forward speed stages and one reverse speed stage by combining four planetary gear sets with six control elements.
In addition, since gear ratio span greater than 9.0 is secured, driving efficiency of the engine may be maximized.
In addition, since linearity of step ratios is secured, drivability such as acceleration before and after shift, rhythmical engine speed, and so on may be improved.
The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a planetary gear train according to the first exemplary embodiment of the present invention.
FIG. 2 is a schematic diagram of a planetary gear train according to the second exemplary embodiment of the present invention.
FIG. 3 is an operation chart of control elements at each speed stage in the planetary gear train according to the first and second exemplary embodiments of the present invention.
It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.
In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.
DETAILED DESCRIPTION
Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that the present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
However, parts which are not related with the description are omitted for clearly describing the exemplary embodiments of the present invention and like reference numerals refer to like or similar elements throughout the specification.
In the following description, dividing names of components into first, second, and the like is to divide the names because the names of the components are the same as each other and an order thereof is not particularly limited.
FIG. 1 is a schematic diagram of a planetary gear train according to the first exemplary embodiment of the present invention.
Referring to FIG. 1 , a planetary gear train according to the first exemplary embodiment of the present invention includes first, second, third, and fourth planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 disposed on the same axis, and input shaft IS, an output shaft OS, nine rotation shafts TM 1 to TM 9 connected to at least one of rotation elements of the first, second, third, and fourth planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 , six control elements C 1 to C 4 and B 1 to B 2 , and a transmission housing H.
As a result, torque input from the input shaft IS is changed by cooperation of the first, second, third, and fourth planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 , and the changed torque is output through the output shaft OS.
The simple planetary gear sets are disposed in a sequence of the first, second, third, and fourth planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 from an engine side.
The input shaft IS is an input member and power from a crankshaft of an engine is torque-converted through a torque converter to be input into the input shaft IS.
The output shaft OS is an output member, is disposed in parallel with the input shaft IS, and transmits driving torque to a driving wheel through a differential apparatus.
The first planetary gear set PG 1 is a single pinion planetary gear set and includes a first sun gear S 1 , a first planet carrier PC 1 rotatably supporting a first pinion P 1 that is externally meshed with the first sun gear S 1 , and a first ring gear R 1 that is internally meshed with the first pinion P 1 respectively as first, second, and third rotation elements N 1 , N 2 , and N 3 .
The second planetary gear set PG 2 is a single pinion planetary gear set and includes a second sun gear S 2 , a second planet carrier PC 2 rotatably supporting a second pinion P 2 that is externally meshed with the second sun gear S 2 , and a second ring gear R 2 that is internally meshed with the second pinion P 2 respectively as fourth, fifth, and sixth rotation elements N 4 , N 5 , and N 6 .
The third planetary gear set PG 3 is a single pinion planetary gear set and includes a third sun gear S 3 , a third planet carrier PC 3 rotatably supporting a third pinion P 3 that is externally meshed with the third sun gear S 3 , and a third ring gear R 3 that is internally meshed with the third pinion P 3 respectively as seventh, eighth, and ninth rotation elements N 7 , N 8 , and N 9 .
The fourth planetary gear set PG 4 is a single pinion planetary gear set and includes a fourth sun gear S 4 , a fourth planet carrier PC 4 rotatably supporting a fourth pinion P 4 that is externally meshed with the fourth sun gear S 4 , and a fourth ring gear R 4 that is internally meshed with the fourth pinion P 4 respectively as tenth, eleventh, and twelfth rotation elements N 10 , N 11 , and N 12 .
The third rotation element N 3 is directly connected to the tenth rotation element N 10 , the eighth rotation element N 8 is directly connected to the twelfth rotation element N 12 , and the ninth rotation element N 9 is directly connected to the eleventh rotation element N 11 such that the first, second, third, and fourth planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 are operated with nine rotation shafts TM 1 to TM 9 .
The nine rotation shafts TM 1 to TM 9 will be described in further detail.
The first rotation shaft TM 1 is connected to the first sun gear S 1 and id directly connected to the transmission housing H.
The second rotation shaft TM 2 is connected to the first planet carrier PC 1 .
The third rotation shaft TM 3 connects the third ring gear R 3 to the fourth sun gear S 4 .
The fourth rotation shaft TM 4 is connected to the second sun gear S 2 and is directly connected to the input shaft IS so as to be continuously operated as an input element.
The fifth rotation shaft TM 5 is connected to the second planet carrier PC 2 , is selectively connected respectively to the third rotation shaft TM 3 and the fourth rotation shaft TM 4 , and is selectively connected to the transmission housing H.
The sixth rotation shaft TM 6 is connected to the second ring gear R 2 and is selectively connected to the second rotation shaft TM 2 .
The seventh rotation shaft TM 7 is connected to the third sun gear S 3 and is selectively connected to the transmission housing H.
The eighth rotation shaft TM 8 connects the third planet carrier PC 3 to the fourth ring gear R 4 and is directly connected to the output shaft OS so as to be continuously operated as an output element.
The ninth rotation shaft TM 9 connects the third ring gear R 3 to the fourth planet carrier PC 4 and is selectively connected to the input shaft IS.
In addition, four clutches C 1 , C 2 , C 3 , and C 4 being control elements are disposed at connection portions between any two rotation shafts among the rotation shafts TM 1 to TM 9 or between the input shaft IS and any one rotation shaft among the rotation shafts TM 1 to TM 9 .
addition, two brakes B 1 and B 2 being control elements are disposed at connection portions between any one rotation shaft among the rotation shaft TM 1 to TM 9 and the transmission housing H.
The six control elements C 1 to C 4 and B 1 to B 2 will be described in further detail.
The first clutch C 1 is disposed between the input shaft IS and the ninth rotation shaft TM 9 and selectively causes the input shaft IS and the ninth rotation shaft TM 9 to be integrally rotate with each other.
The second clutch C 2 is disposed between the fourth rotation shaft TM 4 and the fifth rotation shaft TM 5 and selectively causes the fourth rotation shaft TM 4 and the fifth rotation shaft TM 5 to integrally rotate with each other.
The third clutch C 3 is disposed between the third rotation shaft TM 3 and the fifth rotation shaft TM 5 and selectively causes the third rotation shaft TM 3 and the fifth rotation shaft TM 5 to integrally rotate with each other.
The fourth clutch C 4 is disposed between the second rotation shaft TM 2 and the sixth rotation shaft TM 6 and selectively causes the second rotation shaft TM 2 and the sixth rotation shaft TM 6 to integrally rotate with each other.
The first brake B 1 is disposed between the fifth rotation shaft TM 5 and the transmission housing H and causes the fifth rotation shaft TM 5 to be operated as a fixed element.
The second brake B 2 is disposed between the seventh rotation shaft TM 7 and the transmission housing H and causes the seventh rotation shaft TM 7 to be operated as a selective fixed element.
The control elements including the first, second, third, and fourth clutches C 1 , C 2 , C 3 , and C 4 and the first and second brakes B 1 and B 2 may be multi-plates friction elements of wet type that are operated by hydraulic pressure.
FIG. 2 is a schematic diagram of a planetary gear train according to the second exemplary embodiment of the present invention.
Referring to FIG. 2 , the second clutch C 2 is disposed in front of the first planetary gear set PG 1 in first exemplary embodiment of the present invention, but the second clutch C 2 is disposed between the second planetary gear train PG 2 and the third planetary gear train PG 3 in the second exemplary embodiment.
The second clutch C 2 in the second exemplary embodiment, the same as the second clutch C 2 in the first exemplary embodiment, selectively connects the fourth rotation shaft TM 4 to the fifth rotation shaft TM 5 and causes the second planetary gear set PG 2 to become a lock-up state.
FIG. 3 is an operation chart of control elements at each speed stage in the planetary gear train according to the first and second exemplary embodiments of the present invention.
As shown in FIG. 3 , three control elements are operated at each speed stage in the planetary gear train according to the exemplary embodiments of the present invention.
The third and fourth clutches C 3 and C 4 and the second brake B 2 are operated at a first forward speed stage D 1 . In a state that the third rotation shaft TM 3 is connected to the fifth rotation shaft TM 5 by operation of the third clutch C 3 and the second rotation shaft TM 2 is connected to the sixth rotation shaft TM 6 by operation of the fourth clutch C 4 , torque of the input shaft IS is input to the fourth rotation shaft TM 4 . In addition, the first rotation shaft TM 1 is operated as the fixed element and the seventh rotation shaft TM 7 is operated as the fixed element by operation of the second brake B 2 . Therefore, the torque of the input shaft IS is shifted into the first forward speed stage, and the first forward speed stage is output through the eighth rotation shaft TM 8 .
The second and third clutches C 2 and C 3 and the second brake B 2 are operated at a second forward speed stage D 2 . In a state that the fourth rotation shaft TM 4 is connected to the fifth rotation shaft TM 5 by operation of the second clutch C 2 and the third rotation shaft TM 3 is connected to the fifth rotation shaft TM 5 by operation of the third clutch C 3 , the torque of the input shaft IS is input to the fourth rotation shaft TM 4 . In addition, the first rotation shaft TM 1 is operated as the fixed element and the seventh rotation shaft TM 7 is operated as the fixed element by operation of the second brake B 2 . Therefore, the torque of the input shaft IS is shifted into the second forward speed stage, and the second forward speed stage is output through the eighth rotation shaft TM 8 .
The second and fourth clutches C 2 and C 4 and the second brake B 2 are operated at a third forward speed stage D 3 . In a state that the fourth rotation shaft TM 4 is connected to the fifth rotation shaft TM 5 by operation of the second clutch C 2 and the second rotation shaft TM 2 is connected to the sixth rotation shaft TM 6 by operation of the fourth clutch C 4 , the torque of the input shaft IS is input to the fourth rotation shaft TM 4 . In addition, the first rotation shaft TM 1 is operated as the fixed element and the seventh rotation shaft TM 7 is operated as the fixed element by operation of the second brake B 2 . Therefore, the torque of the input shaft IS is shifted into the third forward speed stage, and the third forward speed stage is output through the eighth rotation shaft TM 8 .
The first and second clutches C 1 and C 2 and the second brake B 2 are operated at a fourth forward speed stage D 4 . In a state that the input shaft IS is connected to the ninth rotation shaft TM 9 by operation of the first clutch C 1 and the fourth rotation shaft TM 4 is connected to the fifth rotation shaft TM 5 by operation of the second clutch C 2 , the torque of the input shaft IS is input to the fourth rotation shaft TM 4 . In addition, the first rotation shaft TM 1 is operated as the fixed element and the seventh rotation shaft TM 7 is operated as the fixed element by operation of the second brake B 2 . Therefore, the torque of the input shaft IS is shifted into the fourth forward speed stage, and the fourth forward speed stage is output through the eighth rotation shaft TM 8 .
The first and fourth clutches C 1 and C 4 and the second brake B 2 are operated at a fourth forward speed stage D 4 . In a state that the input shaft IS is connected to the ninth rotation shaft TM 9 by operation of the first clutch C 1 and the second rotation shaft TM 2 is connected to the sixth rotation shaft TM 6 by operation of the fourth clutch C 4 , the torque of the input shaft IS is input to the fourth rotation shaft TM 4 . In addition, the first rotation shaft TM 1 is operated as the fixed element and the seventh rotation shaft TM 7 is operated as the fixed element by operation of the second brake B 2 . Therefore, the torque of the input shaft IS is shifted into the fourth forward speed stage, and the fourth forward speed stage is output through the eighth rotation shaft TM 8 .
The first, second, and fourth clutches C 1 , C 2 , and C 4 are operated at a fifth forward speed stage D 5 . In a state that the input shaft IS is connected to the ninth rotation shaft TM 9 by operation of the first clutch C 1 , the fourth rotation shaft TM 4 is connected to the fifth rotation shaft TM 5 by operation of the second clutch C 2 , and the second rotation shaft TM 2 is connected to the sixth rotation shaft TM 6 by operation of the fourth clutch C 4 , the torque of the input shaft IS is input to the fourth rotation shaft TM 4 . In addition, the first rotation shaft TM 1 is operated as the fixed element. Therefore, the torque of the input shaft IS is shifted into the fifth forward speed stage, and the fifth forward speed stage is output through the eighth rotation shaft TM 8 .
The first, second, and third clutches C 1 , C 2 , and C 3 are operated at a sixth forward speed stage D 6 . In a state that the input shaft IS is connected to the ninth rotation shaft TM 9 by operation of the first clutch C 1 , the fourth rotation shaft TM 4 is connected to the fifth rotation shaft TM 5 by operation of the second clutch C 2 , and the third rotation shaft TM 3 is connected to the fifth rotation shaft TM 5 by operation of the third clutch C 3 , the torque of the input shaft IS is input to the fourth rotation shaft TM 4 . In addition, the first rotation shaft TM 1 is operated as the fixed element. Therefore, the torque of the input shaft IS is shifted into the sixth forward speed stage, and the sixth forward speed stage is output through the eighth rotation shaft TM 8 .
The first, third, and fourth clutches C 1 , C 3 , and C 4 are operated at a seventh forward speed stage D 7 . In a state that the input shaft IS is connected to the ninth rotation shaft TM 9 by operation of the first clutch C 1 , the third rotation shaft TM 3 is connected to the fifth rotation shaft TM 5 by operation of the third clutch C 3 , and the second rotation shaft TM 2 is connected to the sixth rotation shaft TM 6 by operation of the fourth clutch C 4 , the torque of the input shaft IS is input to the fourth rotation shaft TM 4 . In addition, the first rotation shaft TM 1 is operated as the fixed element. Therefore, the torque of the input shaft IS is shifted into the seventh forward speed stage, and the seventh forward speed stage is output though the eighth rotation shaft TM 8 .
The first and third clutches C 1 and C 3 and the first brake B 1 are operated at an eighth forward speed stage D 8 . In a state that the input shaft IS is connected to the ninth rotation shaft TM 9 by operation of the first clutch C 1 and the third rotation shaft TM 3 is connected to the fifth rotation shaft TM 5 by operation of the third clutch C 3 , the torque of the input shaft IS is input to the fourth rotation shaft TM 4 . In addition, the first rotation shaft TM 1 is operated as the fixed element and the fifth rotation shaft TM 5 is operated as the fixed element by operation of the first brake B 1 . Therefore, the torque of the input shaft IS is shifted into the eighth forward speed stage, and the eighth forward speed stage is output through the eighth rotation shaft TM 8 .
The first and fourth clutches C 1 and C 4 and the first brake B 1 are operated at a ninth forward speed stage D 9 . In a state that the input shaft IS is connected to the ninth rotation shaft TM 9 by operation of the first clutch C 1 and the second rotation shaft TM 2 is connected to the sixth rotation shaft TM 6 by operation of the fourth clutch C 4 , the torque of the input shaft IS is input to the fourth rotation shaft TM 4 . In addition, the first rotation shaft TM 1 is operated as the fixed element and the fifth rotation shaft TM 5 is operated as the fixed element by operation of the first brake B 1 . Therefore, the torque of the input shaft IS is shifted into the ninth forward speed stage, and the ninth forward speed stage is output through the eighth rotation shaft TM 8 .
The fourth clutch C 4 and the first and second brakes B 1 and B 2 are operated at a reverse speed stage REV. In a state that the second rotation shaft TM 2 is connected to the sixth rotation shaft TM 6 by operation of the fourth clutch C 4 , the torque of the input shaft IS is input to the fourth rotation shaft TM 4 . In addition, the first rotation shaft TM 1 is operated as the fixed element, and the fifth rotation shaft TM 5 and the seventh rotation shaft TM 7 are operated as the fixed elements by operation of the first and second brakes B 1 and B 2 . Therefore, the torque of the input shaft IS is shifted into the reverse speed stage, and the reverse speed stage is output through the eighth rotation shaft TM 8 .
The planetary gear train according to the exemplary embodiments of the present invention may achieve nine forward speed stages and one reverse speed stage by control of four planetary gear sets PG 1 , PG 2 , PG 3 , and PG 4 , four clutches C 1 , C 2 , C 3 , and C 4 , and two brakes B 1 and B 2 .
In addition, since linearity of step ratios is secured, drivability such as acceleration before and after shift, rhythmical engine speed, and so on may be improved.
In addition, since gear ratio span greater than 9.0 is secured, driving efficiency of the engine may be maximized.
For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.
The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.
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A planetary gear train of an automatic transmission for a vehicle may include: an input shaft receiving torque of an engine; an output shaft outputting changed torque; a first planetary gear set including a first rotation element, a second rotation element, and a third rotation element; a second planetary gear set including a fourth rotation element, a fifth rotation element, and a sixth rotation element; a third planetary gear set including a seventh rotation element, an eighth rotation element, and a ninth rotation element; and a fourth planetary gear set including a tenth rotation element, an eleventh rotation element, and a twelfth rotation element.
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TECHNICAL FIELD
This invention relates to telecommunications switching, and in particular, to wireless terminals.
BACKGROUND OF THE INVENTION
Wireless terminals utilized in an in-building environment normally are part of the user's call coverage group (also referred to as a call coverage path). Often, the call coverage group will consist of the user's wired telephone, wireless telephone, secretarial support telephone, and voice messaging system. In most instances, a wireless terminal is left in a desktop or a bulk charging unit when the user is not expecting to receive calls or has left the building. Since the wireless terminal is typically within the wireless coverage area of the wireless telecommunication switching system capable of receiving calls, the wireless telecommunication switching system attempts to deliver calls to the wireless terminal as part of the call coverage group. Normally, a wireless telecommunication switching system will attempt to alert a wireless terminal for 24 seconds before attempting to complete an incoming call on the next unit in the call coverage group. The wireless telecommunication switching system has no mechanism for determining that the wireless terminal is being charged. In many installations, bulk charging units are utilized. The bulk charging unit is placed next to the exit and entrance from the building and is utilized to charge a number of wireless terminals at one time while the users are out of the building.
The prior art has attempted to resolve this problem by allowing the user to turn the wireless terminal off, thus providing an “out of area” indication to the wireless telecommunication system when the wireless terminal is turned off. Unfortunately, it takes a great amount of time before the wireless telecommunication system detects that the wireless terminal is no longer powered on. In addition, it is very easy for the user to forget to power down the wireless terminal when inserting it into a battery charger. Other prior art wireless telecommunication systems allow the user to activate a button on the wireless terminal to place the wireless terminal in a “send all calls” state by initiating the “send all calls” feature. This causes the prior art wireless telecommunication switching system to immediately advance to the next device in the call coverage path. Unfortunately, users forget to initiate the “send all calls” state before they insert their wireless terminal into the charger. Also, users will forget to deactivate the “send all calls” feature after removing their wireless terminals from the charger. This results in the users missing calls that normally would have been received on their wireless terminals.
SUMMARY OF THE INVENTION
This invention is directed to solving these and other problems and disadvantages of the prior art. Illustratively according to the invention, a wireless terminal when inserted into a charging unit transmits to a wireless telecommunication switching system a “plugged into charger” message. The wireless telecommunication switching system is responsive to the “plugged into charger” message to remove the wireless terminal from the call coverage path of the user.
Advantageously, the wireless telecommunication switching system can add to the call coverage path of the user the telephone number of the cellular telephone utilized by the user when the user is out of the building.
Advantageously, in a second embodiment of the invention, the wireless terminal transmits the message to invoke the “send all calls” state when the wireless terminal is plugged into a charging unit. Advantageously, in a third embodiment of the invention, the wireless terminal transmits a call transfer message that transfers all incoming calls to another terminal when the wireless terminal is plugged into the charging unit.
These and other features and advantages of the present invention will become apparent from the following description of illustrative embodiments of the invention considered together with the drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates, in block diagram form, a system for implementing the invention;
FIG. 2 illustrates, in flow chart form, steps for implementing the first embodiment of the invention by a wireless terminal;
FIG. 3 illustrates, in flow chart form, steps for implementing the second embodiment of the invention by a wireless terminal;
FIG. 4 illustrates, in flow chart form, steps for implementing a third embodiment of the invention by a wireless terminal;
FIG. 5 illustrates, in flow chart form, steps for implementing the first embodiment of the invention by a wireless telecommunication switching system;
FIG. 6 illustrates, in flow chart form, steps for implementing the second embodiment of the invention by a wireless telecommunication switching system; and
FIG. 7 illustrates, in flow chart form, steps for implementing the third embodiment of the invention by a wireless telecommunication switching system.
DETAILED DESCRIPTION
FIG. 1 illustrates an embodiment for implementing the invention. In-building wireless telecommunication switching system 101 provides a wireless service via base stations 103 - 104 to wireless terminals 107 - 108 . In addition, in-building switching system 101 provides wired service to wired terminals 109 - 110 . Voice messaging system 102 is connected to in-building switching system 101 so as to provide voice messaging capabilities. In-building switching system 101 is interconnected to public telephone system 111 and to cellular switching system 112 via public telephone system 111 . When in the building serviced by in-building switching system 101 , each user has associated with them a wired terminal and a wireless terminal. In addition, each user has a call coverage path which includes their wired terminal, their wireless terminal, voice messaging system 102 , and another wired terminal. For example, assume that a user is assigned wired terminal 109 , is assigned wireless terminal 107 , and is provided coverage by wired terminal 110 . The user's call coverage path could advantageously be that the call is first placed to wired terminal 109 , then to wireless terminal 107 , then to wired terminal 110 , and finally if none of the terminals answered, to voice messaging system 102 . In the first embodiment of the invention, when the user inserts wireless terminal 107 into battery charger 106 , wireless terminal 107 sends a message to in-building switching system 101 informing in-building switching system 101 that it has been inserted into a battery charger. In-building switching system 101 is responsive to the message to alter the call coverage path for the user of wireless terminal 107 . This alteration of the call coverage path may be as simple as temporarily removing wireless terminal 107 from the call coverage path so that a call is first routed to wired terminal 109 , then to wired terminal 110 , and finally to voice messaging system 102 . Advantageously, if the user has assigned to them cellular terminal 113 and it is assumed they have left the building, then, in-building switching system 101 substitutes the telephone number for cellular terminal 113 in place of the telephone number of wireless terminal 107 .
In the second embodiment of the invention, when plugged into battery charger 106 , wireless terminal 107 sends a “send all calls” message to in-building switching system 101 . In-building switching system 101 responds to this message as if the user had manually caused the “send all calls” message to be transmitted.
In the third embodiment of the invention when plugged into battery charger 106 , wireless terminal 107 sends a “call transfer” message to in-building switching system 101 . The “call transfer” message includes the telephone number to which all calls directed to wireless terminal 107 are to be redirected. In general, when the third embodiment is implemented, wireless terminal 107 is not part of a call coverage path. For example, if the user of wireless terminal 107 is going to be out of the building and using cellular terminal 113 , wireless terminal 107 is programmed by the user to transmit the telephone number of cellular terminal 113 as part of the “call transfer” message.
FIG. 2 illustrates, in flow chart form, the steps performed by a wireless terminal in implementing the first embodiment of the invention. Once started, decision block 201 determines if the wireless terminal is plugged into a charger. If the answer is no, control is transferred to decision block 202 which determines if the charger flag is set. The charger flag is set by the wireless terminal when it is plugged into the charger. If the answer is no in decision block 202 , control is transferred to decision block 203 for normal processing before control is returned back to decision block 201 . A no in decision block 202 indicates that the wireless terminal has not just been removed from the battery charger. If the answer in decision block 202 is yes, control is transferred to block 204 which resets the charger flag before transferring control to block 206 . Block 206 sends the “unplugged from charger” message to in-building switching system 101 before returning control back to decision block 201 .
Returning to decision block 201 , if the answer is yes, control is transferred to decision block 207 which determines if the charger flag is set. If the answer in decision block 207 is yes, the wireless terminal has remained plugged into the battery charger and no action is necessary. Hence, control is transferred to block 211 for normal processing before being transferred back to decision block 201 . If the answer in decision block 207 is no, control is transferred to block 208 which sets the charger flag before transferring control to block 209 . Block 209 sends the “plugged into charger” message to in-building switching system 101 before transferring control back to decision block 201 .
FIG. 3 illustrates, in flow chart form, the steps performed by a wireless terminal in implementing the second embodiment of the invention. Once started, decision block 301 determines if the wireless terminal is plugged into a charger. If the answer is no, control is transferred to decision block 302 which determines if the charger flag is set. The charger flag is set by the wireless terminal when it is plugged into the charger. If the answer is no in decision block 302 , control is transferred to decision block 303 for normal processing before control is returned back to decision block 301 . A no in decision block 302 indicates that the wireless terminal has not just been removed from the battery charger. If the answer in decision block 302 is yes, control is transferred to block 304 which resets the charger flag before transferring control to block 306 . Block 306 sends the “cancel send all calls” message to in-building switching system 101 before returning control back to decision block 301 .
Returning to decision block 301 , if the answer is yes, control is transferred to decision block 307 which determines if the charger flag is set. If the answer in decision block 307 is yes, the wireless terminal has remained plugged into the battery charger and no action is necessary. Hence, control is transferred to block 311 for normal processing before being transferred back to decision block 301 . If the answer in decision block 307 is no, control is transferred to block 308 which sets the charger flag before transferring control to block 309 . Block 309 sends the “send all calls” message to in-building switching system 101 before transferring control back to decision block 301 .
FIG. 4 illustrates, in flow chart form, the steps performed by a wireless terminal in implementing the third embodiment of the invention. Once started, decision block 401 determines if the wireless terminal is plugged into a charger. If the answer is no, control is transferred to decision block 402 which determines if the charger flag is set. The charger flag is set by the wireless terminal when it is plugged into the charger. If the answer is no in decision block 402 , control is transferred to decision block 403 for normal processing before control is returned back to decision block 401 . A no in decision block 402 indicates that the wireless terminal has not just been removed from the battery charger. If the answer in decision block 402 is yes, control is transferred to block 404 which resets the charger flag before transferring control to block 406 . Block 406 sends the “cancel call forwarding” message to in-building switching system 101 before returning control back to decision block 401 .
Returning to decision block 401 , if the answer is yes, control is transferred to decision block 407 which determines if the charger flag is set. If the answer in decision block 407 is yes, the wireless terminal has remained plugged into the battery charger and no action is necessary. Hence, control is transferred to block 411 for normal processing before being transferred back to decision block 401 . If the answer in decision block 407 is no, control is transferred to block 408 which sets the charger flag before transferring control to block 409 . Block 409 sends the “call forwarding with telephone number” message to in-building switching system 101 before transferring control back to decision block 401 . The telephone number included in the message to invoke call forwarding is the telephone number to which calls are to be forward.
FIG. 5 illustrates, in flow chart form, the steps performed by in-building wireless telecommunication switching system 101 in implementing the first embodiment of the invention. When started, decision block 501 examines a message to determine if it is from a wireless terminal. If the answer is no, block 502 performs normal processing before returning control back to decision block 501 . Block 502 performs processing that is well-known by those skilled in the art for a switching system such as in-building switching system 101 . If the answer is yes in decision block 501 , control is transferred to decision block 503 which determines if a “plugged into charger” message has been received from a wireless terminal. If the answer is yes, control is transferred to block 504 which updates the call coverage path of which the wireless terminal is part. In the previously described examples for the first embodiment, the operations performed by block 504 could consist of removing wireless terminal 107 from the call coverage path associated with the user of wireless terminal 107 or could involve replacing the telephone number of wireless terminal 107 with the telephone number of cellular terminal 113 .
If the answer is no in decision block 503 , control is transferred to decision block 506 . The latter decision block determines if a “unplugged from charger” message has been received from a wireless terminal. If the answer is no, control is transferred to block 508 which performs the processing that is well-known by those skilled in the art for providing service to a plurality of wireless terminals by a system such as in-building wireless telecommunication switching system 101 . If the answer yes in decision block 506 , control is transferred to block 507 which resets the call coverage path for the user of the wireless terminal 107 as it would be when wireless terminal 107 is in use by the user.
FIG. 6 illustrates, in flow chart form, the steps performed by in-building wireless telecommunication switching system 101 in implementing the second embodiment of the invention. When started, decision block 601 examines a message to determine if it is from a wireless terminal. If the answer is no, block 602 performs normal processing before returning control back to decision block 601 . Block 602 performs processing that is well-known by those skilled in the art for a switching system such as in-building switching system 101 . If the answer is yes in decision block 601 , control is transferred to decision block 603 which determines if a “send all calls” message has been received from a wireless terminal. If the answer is yes, control is transferred to block 604 which performs normal processing to implement the “send all calls” feature.
If the answer is no in decision block 603 , control is transferred to decision block 606 . The latter decision block determines if a “cancel send all calls” message has been received from a wireless terminal. If the answer is no, control is transferred to block 608 which performs the processing that is well-known by those skilled in the art for providing service to a plurality of wireless terminals by a system such as in-building wireless telecommunication switching system 101 . If the answer yes in decision block 606 , control is transferred to block 607 which cancels the “send all calls” feature as it would if wireless terminal 107 had been manually activated by the user.
FIG. 7 illustrates, in flow chart form, the steps performed by in-building wireless telecommunication switching system 101 in implementing the third embodiment of the invention. When started, decision block 701 examines a message to determine if it is from a wireless terminal. If the answer is no, block 702 performs normal processing before returning control back to decision block 701 . Block 702 performs processing that is well-known by those skilled in the art for a switching system such as in-building switching system 101 . If the answer is yes in decision block 701 , control is transferred to decision block 703 which determines if a “call forwarding” message has been received from a wireless terminal. If the answer is yes, control is transferred to block 704 which performs normal processing to implement the “call forwarding” feature by forwarding calls to the telephone number included in the message.
If the answer is no in decision block 703 , control is transferred to decision block 706 . The latter decision block determines if a “cancel send all calls” message has been received from a wireless terminal. If the answer is no, control is transferred to block 708 which performs the processing that is well-known by those skilled in the art for providing service to a plurality of wireless terminals by a system such as in-building wireless telecommunication switching system 101 . If the answer yes in decision block 706 , control is transferred to block 707 which cancels the “call forwarding” feature as it would if wireless terminal 107 had been manually activated by the user.
Of course, various changes and modifications to the illustrative embodiments described above will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and the scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be covered by the following claims except insofar as limited by the prior art.
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Transmitting a “plugged into charger” message to a wireless telecommunication switching system by a wireless terminal when inserted into a charging unit. The wireless telecommunication switching system is responsive to the “plugged into charger” message to remove the wireless terminal from the call coverage path of the user. The wireless telecommunication switching system can add to the call coverage path of the user the telephone number of the cellular telephone utilized by the user when the user is out of the building. In a second embodiment of the invention, the wireless terminal transmits the message to invoke the “send all calls” state when the wireless terminal is plugged into a charging unit. In a third embodiment of the invention, the wireless terminal transmits a call transfer message that transfers all incoming calls to another terminal when the wireless terminal is plugged into the charging unit.
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FIELD OF THE INVENTION
This invention relates to systems for obtaining physiologic fluid samples. More particularly, a lancing device for obtaining blood samples with minimum user discomfort is disclosed.
BACKGROUND OF THE INVENTION
Numerous lancing mechanism for obtaining blood samples have been developed. Many of these are optimized for effectiveness in quickly sticking a user with a lancing pin or blade to reduce the sensation of physical pain. Whether intentional or not, others are also designed in a manner that reduces physiological factors associated with obtaining a blood sample.
One such factor contributing to physiological discomfort in using known lancing mechanism results from loud slapping or popping noises certain devices make upon actuation. Another negative stimulus often noticed by users is recoil or sudden motion of the housing of a lancing device associated with lance firing. Anticipation of the noise or jolting motion of a lancing device can be as disconcerting as the needle stick itself. As observed by a Dr. Chapman, “Pain is far from being and emotionally neutral experience; it is almost always accompanied by emotional disturbance and distress. The physiologic accompaniments of such arousal vary with individual, but that may interact powerfully with the sensory mechanism of pain to exacerbate the pain state.” Chapman, The Management of Pain, 2 nd Edition, Vol. 1, pg. 122 (1990).
Certain lancing devices are configured in such a way that they should run silently. Examples include those found in U.S. Pat. Nos. 4,924,879; 5,196,025; 5,304,193 and 5,938,679. These employ linkage or lever type mechanisms that advance and retract a lance without impulse loading or impact by or on the lance against opposing mechanism to cause serious noise. Other devices, even some employing camming or linkage mechanisms (such as in U.S. Pat. Nos. 5,527,334 and 5,554,166) do not.
As for the device described in U.S. Pat. No. 4,924,879 to O'Brien, it discloses a lancet driven and retracted into a cocked position by 180° oscillation of a torsion spring driven crank wheel attached to a connecting rod secured to a blade carrier constrained to slide in and out relative to an internal housing portion. A significant disadvantage of this system is presented by the fact that returning the mechanism to a cocked position results in the lance blade extension where it might present a danger in spite of an external housing provided to facilitate finger positioning. Cocking the mechanism is accomplished by a winding handle that winds a torsion spring one-half turn. A catch locks the loaded assembly until it is released by pressing a button. If cocked ahead of time, the system also presents the safety hazard of inadvertent misfire.
Similar hazards with respect to potential misfire due to stored energy in a cocked position are presented in the use of the devices described in U.S. Pat. Nos. 5,196,025 and 5,304,193. Each device utilizes a lever or linkage system that is flexed one way and then another to, respectively, fire and retract a lance member upon release from a cocked position by a latch.
The system described in U.S. Pat. No. 5,938,679 to Freeman, et al. includes an actuator having a crank wheel or link (referred to as a cam) and a connector link (referred to or pivotal arm) like the O'Brien device, but the wheel/link run in a full circle to actuate a blade assembly. The patent fails to disclose further structural details of the actuator. It does, however, describe a use where it moves an attached blade structure to penetrate and remain in a wound site for a preset length of time to fill a capillary tube associated with the blade and then retract. Such an actuator differs functionally from that of the present invention, which is intended to stick a patient and immediately retract to minimize pain. An actuator according to the present invention is not physically capable of such action or control.
It does, however, provide an exceptionally inexpensive, durable and easy to use means of actuating a lance. All this is accomplished in a smooth-operating, substantially noise free device, distinguishing the present invention over other know systems as well.
SUMMARY OF THE INVENTION
The present invention comprises a lancing device with automatic stick and lance return features once a user has cocked the device. A drive mechanism within the unit comprises a slider-crank linkage combination in the form of a crank member, a coupler link and a reciprocating lance-carrying member/slider. The drive mechanism is biased by a spring member to cause automatic firing once the crank member over-runs an equilibrium point of the spring. Any of a variety of spring types or linkage configurations may be employed. In addition, component placement may vary widely while still achieving the intended function.
Prior to cocking the device for firing, the spring preferably sets the position of the lance or lance carrier at a partially retracted position so that a tip of the lance does not pose a safety hazard. The system is preferably configured so that this position substantially coincides with a minimum energy state for the device alleviating risk of lancet misfire. A clutch may be provided in the system, typically at the crank pivot. The drive may be actuated by any number of approaches. However, a ratchet-type mechanism is most preferred.
The present invention further includes systems comprising any of these features described herein. Methodology described in association with the devices disclosed also forms part of the invention. The invention also comprises such hardware and methodology as may be used in connection with that described which is incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
Each of the following figures provide examples diagrammatically illustrating aspects of the present invention. Variation of the invention from that shown in the figures is contemplated. Like elements in the various figures are often indicated by identical numbering. For the sake of figure clarity, however, some such numbering is omitted.
FIGS. 1A through 1E are front view of the inventive lancing mechanism in various stages of operation.
FIG. 2 is a perspective view of an alternate lancing members.
FIG. 3 is a front view of a preferred cocking mechanism in first and second stages of operation.
FIG. 4 is a perspective view of a lancing device according to the present invention in the process of being actuated by a user.
DETAILED DESCRIPTION OF THE INVENTION
Before describing variations of the present invention in detail, first, it is to be understood that this invention is not limited to particular variations set forth and may, of course, vary. Various changes may be made to the invention described and equivalents may be substituted without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process step or steps, to the objective, spirit and scope of the present invention. All such modifications are intended to be within the scope of the claims made herein. Also, it is contemplated that any optional feature of the inventive variations described herein may be set forth and claimed independently, or in combination with any one or more of the features described herein.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, the preferred methods and materials are described. All existing subject matter mentioned herein (e.g., publications, patents, patent applications and hardware) is incorporated by reference herein in its entirety. The referenced items are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such material by virtue of prior invention.
Also, it is noted that as used herein and in the appended claims, the singular forms “a,” “and,” “said” and “the” include plural referents unless the context clearly dictates otherwise. Conversely, it is contemplated that the claims may be so-drafted to require singular elements or exclude any optional element indicated to be so here in the text or drawings. This statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements or the use of a “negative” claim limitation(s).
Turning now to FIGS. 1A-1E , the basic operation of a drive mechanism 2 for a lancing apparatus is shown in various stages of operation. First, the constituent parts will be described, then their sequence of motion.
Drive mechanism 2 is generally referred to as a slider-crank linkage. It comprises a slider portion 4 a crank member 6 and a coupler link 8 . The slider portion includes a shuttle 10 in the form of a lance-carrying member. As shown in FIGS. 1A-1E , this member actually includes a lance tip or blade 12 . The shuttle/lance-carrying member 10 is preferably confined in a channel or way 14 . As configured, the channel permits only reciprocal, rectilinear movement. It is easily formed integrally with housing 16 of a complete lancing device or apparatus 18 as shown in FIG. 4 , for instance, by injection molding to minimize cost. Alternate manners of directing the lance or lance tip may also be employed. Exemplary options include, another link, track, ridge or a linear bearing setup.
Shuttle 10 is rotably connected to coupler link, preferably by a simple pin 20 . The coupler link is also rotably attached to crank member 6 via a pin 20 . In a most basic variation of the invention, the crank member is rotably fixed to a crank support 22 such as device housing 16 by a pin 20 . If each of the members are not to be held together by adjacent or opposing material faces in the lancing device housing, the pins may include a groove to receive a C-clip or snap ring instead. A further alternative construction could employ snap together molded parts, shoulder bolts or capped pins press fit into either of the crank, coupler or shuttle. If a connector pin 20 is to be press fit in a member as shown in FIG. 2 , the member receiving the same preferably comprises a lubricious material irrespective of how the pin is configured.
In a preferred embodiment of the invention, the connection at the crank member includes a one-way clutch 54 as may be purchased in the form of one-way cartridge bearings rather that a rotably unconstrained interface. Suitable clutch members are well known in the art. An exemplary type is commonly known as an “overrunning clutch” and illustrated in connection with FIG. 3 . Such a device may also be regarded as a form of ratchet. When driven clockwise as shown in the figure, rollers or balls 56 are free to move within tapered recesses 58 and the device spins freely. When counter-rotated, the balls are wedged within the tapered recesses between the anchored center 60 and outer wheel member 6 . The purpose of including a clutch is to remove oscillations from the system or prevent inadvertent unwinding from a cocked position instead of firing the lance.
For such purposes, a clutch could equally well be included at the connector/crank interface or be provided for by a more sophisticated setup. The approach described is, however, preferred for its simplicity and ease of implementation. FIG. 3 shows a preferred implementation or crank member 6 . A round body is provided instead of a typical elongate link member. Though not preferred, coupler 18 may be provided by a member having a shape different than shown as well. Yet using a round body for crank member 6 offers more room for a clutch bearing 24 and also enables such other features as discussed below. A pin or shoulder bolt affixed to housing 16 and running through the center of the clutch interfaces with the same to provide reaction forces to prevent rotation.
Of course, the direction in which rotation is permitted or the drive mechanism in general may be either clockwise or counterclockwise. FIGS. 1A-1E and 3 , depict clockwise crank member movement in use.
Another common variation is to configure lance carrying member 10 as shown in FIG. 2 as opposed to as shown in FIGS. 1A-1E . In FIGS. 1A-1E , the shuttle or lance carrying member integrally includes the lance blade 12 . In the variation in FIG. 2 , lance carrying member 10 merely includes a receptacle section 26 to receive a snap-in disposable lance 28 such as One Touch® FinePoint™ lancets from LifeScan, Inc. (Milpitas, Calif.). It is common for such devices to have a twist-off or break-off safety cap to be removed to expose the lance tip before use. An interface post 62 may additionally or alternately be provided to retain a lancet. Yet another option is to use a conventional split collar device or style of loading. It is preferred, however, that the present invention employ a side or breach loading/removal approach as seen, for example, in U.S. Pat. No. 4,577,630.
Yet another optional feature shown in connection with the lance carrier in FIG. 2 is the presence outboard rails 30 . When engaged with complimentary runners (not shown) the lance carrier 10 is both held down and permitted to move in and out with respect to a face 32 of the housing which abuts a users finger to be stuck as shown in FIG. 4 where the lance is indicated in phantom line.
Irrespective of such constructional details as to the linkage, drive 2 further includes a spring or biasing member 34 . Force generated in the spring both fires the lance and retracts it at least partially so it does not pose a safety hazard. The spring shown is an extension spring. However, other types of springs may be used, including leaf springs, torsion springs and compression springs. The extension spring preferably comprises a coiled metal member, though an elastic member may be alternately employed.
Whatever the spring type or composition, one end is affixed or restrained to a spring support 36 , which is preferably provided in connection with housing 16 . Another end of the biasing member may be attached at the junction of the crank and coupler members as shown or along either member, for example, to produce a more compact design. This may be accomplished by looking a curved end of the extension spring about optional pin 20 or otherwise. In any case, the principles of the invention will not change, though the details of the particular device would.
The relative placement of the spring and slider-crank elements is of particular importance in the present invention. The members should be configured to as to affect the motion and function now described in connection with FIGS. 1A-1E . Details as to the specifics of the configuration may vary widely, but are well within the design and testing abilities of those ordinarily level of skill in the art.
First, FIG. 1A shows drive mechanism 2 in an uncocked position. In this position, lance tip 12 is partially withdrawn from its most advanced position shown in FIG. 1 E. In this state (the state which the device returns by its own power to after firing), the extension spring is substantially aligned with the crank member pivots. Accordingly, it is at its shortest length and in its least-stressed position through the cycle of drive device 2 .
Even in variation of the invention in which the type or relative locations of the spring and links vary (including the location of the association of the spring to the linkage members) there will be a state like that in FIG. 1A representing a minimum energy configuration for the spring in which it has release energy stored in cocking it to the extent possibly. With or without any clutch features as introduced above, such a state also represents a stable equilibrium position.
FIG. 1B shows the drive mechanism in the process of being cocked. Lance shuttle 10 is retracted as crank 6 is advanced, such as by user input. This in turn results in energy storage in spring 34 . In the configuration of the invention shown, as the crank and coupler members approach alignment, the lance-carrying member reaches it most withdrawn state.
FIG. 1C shows drive mechanism 2 in a fully-cocked position. At this point, spring 34 reaches its maximum stored energy potential. The shuttle 10 has advanced slightly from its most retracted position but still has room in which to accelerate in firing before full extension and impacting a user's finger or other location. When fully cocked for firing, as shown in FIG. 1C , the system is in a state of unstable equilibrium. Advancement beyond the point of alignment will cause lance firing in a clockwise direction under the power of the spring. That is, when the spring goes “over-center” with respect to the crank, the firing motion commences.
FIG. 1D illustrates this firing action. The large arrow dramatizes rapid movement in the direction indicated. After passing the unstable equilibrium or fully-cocked position in FIG. 1C where force applied by the spring has no moment arm to work on, as crank arm 6 progresses through its travel the spring is able to quickly draw the slider-crank mechanism though its prescribed motion.
FIG. 1E show the maximum-extension point in the firing motion. Following this, spring 34 draws crank member 6 around so as to withdraw the lance end from the user's flesh. Again, by virtue of the length moment arm available for the spring to drive the crank, withdraw from firing occurs very rapidly as indicated by the arrow. Such action is further assisted by the inertia of the rotating crank. Accordingly, the transition between lancet puncture to withdraw occurs nearly instantaneously.
Beyond the actuation stage shown in FIG. 1E , the crank continues in the same direction as the spring continues to contract (or otherwise recover) until it swings the crank arm around to a position substantially as shown in FIG. 1 A.
Of course, momentum imparted to the system by the spring in firing and retracting the lance may cause slight overrun. If no clutch is present, this can result in system oscillation. However, with a one-way clutch incorporated in the system, the drive advances to a given point possibly slightly loading the spring and is locked from returning the other direction.
In all, the drive provides a means for very rapid lance firing, followed by puncture and needle withdraw. In addition, its configuration lends itself to silent operation. By eliminating play in any connections, impulse loading that can produce noise is avoided.
A preferred manner of cocking the device to set such action in motion is shown in FIG. 3 . As noted above, it shows crank member 6 configured as a wheel or disk. A recess 36 in the wheel is provided for receipt of the end of a pawl 38 in connection with an actuator in the form of a lever 40 . It is shown in FIG. 4 as a depressible lever.
The lever arm pivots about a lever support 42 , preferably provided in connection with housing 16 . This action of lever 40 is depicted by the phantom-line illustration in FIG. 3 . It shows movement of the lever arm by some angle Φ. With pawl 38 engaged in with wheel 6 via a flat, recessed section or otherwise, the wheel is driven by such action through an angel θ. Once the spring set to drive the crank goes over-center (passes the unstable equilibrium state of the drive mechanism 2 ), the crank will take-off and rotate on its own, firing the lance.
Preferably, the relation between the actuator elements shown in FIG. 3 is such that maximum travel of the lever results in surpassing the firing trigger point that frictional forces are not a factor, but not so far as to overly limit the amount of spring-powered rotation as to negatively effect the top speed of the lance.
Further, the lever, pawl and wheel forming a ratchet-type device are preferably configured so that the wheel easily over runs the pawl once it reaches an angular displacement prompting firing. Some bias of the pawl against the wheel may be required to ensure subsequent engagement. This may be provided by a spring member between the lever arm and pawl. As shown, the two items be formed by a unitary structure including a “living hinge,” especially one including some resilience to provide for such bias.
Actually, a living hinge at the joint between coupler 8 and shuttle 10 and between lever 40 and support 42 may be advantageously employed as well. Of course, the rotable association between pawl 38 and lever 40 may be provided by a simple, pinned connection as shown elsewhere.
However the ratchet combination is configured, in use a user merely need depress the lever to take the system from an uncocked position, to cock and fire the lance. This turns operation into a one-step process. In other words, a user does not first have to cock and then release a catch to fire the device.
A preferred manner in which a user grasps and actuates the lancing mechanism of the present invention is illustrated in FIG. 4 . After actuating lever 40 by applying force between the thumb 44 and one or more fingers 46 , the housing face 32 is withdrawn from the target site 48 , leaving a puncture or lance stick 50 to well-up a sample of blood.
The whole blood sample then may be tested using any number of a variety of analyte test strips 52 or another diagnostic instrument. Optional types of test strips may include those for measuring glucose levels, prothrombin time etc. Life Scan, Inc. (Milpitas, Calif.), produces a number of such analyte test strips preferably used in connection with the present invention.
Though the invention has been described in reference to a certain examples, optionally incorporating various features, the invention is not to be limited to the set-ups described. The invention is not limited to the uses noted or by way of the exemplary description provided herein. It is to be understood that the breadth of the present invention is to be limited only by the literal or equitable scope of the following claims. In the claims, certain terms represent examples of lexicography. With respect to these, by a “linear path,” it is mean a straight-line path or curvilinear path; by “lance-carrying structure,” it is meant a member that integrally includes a lance blade or a member such as a housing or shuttle that receives a lance blade or a separate member that integrally includes a lance blade such as in the various disposable lance assemblies noted above; by “user,” it is meant the recipient of lancing action, whether or not the individual is actuating the device; and by “actuator,” it is meant a structural member such as a lever, pusher, handle, button, knob, pull string, cord or any other feature a user may grasp, pull or push to effect movement of communicative structure. That being said, I claim:
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A lancing device with automatic stick and lance return features is disclosed. A drive mechanism within the unit comprises a slider-crank linkage combination. It is biased by a spring member to cause automatic firing once a crank member advanced by a user causes movement of an internal linkage member beyond its fully-cocked position. After firing, the lance is withdrawn so as not to pose a threat of secondary injury to the user. In use, the device is substantially silent though its course of operation. Yet, its configuration lends itself to producing a very quick, virtually painless stick with minimal recoil or shock to the device.
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REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of U.S. Ser. No. 719,504 filed Apr. 3, 1985, now abandoned by Angel K. Markov entitled "Method for Treating Adult Respiratory Distress Syndrome Using Fructose-1,6-Diphosphate."
The present invention relates to the treatment of adult respiratory distress syndrome after shock, sepsis, trauma and the like.
Acute pulmonary edema can be induced by intravenous or intraperitoneal injection of alpha-naphthylthiourea (ANTU). ANTU causes an increase in microvascular permeability, which leads to pulmonary edema. Investigators have quantitated the degree of edema, and described the morphological changes which accompany ANTU poisoning, the severity of which appear to be dose related.
It has been suggested that pulmonary edemagenic conditions are intimately coupled with the oxygen radical production associated with tissue damage, particularly that of the leukocytes. Upon challenge, the phagocytic cells undergo an increase in hexomonophosphate shunt (HMS) activity, an increase in oxygen uptake, an increase in superoxide (O 2 --) production, and an increase in hydrogen peroxide (H 02 ) production.
During the increase in HMS activity, the reduction potential of the cell is increased via increase in NADPH concentration (and, thereby O 2 --and H 2 O 2 concentration). In the HMS, there are two steps which reduce NADP + : (1) oxidation of glucose 6-phosphate (G6P) with the enzyme glucose 6-phosphate dehydrogenase, and (2) oxidation of 6-phosphogluconate with the enzyme 6-phospho-gluconate dehydrogenase (PGDH). Fructose 1,6-diphosphate (FDP) has been shown to inhibit PGDH and in the resting phagocyte would serve to shut down HMS, increasing the flux of G6P into the glycolytic pathway.
Energy for phagocytosis has been shown to be derived almost exclusively from glycolysis. The concentration of FDP is dependent on the activity of phosphofructokinase I (PFK1) and the availability of its substrate fructose 6-phosphate. As the concentration of lactate increases (decreasing the pH) the activity of PFK1 decreases, thereby decreasing the concentration of FDP, and allowing the inflow of G6P into the HMS with the accompanying rise in NADPH concentration, which allows for the production of O 2 --and H 2 O 2 .
Histamine has also been suggested to be a possible mediator of pulmonary edema via an increase in vascular permeability. FDP has been shown to inhibit the release of histamine from mast cells.
This study was undertaken to examine the effects of FDP on the generation of pulmonary edema produced by ANTU. Treatment with FDP could serve three functions: (1) overcome the inhibition of PFK1, as FDP is a strong activator of this enzyme, (2) inhibit PGDH, thereby lowering the reduction potential, thus reducing the oxygen radical production, and possible tissue damage, and (3) inhibits histamine release from mast cells.
GENERAL DISCUSSION OF THE PRESENT INVENTION
Discussions of Adult Respiratory Distress Syndrome can be seen, for example, in the New England Journal of Medicine in an article entitled "Changing Concepts of Lung Injury and Repair," New England Journal of Medicine Vol. 306 No. 15, Apr. 15, 1982 at p. 900. Another article discussing ARDS can be found in the "Annals of Internal Medicine," May 1983 at p. 593 entitled "Adult Respiratory Distress Syndrome: Risk with Common Predispositions." A Baylor College of Medicine Cardiology Series dated 1984 (Vol. 7, No. 5) provides an article on Adult Respiratory Distress Syndrome by Gordon Bernard and Kenneth Brigham. Each of the above-discussed publications is incorporated herein by reference.
The Adult Respiratory Distress Syndrome (ARDS) representing pulmonary edema of non-cardiac origin can be observed following shock, sepsis, trauma and other insults on the pulmonary parenchyma causing alteration of capillary permeability. In treating patients in shock with Fructose 1-6 Diposphate (FDP), in those who had concomitantly ARDS I noted significant hemodynamic, radiographic, and pulmonary function improvement. In an effort to elicit the mechanism for this protective action of FDP in ARDS, I simulated the condition in 25 dogs by injecting them intravenously with alpha-Naphthylthiourea (ANTU). The animals were randomly assigned into two groups and 30 minutes after administration of ANTU, 12 were treated with FDP and those serving as controls received glucose solution in the same concentration and volume.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Mammalian subjects including ten mongrel dogs (weights =14.0-32.0 Kg; mean=19.5 kg) and fifteen greyhounds (17.7-32.2 kg; mean=25.7 kg) of both sexes were anesthetized with Surital (thiamylal sodium, Parke-Davis, Morris Plains, N.J.) at 30 mg/kg thirty minutes after pre-anesthetic treatment with 10 mg acepromazine maleate. Dogs received additional 50 mg doses of Surital as needed. After induct of anesthesia, dogs were intubated and ventilated, when necessary, with a piston-type respiratory pump. Secured in the left decubitus position on the fluoroscopic table, catheters were percutaneously introduced into the left ventricle via the left external carotid; the pulmonary artery via the right jugular; the right femoral vein (for infusion and withdrawal); and the right femoral artery (for cardiac output measurements).
Pulmonary arterial, the left ventricular pressures were monitored throughout the experiment with Gould-Statham strain gauges interfaced with an Electronics for Medicine DR-8 recorder. EKG and heart rate were also monitored using the EM DR-8 recorder. Cardiac output was measured using Lexington Instruments Cardiac Output Computer and indocyanine green as indicator dye. Blood pH, Pco 2 and Po 2 were measured using a Radiometer/Copenhagen ABL3 OR ABL309 blood analyzer. ANTU [1-(1-naphthyl)-2-thiourea; Fairfield Chemical, Blythewood, SC] was prepared as a 1% suspension (w/v) in propylene glycol. FDP Esafosfina (TM); Biomedica Foscma; Rome, Italy) was prepared as a 10% solution (w/v) in sterile distilled H 2 O). FDP and ANTU were prepared thirty minutes prior to administration.
After a thirty-minute control period, sixteen dogs received intravenous injections of ANTU at 5.0 mg/kg body weight and eight dogs at 10.0 mg/kg into the right femoral vein. Thirty minutes after administration of ANTU, the FDP 4reated goups (12 dogs; 8 having received ANTU at 5 mg/kg and 4 at 10 mg/kg) received 75 mg/kg FDP in slow I.V. bolus, then 600 mg/kg FDP at 191 mg/min. The control group (12 dogs; 8 having received ANTU at 5 mg/kg and 4 at 10 mg/kg) received normal saline at 0.75 ml/kg in slow I.V. bolus, then 6.0 ml/kg saline at 1.91 ml/min. Some received propylene glycol at 0.5 mg/kg, then, at 30 minutes received normal saline as per the control group. Hemodynamic measurements [means pulmonary arterial pressure (PaP), left ventricular pressure (LVP), cardiac output (CO), hemotocrit (Hct), and arterial and venous pH, Pco 2 and Po 2 ] were taken every 15 minutes for the first hour, then at 90, 120, 150, 180, and 240 minutes. At 4 hours the experiment was terminated, and the dogs were sacrificed with a KC1 solution. Lungs were inflated (to remove blood), excised, weighed and examined microscopically for edema and hemorrhage. Biopsies (500-900 mg) were taken from the lungs, weighed and dried under vacuum for 48 hours for wet weight/dry weight (wet/dry). Significance of difference between groups were determined using Student's t test, and within groups using paired t tests. Pulmonary resistance (R p ) was calculated in CGS unit (dyne sec cm -5 ) with the equation: R p =[79.98×Pap (mm hg)]/[CO (L/min)].
At 4 hours the dogs were killed, the lungs exsanguinated and wet and dry weights recorded. The pulmonary pressure in the dogs treated with FDP remained unchanged while in those serving as controls increased from 12.9+2.4 to 21.8+3.14 mm Hg<(p 0.001). There were no differences between the two groups in left ventricular diastolic and arterial pressures, and cardiac outputs; however, pulmonary resistances in the dogs receiving glucose was significantly higher (p<0.001). Lung to body weight (gm/kg) ratio for the FDP group was 9.83+0.684 and for the controls 16.7+0.990 (p<0.001). The wet to dry lung weight ratio (gm/kg) for the treated dogs was 4.32+0.17 and for those receiving glucose 6.18+0.396 (p<0.001). Nine patients in severe shock who had ARDS received 75 mg/kg of FDP (Esafosfina (TM)) as 10% solution every six hours. Hemodynamic and pulmonary function parameters were measured prior to and post FDP administration. FDP administration caused immediate and significant increase in arterial pressure (p<0.001), cardiac output (p<0.001 ), arterial pO 2 (p<0.001), while lowering pulmonary arterial pressure and resistance (p<0.00) and p<0.001 respectively), heart rate (p<0.025), arterial pCO 2 )p<0.025) and pulmonary wedge pressure (p<0.001). These changes were evident immediately after FDP administration and persisted as long as the FDP was administered at the specified regiment. In most cases, vasopressor therapy was discontinued and FiO 2 and PEEP were decreased after FDP administration. The experimental data and clinical observation indicates that FDP is useful in the treatment of ARDS and supports the contention that FDP attenuates pulmonary microvascular damage by inhibiting histamine release from the mast cells in dose related fashion and by inactivation of the hexose monophosphate shunt in the neutrophils which generates free radicals (superoxides and peroxides). In the latter case, FDP directly inhibits the activity of 6-phosphogluconate dehydrogenase.
FIG. 3 represents the pulmonary pressure changes in dogs who are injected with alpha-Naphthylthiourea (ANTU). This agent produces conditions similar to ARDS in animal model. As you see in FIG. 3, the Fructose Di-phosphate is administered 30 minutes after the injection of the alpha-Naphthylthiourea and this Fructose Di-phosphate prevents an increase in the pulmonary pressure.
FIG. 2 represents the pulmonary vascular resistance in dogs injected with ANTU. The pulmonary resistance increased significantly (p 0.001) in the dogs treated with saline, while in those receiving FDP the pulmonary resistance did not change significantly from control values.
FIG. 1 is the left ventricular end diastolic pressure which is in normal limits. This is shown because if there is an increase in it (above 28 mm Hg), pulmonary edema will occur, but it will be of cardiogenic origin. Pulmonary edema is defined as accumulation of fluid (water) in the lungs (alveolic, parenchyma, etc.). Such elevated left ventricular pressures can be seen in patients with cardiac failure, myocardial infarction or primary myocardial disease comprising the ventricular function; conditions which will produce pulmonary edema. This finding substantiates the fact that the ventricular function was normal and therefore the edema formed by ANTU is not from a cardiogenic origin.
FIG. 4 shows that there was no difference in the cardiac output between the controls and those treated with FDP. Thus, the ANTU did not compromise the heart functions. There was no significant difference in the heart rate in FIG. 1 between the controls and the FDP treated dogs. FIG. 6 shows there was no significant difference in the left ventricular pressures between the two groups of dogs.
FIG. 7 shows that the Hematocrit was no different between the FDP treated and control animals, and FIG. 8 (which is one of the most important findings in this study), illustrates that the lungs on the dogs treated with FDP had a normal lung to body weight ratio as well as wet to dry ratio. That is to say, no water was accumulated in the FDP treated dog after an injection of alpha-Naphthyltiourea, confirming our hypothesis that the agent prevents non-cardiogenic pulmonary edema which is comparable with the human ARDS patient.
FIG. 9 represents the Systolic and Diastolic pressures of nine patients which were in shock and were treated with FDP. These patients happened to have ARDS. The shock was from sepsis, trauma and other causes. As you can see, FDP improved the arterial pressures (both Systolic and Diastolic) significantly. The pulmonary artery pressures on these patients were obviously elevated (as seen in ARDS) and after the administration of the FDP it declined significantly (see FIG. 10).
FIG. 11 clearly shows how FDP decreased the pulmonary vascular resistance in all of the patients with ARDS. FIG. 12 shows that cardiac output improved in all of these patients. Those who had a very high cardiac output (normally seen in patients in septic shock) was also increased.
FIG. 13 demonstrates that the wedge pressure or the left ventricular pressure were in the high normal range except for one patient which was pathological (about 27 mm Hg). That is to indicate that these patients did not have a pulmonary edema from a cardiogenic origin, perhaps except for one, and after the injection of FDP, the pulmonary wedge pressure declined significantly attaining near normal values. The condition ARDs manifests itself by pulmonary edema of non-cardiogenic origin and arterial hypoxemia. That is to say, the oxygen in the arterial blood is very low and after the administration of FDP (see FIG. 14), the arterial oxygen partial pressure increased significantly higher after those patients received the FDP.
FIGS. 1, 2, 3, 4, 5, 6, 7 and 8 are in dogs. The remaining figures are all human patients (i.e., FIGS. 9 through 22).
In FIG. 15, those patients that had the reverse gases PCO 2 in the arterial blood (i.e., the carbondioxide was higher than the oxygen) and the FDP treatment corrected these abnormalities.
FIG. 16 gives the response of a single patient in the time span of six hours between two administrations of FDP. FIG. 16 represents the response of his arterial pressure to FDP administration (which was very low, sine he was in shock). We were able to discontinue the dopamine (a drug used to maintain blood pressure in patients in shock). In the same patient following FDP treatment, the arterial PO 2 increased immediately from 70 to 90 millimeters of mercury. This enabled us to decrease the oxygen delivered by the respirator (percentage of oxygen). By 3:00 a.m. that morning the patient had a 120 mm Hg at 35% percent of ogygen (see FIG. 21).
FIG. 17 shows a response of the cardiac output. You can see it doubled after the administration of FDP. In FIG. 18, the pulmonary pressure was elevated (above normal) and after the administration of FDP the pressure declined back to normal limits.
FIG. 19 shows the patient had a marginal renal function and following administration of FDP, his urinary output increased from 16 milliliters per hour up to 60 milliliters per hour. Wedge pressure was normal in this patient, which substantiates that the pulmonary edema or ARDs was not from cardiogenic origin. The genesis of ARDS in man generally is attributed to accumulation and sequestration of neutrophils in the lungs following direct or indirect injury of the lungs. The neutrophils damage the pulmonary capillary (blood vessels) by releasing toxic oxygen redicals O 2 H 2 O.sub. 2 OH, causing fluid to leak from the capillary into the lung alveolic and parenchyma.
FIG. 22 gives direct support of the hypothesis that FDP inhibits free radical formation by the Leukocytes (neutrophils). As approximately 98% of the oxygen used by stimulated human Leukocytes and as well as dog Leukocytes (known as respiratory burst) is consumed to convert glucose to a pentose and CO 2 , concomitantly free radicals such as single oxygen, (O 2 ) hydrogen peroxide (H 2 O 2 ) and others are formed which are very toxic for the pulmonary parenchyma and capillaries. Most of the authors believe that activated Neutrophis cause the damage in the lung during the condition called ARDs. Here we have demonstrated that in this vitro study, FDP inhibits completely the respiratory burst. This has been confirmed in vitro on animal models and in vitro on human and dog neutrophis.
The foregoing description of the invention is illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.
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Fructose-1,6-diphosphate is administered intravenously to a mammalian subject experiencing adult respiratory distress syndrome (ARDS) in an amount sufficient to inhibit pulmonary microvascular damage.
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BACKGROUND
The invention relates to electronic devices, and in particular, to electronic devices with adjustment mechanisms for quickly adjusting bodies thereof.
When a conventional projector is placed on a desk to be operated, its body needs to be adjusted. To obtain accurate projection, desk levelness, desk smoothness, projecting direction and projecting size need to be considered during adjustment.
The adjustment of the conventional projector is often operated separately by several adjustable feet. FIG. 1 depicts a conventional electronic device 10 in need of adjustment. The electronic device 10 comprises a plurality of adjustable feet 12 . Note that only one adjustable foot 12 is shown in FIG. 1 . A pad 13 is disposed on the adjustable foot 12 , which is fixed to a housing 11 via a nut 14 . The adjustment foot 12 may be moved upward/downward in a direction shown by arrow B 1 by rotating the adjustable foot 12 in a direction shown by arrow A 1 . Since the above adjustment is performed by manual rotation, its speed is extremely slow.
FIG. 2 depicts another conventional electronic device 20 in need of adjustment. The electronic device 20 comprises a plurality of adjustable feet 22 . Note that only one adjustable foot 22 is shown in FIG. 2 . A pad 23 is disposed on the adjustable foot 22 , which is positioned in a housing 21 via an elastic member 24 . The adjustable foot 22 can be roughly adjusted by releasing the elastic member 24 , and slightly adjusted to be moved up and down in a direction (shown by arrow B 2 ) by self-rotating in a direction (shown by arrow A 2 ).
Although the elastic member 24 in FIG. 2 shortens adjustment time, the operation is still inconvenient since moving the elastic member 24 and pulling the adjustable foot 22 occur at the same time. Additionally, different adjustable feet may need to be adjusted respectively, thus increasing adjustment time.
Specifically, each adjustable foot in the conventional adjustment mechanism requires manual adjustment. Moreover, one adjustable foot may be adjusted by both hands. Thus, the adjustment time cannot be significantly shortened, nor can the position of the body be accurately adjusted, due to inconvenience of the adjustment operation.
SUMMARY
Electronic devices are provided. An exemplary embodiment of an electronic device comprises a housing, an adjusting member, a first elastic member, a gear, a second elastic member, and a transmission unit. The adjusting member comprises a plurality of teeth, and is connected to the object in a moveable manner. The first elastic member abuts the adjusting member and the housing respectively to move the adjusting member with respect to the housing. The gear meshes with the teeth of the adjusting member for positioning the adjusting member. The second elastic member is connected to the housing and separably connected to the gear for positioning the gear. The transmission unit is separably connected to the second elastic member to separate the second elastic member from the gear. When the second elastic member is separated from the gear by the transmission unit, the adjusting member is moved with respect to the housing by the first elastic member. Thus, the position of the housing is adjusted.
Note that the second elastic member may be a tension spring, and the electronic device may be a projector.
Furthermore, the electronic device comprises a shaft, an intermediate wheel, a damper, and a brake plate. The shaft is connected to the housing. The gear is disposed on the shaft. The intermediate wheel is disposed on the shaft to connect to the second elastic member. The damper is disposed on the shaft to restrain the speed of the adjusting member. The brake plate is disposed on the second elastic member, such that the second elastic member is connected to the gear via the brake plate.
Moreover, the transmission unit comprises a release member and a rod. The release member separably abuts the elastic member to separate the elastic member from the gear. The rod is connected to the release member.
Additionally, the electronic device further comprises a button disposed on the housing and connected to the transmission unit so that the transmission unit is connected to the second elastic member. Alternatively, the electronic device further comprises a solenoid, a switch, and a delay circuit. The solenoid is connected to the transmission unit so that the transmission unit is connected to the second elastic member. The switch is disposed on the housing and electrically connected to the solenoid to actuate the solenoid. The switch may be a tactile switch. The delay circuit is electrically connected to the switch and the solenoid so that the transmission unit is connected to the second elastic member within a predetermined time after the solenoid is actuated by the switch.
Adjustment mechanisms are provided. An exemplary embodiment of an adjustment mechanism is connected to an object to adjust the height of the object, and comprises an adjusting member, a lifting assembly, and a driving assembly. The adjusting member is moveably connected to the object. The lifting assembly is connected to the adjusting member to move the adjusting member. The driving assembly is connected to the lifting assembly to drive the lifting assembly to move the adjusting member. Thus, the height of the object is adjusted.
DESCRIPTION OF THE DRAWINGS
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
FIG. 1 is a schematic view of a conventional adjustment mechanism;
FIG. 2 is a schematic view of another conventional adjustment mechanism;
FIG. 3 is a schematic view of an embodiment of an electronic device;
FIG. 4 is a schematic view of an adjustment mechanism in FIG. 3 ;
FIG. 5 is a side view of a gear, an intermediate wheel, and a damper in FIG. 4 ;
FIG. 6 is a schematic view of another embodiment of an electronic device; and
FIG. 7 is a schematic view of an adjustment mechanism in FIG. 6 .
DETAILED DESCRIPTION
FIGS. 3 and 4 depict an embodiment of an electronic device 100 comprising a housing 110 , four adjusting members 120 , four lifting assemblies 130 , and two driving assemblies 140 . The adjusting members 120 , the lifting assemblies 130 , and the driving assemblies 140 constitute an embodiment of an adjustment mechanism.
The housing 110 comprises two pads 111 on its upper surface, and a projection lens 112 at its front surface. While an embodiment of the electronic device is described based on a projector, it is not limited thereto, and may be applied to other electronic devices with a body required to be adjusted.
Each adjusting member 120 is connected to the housing 110 via a first elastic member 131 of the lifting assembly 130 so as to be moveable with respect to the housing 110 . Each adjusting member 120 comprises a plurality of teeth 121 at its side surface. Note that each adjusting member 120 further comprises a hollow portion 122 at its upper portion, as shown in FIG. 4 . Thus, when the adjusting member 120 moves upward/downward, a rod 113 of the housing 110 enters the hollow portion 122 of the adjusting member 120 .
Each lifting assembly 130 is disposed on the housing 110 , and comprises the first elastic member 131 , a gear 132 , a shaft 133 , an intermediate wheel 134 , and a damper 135 . The first elastic member 131 surrounds the rod 113 to abut the adjusting member 120 and housing 110 . The first elastic member 131 may be a tension spring to move the adjusting member 120 .
As shown in FIG. 5 , the shaft 133 is fixed to the housing 110 . The gear 132 , the intermediate wheel 134 , and the damper 135 are disposed on the shaft 133 . The gear 132 meshes with the teeth 121 of the adjusting member 120 to position the adjusting member 120 in a predetermined position. The intermediate wheel 134 abuts a brake plate 142 of the driving assembly 140 so that the adjusting member 120 may be moved upward/downward in a stepless manner. Moreover, the intermediate wheel 134 may reduce external pressure applied on the brake plate 142 via the gear 132 so that the adjustment can be quickly and accurately performed. The damper 135 restrains the speed of the adjusting member 120 so that the adjusting member 120 may be smoothly adjusted.
Note that the intermediate wheel 134 and the damper 135 may be omitted based on requirements. When omitting the intermediate wheel 134 , the brake plate 142 of the driving assembly 130 abuts the gear 132 .
Each driving assembly 140 is connected to the housing 110 , and comprises two second elastic members 141 , two brake plates 142 , two transmission units 143 , a button 144 , and a third elastic member 145 . That is, each driving assembly 140 is connected to two lifting assemblies 130 . Note that only one lifting assembly 130 and one driving assembly 140 are specifically shown in FIG. 4 for simplicity.
One end of the second elastic member 141 is connected to the housing 110 , and partially abuts the intermediate wheel 134 via the brake plate 142 in a separable manner to fix the intermediate wheel 134 in a predetermined position.
The transmission unit 143 comprises a release member 143 a and a rod 143 b . The release member 143 a separably abuts the second elastic member 141 . When the release member 143 a is pressed downward to abut the second elastic member 141 , the brake plate 142 on the second elastic member 141 is separated from the intermediate wheel 134 . The rod 143 b is connected to the release member 143 a and the button 144 respectively. When the button 144 is pressed, the release member 143 a is pressed downward by the rod 143 b . Note that the rod 143 b is represented by an arrow in FIG. 4 , and is aligned with the release member 143 a for simplicity. In practice, the rod 143 b may be, for example, perpendicular to the release member 143 a.
The button 144 is disposed on the housing 110 , and comprises a connecting portion 144 a connected to the rod 143 b . When the button 144 is pressed, the rod 143 b is pressed downward so that the release member 143 a abuts the second elastic member 141 . The third elastic member 145 is disposed around the connecting portion 144 a , and abuts the housing 110 and a bottom of the button 144 respectively to return the button 144 to a predetermined position.
To adjust the position of the body of the electronic device 100 , because the elastic spring force of the first elastic member 131 is much higher than the elastic spring force of the third elastic member 145 , the housing 110 is first slightly lifted while the buttons 144 are pushed.
Thus, the rods 143 b actuate the release members 143 a to move the second elastic members 141 and the brake plates 142 . Once the brake plates 142 are released, the intermediate wheels 134 on the shafts 133 move freely so that the gears 132 on the shafts 133 and the adjusting members 120 are also released. As a result, the adjusting members 120 are ejected outward from the housing 110 to a maximum length by the first elastic member 131 . Then, the housing 110 is slightly depressed while the buttons 144 are still pushed. After the body reaches a desired position, the buttons 144 are released so that the position of the body is fixed.
With the adjustment mechanism of the embodiment, the body may be adjusted without touching the adjusting members. Also, since the adjustment is stepless, the position of the body may be smoothly adjusted. Furthermore, the adjustment is performed by pushing the buttons, thus enhancing convenience. Moreover, the adjusting members may be quickly returned to within the housing by pushing the buttons while pressing the housing.
FIGS. 6 and 7 depict another embodiment of an electronic device 100 ′ comprising a housing 110 , four adjusting members 120 , four lifting assemblies 130 , and a driving assembly 140 ′. While the housing 110 , the adjusting members 120 , and the lifting assemblies 130 in FIG. 7 are the same as those in FIG. 4 , they are labeled by the same references and their description is omitted.
The difference between the electronic device 100 ′ in FIG. 6 and the electronic device 100 in FIG. 3 is that one driving assembly 140 ′ controls four lifting assemblies 130 in the electronic device 100 ′ in FIG. 6 . Specifically, the driving assembly 140 ′ comprises four second elastic members 141 , four brake plates 142 , four transmission units 143 , a solenoid 146 , a switch 147 , and a delay circuit 148 . While the second elastic members 141 , the brake plates 142 , and the transmission units 143 in FIG. 7 are the same as those in FIG. 4 , they are labeled by the same references and their description is omitted.
The solenoid 146 is connected to the rods 143 b of the transmission units 143 so that the release member 143 a of the transmission unit 143 is connected to the second elastic member 141 . The switch 147 is disposed on the housing 110 , and is electrically connected to the solenoid 146 to actuate the solenoid 146 . The delay circuit 148 is electrically connected to the switch 147 and the solenoid 146 so that the release member 143 a of the transmission unit 143 abuts the second elastic member 141 within a predetermined time after the solenoid 146 is actuated by the switch 147 .
To adjust the body of the electronic device 100 ′, the switch 147 is pressed by a single hand solely and no need to hold the button down so that the delay circuit 148 provides the predetermined time for adjustment. The operator could free his finger from the button and focus on accurate adjustment quickly and effortlessly.
Specifically, after the switch 147 is pressed, the release member 143 a is moved. Thus, the intermediate wheel 134 and the gear 132 are released, and the adjusting members 120 are ejected outward. During the predetermined time, the position of the body may be adjusted to a required position by a single hand depressing the housing 110 . After the predetermined time elapses, the position of the body is fixed.
Note that the delay circuit 148 may be omitted based on requirements. When the delay circuit 148 is omitted, the switch 147 may be a tactile switch. Thus, when the tactile switch 147 is touched, the solenoid 146 is always turned on to be conveniently adjusted. Furthermore, even if the delay circuit 148 is provided in the electronic device 100 ′, the switch 147 may be a tactile switch.
Since the adjustment of the body of the electronic device 100 ′ is controlled by a single switch, it may be performed by a single hand, thus enhancing the convenience.
While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
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An electronic device and an adjustment mechanism thereof. The electronic device includes a housing, an adjusting member, a lifting assembly, and a driving assembly. The adjusting member is moveably connected to the housing. The lifting assembly connects the adjusting member and the housing to move the adjusting member with respect to the housing. The driving assembly connects the lifting assembly and the housing to drive the lifting assembly to move the adjusting member. Thus, the housing is adjusted.
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FIELD OF THE INVENTION
[0001] The present invention relates to nucleotide sequences that are useful in agrochemical, veterinary or pharmaceutical fields. In particular, the invention relates to nucleotide sequences that encode or may be used to express amino acid sequences that are useful in the identification or development of compounds with (potential) activity as pesticides or as pharmaceuticals. Even more particularly, the invention also relates to the amino acid sequences—such as proteins or polypeptides—that are encoded by, or that may be obtained by suitable expression of, the nucleotide sequences of the invention.
BACKGROUND OF THE INVENTION
[0002] Gamma amino-n-butyric acid (“GABA”) plays an important role in inhibiting synaptic transmission in both vertebrate and invertebrate nervous systems. L-glutamate decarboxylase (“GAD”) is a rate-limiting enzyme involved in the synthesis of GABA. Hence, interruption of GABA synthesis by inhibiting GAD can result in various biological effects (W. Loscher, J. Neurochem., (1981), Vol. 36, No. 4, pp. 1521-1527). As such, there is a desire to develop ways to target this enzyme as a means of identifying biologically active compounds, including insecticides (Gammon et al., Sites of Action of Neurotoxic Pesticides, (1987), Chapter 9, pp. 122-134).
[0003] Mammalian GADs, in particular human and mouse GADs, have been cloned and found to be functional when expressed in E. coli and mammalian cells (Huang et al., Proc. Natl. Acad. Sci. U.S.A., (1990), 87(21), pp. 8491-8495; Yamashita et al., Biochem. Biophys. Res. Commun., (1993), 192(3), pp. 1347-52; W. Loscher, J. Neurochem., (1981), Vol. 36, No. 4, pp. 1521-1527; and Davis et al., Biochem. Biophys. Res. Commun., (2000), 267(3), pp. 777-782). Similarly, bacteria, for example, E. coli, Clostridium perfringens, and Lactobacillus brevis, and fungi, for example, Neurospora crassa, GADs have been cloned and expressed (Hao et al., Biochem. J., (1993), 293(3), pp. 735-738; De Biase et al., Biotechnol. Appl. Biochem., (1993), 18(2), pp. 139-142; De Biase et al., Protein Expression Purif., (1996), 8(4), pp. 430438; M. L. Fonda, Methods in Enzymology, (1985), Vol. 113, pp. 11-16; and Ueno et al., (1997), Biosci. Biotech. Biochem., 61 (7), pp. 1168-1171).
[0004] In 1979, the Drosophila melanogaster GAD was partial purified (Chude et al., J. Neurochem. (1979), Vol. 32, 1409-1415). Later on, the Drosophila melanogaster GAD was cloned and found to be functional when expressed in oocytes and in mammalian cells (Jackson et al., J. Neurochem., (1990), 54(3), 1068-78; and Phillips et al., J. Neurochem., (1993), 61(4), 1291-301).
SUMMARY OF THE INVENTION
[0005] The present invention relates to novel hemipteran decarboxylase protein, fragments thereof, nucleic acid molecules encoding the novel hemipteran decarboxylase proteinand fragments thereof, antibodies that specifically bind to the novel hemipteran decarboxylase protein, methods of using the novel hemipteran decarboxylase protein including methods of identifying modulators and inhibitors of the same, and methods of inhibinting insect populations by inhibiting the novel hemipteran decarboxylase protein.
[0006] The present invention relates to nucleotide sequences that encode polypeptides that are useful in the identification or development of compounds with activity as pesticides or as pharmaceuticals. The present invention also relates to polypeptide sequences that are useful in the identification or development of compounds with activity as pesticides or as pharmaceuticals. These nucleotide sequences and polypeptide sequences, will also be referred to herein as “nucleotide sequences of the invention” and “polypeptide sequences of the invention”, respectively.
[0007] Another aspect of the invention relates to the use of the nucleotide sequences of the invention, preferably in the form of a suitable genetic construct as described below, in the transformation of host cells or host organisms, for example for the expression of the amino acid sequences of the invention. The invention also relates to host cells or host organisms that have been transformed with the nucleotide sequences of the invention including those that can express the amino acid sequences of the invention.
[0008] In still another aspect, the invention relates to methods for the identification and/or development of compounds that can modulate and/or inhibit the biological activity of the amino acid sequences of the invention, in which the above-mentioned nucleotide sequences, amino acid sequences, genetic constructs, host cells or host organisms may be used. Such methods, which will usually be in the form of an assay or screen, will also be further described below.
[0009] In a further aspect the invention relates to methods of controlling insect populations by inhibiting activity or expression of their glutamate decarboxylase protein Such methods, which will usually be in the form of an assay or screen, will also be further described below.
Definitions
[0010] Collectively, the nucleic acids of the present invention will be referred to herein as “nucleic acids of the invention”. Also, where appropriate in the context of the further description of the invention below, the terms “nucleotide sequence of the invention” and “nucleic acid of the invention” may be considered essentially equivalent and essentially interchangeable.
[0011] Also, for the purposes of the present invention, a nucleic acid is considered to be “(in) essentially isolated (form)”—for example, from its native biological source—when it has been separated from at least one other nucleic acid molecule and sequence with which it is usually associated. Similarly, a polypeptide is considered to be “(in) essentially isolated (form)”—for example, from its native biological source—when it has been effectively separated from other polypeptide molecules with which it is normally assocaited with. In particular, a nucleic acid or polypeptide is considered “essentially isolated” when it has been purified at least 2-fold, in particular at least 10-fold, more in particular at least 100-fold, and up to 1000-fold or more.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The present invention was established from the finding that the amino acid sequences of the invention can be used as (potential) “target(s)” for in vitro or in vivo interaction with chemical compounds and other factors (with the term “target” having its usual meaning in the art, provide for example the definition given in WO 98/06737). Consequently, compounds or factors that have been identified as interacting with the amino acid sequences of the invention (e.g. by the methods as described herein below) may be useful as active agents in the agrochemical, veterinary or pharmaceutical fields.
[0013] In one embodiment, the invention relates to a nucleic acid, preferably in (essentially) isolated form, which nucleic acid comprises a nucleotide sequence of the invention, and in particular the nucleotide sequence of SEQ ID NO: 1. The nucleotide sequence of SEQ ID NO: 1 was derived or isolated from the Aphis gossypii organism, in the manner as further described in the Experimental Part below.
[0014] Yet another embodiment relates to a double stranded RNA molecule directed against a nucleotide sequence of the invention (one strand of which will usually comprise at least part of a nucleotide sequence of the invention). The invention also relates to genetic constructs that can be used to provide such double stranded RNA molecules (e.g. by suitable expression in a host cell or host organism, or for example in a bacterial strain such as E. coli ). For such constructs, reference is made to Maniatis et al., Molecular Cloning, a Laboratory Manual (Cold Spring Harbor Press, 1989).
[0015] In a broader sense, the term “nucleotide sequence of the invention” also comprises:
parts or fragments of the nucleotide sequence of SEQ ID NO: 1; (natural or synthetic) mutants, variants, alleles, analogs, orthologs (herein below collectively referred to as “mutants”) of the nucleotide sequence of SEQ ID NO: 1, as further described below. parts or fragments of such (natural or synthetic) mutants; nucleotide fusions of the nucleotide sequence of SEQ ID NO: 1 (or a part or fragment thereof) with at least one further nucleotide sequence; nucleotide fusions of (natural or synthetic) mutants (or a part or fragment thereof) with at least one further nucleotide sequence;
in which such mutants, parts, fragments or fusions are preferably as further described below.
[0021] Preferably, a nucleotide sequence of the invention will have a length of at least 500 nucleotides, preferably at least 1,000 nucleotides, more preferably at least 2,000 nucleotides; and up to a length of at most 5,500 nucleotides, preferably at most 5,000 nucleotides, more preferably at most, 4,600 nucleotides.
[0022] Examples of parts or fragments of the nucleotide sequence of SEQ ID NO: 1; or a part or fragment of a (natural or synthetic) mutant thereof include, but are not limited to, 5′ or 3′ truncated nucleotide sequences, or sequences with an introduced in frame start codon or stop codon. Also, two or more such parts or fragments of one or more nucleotide sequences of the invention may be suitably combined (e.g. ligated in frame) to provide a further nucleotide sequence of the invention.
[0023] Preferably, any such parts or fragments will be such that they comprise at least one continuous stretch of at least 100 nucleotides, preferably at least 250 nucleotides, more preferably at least 500 nucleotides, even more preferably more than 1,000 nucleotides, of the nucleotide sequence of SEQ ID NO: 1.
[0024] Also, it is expected that—based upon the disclosure herein—the skilled person will be able to identify, derive or isolate natural “mutants” (as mentioned above) of the nucleotide sequence of SEQ ID NO: 1 from (other individuals of) the same species (for example from an individual of a different strain or line, including but not limited to mutant strains or lines). It is also expected that—based upon the disclosure herein—the skilled person will be able to provide or derive synthetic mutants (as defined hereinabove) of the nucleotide sequence of SEQ ID NO: 1.
[0025] In one specific embodiment, the mutant is such that it encodes the nucleotide sequence of SEQ ID NO: 1 or a part or fragment thereof.
[0026] Preferably, any mutants as described herein will have one or more, and preferably all, of the structural characteristics or conserved features referred to below for the nucleotide sequences of SEQ ID NO: 1.
[0027] In particular, any mutants, parts or fragments as described herein may be such that they at least encode the active or catalytic site of the corresponding amino acid sequence of the invention and a binding domain of the corresponding amino acid sequence of the invention.
[0028] Also, any mutants, parts or fragments as described herein will preferably have a degree of “sequence identity”, at the nucleotide level, with the nucleotide sequence of SEQ ID NO 1, of at least 75%, preferably at least 80%, more preferably at least 85%, and in particular more than 90%, and up to 95% or more.
[0029] Also, preferably, any mutants, parts or fragments of the nucleotide sequence of the invention will be such that they encode an amino acid sequence which has a degree of “sequence identity”, at the amino acid level, with the amino acid sequence of SEQ ID NO: 2, of at least 50%, preferably at least 60%, more preferably at least 70%, even more preferably at least 80%, and in particular more than 90% and up to 95% or more, in which the percentage of “sequence identity” is calculated as described below.
[0030] For this purpose, the percentage of “sequence identity” between a given nucleotide sequence and the nucleotide sequence of SEQ ID NO: 1 may be calculated by dividing the number of nucleotides in the given nucleotide sequence that are identical to the nucleotide at the corresponding position in the nucleotide sequence of SEQ ID NO: 1 by the total number of nucleotides in the given nucleotide sequence and multiplying by 100%, in which each deletion, insertion, substitution or addition of a nucleotide—compared to the sequence of SEQ ID NO:1—is considered as a difference at a single nucleotide position.
[0031] Also, in a preferred aspect, any mutants, parts or fragments as described herein will encode proteins or polypeptides having biological activity that is essentially similar to the biological activity described above for the sequences of SEQ ID NO: 1, i.e. to a degree of at least 50%, preferably at least 75%, and up to 90%, as measured by standard assay techniques as described below.
[0032] Any mutants, parts or fragments as described herein are preferably such that they are capable of hybridizing with the nucleotide sequence of SEQ ID NO: 1, i.e. under conditions of “moderate stringency”, and preferably under conditions of “high stringency”. Such conditions will be clear to the skilled person, for example from the standard handbooks, such as Sambrook et al. and Ausubel et al., mentioned above, as well as in EP 0 967 284, EP 1085 089 or WO 00/55318.
[0033] It is also within the scope of the invention to use a fusion of a nucleotide sequence of the invention (as described above) with one or more further nucleotide sequence(s), including but not limited to one or more coding sequences, non-coding sequences or regulatory sequences. Preferably, in such fusions, the one or more further nucleotide sequences are operably connected (as described below) to the nucleotide sequence of the invention (for example so that, when the further nucleotide sequence is a coding sequence, the nucleotide fusion encodes a protein fusion as described below).
[0034] In another embodiment, the invention relates to an antisense molecule against a nucleotide sequence of the invention.
[0035] The nucleic acids of the invention may also be in the form of a genetic construct, again as further described below. Genetic constructs of the invention will generally comprise at least one nucleotide sequence of the invention, optionally linked to one or more elements of genetic constructs known per se, as described below. Such genetic constructs may be DNA or RNA, and are preferably double-stranded DNA. The constructs may also be in a form suitable for transformation of the intended host cell or host organism, in a form suitable for integration into the genomic DNA of the intended host cell or in a form suitable independent replication, maintenance and inheritance in the intended host organism. For instance, the genetic construct may be in the form of a vector, such as for example a plasmid, cosmid, a yeast artificial chromosome (“YAC”), a viral vector or transposon. In particular, the vector may be an expression vector, i.e. a vector that can provide for expression in vitro or in vivo (e.g. in a suitable host cell or host organism as described below). An expression vector comprising a nucleotide sequence of the invention is also referred to herein as a recombinant expression vector. These constructs will also be referred to herein as “genetic constructs of the invention”.
[0036] In a preferred embodiment, such a construct a recombinant expression vector which will comprise:
a) the nucleotide sequence of the invention; operably connected to: b) one or more regulatory elements, such as a promoter and optionally a suitable terminator;
and optionally also:
c) one or more further elements of genetic constructs known per se; in which the terms “regulatory element”, “promoter”, “terminator”, “further elements” and “operably connected” have the meanings indicated herein below.
[0040] As the one or more “further elements” referred to above, the genetic construct(s) of the invention may generally contain one or more suitable regulatory elements (such as a suitable promoter(s), enhancer(s), or terminator(s)), 3′- or 5′-untranslated region(s) (“UTR”) sequences, leader sequences, selection markers, expression markers or reporter genes, or elements that may facilitate or increase (the efficiency of) transformation or integration. These and other suitable elements for such genetic constructs will be clear to the skilled person, and may for instance depend upon the type of construct used, the intended host cell or host organism; the manner in which the nucleotide sequences of the invention of interest are to be expressed (e.g. via constitutive, transient or inducible expression); and the transformation technique to be used.
[0041] Preferably, in the genetic constructs of the invention, the one or more further elements are “operably linked” to the nucleotide sequence(s) of the invention or to each other, by which is generally meant that they are in a functional relationship with each other. For instance, a promoter is considered “operably linked” to a coding sequence if said promoter is able to initiate or otherwise control or regulate the transcription or the expression of a coding sequence (in which said coding sequence should be understood as being “under the control of” said promoter)
[0042] Generally, when two nucleotide sequences are operably linked, they will be in the same orientation and usually also in the same reading frame. They will usually also be essentially contiguous, although this may also not be required.
[0043] Preferably, the optional further elements of the genetic construct(s) used in the invention are such that they are capable of providing their intended biological function in the intended host cell or host organism.
[0044] For instance, a promoter, enhancer or terminator should be “operable” in the intended host cell or host organism, by which is meant that (for example) said promoter should be capable of initiating or otherwise controlling or regulating the transcription or the expression of a nucleotide sequence—e.g. a coding sequence—to which it is operably linked (as defined above).
[0045] Such a promoter may be a constitutive promoter or an inducible promoter, and may also be such that it (only) provides for expression in a specific stage of development of the host cell or host organism, or such that it (only) provides for expression in a specific cell, tissue, organ or part of a multicellular host organism.
[0046] Some particularly preferred promoters include, but are not limited to, constitutive promoters, such as cytomegalovirus (“CMV”), Rous sarcoma virus (“RSV”), simian virus-40 (“SV40”), for example, pSVL SV40 Late Promoter Expression Vector (Pharmacia Biotech Inc., Piscataway, N.J.), or herpes simplex virus (“HSV”) for expression in mammalian cells or insect constitutive promoters such a the immediate early baculovirus promoter described by Jarvis et al. Methods in Molecular Biology Vol. 39 Baculovirus Expression Protocols ed. C. Richardson. Hamana Press Inc., Totowa, N.J. 1995 available in pIE vectors from Novagen (Novagen, Inc. Madison, Wis.) or insect inducible promoters such as the Drosophila metallothionein promoter described by Bunch et al. Nucleic Acids Research, Vol. 6, No. 3 1043-106, 1988 available in vectors from Invitrogen (Invitrogen Corporation, Carlsbad, Calif.).
[0047] Another embodiment of the invention relates to a host cell or host organism that has been transformed or contains a nucleotide sequence, with a nucleic acid or with a genetic construct of the invention. The invention also relates to a host cell or host organism that expresses, or (at least) is capable of expressing (e.g. under suitable conditions), an amino acid sequence of the invention. Collectively, such host cells or host organisms will also be referred to herein as “host cells or host organisms of the invention”.
[0048] The host cell may be any suitable (fungal, prokaryotic or eukaryotic) cell or cell line, for example:
a bacterial strain, including but not limited to strains of E. coli, Bacillus, Streptomyces and Pseudomonas; a fungal cell, including but not limited to cells from species of Aspergillus and Trichoderma; a yeast cell, including but not limited to cells from species of Kluyveromyces or Saccharomyces; an amphibian cell or cell line, such as Xenopus oocytes.
[0053] In one specific embodiment, which may be particularly useful when the nucleotide sequences of the invention are (to be) used in the discovery and development of insecticidal compounds, the host cell may be an insect-derived cell or cell line, such as:
cells or cell lines derived from Lepidoptera, including but not limited to Spodoptera SF9 and Sf21 cells, cells or cell lines derived from Aphis; cells or cell lines derived from Drosophila, such as Schneider and Kc cells; and cells or cell lines derived from a pest species of interest (as mentioned below), such as from Heliothis virescens.
[0058] The host cell may also be a mammalian cell or cell line, including but not limited to CHO- and BHK-cells and human cells or cell lines such as HeK, HeLa and COS.
[0059] The host organism may be any suitable multicellular (vertebrate or invertebrate) organism, including but not limited to:
a nematode, including but not limited to nematodes from the genus Caenorhabditis, such as C. elegans, an insect, including but not limited to species of Aphis, Drosophila, Heliothis, or a specific pest species of interest (such as those mentioned above); other well known model organisms, such as zebrafish; a mammal such as a rat or mouse;
[0064] Other suitable host cells or host organisms will be clear to the skilled person, for example from the handbooks and patent applications mentioned above.
[0065] It should be noted that when a nucleotide sequence of the invention is expressed in a multicellular organism, it may be expressed throughout the entire organism, or only in one or more specific cells, tissues, organs or parts thereof, for example by expression under the control of a promoter that is specific for said cell(s), tissue(s), organ(s) or part(s).
[0066] The nucleotide sequence may also be expressed during only a specific stage of development or life cycle of the host cell or host organism, again for example by expression under the control of a promoter that is specific for said stage of development or life cycle. Also, as already mentioned above, said expression may be constitutive, transient or inducible.
[0067] Preferably, these host cells or host organisms are such that they express, or are (at least) capable of expressing (e.g. under suitable conditions), an amino acid sequence of the invention (and in case of a host organism: in at least one cell, part, tissue or organ thereof). The invention also includes further generations, progeny and offspring of the host cell or host organism of the invention, which may for instance be obtained by cell division or by sexual or asexual reproduction.
[0068] In yet another aspect, the invention relates to a nucleic acid, preferably in (essentially) isolated form, which nucleic acid encodes or can be used to express an amino acid sequence of the invention (as defined herein), and in particular the amino acid sequence of SEQ ID NO: 2.
[0069] The amino acid sequence of SEQ ID NO: 2 may be isolated from the species mentioned above, using any technique(s) for protein isolation and purification known to one skilled in the art. Alternatively, the amino acid sequence of SEQ ID NO: 2 may be obtained by suitable expression of a suitable nucleotide sequence—such as the nucleotide sequence of SEQ ID NO: 1 or a suitable mutant thereof—in an appropriate host cell or host organism, as further described below.
[0070] In another aspect, the invention relates to a protein or polypeptide, preferably in (essentially) isolated form, said protein or polypeptide comprising an amino acid sequence of the invention (as defined above), in particular the amino acid sequence of SEQ ID NO: 2.
[0071] In a broader sense, the term “amino acid sequence of the invention” also comprises:
parts or fragments of the amino acid sequence of SEQ ID NO: 2; (natural or synthetic) mutants, variants, alleles, analogs, orthologs (herein below collectively referred to as “analogs”) of the amino acid sequence of SEQ ID NO: 2; parts or fragments of such analogs; fusions of the amino acid sequence of SEQ ID NO: 2 (or a part or fragment thereof) with at least one further amino acid residue or sequence; fusions of the amino acid sequence of an analog (or a part or fragment thereof) with at least one further amino acid residue or sequence;
in which such mutants, parts, fragments or fusions are preferably as further described below.
[0077] The term “amino acid sequence of the invention” also comprises “immature” forms of the abovementioned amino acid sequences, such as a pre-, pro- or prepro-forms or fusions with suitable leader sequences. Also, the amino acid sequences of the invention may have been subjected to post-translational processing or be suitably glycosylated, depending upon the host cell or host organism used to express or produce said amino acid sequence; or may be otherwise modified (e.g. by chemical techniques known per se in the art).
[0078] Examples of parts or fragments of the amino acid sequence of SEQ ID NO: 2, or a part or fragment of a (natural or synthetic) analog thereof mutant thereof include, but are not limited to, N- and C-truncated amino acid sequence. Also, two or more parts or fragments of one or more amino acid sequences of the invention may be suitably combined to provide an amino acid sequence of the invention.
[0079] Preferably, an amino acid sequence of the invention has a length of at least 100 amino acids, preferably at least 250 amino acids, more preferably at least 500 amino acids; and up to a length of at most 2,000 amino acids, preferably at most 1,000 amino acids, more preferably at most 750 amino acids.
[0080] Preferably, any such parts or fragments will be such that they comprise at least one continuous stretch of at least 5 amino acids, preferably at least 10 amino acids, more preferably at least 20 amino acids, even more preferably more than 30 amino acids, of the amino acid sequence of SEQ ID NO: 2.
[0081] In particular, any parts or fragments as described herein are such that they (at least) comprise the active or catalytic site of the corresponding amino acid sequence of the invention or a binding domain of the corresponding amino acid sequence of the invention. As will be clear to the skilled person, such parts or fragments may find particular use in assay- and screening techniques (as generally described below) and (when said part or fragment is provided in crystalline form) in X-ray crystallography.
[0082] Also, it is expected that—based upon the disclosure herein—the skilled person will be able to identify, derive or isolate natural “analogs” (as mentioned above) of the amino acid sequence of SEQ ID NO: 2. Such mutants could be derived from (other individuals of) the same species (for example from an individual of a different strain or line, including but not limited to mutant strains or lines); or from (individuals of) other species. For example, such analogs could be derived from the insect species mentioned above.
[0083] It is also expected that—based upon the disclosure herein—the skilled person will be able to provide or derive synthetic “analogs” (as mentioned above) of the amino sequence of SEQ ID NO: 2.
[0084] Preferably, any mutants as described herein will have one or more, and preferably all, of the structural characteristics or conserved features referred to below for the sequences of SEQ ID NO: 2.
[0085] Preferably, any analogs, parts or fragments as described herein will be such that they have a degree of “sequence identity”, at the amino acid level, with the amino acid sequence of SEQ ID NO: 2 of at least 50%, preferably at least 60%, more preferably at least 70%, even more preferably at least 80%, and in particular more than 90% and up to 95% or more.
[0086] For this purpose, the percentage of “sequence identity” between a given amino acid sequence and the amino acid sequence of SEQ ID NO: 2 may be calculated by dividing the number of amino acid residues in the given amino acid sequence that are identical to the amino acid residue at the corresponding position in the amino acid sequence of SEQ ID NO: 2 by the total number of amino acid residues in the given amino acid sequence and multiplying by 100%, in which each deletion, insertion, substitution or addition of an amino acid residue—compared to the sequence of SEQ ID NO: 2—is considered as a difference at a single amino acid (position).
[0087] Alternatively, the degree of sequence identity may be calculated using a known computer program, such as those mentioned above.
[0088] Also, such sequence identity at the amino acid level may take into account so-called “conservative amino acid substitutions”, which are well known in the art, for example from GB-A-2 357 768, WO 98/49185, WO 00/46383 and WO 01/09300; and (preferred) types or combinations of such substitutions may be selected on the basis of the pertinent teachings from the references mentioned in WO 98/49185.
[0089] Also, preferably, any analogs, parts or fragments as described herein will have a biological activity that is essentially similar to the biological activity described above for the sequences of SEQ ID NO: 2, i.e. to a degree of at least 10%, preferably at least 50% more preferably at least 75%, and up to 90%, as measured by standard assay techniques as described below.
[0090] It is also within the scope of the invention to use a fusion of an amino acid sequence of the invention (as described above) with one or more further amino acid sequences, for example to provide a protein fusion. Generally, such fusions may be obtained by suitable expression of a suitable nucleotide sequence of the invention—such as a suitable fusion of a nucleotide sequence of the invention with one or more further coding sequences—in an appropriate host cell or host organism, as further described below.
[0091] One particular embodiment, such fusions may comprise an amino acid sequence of the invention fused with a reporter protein such as glutathione S-transferase (“GST”), green fluorescent protein (“GFP”), luciferase or another fluorescent protein moiety. As will be clear to the skilled person, such fusions may find particular use in expression analysis and similar methodologies.
[0092] In another embodiment, the fusion partner may be an amino acid sequence or residue that may be used in purification of the expressed amino acid sequence, for example using affinity techniques directed against said sequence or residue. Thereafter, said sequence or residue may be removed (e.g. by chemical or enzymatical cleavage) to provide the nucleotide sequence of the invention (for this purpose, the sequence or residue may optionally be linked to the amino acid sequence of the invention via a cleavable linker sequence). Some preferred, but non-limiting examples of such residues are multiple histidine residues and glutatione residues.
[0093] In one preferred, but non-limiting aspect, any such fusion will have a biological activity that is essentially similar to the biological activity described above for the sequences of SEQ ID NO: 2, i.e. to a degree of at least 10%, preferably at least 50% more preferably at least 75%, and up to 90%, as measured by standard assay techniques as described below.
[0094] The nucleotide sequences and amino acid sequences of the invention may generally be characterized by the presence of one or more of the following structural characteristics or conserved features:
[0095] For the gene Aphis gossypii: SEQ ID NO: 1 is a cDNA sequence encompassing the open reading frame; and SEQ ID NO: 2 is the protein encoded by SEQ ID NO: 1.
[0096] By analogy to other GADs, it is likely that the functional protein is monomeric. See, e.g., Hannan and Hall, In Comparative Molecular Neurobiology, Y. Pichon, 1993, Birkhuaser Verlag Basel Switzerland).
[0097] On the basis of the above, and although the invention is not specifically limited to any specific explanation or mechanism, the nucleotide sequences and amino acid sequences have (biological) activity as a decarboxylase. In particular, the present invention has shown activity as a decarboxylase from insects of the order Hemiptera, which are aphids, leafhoppers, whiteflies, scales and true bugs that have mouthparts adapted to piercing and sucking.
[0098] As is known in the art, biological activity of this kind can be measured using standard assay techniques (see I. Cozzani, Analytical Biochem., (1970), 33, pp. 125-131; Scriven et al., Analytical Biochem., (1988), 170, pp. 367-371; Holdiness ea al., Analytical Letters, (1980), 13 (B15), pp. 1333-1344; Heerze et al., Analytical Biochem., (1990), 185, pp. 201-205; G. Zhang and A. W. Bown, Phytochemistry, (1997), Vol. 44, No. 6, pp. 1007-1009; O. Chude and J. Wu, J. Neurochem., (1976), Vol. 27, pp. 83-86; Torchinskiy et al., Doklady Akademii nauk SSR, (1972), Vol. 205, No. 3; and Rosenberg et al., Analytical Biochem., (1989), 181, pp. 59-65).
[0099] Another embodiment of the invention relates to a nucleic acid probe that is capable of hybridizing with a nucleotide sequence of the invention under conditions of moderate stringency, preferably under conditions of high stringency, and in particular under stringent conditions (all as described above). Such nucleotide probes may for instance be used for detecting or isolating a nucleotide sequence of the invention or as a primer for amplifying a nucleotide sequence of the invention; all using techniques known per se, for which reference is again made to the general handbooks such as Sambrook et al. and Ausubel et al., mentioned above.
[0100] Preferably, when to be used for detecting or isolating another nucleotide sequence of the invention, such a nucleotide probe will usually have a length of between 15 and 100 nucleotides, and preferably between 20 and 80 nucleotides. When used as a primer for amplification, such a nucleotide probe will have a length of between 25 and 75 nucleotides, and preferably between 20 and 40 nucleotides.
[0101] Generally, such probes can be designed by the skilled person starting from a nucleotide sequence or amino acid sequence of the invention—and in particular the sequence of SEQ ID NO: 1 or SEQ ID NO: 2—optionally using a suitable computer algorithm.
[0102] In a further aspect, the invention relates to methods for preparing mutants and genetic constructs of the nucleotide sequences of the present invention.
[0103] Natural mutants of the nucleotide sequences of the present invention may be obtained in a manner essentially analogous to the method described in the Experimental Part, or alternatively by:
construction of a DNA library from the species of interest in an appropriate expression vector system, followed by direct expression of the mutant sequence; construction of a DNA library from the species of interest in an appropriate expression vector system, followed by screening of said library with a probe of the invention (as described below) or with a nucleotide sequence of the invention; isolation of mRNA that encodes the mutant sequence from the species of interest, followed by cDNA synthesis using reverse transcriptase;
or by any other suitable method(s) or technique(s) known per se, for which reference is for instance made to the standard handbooks, such as Sambrook et al., “Molecular Cloning: A Laboratory Manual” (2nd.ed.), Vols. 1-3, Cold Spring Harbor Laboratory Press (1989) and F. Ausubel et al., “Current protocols in molecular biology”, Green Publishing and Wiley Interscience, New York (1987).
[0107] Techniques for generating such synthetic sequences of the nucleotide sequences of the present invention will be clear to the skilled person and may for instance include, but are not limited to, automated DNA synthesis; site-directed mutagenesis; combining two or more parts of one or more naturally occurring sequences, introduction of mutations that lead to the expression of a truncated expression product; introduction of one or more restriction sites (e.g. to create cassettes or regions that may easily be digested or ligated using suitable restriction enzymes), and the introduction of mutations by means of a PCR reaction using one or more “mismatched” primers, using for example a sequence of a naturally occurring GAD as a template. These and other techniques will be clear to the skilled person, and reference is again made to the standard handbooks, such as Sambrook et al. and Ausubel et al., mentioned above.
[0108] The genetic constructs of the invention may generally be provided by suitably linking the nucleotide sequence(s) of the invention to the one or more further elements described above, for example using the techniques described in the general handbooks such as Sambrook et al. and Ausubel et al., mentioned above.
[0109] Often, the genetic constructs of the invention will be obtained by inserting a nucleotide sequence of the invention in a suitable (expression) vector known per se. Some preferred, but non-limiting examples of suitable expression vectors include:
vectors for expression in mammalian cells: pSVL SV40 (Pharmacia), pMAMneo (Clontech), pcDNA3 (Invitrogen), pMC1neo (Stratagene), pSG5 (Stratagene), EBO-pSV2-neo (ATCC 37593), pBPV-1 (8-2) (ATCC 37110), pdBPV-MMTneo (342-12) (ATCC 37224), pRSVgpt (ATCC37199), pRSVneo (ATCC37198), pSV2-dhfr (ATCC 37146), pUCTag (ATCC 37460) and 1ZD35 (ATCC 37565); vectors for expression in bacterials cells: pET vectors (Novagen) and pQE vectors (Qiagen); vectors for expression in yeast or other fungal cells: pYES2 (Invitrogen) and Pichia expression vectors (Invitrogen);
[0113] vectors for expression in insect cells: pBlueBacII (Invitrogen), pEI1 (Novagen), pMT/V5His (Invitrogen).
[0114] In a further aspect, the invention relates to methods for transforming a host cell or a host organism with a nucleotide sequence, with a nucleic acid or with a genetic construct of the invention. The invention also relates to the use of a nucleotide sequence, of a nucleic acid or of a genetic construct of the invention transforming a host cell or a host organism.
[0115] According to one specific embodiment, the expression of a nucleotide sequence of the invention in a host cell or host organism may be reduced, compared to the original (e.g. native) host cell or host organism. This may for instance be achieved in a transient manner using antisense or RNA-interference techniques well known in the art, or in a constitutive manner using random, site specific or chemical mutagenesis of the nucleotide sequence of the invention.
[0116] Suitable transformation techniques will be clear to the skilled person and may depend on the intended host cell or host organism and the genetic construct to be used. Some preferred, but non-limiting examples of suitable techniques include ballistic transformation, (micro-)injection, transfection (e.g. using suitable transposons), electroporation and lipofection. For these and other suitable techniques, reference is again made to the handbooks and patent applications mentioned above.
[0117] After transformation, a step for detecting and selecting those host cells or host organisms that have been successfully transformed with the nucleotide sequence or genetic construct of the invention may be performed. This may for instance be a selection step based on a selectable marker present in the genetic construct of the invention or a step involving the detection of the amino acid sequence of the invention, e.g. using specific antibodies.
[0118] The transformed host cell (which may be in the form or a stable cell line) or host organisms (which may be in the form of a stable mutant line or strain) form further aspects of the present invention.
[0119] In yet another aspect, the invention relates to methods for producing an amino acid sequence of the invention.
[0120] To produce or obtain expression of the amino acid sequences of the invention, a transformed host cell or transformed host organism may generally be kept, maintained or cultured under conditions such that the (desired) amino acid sequence of the invention is expressed or produced. Suitable conditions will be clear to the skilled person and will usually depend upon the host cell or host organism used, as well as on the regulatory elements that control the expression of the (relevant) nucleotide sequence of the invention. Again, reference is made to the handbooks and patent applications mentioned above in the paragraphs on the genetic constructs of the invention.
[0121] Generally, suitable conditions may include the use of a suitable medium, the presence of a suitable source of food or suitable nutrients, the use of a suitable temperature, and optionally the presence of a suitable inducing factor or compound (e.g. when the nucleotide sequences of the invention are under the control of an inducible promoter); all of which may be selected by the skilled person. Again, under such conditions, the amino acid sequences of the invention may be expressed in a constitutive manner, in a transient manner, or only when suitably induced.
[0122] It will also be clear to the skilled person that the amino acid sequence of the invention may (first) be generated in an immature form (as mentioned above), which may then be subjected to post-translational modification, depending on the host cell or host organism used. Also, the amino acid sequence of the invention may be glycosylated, again depending on the host cell or host organism used.
[0123] The amino acid sequences of the invention may then be isolated from the host cell or host organism or from the medium in which said host cell or host organism was cultivated, using protein isolation and purification techniques known per se, such as (preparative) chromatography and electrophoresis techniques, differential precipitation techniques, affinity techniques (e.g. using a specific, cleavable amino acid sequence fused with the amino acid sequence of the invention) and preparative immunological techniques (i.e. using antibodies against the amino acid sequence to be isolated).
[0124] In one embodiment, the amino acid sequence thus obtained may also be used to generate antibodies specifically against said sequence or an antigenic part or epitope thereof.
[0125] In one embodiment, the present invention relates to antibodies, for example monoclonal and polyclonal antibodies, that are generated specifically against amino acid sequences of the present invention, preferably SEQ ID NO: 2, or an analog, variant, allele, ortholog, part, fragment or epitope thereof.
[0126] Such antibodies, which form a further aspect of the invention, may be generated in a manner known per se, for example as described in GB-A-2 357 768, U.S. Pat. No. 5,693,492, WO 95/32734, WO 96/23882, WO 98/02456, WO 98/41633 and WO 98/49306. Often, but not exclusively, such methods will involve as immunizing a immunocompetent host with the pertinent amino acid sequence of the invention or an immungenic part thereof (such as a specific epitope), in amount(s) and according to a regimen such that antibodies against said amino acid sequence are raised, and than harvesting the antibodies thus generated, e.g. from blood or serum derived from said host.
[0127] For instance, polyclonal antibodies can be obtained by immunizing a suitable host such as a goat, rabbit, sheep, rat, pig or mouse with (an epitope of) an amino acid sequence of the invention, optionally with the use of an immunogenic carrier (such as bovine serum albumin or keyhole limpet hemocyanin) or an adjuvant such as Freund's, saponin, aluminium hydroxide or a similar mineral gel, or keyhole limpet hemocyanin or a similar surface active substance. After a suitable immune response has been raised (usually within 1-7 days), the antibodies can be isolated from blood or serum taken from the immunized animal in a manner known per se, which optionally may involve a step of screening for an antibody with desired properties (i.e. specificity) using known immunoassay techniques, for which reference is again made to for instance WO 96/23882.
[0128] Monoclonal antibodies may for example be produced using continuous cell lines in culture, including hybridoma-based and similar techniques, again essentially as described in the above cited references. Accordingly, cells and cell lines that produce monoclonal antibodies against an amino acid sequence of the invention form a further aspect of the invention, as do methods for producing antibodies against amino acid sequences of the invention, which methods may generally involve cultivating such a cell and isolating the antibodies from the culture or medium, again using techniques known per se.
[0129] Also, Fab-fragments against the amino acid sequences of the invention (such as F(ab) 2 , Fab′ and Fab fragments) may be obtained by digestion of an antibody with pepsin or another protease, reducing disulfide-linkages and treatment with papain and a reducing agent, respectively. Fab-expression libraries may for instance be obtained by the method of Huse et al., 1989, Science 245:1275-1281.
[0130] In another embodiment, the amino acid sequence of the invention, or a host cell or host organism that expresses such an amino acid sequence, may also be used to identify or develop compounds or other factors that can modulate the (biological) activity of, or that can otherwise interact with, the amino acid sequences of the invention, and such uses form further aspects of the invention. As will be clear to the skilled person, in this context, the amino acid sequence of the invention will serve as a target for interaction with such a compound or factor.
[0131] In this context, the terms “modulate”, “modulation, “modulator” and “target” will have their usual meaning in the art, for which reference is inter alia made to the definitions given in WO 98/06737. Generally, a modulator is a compound or factor that can enhance, inhibit or reduce or otherwise alter, influence or affect (collectively referred to as “modulation”) a functional property of a biological activity or process (for example, the biological activity of an amino acid sequence of the invention).
[0132] In this context, the amino acid sequence of the invention may serve as a target for modulation in vitro (e.g. as part of an assay or screen) or for modulation in vivo (e.g. for modulation by a compound or factor that is known to modulate the target, which compound or factor may for example be used as an active compound for agrochemical, veterinary or pharmaceutical use).
[0133] For example, the amino acid sequences, host cells or host organisms of the invention may be used as part of an assay or screen that may be used to identify or develop modulators of the amino acid sequence of the invention, such as a primary screen (e.g. a screen used to identify modulators of the target from a set or library of test chemicals with unknown activity with respect to the target) or a secondary assay (e.g. an assay used for validating hits from a primary screen or used in optimizing hit molecules, e.g. as part of hits-to-leads chemistry).
[0134] For instance, such an assay or screen may be configured as an in vitro assay or screen, which will generally involve binding of the compound or factor to be tested as a potential modulator for the target (herein below also referred to as “test chemical”) to the target, upon which a signal generated by said binding is measured. Suitable techniques for such in vitro screening will be clear to the skilled person, and are for example described in Eldefrawi et al., (1987). FASEB J., Vol. 1, pages 262-271 and Rauh et al., (1990), Trends in Pharmacol. Sci., vol. 11, pages 325-329. For example, such an assay or screen may be configured as a binding assay or screen, in which the test chemical is used to displace a detectable ligand from the target (e.g. a radioactive or fluorescent ligand), upon which the amount of ligand displaced from the target by the modulator is determined.
[0135] Such an assay or screen may also be configured as a cell-based assay or screen, in which a host cell of the invention is contacted with or exposed to a test chemical, upon which at least one biological response by the host cell is measured.
[0136] Also, such an assay or screen may also be configured as an whole animal screen, in which a host organism of the invention is contacted with or exposed to a test chemical, upon which at least one biological response (such as a phenotypical, behavioral or physiological change, including but not limited to paralysis or death) by the host organism is measured.
[0137] Thus, generally, the assays and screens described above will comprise at least one step in which the test chemical is contacted with the target (or with a host cell or host organism that expresses the target), and in particular in such a way that a signal is generated that is representative for the modulation of the target by the test chemical. In a further step, said signal may then be detected.
[0138] Accordingly, in one aspect, the invention relates to a method for generating a signal that is representative for the interaction of an amino acid sequence of the invention with a test chemical, said method at least comprising the steps of:
a) contacting the amino acid sequence of the invention, or a host cell or host organism containing or expressing an amino acid sequence, with said test chemical, in such a way that a signal may be generated that is representative for the interaction between said test chemical and said amino acid sequence; and optionally b) detecting the signal that may thus be generated.
[0141] In another aspect, the invention relates to a method for identifying modulators and/or inhibitors of an amino acid sequence of the invention (e.g. from a set or library of test chemicals), said method at least comprising the steps of:
a) contacting the amino acid sequence of the invention, or a host cell or host organism containing or expressing an amino acid sequence, with a test chemical, in such a way that a signal may be generated that is representative for the interaction between said test chemical and said the target; and optionally b) detecting the signal that may thus be generated, said signal identifying the modulator and/or inhibitor of said amino acid sequence.
[0144] Accordingly, the present invention provides methods of identifying a modulator and/or inhibitor of a hemipteran GAD protein activity. In preferred embodiments, the hemipteran GAD protein used in the methods has an amino acid sequence selected from the group consisting of SEQ ID NO: 2, a mutant thereof, and a fragment thereof. In some embodiments, the nucleic acid sequence that encodes the hemipteran GAD is SEQ ID NO: 1.
[0145] A test chemical may be part of a set or library of compounds, which may be a diverse set or library or a focussed set or library, as will be clear to the skilled person. The libraries that may be used for such screening can be prepared using combinatorial chemical processes known in the art or conventional means for chemical synthesis.
[0146] The assays and screens of the invention may be carried out at medium throughput to high throughput, for example in an automated fashion using suitable robotics. In particular, in this embodiment, the method of the invention may be carried out by contacting the target with the test compound in a well of a multi-well plate, such as a standard 24, 96, 384, 1536 or 3456 well plate.
[0147] Usually, in a screen or assay of the invention, for each measurement, the target or host cell or host organism will be contacted with only a single test compound. However, it is also within the scope of the invention to contact the target with two or more test compounds—either simultaneously or sequentially—for example to determine whether said combination provides a synergistic effect.
[0148] Once a test chemical has been identified as a modulator and/or inhibitor for an amino acid sequence of the invention (e.g. by means of a screen or assay as described hereinabove), it may be used per se as a modulator and/or inhibitor of the relevant amino acid sequence of the invention, preferably, an amino acid sequence of SEQ ID NO: 2, a mutant thereof, and a fragment thereof, more preferably SEQ ID NO: 2 (e.g. as an active substance for agrochemical, veterinary or pharmaceutical use), or it may optionally be further optimized for final use, e.g. to improve properties such as solubility, adsorption, bio-availability, toxicity, stability, persistence, environmental impact, etc. It will be clear to the skilled person that the nucleotide sequences, preferably SEQ ID NO: 1, amino acid sequences, host cells or host organisms and methods of the invention may find further use in such optimization methodology, for example as (part of) secondary assays.
[0149] The invention is not particularly limited to any specific manner or mechanism in or via which the modulator and/or inhibitor (e.g. the test chemical, compound or factor) modulates, inhibits, or interacts with, the target (in vivo or in vitro). For example, the modulator and/or inhibitor may be a competitive inhibitor, a non-competitive inhibitor, a cofactor, an allosteric inhibitor or other allosteric factor for the target, or may be a compound or factor that enhances or reduces binding of target to another biological component associated with its (biological) activity, such as another protein or polypeptide, a receptor, or a part of organelle of a cell. As such, the modulator and/or inhibitor may bind with the target (at the active site, at an allosteric site, at a binding domain or at another site on the target, e.g. covalently or via hydrogen bonding), block and/or inhibit the active site of the target (in a reversible, irreversible or competitive manner), block and/or inhibit a binding domain of the target (in a reversible, irreversible or competitive manner), or influence or change the conformation of the target.
[0150] As such, the test chemical, modulator and/or inhibitor may for instance be:
an analog of a known substrate of the target; an oligopeptide, e.g. comprising between 2 and 20, preferably between 3 and 15 amino acid residues; an antisense or double stranded RNA molecule; a protein, polypeptide; a cofactor or an analog of a cofactor.
[0156] The test chemical, modulator and/or inhibitor may also be a reference compound or factor, which may be a compound that is known to modulate, inhibit or otherwise interact with the target (e.g. a known substrate or inhibitor for the target) or a compound or factor that is generally known to modulate, inhibit or otherwise interact with other members from the general class to which the target belongs (e.g. a known substrate or inhibitor of said class).
[0157] Preferably, however, the test chemical, modulator and/or inhibitor is a small molecule, by which is meant a molecular entity with a molecular weight of less than 1,500, preferably less than 1,000. This may for example be an organic, inorganic or organometallic molecule, which may also be in the form or a suitable salt, such as a water-soluble salt. The term “small molecule” also covers complexes, chelates and similar molecular entities, as long as their (total) molecular weight is in the range indicated above.
[0158] As already mentioned above, the compounds or factors that have been identified or developed as modulators and/or inhibitors of the amino acid sequences of the invention, preferably, an amino acid sequence of SEQ ID NO: 2, a mutant thereof, and a fragment thereof, more preferably SEQ ID NO: 2, (and precursors for such compounds) may be useful as active substances in the agrochemical, veterinary or pharmaceutical fields, for example in the preparation of agrochemical, veterinary or pharmaceutical compositions, and both such modulators as well as compositions containing them further aspects of the invention.
[0159] For example, in the agrochemical field, the modulators and/or inhibitors of the invention may be used as an insecticide, nematicide, molluscide, helminticide, acaricide or other types of pesticides or biocides, e.g. to prevent or control (infestations with) harmful organisms, both as contact agents and as systemic agents. As such, the modulators and/or inhibitors may for example be used as a crop protection agent, as a pesticide for household use, or as an agent to prevent or treat damage caused by harmful organisms (e.g. for the protection of seed, wood or stored crops or fruits). Preferably, the modulators and/or inhibitors of the invention are used as insecticides.
[0160] For any such application, one or more modulators and/or inhibitors of the invention may be suitably combined with one or more agronomically acceptable carriers, adjuvants or diluents—and optionally also with one or more further compounds known per se with activity as (for example) a plant protection agent (to broaden the spectrum of action and optionally to provide a synergistic effect), herbicide, fertilizer or plant growth regulator—to provide a formulation suitable for the intended final use. Such a formulation may for example be in the form of a solution, emulsion, dispersion, concentrate, aerosol, spray, powder, flowable, dust, granule, pellet, fumigation candle, bait or other suitable solid, semi-solid or liquid formulation, and may optionally also contain suitable solvents, emulsifiers, stabilizers, surfactants, antifoam agents, wetting agents, spreading agents, sticking agents, attractants or (for a bait) food components. Reference is made to the standard manuals, such as “Pesticidal Formulation Research”, ACS-publications (1969) and “Pesticide Formulations”, Wade van Valkenburg Ed, Marcel Dekker publications (1973).
[0161] Such compositions may generally contain one or more modulators and/or inhibitors of the invention in a suitable amount, which generally may be between 0.1 and 99%, and in particular between 10 and 50%, by weight of the total composition.
[0162] The modulators and/or inhibitors and compositions of the invention may be particularly useful as insecticides, for example to combat or control undesired or harmful insects (both adult and immature forms, such as larvae) from following orders:
Coleoptera, such as Pissodes strobi, Diabrotica undecimpunctata howardi, and Leptinotarsa decemlineata; Diptera, such as Rhagoletis pomonoella, Mayetiola destructor, and Liriomyza huidobrensis; Hymenoptera, such as Neodiprion taedae tsugae, Camponotus pennsylvanicus, and Solenopsis wagneri; Hemiptera, such as Pseudatomoscelis seriatus, Lygus lineolaris (Palisot de Beauvois), Acrosternum hilare, and Aphis gossypii Homoptera; and Lepidoptera such as Heliothis virescens.
[0169] When used to control harmful or undesired organisms, these organisms may be directly contacted with the modulators, inhibitors, or compositions of the invention in an amount suitable to control (e.g. kill or paralyze) the organism. This amount may be readily determined by the skilled person (e.g. by testing the compound on the species to be controlled) and will usually be in the region of between particular between 10 and 500 g/ha, in particular between 100 and 250 g/ha.
[0170] The modulators, inhibitors, or compositions of the invention may also be applied systemically (e.g. to the habitat of the organism to be controlled or to the soil), and may also be applied to the plant, seed, fruit etc. to be protected, again in suitable amounts, which can be determined by the skilled person. The modulators and/or inhibitors of the invention may also be incorporated—e.g. as additives—in other compositions known per se, for example to replace other pesticidal compounds normally used in such compositions.
[0171] In one specific embodiment, the modulators and/or inhibitors and compositions of the invention may be used in the fields of agrochemical, veterinary or human health to prevent or treat infection or damage or discomfort caused by parasitic organisms, and in particular by parasitic arthropods, nematodes and helminths such as:
ectoparasitic arthropods such as ticks, mites, fleas, lice, stable flies, horn flies, blowflies and other biting or sucking ectoparasites; endoparasites organisms such as helminths;
and also to prevent or treat diseases that are caused or transferred by such parasites. For such purposes, the modulators and/or inhibitors of the invention may for example be formulated as a tablet, an oral solution or emulsion, an injectable solution or emulsion, a lotion, an aerosol, a spray, a powder, a dip or a concentrate.
[0174] In the fields of animal and human health, the modulators, inhibitors, and compositions of the invention may also be used for the prevention or treatment of diseases or disorders in which the amino acid sequence of the invention may be involved as a target. For this purpose, the modulators and/or inhibitors of the invention may be formulated with one or more additives, carriers or diluents acceptable for pharmaceutical or veterinary use, which will be clear to the skilled person.
[0175] Thus, in a further aspect, the invention relates to the use of a modulator and/or inhibitor of the invention in the preparation of a composition for agrochemical, veterinary or pharmaceutical use, as described hereinabove. The invention relates to the use of the modulators, inhibitors and compositions of the invention in controlling harmful organisms and in preventing infestation or damage caused by harmful organisms, again as described above.
[0176] The invention will now be further illustrated by means of the following non-limiting Experimental Part.
[0000] Experimental Part:
EXAMPLE 1
Cloning of Cotton Aphid (“CA”) Glutamate Decarboxylase
[0000] 1. Isolation of poly(A + ) RNA.
[0177] Cotton aphids were collected from cotton plants and placed in ice-chilled glass centrifuge tubes which had been cleaned and baked for 6 hours at 180° C. prior to use. Aliquots of approximately 0.4 gram of cotton aphids was used for isolation of poly(A + ) RNA.
[0178] Diethyl pyrocarbonate (DEPC)-treated water was made by incubating DEPC (Aldrich Chemical Co., Inc. Milwaukee, Wis.) in water at concentration of 0.1% (v/v) for 16 hours at room temperature, followed by autoclaving. The microprobe of a Braun homogenizer (B. Brawn Biotech International, Allentown, Pa.) was soaked in 100% ethanol and dried prior to use.
[0179] RNA isolation was done using QuickPrep mRNA Purification kit (Amersham Pharmacia biotech, Piscataway, N.J.) according to the manufacturer's instruction. All the buffers and solutions mentioned here are included in the kit. An aliquot of 0.4 gram of cotton aphid was homogenized at full speed in 1.5 ml chilled extraction buffer until it is in a uniform suspension. After adding 3 ml of elution buffer, the sample was homogenized again briefly and the resulting mixture was centrifuged at approximately 12000×g for 10 minutes at room temperature. The supernatant was used for poly(A + ) RNA isolation. After application of supernatant to the resin of oligo(dT)-cellulose spun column, washing with high salt and low salt buffers, the bound poly(A + ) RNA was eluted with three washes of 0.25 ml elution buffer pre-warmed to 65° C. To precipitate the mRNA, 50 μl of K Acetate solution, 10 μl of Glycogen solution, and 1 ml of 95% Ethanol were added to 0.5 ml of elute. The mixture was placed at −20° C. for one hour and then centrifuged at maximal speed at room temperature in an eppendorf microcentrifuge. Precipitated poly(A + ) RNA was then dissolved in 50 μl DEPC-treated water and stored at −80° C. until use.
[0000] 2. Reverse Transcription and PCR Amplification (RT-PCR).
[0180] Bioinformatics research indicates that two of the ESTs (Expressed Sequence Tag), both of which from FMC proprietary Aphis gossypii EST (Expressed Sequencing Tag) library, are the partial transcripts of our target gene. These two ESTs have extensive coverage on both 5′ end and 3′ end, including the 5′ UTR and 3′ UTR. The cloning strategy was to select gene-specific sense primer from known 5′ UTR, and gene-specific antisense pimer from known 3′ UTR. The sense primer was CCACTGCGTCACTTCCATAAG, and the antisense primer was CAGGAAGATTTGGAATAACGC.
[0181] RT-PCR was done using the Titanium™ One-Step RT-PCR kit. RT-PCR Master Mix (43.5 μl per reaction) was prepared according to the manufacturer's protocol. RT-PCR reaction was run at the volume of 50 μl containing the following components: 0.5 μl each of primers (45 μM), 2 μl of poly(A + ) RNA (0.2 μg/μl), and 3.5 μl of DEPC-treated water. RT-PCR was run on a Perkin Elmer cycler using the following conditions: 50° C. for 60 min, 94° C. for 5 min, followed 40 cycles of the PCR reaction: 94° C. for 30 sec, 65° C. for 30 sec, and 68° C. for 60 sec. The completion of cycling was followed by incubation at 68° C. for 2 min.
[0000] 3. Subcloning of RT-PCR Product and Sequencing.
[0182] From above-described RT-PCR reaction we obtained very small quantity of PCR product which is not sufficient for sequencing. We have tried re-amplification by eLONGase and sub-cloning by restriction digestion into cloning vectors but failed. We then use pCRII-TOPO vector (Invitrogen, Carlsbad, Calif.) for sub-cloning. We directly used PCR product from Taq amplification in TOPO cloning; or before TOPO cloning, we incubated PCR product from eLONGase amplification with Taq polymerase at 72° C. to add A's to the PCR product. TOPO cloning was done according to manufacturer's instruction. The resulting plasmid was sequencd using T7 or SP6 as sequencing primers.
[0183] Primers. The primers utilized were as follows:
Primer Sequence Translation Orientation 1 CCACTGCGTCACTTCCATAAG N/A Forward 2 CAGGAAGATTTGGAATAACGC N/A Reverse
[0184]
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Novel nucleic acid sequences encoding hemipteran L-glutamate decarboxylases, and the amino acid sequence of such protein are disclosed. Methods of making and using the same are disclosed.
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FIELD OF THE INVENTION
This invention generally relates to automatically moving doors. More particularly, this invention relates to controlling movement of an automatically moveable door.
DESCRIPTION OF THE RELATED ART
There are various automated door arrangements used in various contexts. In some instances, the automated door slides in a direction parallel to the door panel between open and closed positions. This type of arrangement is commonly used for providing access to an elevator car.
Whenever an automated door moves toward a position where an edge of the door approaches another structural member in a closed position, it is possible for an object to get caught between the door and the other structural member. Various arrangements have been proposed to avoid such a situation.
In the case of elevator doors, it has been known to use a safety shoe that mechanically detects an obstacle near a closed position of a door by including a bar at the leading edge of the door. If an obstacle contacts the bar, that provides an indication that the door should not be fully closed automatically to allow for the obstacle to be removed so that it will not be caught between the door and another surface. Another example approach has been to use light-based detectors that generate a sensing light beam across an opening. If an obstacle is within the opening while a door is automatically closing and interrupts the light beam, the door will not be fully closed automatically to avoid the object being caught by the door.
There are limitations to such devices. For example, the safety shoe bar typically is not sensitive enough to detect relatively small objects such as a strap on a handbag or an individual finger. Additionally, such small objects may get caught if they are not located at the same position as the bar of the safety shoe. The light-based detectors are also limited in that an object may not be within the field of vision (e.g., the light beam) even though the object is in a position where it can be caught by the door. Another drawback to known light-based arrangements is that they are typically exposed to dust or debris that can interfere with proper operation. Another potential issue is presented if other light sources interfere with the detectors.
Another shortcoming of such devices is that they only address the possibility of an object being caught at the leading edge of the door as it moves toward a closed position.
It would be desirable to provide an improved arrangement for detecting when an object may be in a position to be caught by a door that is automatically moving. It would be beneficial to provide an arrangement that can detect the potential for an object being caught when a door is automatically moving toward a closed position, toward an open position or both. This invention addresses those needs.
SUMMARY OF THE INVENTION
An exemplary door assembly includes a door panel that is automatically moveable between open and closed positions. At least one switch is activated responsive to an increase in a gap at an interface between the door panel and another surface that the door panel moves past while the door panel moves between the open and closed positions. A controller controls automatic movement of the door responsive to activation of the switch.
In one example, the switch is supported on the door and is activated responsive to movement of the door panel away from the surface the door moves past. The switch is activated when the door panel moves in a direction generally perpendicular to a direction of movement of the door panel as it moves between the open and closed positions.
One example includes two switches. One switch is activated when a first amount of pressure is applied to the door panel. This switch provides an indication that an object may be in a position where it could become caught at the interface between the door panel and the other surface. Another switch is activated responsive to more pressure on the door panel. This other switch provides an indication that an object has become caught at the interface.
Another example includes a switch supported on a return panel associated with a door frame. In one example, the return panel has at least one portion that flexes or moves responsive to pressure applied by an object approaching or caught in the interface between the door and the return panel.
An exemplary method of automatically controlling movement of the door panel includes determining whether a gap increases at an interface between the door panel and another surface that the door panel moves past as the door panel moves between open and closed positions. If the gap increases, an indication that an object should be moved away from the interface can be provided, automatic movement of the door panel can be at least temporarily prevented, the door panel may be automatically moved in a first direction and then in a second, opposite direction, or a combination of more than one of these may be done responsive to determining that the gap has increased.
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates an example door assembly.
FIG. 2 schematically illustrates one example sensor placement.
FIG. 3 schematically illustrates another example sensor placement.
FIG. 4 schematically illustrates another example sensor placement.
FIG. 5 is a flowchart diagram summarizing one example control strategy useful in an embodiment of this invention.
FIG. 6 is a flowchart diagram summarizing another example control strategy.
FIG. 7 is a flowchart diagram summarizing another example control strategy.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Disclosed examples include a sensor on at least one of a door panel or a door frame that allow for detecting when a gap between the door panel and the door frame is caused by an object being in a position relative to the door panel or door frame where the object may be caught during automatic movement of the door panel relative to the frame. With the example approach, a wider variety of objects may be reliably detected and a larger number of scenarios within which an object may be caught during automatic door movement can be addressed.
FIG. 1 schematically shows selected portions of an example door assembly 20 . Door panels 22 are automatically moveable between open and closed positions within an opening 24 . The example of FIG. 1 shows the door panels 22 in a closed position. In the illustrated example, each door panel 22 moves relative to a return panel 26 as the door panels 22 move between the open and closed positions. The return panel 24 is part of the door frame in this example and is adjacent a pocket for receiving the door panel 22 in the open position.
FIG. 2 schematically represents an end view of a door assembly as shown in FIG. 1 . Such an arrangement may be useful as an elevator door on the elevator car side or the hoistway side, for example. Each of the door panels 22 in this example includes a first switch 30 that is supported on the door panel 22 . In this example, the first switch 30 comprises a microswitch that operates in a known manner to provide an electrical output upon switch activation. In this example, an arm 32 of the first switch 30 is positioned relative to a first side 34 of the door panel 22 , which faces the interface 28 . In the illustrated example, at least a portion of the first switch 30 is physically supported to remain stationary relative to a second surface 36 of the door panel 22 .
Whenever pressure is applied on the first surface 34 , there will be some flexing or movement of the first surface 34 relative to the second surface 36 . In one example, this occurs because of the material used for the first surface 34 . A sheet of metal, for example, has some resiliency or flexibility such that it can be deflected toward the second surface 36 when pressure is applied onto the first surface 34 (e.g., from the bottom according to the drawing). The first switch 30 is positioned to detect such pressure on the first surface 34 and the switch arm 32 moves responsive to such pressure-induced movement of the first panel 34 .
The switch 30 provides an output indicative of the detected movement of the first surface 34 responsive to an object applying pressure against the first surface 34 . The output signal from the switch 30 is provided to a controller 40 that responsively controls automatic movement of the door assembly by controlling a door mover 42 . Example control strategies are described below.
In one example, the first switch 30 is configured to provide an indication of an amount of movement of the door panel 22 , such as movement of the first surface 34 relative to the return panel 26 , that corresponds to an increase in the gap at the interface 28 between the door panel 22 and the return panel 26 . An increase in the gap may correspond to deflection of the first surface 34 or movement of the entire door panel 22 in a direction that corresponds to an increase in the gap at the interface 28 . The increase will occur in some cases at only a localized portion of the interface 28 . Depending on the object, the gap along the entire interface 28 may change.
Microswitches are used in one example because they have the ability to provide a significant electrical output responsive to a very minor change in position of a switch component. In other words, microswitches are used in one example because of the ability to detect very small changes in a gap between the door panel 22 and the return panel 26 at the interface 28 .
The example door panels 22 also include a second switch 50 . An activating switch arm 52 in this example, moves responsive to a deflection or movement of the first surface 34 corresponding to increased pressure on the first surface 34 compared to the amount of pressure applied to cause the movement for activating the switch 30 . The switch 50 in this example provides a second level of object detection. Further movement of the first surface 34 in many circumstances will correspond to an object becoming caught at the interface 28 resulting in the increased pressure on and corresponding increased movement of the surface 34 . The second switch 50 provides an output to the controller 40 indicative of this condition.
FIGS. 1 and 2 show one example door arrangement. Another example is schematically shown in FIG. 3 . In this arrangement, the first switch 30 and the second switch 50 are supported on the return panel 26 . In this example, a portion 60 of the return panel 26 is flexible or moveable from a standard position responsive to an object approaching or getting caught in the interface 28 during automated door movement, for example. The illustrated example includes a portion 60 that is supported relative to a remainder of the return panel 26 so that the portion 60 can move between a rest position (shown in solid line) to a deflected position (shown in phantom in the drawing).
A first amount of movement or deflection of the portion 60 activates the switch 30 to provide an indication that an object is approaching the interface 28 . The second switch 50 is configured to provide an indication when a further deflection occurs corresponding to an object becoming caught at the interface 28 . As can be appreciated from the illustration, when the portion 60 moves from the position shown in solid lines to the position shown in phantom lines, the corresponding gap between the return panel 26 and the door panel 22 increases. The first switch 30 and the second switch 50 are supported and configured to provide respective indications of an initial amount of an increase in the gap and a further increase. The two switches provide corresponding outputs indicating conditions that are interpreted by the controller 40 as corresponding to an object being at the interface 28 or caught I the interface 28 .
FIG. 4 shows another example arrangement where first sensor 30 and a second sensor 50 are provided on door panels 22 A and 22 B. In this example, the door panel 22 A is a so-called high speed door panel and the door panel 22 B is a so-called low speed door panel. There is an interface 28 between the door panel 22 B and the return panel 26 . There is another interface 28 ′ between the door panels 22 A and 22 B. During movements between open and closed positions there is relative movement between the door panels 22 A and 22 B and between the door panel 22 B and the return panel 26 . The first switches 30 and second switches 50 allow for detecting an increase in the gap at either interface 28 or 28 ′ in the event that an object applies pressure against the corresponding door panel 22 A or 22 B.
FIG. 5 includes a flow chart diagram 70 summarizing one example control approach for controlling automated movement of a door panel responsive to an indication from at least one of the switches 30 , 50 regarding an object near or in the interface 28 . A decision is made at 72 whether the door panel of interest is stationary. If so, a decision is made at 74 whether the door is about to open. If not, the example of FIG. 5 allows for overriding or ignoring an output from one of the switches 30 or 50 under conditions where there is no likelihood that an object is going to become caught at the interface 28 because the door is not moving or not about to move.
In the event that the door is about to move, a decision is made at 76 whether the first switch 30 has been activated. If so, the example of FIG. 5 includes issuing an audible warning at 78 and a visual warning at 80 to advise an individual that there is an object in a position relative to the door panel 22 where the object may get caught during door movement. Other examples include only a visual warning. Still other examples include using only an audible warning. In one example, after the appropriate warning has been provided, a selected amount of time is allowed to elapse before commencing door movement.
In the example of FIG. 5 , when the door panel is moving (e.g., a negative result at the decision 72 ), a decision is made whether at least the first switch 30 has been activated at 82 . If so, the door stops at 84 and a timer begins to allow a predetermined amount of time to pass. A decision at 86 is made whether that time has passed. If not, the example of FIG. 5 includes continuing to monitor whether the switch is still activated indicating that an object is still in a position where it may be or is caught at the interface 28 . Once the appropriate amount of time has passed or the switch is no longer activated, a decision is made at 88 whether a door close instruction has issued. If so, the door is closed at 90 . If not, the door continues opening at 92 .
FIG. 6 includes a flow chart diagram 100 illustrating one example approach for responding to an indication from the first switch 30 regarding the presence of an object in a position where it may become caught at the interface 28 . In other words, the flow chart diagram 100 in the example of FIG. 6 summarizes one example approach for responding to an increase in the gap at the interface 28 that is small enough to only activate the first switch 30 . In this example, a decision is made at 102 whether the door is being opened. If not, a command is issued at 104 to ensure that the doors are fully closed. If the doors are being opened, a determination is made at 106 whether the first switch 30 has been activated. If so, the door stops moving at 108 . A timer begins running at 110 to allow for a predetermined amount of time to lapse before the door is allowed to move again. At 112 , a decision is made whether that time has passed. Until it has, the door remains stationary. After the time has passed, the door continues opening at 114 . During the time between stopping the door and opening the door, it is possible to provide at least one of an audible or visual warning to move an object away from the door panel 22 to reduce the risk of being caught at the interface 28 .
In some circumstances, enough pressure is applied on the door panel 22 to increase the gap between the door panel 22 and the return panel 26 , for example, to activate the second switch 50 . As mentioned above, the second switch 50 preferably is configured to be activated responsive to an amount of movement of the door panel 22 corresponding to an object being caught in the interface 28 . The example of FIG. 7 includes a flowchart diagram 120 summarizing one approach for responding to an output from the second switch 50 . In this example, if the door is not being opened a command to make sure the door is closed is issued at 104 .
If the second switch 50 has been activated at 126 , the door stops moving at 128 . A timer begins at 130 to allow for a predetermined amount of time to pass before the door will continue moving in an opening direction. In this example, the determination regarding that amount of time is made at 132 . If that amount of time has not passed, a command is issued at 136 to move the door in a closing direction for a short period of time to assist in removing any object that was caught at the interface 28 . In this example, the determination at 132 includes determining whether the amount of time for moving the door in the closed direction has passed, also. Once that has passed, the door continues opening at 134 .
In one example, continued movement of the door in the opening direction is carried out at a lower speed and with less torque than would have been done if no indication was provided from either the first switch 30 or the second switch 50 . In other words, one aspect of the example technique for controlling automatic door movement includes reducing the speed and torque used for opening a door responsive to activation of at least one of the switches to provide additional protection to the object involved. Using lower speed and lower torque also facilitates allowing for an object to be removed from the interface 28 in the event that it became caught but could not be freed during the reversed movement of the door in the closing direction for the short period of time.
The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.
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An assembly ( 20 ) for controlling movement of an automatically moveable door panel ( 22 ) includes sensors ( 30, 50 ) such as microswitches positioned on at least one of a door panel ( 22 ) or a door frame member ( 26 ). The sensors provide an indication of different levels of relative movement between the door panel and the door frame member at an interface ( 28 ) between them. Such relative movement includes an increase in a gap between them that corresponds to a situation when an object is at the interface ( 28 ) and may be caught. The sensors ( 30, 50 ) respectively provide an indication of when an object may become caught and when one has. Automated movement of a door is controlled responsive to an indication of the presence of an object in a location where the object may become caught during automatic movement of the door.
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RELATED APPLICATION DATA
The instant application claims priority to U.S. provisional application Ser. No. 61/774,131 filed Mar. 7, 2013, the subject matter of which is incorporated herein by reference in its entirety.
BACKGROUND
Aspects and embodiments of the invention are directed to item handling systems, methods, and applications thereof. More particularly, a storage, dispensing, and receiving system and associated methods adapted for seismic sensors (nodes). Most particularly, a storage, dispensing, and receiving system and associated methods adapted for nodes in a marine environment. A seismic sensor (‘node’) handling system is described in co-owned U.S. Pat. No. 8,087,848. The '848 patent describes a node storage device comprised of a series of independently actuatable conveyor sections horizontally oriented one above the other at different, fixed heights above the back deck of the ship. These sub-systems are replicated side-by-side and end-to end so as to provide storage for, and more importantly fast access to, a large number of nodes. The speed with which nodes can be delivered to the node deployment/recovery workstation limits in part the maximum speed at which the entire node deployment/recovery operation can be conducted, including vessel speed. The main reason each node has a place on an independently actuatable conveyor is for speedy access and (horizontal) transit.
While this system has been employed successfully, there are recognized shortcomings in its design. There is vast amount of machinery to purchase, install, and maintain related to the conveyors themselves. Each conveyor belt has its own motors, gears, sprockets, bearings, and slip surfaces. Since each belt is continuous, it traverses the length of the storage rack twice. In one installation almost two miles of conveyor belt are required to store fewer than 3000 nodes. The physical space required for the storage and conveyance structures presents another issue. The nodes themselves are heavy, requiring the conveyor mechanism on which they rest to be of substantial mechanical strength. The conveyors, at a minimum, must be separated vertically by S=the sum of: 1) the height of the nodes; 2) the height of the conveyor machinery; and 3) space for the belt to traverse the return path beneath the conveyor machinery without interference. In many instances the conveyors and their related machinery may consume more space than the nodes themselves. This drastically reduces the density of node storage possible in a given space. For any given number of nodes this may require a larger vessel than might otherwise be necessary and the substantial cost associated therewith.
For these reasons and others appreciated by those skilled in the art, there exists a need for a node storage, dispensing, and receiving apparatus and method that maintains current or provides improved speed of access, and further provides higher storage density and reduced complexity and machinery to purchase, install, and maintain than available under the current state of the art.
Definitions as Used Herein
The term ‘about’ means the amount of the specified quantity plus/minus a fractional amount (e.g., ±10%, ±9%, ±8%, ±7%, ±6%, ±5%, ±4%, ±3%, ±2%, ±1%, etc.) thereof that a person skilled in the art would recognize as typical and reasonable for that particular quantity or measurement. Likewise, the term ‘substantially’ means as close to or similar to the specified term being modified as a person skilled in the art would recognize as typical and reasonable; for e.g., within typical manufacturing and/or assembly tolerances, as opposed to being intentionally different by design and implementation.
SUMMARY
The most general aspects of the invention are an item storage, dispensing, and receiving apparatus and method.
An aspect of the invention is an item storage, dispensing, and receiving apparatus that includes a frame assembly having a height, H, and a length, L, including at least one section thereof having two opposing side wall sections, wherein each opposing side wall section includes a plurality of vertically spaced rails disposed on an inner surface thereof such that each rail on a respective side wall section is disposed opposite a corresponding rail on the opposing side wall section, further wherein the at least one section has an open space fully extending intermediate the plurality of vertically spaced rails between the two opposing side wall sections over the height H and the length L, and one or more conveyance mechanisms operatively disposed within the open space along at least a portion of the length L, wherein the one or more conveyance mechanisms are movable in a vertical direction traversing the open space along the height H. According to various exemplary, non-limiting embodiments, the method may include the following additional steps, features, limitations, and/or characteristics:
wherein the plurality of vertically spaced rails are rigidly attached to the frame assembly such that the frame assembly is characterized by having no moving parts; wherein the one or more conveyance mechanisms comprise powered conveyor belts and are coupled to one or more lifting mechanisms adapted to controllably position the one or more conveyance mechanisms in the vertical direction in the open space along the height H of the frame assembly;
wherein the one or more lifting mechanisms are disposed below the one or more respective conveyance mechanisms; wherein the one or more respective lifting mechanisms are disposed on a portion of the frame assembly;
further comprising a track disposed in the open space adjacently below a lowest corresponding set of rails of the frame assembly along at least a portion of the length L, wherein the one or more conveyance mechanisms are movably coupled to the track; wherein the frame assembly has an item-input/output end, further comprising a bridge conveyance mechanism having a first end and a second end, further wherein one of the first end and the second end of the bridge conveyance mechanism is operatively coupled to a leading one of the one or more conveyance mechanisms at the input/output end of the frame assembly such that as the one or more conveyance mechanisms move in a vertical direction traversing the open space along the height H, the bridge conveyance mechanism pivots about the other of the first end and the second end thereof so as to provide a continuous path between the leading one of the one or more conveyance mechanisms at the input/output end of the frame assembly and the bridge conveyance mechanism; further comprising at least two of the frame assemblies and respective one or more conveyance mechanisms disposed immediately sideways adjacently; wherein each of the frame assemblies has an item-input/output end, further comprising a bridge conveyance mechanism having a first end and a second end, further wherein one of the first end and the second end of the bridge conveyance mechanism is operatively coupled to a leading one of the one or more conveyance mechanisms of one of the at least two of the frame assemblies at the input/output end thereof such that as the one or more conveyance mechanisms move in a vertical direction traversing the open space along the height H, the bridge conveyance mechanism pivots about the other of the first end and the second end thereof so as to provide a continuous path between the leading one of the one or more conveyance mechanisms of one of the at least two of the frame assemblies at the input/output end and the bridge conveyance mechanism, further wherein the bridge conveyance mechanism is laterally repositionable such that it can be operatively coupled to the leading one of the one or more conveyance mechanisms of the other one of the at least two of the frame assemblies at the input/output end thereof; further comprising a plurality of the immediately sideways adjacent at least two of the frame assemblies and respective one or more conveyance mechanisms disposed sideways adjacently;
wherein each of the frame assemblies has an item-input/output end, further comprising a plurality of bridge conveyance mechanisms each having a first end and a second end, further wherein one of the first end and the second end of each of the bridge conveyance mechanisms is operatively coupled to a leading one of the plurality of the immediately sideways adjacent at least two of the frame assemblies and respective one or more conveyance mechanisms at the input/output ends thereof such that as the one or more conveyance mechanisms move in a vertical direction traversing the open space along the height H, each of the respective bridge conveyance mechanisms pivots about the other of the first end and the second end thereof so as to provide a continuous path between the leading ones of the one or more conveyance mechanisms of one of the plurality of the frame assemblies at the input/output ends and the bridge conveyance mechanisms, further wherein the bridge conveyance mechanisms are laterally repositionable; wherein each of the frame assemblies has an item-input/output end, further comprising a different conveyance mechanism disposed adjacently transverse to the input/output ends of the plurality of the immediately sideways adjacent at least two of the frame assemblies;
wherein the different conveyance mechanism comprises a plurality of linearly adjacent conveyance mechanisms aligned in a horizontal plane;
further comprising a plurality of hanging arms each pivotally connected at a region thereof to an activation member that is connected to the frame assembly, wherein each of the plurality of rails is fixedly attached to a distal region of each of the hanging arms, further wherein at least portions of the side walls have cut-out regions such that, upon activation of the activation member, the rails are movable into and out of the cut-out regions such that the rails are, respectively, disposed out of or in the open space; the apparatus replicated end on end; further wherein only a single conveyance mechanism is disposed in the open space traversable by the respective one or more conveyance mechanisms; further wherein the one or more conveyance mechanisms that are movable in a vertical direction traversing the open space along the height H of the frame assembly are disposed in vertical opposition; wherein the item is one or more seismic sensor nodes, movably disposed on the rails.
An aspect of the invention is an item storage, dispensing, and receiving apparatus including a frame assembly having a height, H, and a length, L, including at least one section thereof having two opposing side wall sections, wherein each opposing side wall section includes a plurality of vertically spaced rails disposed on an inner surface thereof such that each rail on a respective side wall section is disposed opposite a corresponding rail on the opposing side wall section, further wherein the at least one section has an open space fully extending intermediate the plurality of vertically spaced rails between the two opposing side wall sections over the height H and the length L; a track disposed adjacent a top of the frame assembly over the open space along at least a portion of the length L; and a horizontal conveyance mechanism moveably coupled to the track, wherein the conveyance mechanism is further moveable in a vertical direction traversing the open space along the height H. According to various exemplary, non-limiting embodiments, the method may include the following additional steps, features, limitations, and/or characteristics:
wherein the conveyance mechanism includes a hanger member adapted to engage the item for movement.
An aspect of the invention is an item moving method for moving at least one of a plurality of items vertically disposed in tiered, spaced relation including the steps of vertically moving an item conveyance mechanism from at least one of a position below a lowest tiered item until it engages the item and from a position above a highest tiered item until it engages the item; and horizontally conveying the engaged item to a location different than the horizontal engagement location of the item.
It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 schematically illustrates a rigid frame or rack portion or section and an associated conveyance mechanism of an item storage, dispensing, and receiving apparatus, according to an illustrative aspect of the invention.
FIG. 2 schematically illustrates the apparatus of FIG. 1 with a plurality of items (nodes) situated therein, according to an illustrative aspect of the invention.
FIG. 3 schematically illustrates an operation mode of the conveyance mechanism illustrated in FIG. 1 , according to an illustrative aspect of the invention.
FIG. 4 schematically illustrates an in-line, end-to-end replication of the apparatus of FIG. 1 , according to an illustrative aspect of the invention.
FIG. 5 schematically illustrates the in-line, end-to-end replication of the apparatus of FIG. 4 further replicated side-by-side, according to an illustrative aspect of the invention.
FIG. 6 schematically illustrates an exemplary item storage, dispensing, and receiving apparatus with conventional conveyance mechanism for unloading and dispensing the items, according to an illustrative aspect of the invention.
FIGS. 7 a , 7 b schematically illustrate details about the rack portion of the apparatus shown in FIG. 1 , according to an illustrative aspect of the invention.
FIGS. 8 a , 8 b schematically illustrate an alternative embodiment of an item storage, dispensing, and receiving apparatus, according to an illustrative aspect of the invention.
FIGS. 9 a , 9 b , 9 c schematically illustrate an operational sequence of the apparatus of FIG. 8 , according to an illustrative aspect of the invention.
FIGS. 10 a , 10 b are photographs of a fully implemented item storage, dispensing, and receiving apparatus, according to an illustrative aspect of the invention.
FIG. 11 schematically illustrates a lateral conveyor disposed in front of additional rows of storage racks enabled by the invention, according to an illustrative aspect of the invention.
FIGS. 12-14 schematically illustrate alternative aspects of item transport mechanisms, according to illustrative aspects of the invention.
DETAILED DESCRIPTION
FIG. 1 illustrates at least a portion (e.g., a section) of a rigid frame or rack 510 having no moving parts and constructed as indicated, looking much like a baker's rack; that is, a series of spaced vertical support members are connected by spaced horizontal supports 511 (e.g., angle iron geometry forming opposing walls, providing a solution to the aforementioned problems. The spaced horizontal supports include horizontal shelf sections 599 (see also FIG. 7 a ) that can support an item (e.g., a node) at its edge (see also FIG. 7 b ) and thus a plurality of items in a tiered fashion (five tiers shown in FIG. 1 for example only). The rack 510 may be made steady affixed to the floor or bottom of the ship deck, or to a bottom structure and at the top by an upper structure, e.g., an overhead deck (not shown). The rack 510 may be constructed of inexpensive metal angle and pipe, welded, or a suitable plastic or other material. Advantageously, in the embodied aspect there are no moving parts to the rack and the racks may be easily and inexpensively mass-produced.
Nodes 110 are supported on the horizontal supports 511 at their edges alone, the center of the rack, i.e., the space intermediate the opposing walls, being completely open as illustrated in FIG. 2 . Given this property, nodes on any tier (level) can be accessed by a horizontal conveyance mechanism 520 (e.g., a single conveyor belt as shown) whose vertical position within the open space between the walls can be adjusted. The horizontal supports 511 thus need be spaced no further apart than the nominal height of a node (or other ‘item’), permitting much denser vertical storage than the belt-per-level arrangement in present systems such as described in the aforementioned US '848 patent. Each tier shares the same horizontal transport mechanism by virtue of the vertically repositionable conveyance mechanism 520 , reducing by a factor of N (where N is number of tiers) the amount of transport machinery to purchase, install and maintain. If the node height is h and the vertical separation of tiers (in conveyor-per-level configuration) is S, vertical node density is increased approximately 1+S/h. For example, node density on assignee's marine vessel was increased by a factor of 2.26; from 1800 nodes to over 4000.
As illustrated in FIG. 3 , the horizontal conveyance mechanism 520 can be elevated to engage nodes on any tier. The elevation mechanism may be, e.g., one or more scissor jacks 530 as shown, but other elevating mechanisms could be used (covered subsequently).
In a particular aspect, only a single vertically movable conveyance mechanism is disposed in the open space traversable by the respective one or more conveyance mechanisms; that is, for any given number of conveyance mechanisms disposed along the length of a rack or racks, only a single conveyance mechanism occupies the open space vertically serviceable by the given conveyance mechanism.
FIG. 4 illustrates an in-line, end-to-end replication of racks 510 a , 510 b . One can see that activation of the belts will pass nodes from rack to rack and eventually off/on to/from the movable conveyor 232 (also called the bridge). Bridge 232 is adjustable through some angle α such that its first end 232 a reaches all item tiers and allow the nodes to move from their storage level 515 to/from the working conveyor transport level 236 at the conveyor's second end 232 b.
The racks can be replicated side-by-side ( FIG. 5 ) wherein each row might share a transversely movable bridge 232 to carry nodes to the working transport level 236 . Such pairs may be further replicated side-by-side with nominal intervening space for service access as illustrated in FIG. 6 . This rack replication pattern may be continued as required in both X and Y directions, where all rows are serviced by one or more movable bridges 232 .
As shown in FIG. 6 , the bridge conveyor(s) 232 take substantial space across the entire width of the vessel or area where the racks are located, whether laterally movable to service multiple racks or not. An alternative embodiment is illustrated with reference to FIGS. 8, 9, 10 .
As described above, the rack 510 is composed of horizontal angle support members 511 that are rigidly affixed to the vertical support members 512 as further indicated in FIG. 7 a . Nodes 110 are supported on those fixed horizontal angles as indicated in FIG. 7 b.
As illustrated in FIGS. 8 a , 8 b , the horizontal angle support members 511 are affixed to a hanging arm 513 that can pivot on vertical support members 512 ; the vertical support members 512 are cut away sufficiently as shown to allow the horizontal supports 511 to be drawn back; an activation rod 516 is rigidly connected to a cam 515 and that cam is flexibly affixed to a coupling link 514 , which couples the cam 515 to the hanging arm 513 . Rotating the activation rod 516 will cause the horizontal supports 511 to be drawn back away from the open center area of the assembly and retracted into the cut-away regions ( FIG. 8 b ).
FIG. 9 a is the front view of the apparatus of FIG. 8 illustrating the embodied method of operation. The horizontal conveyance mechanism 520 is raised in FIG. 9 b until it engages the lowest tiered node(s) 110 and raises them from contact with the horizontal angle support members 511 . The horizontal angle support members 511 are retracted by rotating activation rod 516 , leaving the nodes free to be moved vertically down (or up) via the down/up movement of the conveyor 520 ( FIG. 9 c ) and ultimately to the working transport level 236 ( FIG. 6 ).
FIGS. 10 a , 10 b are photographs of a fully implemented retractable rail rack 550 as described above. To illustrate the aforementioned point that the horizontal conveyance mechanism 520 can be raised and lowered by other means than a scissors mechanism, in the case implemented the horizontal conveyance mechanism 520 is lifted and lowered on chain 534 by gearbox and motors 532 atop the racks. For added illustration and not limitation, the horizontal conveyance mechanism 520 may be lifted by a worm gear, rack and pinion, or other suitable, known mechanical means.
FIG. 11 illustrates a conveyor 236 disposed laterally in front of additional rows of storage racks 550 that occupy the space previously needed for the bridge conveyors 232 ( FIG. 6 ) because the racks 550 are themselves able to raise or lower nodes to the working conveyor transport level 236 .
FIGS. 12-13 schematically illustrate alternative aspects of item transport mechanisms. As illustrated in FIGS. 12 a , 12 b , the vertically movable conveyance mechanism 520 , rather than (or in addition to) horizontally moving items using a movable conveyor belt, itself can be moved on rails 610 affixed, e.g., to the deck ( FIG. 12 b ).
A related embodiment is schematically illustrated in FIGS. 13 a and 13 b , which illustrate a different horizontal conveyance mechanism 520 . Rails (or tracks) 610 are provided above the open space of the racks 510 . A horizontal conveyance mechanism 520 is movably attached to the rails/tracks and can be vertically raised and lowered by, e.g., the illustrated scissors mechanism. As illustrated, the conveyance mechanism may comprise fingers or hanger members 633 that can engage one or more nodes 110 and slide them along the horizontal support members 511 , which might be made of, or covered with, a low friction material (not shown).
In an embodiment, the system may include both a top-mounted, vertically movable conveyance mechanism as illustrated, e.g., in FIG. 13 and a bottom-mounted, vertically movable conveyance mechanism as illustrated, e.g., in FIG. 1-7, 8-11 , or 12 . Accordingly, the one or more conveyance mechanisms that are movable in a vertical direction traversing the open space along the height H of the frame assembly may be disposed in vertical opposition, such that items in a lowest tier adjacent the bottom-mounted conveyance mechanism can be conveyed via the bottom-mounted conveyance mechanism and items in a highest tier adjacent the top-mounted conveyance mechanism can be conveyed via the top-mounted conveyance mechanism.
FIG. 14 a illustrates another ultra-dense storage apparatus and method embodiment. In this arrangement, inclined planes with no machinery or moving parts are disposed in vertical spaced relation with curved end panels as shown. Rounded/rollable items can thus be transported by gravity alone. Because there are no moving parts or wearing surfaces, no service access needs to be provided, so the racks can abut each other side-by-side to provide very dense storage ( FIG. 14 b ).
While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.
All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.
The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.” The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.
As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.
As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.
It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited. In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.
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An item storage, dispensing, and receiving apparatus includes a frame assembly having a height and length, including at least one section thereof having two opposing side wall sections, wherein each opposing side wall section includes vertically spaced rails disposed on an inner surface thereof such that each rail on a respective side wall section is located opposite a corresponding rail on the opposing side wall section, further wherein the at least one section has an open space fully extending between the vertically spaced rails between the two opposing side wall sections over the height and length, and a conveyance mechanism located within the open space along at least a portion of the length, wherein the conveyance mechanism is movable in a vertical direction in the open space along the height. A method for moving an item in a tiered, spaced relation involves the steps of vertically moving an item conveyance mechanism from a position below a lowest tiered item until it engages the item or from a position above a highest tiered item until it engages the item, and horizontally conveying the engaged item to a location different than the horizontal engagement location of the item.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 191,635 filed Feb. 4, 1994 now U.S. Pat. No. 5,527,381.
BACKGROUND OF THE INVENTION
I. Field of the Invention
This invention relates to a method and apparatus for the treatment of molten metals with a gas prior to casting or other processes involving metal cooling and solidification. More particularly, the invention relates to the treatment of molten metals in this way to remove dissolved gases (particularly hydrogen), non-metallic solid inclusions and unwanted metallic impurities prior to cooling and solidification of the metal.
II. Description of the Prior Art
When many molten metals are used for casting and similar processes they must be subjected to a preliminary treatment to remove unwanted components that may adversely affect the physical or chemical properties of the resulting cast product. For example, molten aluminum and aluminum alloys derived from alumina reduction cells or metal holding furnaces usually contain dissolved hydrogen, solid non-metallic inclusions (e.g. TiB 2 , aluminum/magnesium oxides, aluminum carbides, etc.) and various reactive elements (e.g. alkali and alkaline earth metals). The dissolved hydrogen comes out of solution as the metal cools and forms unwanted porosity in the product. Non-metallic solid inclusions reduce metal cleanliness and the reactive elements and inclusions create unwanted metal characteristics.
These undesirable components are normally removed from molten metals by introducing a gas below the metal surface by means of gas injectors. As the resulting gas bubbles rise through the mass of molten metal, they adsorb gases dissolved in the metal and remove them from the melt. In addition, non-metallic solid particles are swept to the surface by a flotation effect created by the bubbles and can be skimmed off. If the gas used for this purpose is reactive with contained metallic impurities, the elements may be converted to compounds by chemical reaction and removed from the melt in the same way as the contained solids or by liquid-liquid separation.
This process is often referred to as "metal degassing", although it will be appreciated from the above description that it may be used for more than just degassing metals. The process is typically carried out in one of two ways: in the furnace, normally using one or more static gas injection tubes; or in-line, by passing the metal through a box situated in the trough normally provided between a holding furnace and the casting machine so that more effective gas injectors can be used. In the first case, the process is inefficient and time consuming because large gas bubbles are generated, leading to poor gas/metal contact, poor metal stirring and high surface turbulence and splashing. Dross formation and metal loss result from the resulting surface turbulence, and poor metal stirring results in some untreated metal. The second method (as used in various currently available units) is more effective at introducing and using the gas. This is in part because the in-line method operates as a continuous process rather than a batch process.
For in-line treatments to work efficiently, the gas bubbles must be in contact with the melt for a suitable period of time and this is achieved by providing a suitable depth of molten metal above the point of injection of the gas and by providing a means of breaking up the gas into smaller bubbles and dispersing the smaller bubbles more effectively through the volume of the metal, for example by means of rotating dispersers or other mechanical or non-mechanical devices. Residence times in excess of 200 seconds and often in excess of 300 seconds are required in degassers of this type to achieve adequate results. Effectiveness is frequently defined in terms of the hydrogen degassing reaction for aluminum alloys and an adequate reaction is generally considered to be at least 50% hydrogen removal (typically 50 to 60%). This results in the need for deep treatment boxes of large volume (often holding three or more tons of metal) which are unfortunately not self-draining when the metal treatment process is terminated. This in turn gives rise to operational problems and the generation of waste because metal remains in the treatment boxes when the casting process is stopped for any reason and solidifies in the boxes if not removed or kept molten by heaters. Moreover, if the metals or alloys being treated are changed from time to time, the reservoir of a former metal or alloy in a box (unless it can be tipped and emptied) undesirably affects the composition of the next metal or alloy passed through the box until the reservoir of the former metal is depleted. Various conventional treatment boxes are in use, but these require bulky and expensive equipment to overcome these problems, e.g. by making tie box tiltable to remove the metal and/or by providing heaters to keep the metal molten. As a consequence, the conventional equipment is expensive and occupies considerable space in the metal treatment facility. Processes and equipment of this type are described, for example, in U.S. Pat. Nos. 3,839,019 and 3,849,119 to Bruno et al; U.S. Pat. Nos. 3,743,263 and 3,870,511 to Szekeley; U.S. Pat. No. 4,426,068 to Gimond et al; and U.S. Pat. No. 4,443,004 to Hicter et al. Modern degassers of this type generally use less than one litre of gas per kilogram (Kg) of metal treated. In spite of extensive development of dispersers to achieve greater mixing efficiency, such equipment remains large, with metal contents of at least 0.4 m 3 and frequently 1.5 m 3 or more being required. One or more dispersers such as the rotary dispersers previously mentioned may be used, but for effective degassing, at least 0.4 m 3 of metal must surround each disperser during operation.
To avoid problems associated with deep treatment boxes, there have been a number of attempts at metal treatment in shallow vessels such as the trough normally provided between a metal holding furnace and a casting machine. This would provide a vessel which could drain completely after use and thus avoid some of the problems associated with the deep box treatment units. The difficulty is that this would inevitably require a reduction of the metal depth above the point of gas injection while still allowing for effective gas/metal contact times. The use of gas diffusion plates or similar devices in the bottom of such shallow vessels or troughs has been proposed to introduce the gas and create the desired gas/metal contact. These are described, for example, in U.S. Pat. No. 4,290,590 to Montgrain and U.S. Pat. No. 47,714,494 to Eckert. However, bubbles produced in this way still tend to be too large and, given the reduced metal depth, such vessels or troughs necessarily must be made undesirably long to achieve effective degassing, and the volume of gas introduced must be made quite high (typically over 2 litres/Kg). As a result, the apparatus takes up a lot of floor space and the volume of gas introduced creates a risk of chilling the metal so that it may be necessary to provide compensating heaters. Such trough degassers can be drained, but because of large bubble size they still require long residence times to effectively treat metal to the same degree of efficiency as obtained with other in-line methods. In addition, the introduction of large gas bubbles into a shallow metal volume results in excess surface turbulence and splashing. As a result, degassing in shallow troughs is not generally carried out on an industrial scale.
Thus there is a need for a metal treatment method and apparatus that provides effective treatment in short time periods, with correspondingly small volumes of metal, and with low gas consumption. Such processes and equipment would then be able to be carried out in metal delivery troughs with all the advantages of such devices that were noted above, but without the problems of high gas consumption or the space limitations noted.
OBJECTS OF THE INVENTION
An object of the invention is to enable gas treatment of molten metal to be carried out effectively in short time periods and correspondingly small volumes, using relatively low amounts of treatment gas.
Another object of the invention is to provide a method and apparatus for gas treatment of molten metal that can be carried out in small volumes of metal, and in particular in metal within metal delivery troughs or similar devices.
Another object of the invention is to provide a mechanical gas injection system that operates within a small volume of metal, such as found in a metal delivery trough or similar device to achieve effective gas treatment.
Another object of the invention, at least in its preferred aspects, is to provide a method and apparatus for gas treatment of molten metal that allows the metal to be drained substantially completely from the treatment zone after treatment is complete.
Yet another object of the invention is to provide a method and apparatus for gas treatment of molten metal that avoids the need for metal heaters and bulky equipment.
These and other objects and advantages of the present invention will be apparent from the following disclosure.
SUMMARY OF THE INVENTION
It has now surprisingly been found that it is possible to operate gas injectors in such containers, e.g. shallow troughs. In particular rotary gas injectors that generate a radial and horizontal flow of metal and operate at a rotational velocity sufficient to shear the gas bubbles are effective in such applications.
Thus, according to one aspect of the invention, there is provided a method of treating a molten metal with a treatment gas, comprising: introducing the molten metal into a container having a bottom wall and opposed side walls; providing at least one mechanically movable gas injector within the metal in the container; and injecting a gas into the metal in a part of the container forming a treatment zone via said at least one injector to form gas bubbles in the metal while moving said at least one injector mechanically to minimize bubble size and maximize distribution of said gas within said metal.
According to another aspect of the invention, there is provided apparatus for treating a molten metal with a treatment gas, comprising: a container having a bottom wall and opposed side walls for holding and conveying said molten metal; at least one gas injector in use positioned in said container submerged in said metal; means for rotating said gas injector about a central vertical axis thereof; and means for conveying gas to said injector for injection into said metal.
According to another aspect of the invention, there is provided an injector for injecting gas into a molten metal, comprising: rotor having a cylindrical side surface and a bottom surface; a plurality of openings in said side surface spaced symmetrically around the rotor, at least one opening in the bottom surface, and at least one internal passageway for gas delivery and an internal structure for interconnecting said openings in said side surface, said openings in said bottom surface and said at least one internal passageway; said internal structure being adapted to cause gas bubbles emanating from said internal passageway to break up into finer bubbles and to cause a metal/gas mixture to issue from said openings in said side surface in a generally horizontal and radial manner.
According to another aspect of the invention there is provided a method for treating a molten metal with a treatment gas, comprising: continuously introducing the molten metal into a container having a bottom wall and opposed side walls which form a section of a trough; providing at least one mechanically moveable gas disperser within the metal in the container; injecting a gas into the metal adjacent to said gas disperser in a part of said trough forming a treatment zone such that said gas is broken into smaller bubbles by said gas disperser and is dispersed through the treatment zone; said trough section being such that said section exhibits a static to dynamic metal holdup of less than about 50%.
According to yet another aspect of the invention there is provided an apparatus for treating molten metal with a treatment gas; comprising: a container having a bottom wall and opposed side walls forming a trough for conveying said molten metal; at least one gas disperser in use positioned in said container submerged in said metal; means for moving said disperser mechanically in a motion selected from the group consisting of rotation about a central vertical axis, oscillation, or vibration; at least one gas injector located adjacent to said at least one gas disperser; and means for conveying gas to said at least one injector for injection into said metal.
It is a surprising and unexpected feature of this invention that it is possible to operate gas dispensers or injectors in such a way as to disperse gas to generate the required gas holdup and gas-metal surface area within the constraints of the treatment segment, and further within a trough section. Prior art degasser methods generally do not achieve the high values of gas holdup and gas-metal surface area characteristic of the present invention. Furthermore, to maximize performance, prior art methods have relied on shear generation and mixing methods that have produced substantial splashing and turbulence which has required operation using treatment segments of significantly larger volume than the present invention. They therefore could not achieve the overall objective of effective degassing in short time periods.
The present invention makes it possible to treat a molten metal with a gas using a preferably rotary gas injector or dispenser while providing only a relatively small depth of metal above the point of injection of the gas and consequently permits effective treatment of metals contained in small vessels and, in particular, in metal delivery troughs typically used to deliver metal from a holding furnace to a casting machine. Such metal delivery troughs are generally open ended refractory lined sections and, although they can vary greatly in size, are generally about 15 to 50 cm deep and about 10 to 40 cm wide. They can generally be designed to drain completely when the metal supply is interrupted.
The invention, at least in its preferred forms, makes it possible to achieve gas treatment efficiencies, as measured by hydrogen removal from aluminum alloys, of at least 50% using less than one litre of treatment gas per Kg of metal, and to achieve reaction times of between 20 and 90 seconds, and often between 20 and 70 seconds.
In a preferred form of the invention, a metal treatment zone is provided within a metal delivery trough containing one or more generally cylindrical, rapidly rotating gas injection rotors, having at least one opening on the bottom, at least three openings symmetrically placed around the sides, and internal structure such that the bottom openings and side openings are connected by means of passages formed by the internal structure wherein molten metal can freely move; at least one gas injection port communicating with the passageway in the internal structure for injection of treatment gas into metal within the internal structure; wherein the internal structure causes the treatment gas to be broken into bubbles and mixed within the metal within the internal structure, and further causes the metal-gas mixture to flow from the side openings in a radial and substantially horizontal direction. It is further preferred that each rotor have a substantially uniform, continuous cylindrical side surface except in the positions where side openings are located, and that the top surface be closed and in the form of a continuous flat or frusto-conical upwardly tapered surface the top surface and side surfaces thereby meeting at an upper shoulder location. It is further preferred that the side openings on the surface sweep an area, when the rotor is rotated, such that the area of the openings in the side surface is no greater than 60% of the swept area.
It is further preferred that the rotors be rotated at a high speed sufficient to shear the gas bubbles in the radial and horizontal streams into finer bubbles, and in particular that the rotational speed be sufficient that the tangential velocity at the surface of the rotors be at least 2 metres/sec at the location of the side openings. Each rotor must be located in specific geometric relationship to the trough, and preferably with the upper shoulder of the rotor located at least 3 cm below the surface of the metal in the trough, and the bottom surface located at least 0.5 cm from the bottom surface of the trough. There is also defined a treatment segment surrounding the rotor with a volume defined by a length along the trough equal to the distance between the trough walls at the metal surface, and a vertical cross-sectional area equal to the vertical cross sectional area of the metal contained within the trough at the midpoint of the rotor. In some configurations, gas injectors, such as rotors, may be located sufficiently close together that the distance between the centres of the injectors is less than the distance between the trough walls at the midpoint of the injector. Therefore, the treatment segment volume may be further defined as the volume defined by the vertical cross-sectional area of the metal contained within the trough at the midpoint of the gas injector multiplied by the smaller of the distance between the trough walls at the metal surface and the distance between the centres of adjacent gas injectors. The volume of the treatment segment is assumed to include the volume of the immersed portion of the injector itself upon which the volume is defined. The rotor and trough are further related by the requirement that the volume of metal within the treatment segment must not exceed 0.20 m 3 , and most preferably not exceed 0.07 m 3 . The treatment segment volume should, however, preferably be at least 0.01 m 3 for proper operation.
When used to treat aluminum and its alloys, the treatment segment is limited by the equivalent relationship that the amount of aluminum or aluminum alloy contained within the treatment segment must not exceed 470 Kg and most preferably not exceed 165 Kg.
In the preceding description, the mechanically moveable gas injector preferably provides three functions, namely introduction of treatment gas, break up of the treatment gas into fine bubbles, and the dispersion of the treatment gas bubbles. It is possible to separate the introduction process from the remaining two functions and still provide metal treatment in the trough sections that are a feature of this invention. In this process gas bubbles are generated in the molten metal by one or more fixed gas dispensers, and the mechanically moveable gas injector becomes a mechanically moveable gas disperser, providing the functions of break up of gas bubbles and dispersion of the gas bubbles into the surrounding metal. The gas dispersers and gas dispensers act together to perform the function of gas introduction as described above, and operate together with the vessel or trough used to contain the metal, to perform the same metal treatment functions as previously described.
Thus one has a method for treating molten metal with a treatment gas, comprising continuously introducing the molten metal into a container having a bottom wall and opposed side walls which form a section of a trough; providing at least one mechanically moveable gas disperser within the metal in the container; introducing said treatment gas in the form of bubbles into the metal adjacent to said gas disperser in a part of said trough forming a treatment zone such that said gas is broken into smaller bubbles by said gas disperser and is dispersed through the treatment zone; said trough section being such that said section exhibits a static to dynamic metal holdup of less than about 50%.
One similarly has an apparatus for treating molten metal with a treatment gas; comprising a container having a bottom wall and opposed side walls forming a trough for conveying said molten metal; at least one gas disperser in use positioned in said container submerged in said metal; means for moving said disperser mechanically in a motion selected from the group consisting of rotation about a central vertical axis, oscillation, or vibration; at least one gas dispenser located adjacent to said at least one gas disperser; and means for conveying gas to said at least one dispenser for introduction into said metal.
It is preferred that the gas introduction take place via one or more fixed gas dispensers with gas outlets below the gas disperser so that gas bubbles formed by the fixed gas dispenser rise in the metal and contact the mechanically moveable gas disperser. The gas dispensers can be in the form of one or more porous elements in the bottom wall of the trough and connected to a source of treatment gas. The gas dispensers may also be in the form of one or more tubes mounted in the bottom wall and connected to a source of treatment gas. The gas dispensers may further be in the form of one or more tubes mounted above the metal level in the trough and extending down into the metal, terminating in a outlet below the gas disperser and connected at the upper end to a source of treatment gas. It is preferred that there be one gas dispenser, with its outlet located below each gas disperser so that the treatment gas bubbles upwards and contacts or is drawn into the gas disperser where it is efficiently broken into smaller bubbles and dispersed through the metal in the treatment zone.
where gas dispensers are mounted in the bottom wall of the trough, it is particularly convenient that the trough section have substantially zero static to dynamic metal holdup to avoid blockage of the gas dispensers by metal remaining in the trough between casts.
Because the gas bubble break up and dispersion of this invention can take place in a shallow trough of the type used in transferring molten metal, it is possible to use such a preferred configuration.
The fixed gas dispensers can also be advantageously used with mechanically moveable gas dispersers having all three functions of gas introduction, bubble breakup and dispersion of bubbles thereby being functionally the same as the mechanically movable gas injectors previously described. The combination permits treatment gas to be introduced in two ways rather than solely by the mechanically moveable gas injector as previously described. It further permits the use of different treatment gas mixtures in the two introduction means. This is advantageous in permitting a reactive gas to be introduced through one means as a portion of the treatment gas mixture, and an inert gas to be used in the other injection means.
The use of a fixed, but adjacent gas dispenser with the gas disperser permits the effectiveness of bubble breakup and dispersion to be altered by varying the relative location of the two devices. Thus where one treatment gas mixture requires less fine bubbles to be dispersed, introduction via the fixed adjacent dispensers may be advantageous.
The gas disperser can be any of the mechanically moveable devices of this invention, but it is particularly preferred that it be in the form of a rotary device, and such devices can be in every way identical to devices used as integral gas introduction and bubble breaking and dispersion devices, except that a means of conveying gas may be omitted unless specifically required as one of the above options.
In operation, gas bubbles generated by the fixed gas dispensers are entrained in the molten metal and come in contact with the gas disperser where they are broken up and dispersed. In the case of the preferred rotary gas dispersers, the action of the disperser assists by drawing the metal into the disperser along with the entrained gas bubbles.
The volume limitations expressed for the treatment segment create a hydrodynamic constraint on the container plus gas injectors of this invention. The container as described above may take any form consistent with such constraints but most often takes the form of a trough section or channel section. Most conveniently this trough section will have the same cross-sectional dimensions as a metallurgical trough used to convey molten metal from the melting furnace to the casting machine, but where conditions warrant, the trough may have different depths or widths than the rest of the metallurgical trough system in use. To ensure that the rotor is also in proper geometric relationship to the trough even when deeper trough sections are used, the trough depth must be limited, and this limitation may be measured by the ratio of static to dynamic metal holdup. The dynamic metal holdup is defined as the amount of metal in the treatment zone when the gas injectors are in operation, while the static metal holdup is defined as the amount of metal that remains in the treatment zone when the source of metal has been removed and the metal is allowed to drain naturally from the treatment zone. For the desired operation the static to dynamic metal holdup should not exceed 50%. From other considerations, it is also clear that residual metal left in the trough should preferably be minimized to meet all the objectives of the invention, and therefore it is particularly preferred that the static to dynamic metal holdup be approximately zero. Where practical situations require that a non-zero ratio of static to dynamic holdup be used, it is preferred that the ratio not exceed 35%, which permits the residual metal to solidify between casts and permits relatively easy manual removal of the residue. It is most convenient that the trough have opposed sides that are straight and parallel, but other geometries, for example curved side walls, may also be used in opposition to each other.
The treatment segment defines the number of gas injectors required to effectively meet the object of the invention, once the volume flowrate of metal to be treated is known. It is surprising that although the total size of the treatment zone may be substantially less in the present invention than in prior art in-line degassers, the number of gas injectors required may actually be higher in certain circumstances. The treatment segment volume divided by the volume flowrate of metal to be treated should be less than 70 seconds It is preferably less than 35 seconds to ensure that all the metal volume is close enough to the gas injector to ensure that the effect of gas injection is felt throughout the metal volume during the time the metal is near the injector. Treatment of metal that is flowing at a high flowrate will require a larger treatment volume, within the limits already given, than metal flowing at low flowrates. Flowrates typically fall within the range of about 0.0005 to 0.007 cubic metres per second, but may be higher or lower, if desired.
The gas injectors preferably operate with a high specific gas injection rate so that the number of injectors required to achieve effective treatment is acceptably low. The specific gas injection rate is defined as the rate of gas injection via a gas injector divided by the treatment segment volume associated with that injector. For proper degassing by the process of this invention, a specific gas injection rate of at least 800, and more preferably at least 1000, litres of gas/minute/cubic metre of metal is preferred. Because the overall metal treatment operates within normal metallurgical requirements (less than 2345 litre gas/m 3 of metal treated, equivalent to 1 litre gas/kg of aluminum for example, and more typically between 940 and 1640 litres/m 3 ) such higher specific gas injection rates ensure that degassing can be accomplished generally with 10 injectors or less and frequently with fewer than 8 injectors.
The above embodiment may achieve a gas holdup, measured as the change in volume of the metal-gas mixture within a treatment segment with treatment gas added via the gas injection port at a rate of less than 1 litre/Kg, compared to the volume with no treatment gas flowing, of at least 5% and preferably at least 10%.
It is most preferred that the rotor have an internal structure consisting of vanes or indentations and that the side openings be rectangular in shape, formed by the open spaces between the vanes or indentations, and extending to the bottom of the rotor to be continuous with the bottom openings. The rotor as thus described preferably has a diameter of between 5 cm and 20 cm, preferably between 7.5 cm and 15 cm, and is preferably rotated at a speed of between 500 and 1200 rpm, and more preferably between 500 and 850 rpm.
Although various explanations for this invention are possible, the following is at present believed to describe the complex series of interactions necessary for the invention to meet the objective of efficient metal treatment in short time periods.
Conventional degassers of the deep box type or trough diffuser type, for example, all require substantially longer reaction times to achieve effective reaction (such as degassing). The key feature of this invention is the means of generating high gas holdup within the metal in the treatment zone by means of using gas injectors providing mechanical motion within a defined volume of metal per injector. Because a high gas holdup is generally believed to be a result of fine bubbles dispersed throughout the metal with little coalescence, this means that the surface area of the gas in contact with the metal in a high gas holdup situation is substantially increased, and therefore, according to normal chemical principles, reaction can occur in shorter times. Gas bubble size cannot be readily measured in molten metal systems. Gas bubble sizes based on water models are not reliable because of surface tension and other differences. It is possible to estimate gas-metal surface area for a particular degassing apparatus, and by applying further assumptions to estimate gas bubble sizes.
The measurement of gas-metal surface areas can be determined from the work of Sigworth and Engh, "Chemical and Kinetic Factors Related to Hydrogen Removal from Aluminum", Metallurgical Transactions B, American Society for Metals and The Metallurgical Society of AIME, Volume 13B, September 1982, pp 447-460 (the disclosure of which is incorporated herein by reference). The effect of alloy composition on hydrogen solubility was determined based on the method disclosed in Dupuis, et. al., "An analysis of Factors Affecting the Response of Hydrogen Determination Techniques for Aluminum Alloys", Light Metals 1992, The Minerals, Metals & Materials Society of AIME, 1991, pp 1055-1067 (also incorporated herein by reference).
Basically, in order to measure gas-metal surface area, the inlet and outlet hydrogen concentrations of the metal passing through the degasser are measured (for example using Commercial Units such as Alscan or Telegas (trade names)) and the metal flow rate, the metal temperature, the alloy composition and the gas flow rate per rotor are noted. The hydrogen solubility in the specific alloy is then calculated as a function of temperature. Sigworth & Engh's hydrogen balance equations for a continuous reactor (equations 35 and 36, page 451, Sigworth & Engh) are solved simultaneously for each rotor of the degasser. Based on the known operating parameters and measured hydrogen removal, the gas metal contact area is obtained from the previous step. Based on this method, the present invention requires operation with a gas-metal surface area of at least 30 m 2 /m 3 of metal within a treatment segment in order to achieve the desired degassing efficiency in short reaction times. Prior art degassers generally operate with gas-metal interfacial surface areas of less than 10 m 2 /m 3 .
The total interfacial contact area can then be used to "estimate" the volume average equivalent spherical gas bubble diameter produced by the gas injection rotor based on the following assumptions:
1) the gas bubbles are all of the same diameter;
2) the gas bubbles are all spherical;
3) the gas bubbles rise to the liquid metal surface vertically from the depth of gas injection;
4) the gas bubbles ascend through the metal at their terminal rise velocity (calculated using correlations for gas bubbles in water, e.g. according to Szekely, "Fluid Flow Phenomina in Metals Processing", Academic Press, 1979; incorporated herein by reference).
Finally, the volume average equivalent spherical gas bubble diameter is calculated using the equation: ##EQU1## wherein: Q=volumetric gas flow rate taking into account thermal expansion
h o =depth of gas injection
U t =thermal rise velocity of gas bubbles and
R=spherical gas bubble radius.
Based on this method of estimation, gas bubble sizes are 2 to 3 times smaller in the present invention than expected in systems of the deep box type, and there are fewer large bubbles present, thus supporting the explanation of the effectiveness of the present invention.
By associating a gas injector with a defined volume of molten metal (the "treatment segment" volume) that the fine gas bubbles generated by the mechanical motion are properly dispersed fully through the treatment zone and therefore the requirement to achieve high gas holdup is met. It should be noted that although the total volumes of metal within a treatment zone of the present invention are substantially reduced over those in a deep box degasser for example because of reduced reaction time requirements, the number of gas injectors may at the same time be increased because of the above requirements of the treatment segment.
Without wishing to be limited to any particular theory, the following is one explanation of the operation of this invention. The gas injectors within each treatment segment balance a number of requirements. The injectors generate a sufficient metal flow momentum in the streams of gas-containing metal to carry the metal and gas throughout the treatment segment but without impinging on container sides or bottom in such a way as to cause bubbles to coalesce or metal to splash. Bubble coalescence at the sides or bottom of the container will be manifested by a non-uniformity of the distribution of bubbles breaking the surface of the metal in the treatment segment, and such coalescence indicates that the average bubble size has been increased and will therefore, according to the above explanation, result in reduced gas holdup and poorer performance.
In the preferred embodiment of rotary gas injectors operating within a trough and where the rotary gas injectors have side openings, bottom opening and internal structure, the flow momentum is generated in a radial direction to achieve the distribution of gas bubbles required above and this momentum is created by the rotational motion of the injector. The rotary gas injector further operates to generate the fine bubbles of high gas-metal surface area characteristic of one aspect of the invention by generating a surface tangential velocity which in turn depends on the diameter of the rotary injector. It can be appreciated therefore that although rotors can be devised to operate over a wide range of rotational speeds, the optimum performance of a rotary gas injector of this invention within the constraints of its relationship to the trough will result in a relatively narrow range of rotational speeds within which it can operate at maximum effectiveness. The user will adjust the rotational speed to achieve the desired operational results.
While a rapidly rotating gas injector represents a preferred embodiment of the invention, such injectors can generate substantial deep vortices (extending down to the rotor itself) in the metal surface when operated in small volumes of metal. This undesirable effect can be reduced by ensuring that all external surfaces of the rotor are as smooth as possible, with no projections, etc., that might increase drag and form a vortex. However, such smooth surfaces are generally poorer at creating the shear necessary to generate fine gas bubbles, and it is only by balancing the geometry of the rotor with the operating speed and the trough configuration that sufficient shear and metal circulation, with no vortex formation, can be achieved. It has further been found that the bubble dispersing and turbulence and deep vortex reducing features of rotary gas dispersers of this invention are improved by the presence of a directed metal flow within the metal surrounding the rotary gas injectors. Such a directed metal flow is obtained, for example, when the metal flows along a trough, such as a metal delivery trough as described in this disclosure.
Directed metal flows of this type have surprisingly also been found to reduce any residual vortex formation in spite of the relatively low metal velocity compared to the tangential velocity of the rotary gas injector. The presence of flow directing means within the trough which direct the principal flow counter to the direction of the tangential velocity component in the metal introduced by the rotary gas injector are particularly useful.
The presence of directed metal flow changes the momentum vector of the radial metal flow to an extent that the flow direction overall is more longitudinal and the problems associated with impingement on an adjacent trough wall are substantially reduced. The magnitude of the directed metal flow clearly impacts on this effect.
In deep box treatment vessels using rotary gas dispersers, the preceding considerations are not important, and it is indeed felt beneficial to ensure that the radial flow is as high and turbulent as possible, and has a substantial upward or downward component to create large scale stirring within the volume of metal surrounding each gas injector.
It is most preferable and metallurgically advantageous in the present invention to carry out the gas treatment in a treatment zone consisting of one or more stages operated in series. This can be done in a modular fashion and it is possible, where space limitations or other considerations are important, to separate these stages along a metal-carrying trough, provided the total number of stages remain the same as would be used in a more compact configuration. It is also preferred that each stage consist of a gas injector as described above and be delimited from neighbouring stages. Each stage consists of a gas injection rotor as described above and is delimited from neighbouring stages by baffles or other devices designed to minimize the risk of backflow, or bypassing of metal between stages, and to minimize the risk of disturbances in one stage being carried over to adjacent stages.
The baffles can also incorporate the flow directing means described above which counter the tangential velocity component.
It should be understood that the treatment stage refers to the general part of the apparatus adjacent to a gas injector, and may be defined by baffles if they are present. The treatment segment, on the other hand is a portion of the container defined in the specific hydrodynamic terms required for the proper operation of the invention. It may be the same as the treatment stage in some cases.
The provision of plurality of treatment stages is (based on chemical principles) a more effective method for diffusion controlled reactions and removal of non-metallic solid particles for metal treatment. The plurality of rotary gas injectors within a directed metal flow as is created by the trough section operates (in chemical engineering terms) as a pseudo-plug flow reactor rather than a well-mixed reactor which is characteristic of deep box degassers.
It has been found that the effectiveness of the gas bubble shearing action, and hence the effectiveness at obtaining high gas holdup required to meet the object of the invention, increases as the power input intensity to the rotors in the treatment zone increases. When measured as the average power input per unit mass of metal contained within a treatment segment, and assuming that the net power available is typically 80% of installed (motor) power, typical treatment systems based on rotors operate in the range of power input densities of 1 to 2 watts/Kg of metal. The present invention is capable of operation at power input intensities in excess of 2 watts/Kg, and most frequently in excess of 4 watts/Kg, thus ensuring the smaller more stable bubble size required for effective treatment in small quantities of metal.
It should be appreciated that within the operating ranges of number, size and specific design of rotors, rotational speeds, positions relative to the trough and metal surface, metal flowrates and trough sizes and shapes there will be combinations within these ranges which give the desired treatment efficiency in the short times required.
As a result of this the apparatus is also compact and can be operated without the need for heaters and complex ancillary equipment such as hydraulic systems for raising and lowering vessels containing quantities of molten metal. As a result, the equipment normally occupies little space and is usually relatively inexpensive to manufacture and operate.
The requirements of fine bubbles, good bubble dispersion, and avoidance of deep metal vortices can be enhanced in certain instances by the use of fixed vanes located adjacent to the smooth faced rotor and substantially perpendicular to it. The fixed vanes serve to increase the shear in the vicinity of the rotor face, and also ensure that metal is directed radially away from the rotor face thus improving bubble dispersion capability (and avoiding bubble coalescence). The fixed vanes also totally eliminate any tendency for deep metal vortex formation. The rotor/fixed vane radial distance or gap is typically 1 to 25 mm (preferably 4 to 25 mm). When vanes are employed, generally at least two fixed vanes are required per rotor, and more preferably 4 to 12 are used. When fixed vanes are used, the requirements for fine bubbles and good dispersion conditions can be met at lower rotor speeds and in essentially non-moving metal. Thus the rotor plus fixed vane operation is effective at rotational speeds as low as 300 rpm and metal flows as low as zero Kg/min.
The lower operating speeds and the effective suppression of deep metal vortices permits a wider variety of rotor designs to be used without the generation of performance limiting surface disturbances.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a first embodiment of the rotor of this invention;
FIG. 2 is an underside plan view of the rotor of FIG. 1;
FIG. 3 is a side elevation of another embodiment of the rotor of this invention;
FIG. 4 is a representation view of a treatment zone consisting of a series of treatment stages containing a series of rotors and baffles;
FIG. 5 is a longitudinal cross-sectional view on an arrangement as shown in FIG. 3 in slightly modified form;
FIG. 6 is a further longitudinal cross-sectional view of an arrangement as shown in FIG. 3 in slightly modified form;
FIG. 7 is an underside plan view of a rotor operating with fixed vanes surrounding it;
FIG. 8 is a side elevation of the rotor and vanes on FIG. 7 showing the assembly located in a metal delivery trough;
FIG. 9 is a side elevation of another embodiment of a rotor that is suitable for use with fixed vanes (not shown); and
FIG. 10 is an underside plan view of the rotor of FIG. 9;
FIGS. 11(a) and 11(b) are, respectively, a side elevational view of an alternative rotor according to the invention and a plan view of the rotor positioned in a metal trough showing how certain dimensions are calculated;
FIGS. 12(a), 12(b), 12(c) and 12(d) are, respectively, a side elevation of an alternative rotor according to the invention, cross-sectional plan views taken on lines B and C respectively of FIG. 12(a), and underneath plan view of the rotor;
FIG. 13 is a cross-section of a trough containing a rotor shown in side elevation showing how various dimensions are defined;
FIG. 14 is a side elevation of a further embodiment of a rotor according to the invention;
FIG. 15 is a cross section of a trough as used in this invention with the key dimensions labelled;
FIG. 16 shows side elevations and plan views of five rotary injectors as used in this invention with key dimensions labelled;
FIG. 17 is a plot showing the useful and preferred operating ranges for the rotary gas injectors of FIG. 16;
FIG. 18 is a longitudinal cross-sectional view of a treatment zone consisting of a series of treatment stages containing a series of rotary gas dispersers and associated fixed gas dispensers in the form of porous elements mounted in the bottom wall of a trough section;
FIG. 19 is a further longitudinal cross-sectional view similar to FIG. 18, except that there is a single fixed gas dispenser associated with each rotary disperser, and the disperser also has provision for gas introduction;
FIG. 20 is a further longitudinal cross-sectional view similar to FIG. 18, except that the fixed gas dispensers are in the form of tubular elements mounted in the bottom wall of the trough section; and
FIG. 21 is similar to FIG. 20 except that the tubular elements enter the trough from above the metal.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 show a first embodiment of a rotary gas injector of this invention in a metal delivery trough. The injector has a smooth faced rotor body 10 submerged in a shallow trough, formed by opposed side walls (not visible) and a bottom wall 31, filled with molten metal 11 having an upper surface 13.
The rotor 10 is in the form of an upright cylinder 14 having a smooth outer face, mounted on a rotatable vertical shaft 16 of smaller diameter, with the cylinder portion having an arrangement of vanes extending downwardly from a lower surface 20, and the outer faces of the vanes forming continuous smooth downward extensions of the surface of cylinder 14. As can be seen most clearly from FIG. 2, the rotor vanes 18 are generally triangular in horizontal cross-section and extend radially inwardly from the outer surface. The vanes are arranged symmetrically around the periphery of the lower surface 20 in such a way as to define evenly spaced, diametrically-extending channels 22 between the vanes, which channels intersect to form a central space 28. An elongated axial bore 24 extends along the shaft 16, through the upright cylinder 14 and communicates with an opening 26 at the central portion of the surface 20 within the central space 28. This axial bore 24 is used to convey a treatment gas from a suitable source (not shown) to the opening or injection point 26 for injection into the molten metal.
The rotor 10 is immersed in the molten metal in the metal delivery trough to such a depth that at least the channels 22 are positioned beneath the metal surface and normally such that the cylindrical body is fully immersed, as shown. The rotor is then rotated about its shaft 16 at a suitably high speed to achieve the following effects. First of all, the rotation of the rotor causes molten metal to be drawn into the central space 28 between the rotor vanes 18 from below and then causes the metal to be ejected horizontally outwardly at high speed through the channels 22 in the direction of the arrows (FIGS. 1 and 2), thus forming generally radially moving streams. The speed of these radially moving streams depends on the number and shape of the vanes, the spacing between the vanes, the diameter of the cylinder and the rotational speed of the rotor. The treatment gas is injected into the molten metal through the opening 26 and is conveyed along the channels 22 in a co-current direction with the moving molten metal in the form of relatively large, but substantially discrete gas bubbles.
The surface 20 between the vanes at their upper ends closes the channels 22 at the top and constrains the gas bubbles and molten metal streams to move generally horizontally along the channels before the bubbles can move upwardly through the molten metal as a result of their buoyancy. Typically 4 to 8 vanes 18 are provided, and there are normally at least 3, but any number capable of producing the desired effect may be employed.
The rapidly rotating cylindrical rotor creates a high tangential velocity at the outer surface of the cylinder Because the outer surface of the cylinder is smooth and surface disturbances from the inwardly directed vanes are minimized, the tangential velocity is rapidly dissipated in the body of the metal in the metal delivery trough. Consequently a high tangential velocity gradient is created near the outer smooth surface of the rotor. The rapidly moving streams of molten metal and gas exit the channels 22 at the sides of the rotor 10 and encounter the region of high tangential velocity gradient. The resulting shearing forces break up the gas bubbles into finer gas bubbles which can then be dispersed into the molten metal 11 in the trough. The shearing forces and hence the bubble size depend on the diameter of the rotor and the rotational speed of the rotor. Because there are no projections on the smooth surface of the rotor, and the outer ends of the vanes present a relatively smooth aspect, the tangential velocity is rapidly dissipated without creating a deep metal vortex within the molten metal. A small vortex (not shown) associated with the rotation of the shaft 16 will of course still be present but does not cause any operational difficulties.
To facilitate the treatment of molten metal contained in shallow troughs or vessels such as metal delivery troughs, the rotor is preferably designed to inject the gas into the molten metal at a position as close to the bottom of the trough as possible. Consequently the rotor vanes 18 may be made as short as possible while still achieving the desired effect and the rotor is normally positioned as close to the bottom of the trough as possible, e.g. within about 0.5 cm. However in some troughs of non-rectangular cross-section, the trough walls at the bottom of the trough lie sufficiently close to the rotor that the radial metal flow generated by the rotor impinges on the wall and causes excessive splashing. In such cases an intermediate location for gas injection more widely separated from the bottom of the trough will be preferable.
The apparatus makes it possible to disperse small gas bubbles thoroughly and evenly throughout a molten metal held in a relatively shallow trough despite the use of a high speed rotation rotor since vortexing and surface splashing is effectively prevented. By correct combination of the diameter, number and dimensions of vanes and rotational speed, the dispersion of small gas bubbles is achieved without generating excessive outward metal flow that causes splashing when it reaches the sides of the metal delivery trough adjacent the rotor.
FIG. 3 shows a second preferred embodiment of the rotary gas injector of the invention. This injector represents a rotor having the same underneath plan view as the preceding rotor as illustrated in FIG. 2. However, the rotor 10 is in the form of a smooth surfaced upright truncated cone 17, mounted on a rotatable shaft 16 of smaller or equal diameter to the diameter of the upper surface of the cone, with the conical portion having an arrangement of vanes 18 extending downwardly from the lower surface 20, where the outer faces of the vanes form continuous smooth surfaces projecting downwardly from the intersection of the surface of the cone 17 with the vanes 18. By reducing the surface area of the surface of the cylinder 14 as described in FIG. 1 to the minimum required, the tendency to form a vortex is reduced over the embodiment of FIG. 1, and hence permits operations over a wider selection of conditions within the disclosed ranges.
FIG. 4 shows a treatment zone consisting of four treatment stages, where each stage incorporates a rotor 10, and each stage is separated from the next and from the adjacent metal delivery trough by baffles 34 which extend laterally across the trough section containing the treatment zone from sidewall 30 to sidewall except for a gap 36. The metal flows through the treatment zone in the pattern of flow shown by the arrows 37. The gaps 36 permit the metal to flow freely along the trough in a directed manner, but the baffles 34 prevent metal currents and disturbances from one treatment stage affecting the metal flow patterns in an adjacent treatment stage. Overall, a "plug flow" or "quasi-plug flow" is achieved, i.e. the overall movement of the metal is in one direction only along the trough, without backflow or bypassing of treatment stages, although highly localized reversed or eddy currents may be produced in the individual treatment stages.
The gaps 36 in adjacent baffles are arranged on opposite sides of the trough so that the principal molten metal flow is directed first into the regions 39 of the trough, and thence around the rotor into the regions 40 in such a way that overall the metal flows in an alternating pattern through the stages for maximum gas dispersion throughout the molten metal. The rotors rotate in the directions shown by the arrows 38, i.e. essentially counter to the direction of metal flow in regions 39 and 40 as established by the gaps 39 and thereby reduce further any tendency to form a deep vortex around the rapidly rotating rotors 10.
The illustrated equipment has good flow-through properties and low dynamic metal hold-up. The equipment thus creates only small metallostatic head loss over the length of the treatment zone, depending upon the size of the gaps 36 in the baffles 34.
FIGS. 5 and 6 show arrangements similar to FIG. 4, except that the gaps in the baffles are arranged alternately top to bottom in the embodiment of FIG. 5 and bottom to bottom in the embodiment of FIG. 6. These arrangements are also suitable to effect thorough gas dispersion through the molten metal.
FIGS. 7 and 8 show an alternative embodiment where the rotor 10 has an adjacent set of evenly-spaced radially oriented stationary vertical vanes 12 surrounding the rotor symmetrically about the centre of the rotor and separated from each other by radial channels 15. As will be seen from FIG. 8, the lower surfaces of the rotor vanes 18 and of the stationary vanes 12 may be shaped to follow the contours of a non-rectangular trough 31, if necessary. In this embodiment, the tangential velocity generated at the surface of the rotor 10 is substantially stopped by the adjacent stationary vanes and the resulting shearing force acting on the metal is enhanced. As the gas-containing molten metal streams emerging from the channels 22 encounter the stationary vanes, the high shear is particularly effective at creating the fine gas bubbles required for degassing and permits the effect to be achieved at lower rotational speeds of the rotor. Furthermore, the stationary vanes act to channel the molten metal streams emerging from the channels 22 further along the channels 15 to enhance the radial movement of the metal and ensure complete dispersion of the gas bubbles within the metal in the treatment zone. Finally the presence of stationary vanes completely eliminates any tendency to deep metal vortex formation, even in very shallow metal troughs, as well as low flowrates or directed metal flow that is co-current rather than counter to the direction of rotation of the rotors. The use of stationary vanes also reduces the constraints on surface smoothness of the rotor.
For effective operation with the rotors of this invention, there should preferably be at least 4 stationary vanes per rotor and preferably more than 6. The distance between the rotor and the stationary vanes is preferably less than 25 mm and usually about 6 mm, and the smaller the distance the better, provided the rotor and vanes do not touch and thus damage each other.
Any of the embodiments which use stationary vanes may if desired also used in troughs containing baffles as described in FIGS. 4, 5 or 6.
FIGS. 9 and 10 show a further embodiment of rotor that is intended for use with stationary vanes of the type shown in FIG. 7 and 8. FIGS. 9 and 10 show a rotor unit 10 in which two diametrical rotor vanes 18 intersect each other at the centre of the lower surface 20 of the cylinder 14. The axial gas passage extends through the intersecting portion of the vanes to the bottom of the rotor where the gas injection takes place through opening 26. This type of design in which the central area of the lower surface 20 is "closed" and where gas is injected below the upper edge of rotor vane opening 20 is less effective at radial "pumping"of the molten metal than the basic designs of FIGS. 1 and 2, but the manner of operation is basically the same. It falls outside the preferred open surface area requirement and gas injection point requirement for this invention, but nevertheless may be used with the stationary vanes as previously described since it has been noted above that the vanes permit a wider variety of rotors to be used.
FIGS. 11(a) and 11(b) show various dimensions required to determine the amount of gas holdup created by a rotor. A rotor 10 and portion of a shaft 16a are determined to have a volume V g where the volume includes the volume of any channels 22 within the cylindrical surface 14. The central axis of the rotor is located at distances 53a and 53b from the sides 52a and 52b of the trough containing the rotor. A portion of the trough is described by vertical planes 56 lying equidistant upstream and downstream from the axis of the rotor, at a distance 55 is one-half the distance 53 where the distance 55 is the maximum of 53a and 53b. The volume of metal lying between the walls 52a and 52b, the bottom of the trough 51, the upper metal surface 50 and the two vertical planes 56 is referred to as V M . The change 57 in V M resulting from injection of gas into the metal via the rotor is referred to as the gas holdup.
FIGS. 12(a), 12(b), 12(c) and 12(d) represent, respectively, an elevational view, two sectional plan views, and an underneath plan view of another embodiment of the rotor of this invention. The embodiment is similar to the embodiment of FIG. 1 except that the cylindrical body 14 has a lower extending piece 14c in the form of a cylindrical upward-facing cup with an outer surface exactly matching in diameter and curvature the surface of the downward facing vanes 18. The cup has a central opening 19 in the bottom surface. By varying the diameter of the opening 19, the effectiveness of metal pumping can be controlled, thus allowing the radial and horizontal flow to be controlled without altering the tangential velocity of the cylindrical surface required to shear the gas bubbles.
FIG. 13 describes the dimensional constraints as disclosed in this specification. Distance 60 is the immersion of the upper edge of the side of the rotor below the metal surface and is preferably at least 3 cm. Distance 62 is the distance from the bottom of the rotor, measured from the centre of the rotor to the vertically adjacent bottom of the trough and is at least 0.5 cm.
FIG. 14 shows the method of determining the open area of the openings in the side of the rotor. The openings 70 in the side of the rotor 14 on rotation describe a cylindrical surface lying between lines 71 and 72. If the area of this cylindrical surface is referred to as Ac, then the opening area ratio is defined as A o /A c and should preferably not exceed 60%.
FIG. 18 represents, in elevation, a treatment zone where gas is introduced via fixed gas dispensers 100 in the form of porous elements, mounted in the bottom wall 101 of a trough, separate from the gas dispersers 102, but adjacent to them. The gas dispersers are of the rotary type. The number of dispensers does not necessarily equal the number of dispersers, and the dispersers can form a continuous layer on the bottom of the trough if desired. The treatment gas is fed to the dispensers via orifices 103 in the bottom wall of the trough which are connected to a source of treatment gas (not shown). The porous elements and means to supply them with gas and to mounted then in the bottom wall of the trough can be of the type disclosed for example in U.S. Pat. No. 4,290,590 (Montgrain) or U.S. Pat. No. 4,714,494 (Eckert) incorporated here by reference.
FIG. 19 shows an alternative arrangement of gas dispensers 100 in the bottom wall 101 of the trough. In this arrangement there is one gas injector of the same type as in FIG. 15 located centrally under each gas disperser 102, to maximize the contact between the treatment gas and the dispersers and to avoid the escape of gas past the dispersers. Also shown in this figure are gas introduction passages 110 in each of the gas dispersers which permit the use of different treatment gas mixtures Within the same treatment zone. A preferred rotary form of the disperser would resemble that described in FIG. 1 for example. In this type of disperser, the metal is drawn up into the rotor and dispersed sideways (as was previously described), and placing the gas dispensers below each disperser will cause the gas bubbling up from such dispersers to be drawn into the disperser for effect breaking of the bubbles into finer bubbles and dispersion throughout the metal, in this case, along with gas delivered via the gas passage 110.
FIG. 20 shows a third embodiment of fixed gas dispensers. The dispensers are in the form of tubes 120 mounted in the bottom wall 121 of the trough, and are located beneath rotary gas dispersers 122. By adjusting the distance 123 between the bottom of the gas dispersers and the adjacent gas dispenser it is possible to affect the degree of shearing of the bubbles and to alter their size if desired for metallurgical reasons. The tubes are preferably made of refractory or ceramic materials which can be readily joined to gas feeding manifolds or similar devices (not shown).
FIG. 21 shows a fourth embodiment of fixed gas dispensers. The dispensers are in the form of tubes 130 entering the treatment zone from above the metal and mounted above the metal (in a manner which is not shown), and terminating in an upwardly directed manner 131 underneath the gas dispersers 132. This embodiment is useful where there may be metal remaining in the trough between uses, since the gas dispensers as well as the dispersers can be removed.
In operation using any of the fixed injectors described in FIGS. 18 to 21, a gas flow is preferably maintained from a time before the injector comes in contact with molten metal to a time after it is no longer in contact with molten metal to ensure that the gas orifices do not become blocked.
Any of the disperser shown in FIGS. 18, 20 or 21 can of course also be equipped with gas passages for additional treatment gas as described in FIG. 17.
As noted above, a particular advantage of the apparatus of the present invention is that it can be used in shallow troughs such as metal-delivery troughs and this can frequently be done without deepening or widening such troughs. In fact while the baffles 34 and the stationary vanes 12 (when required) may be fixed to the interior of the trough if desired, the assemblies of rotors, baffles and (if used) stationary vanes may alternately all be mounted on an elevating device capable of lowering the components into the trough or raising them out of the metal for maintenance (either of the treatment apparatus or the trough e.g. post-casting trough preparing or cleaning).
The trough lengths occupied by units of this kind are also quite short since utilization of gas is efficient because of the small bubble size and the thorough dispersion of the gas throughout the molten metal. The total volume of gas introduced is relatively small per unit volume of molten metal treated and so there is little cooling of the metal during treatment. There is therefore no need for the use of heaters associated with the treatment apparatus. A typical trough section required for a treatment zone with only one rotor would have a length to width ratio of from 1.0 to 2.0. Although a treatment zone containing a single rotor is possible, generally the treatment zone is divided into more than one treatment stages containing one rotor per treatment stage meeting the treatment segment volume limitations given above. The method and apparatus for metal treatment in a treatment zone can thereby be made modular so that more or less treatment stages and rotors can be used as required. Moreover the treatment stages which comprise the treatment zone need not be located adjacent to each other in a metal delivery trough if the design of the trough does not permit this. The usual number of rotors in a treatment zone is at least two and often as many as six or eight.
As indicated above, the metal treatment apparatus may be used for removing dissolved hydrogen, removing solid contaminants and removing alkali and alkaline earth components by reaction. Many metals may be treated, although the invention is particularly suited for the treatment of aluminum and its alloys and magnesium. The treatment gas may be a gas substantially inert to molten aluminum, its alloys and magnesium, such as argon, helium or nitrogen, or a reactive gas such as chlorine, or a mixture of inert and reactive gases. If chlorine is used for the treatment of magnesium-containing alloys, a liquid reaction product is formed which under the high shear generated in this treatment may be broken into an emulsion of very small droplets (typically 10 μm in diameter) which are easily entrained with the liquid metal downstream of the in-line treatment unit. This is undesirable due to the negative impact these inclusions have on specific aspects of the cast metal quality. The preferred reactive gas for this application is a mixture of chlorine and a fluoride-containing gas (e.g. SF 6 ) as described in U.S. Pat. No. 5,145,514 to Gariepy et al (the disclosure of which is incorporated herein by reference), which chemically converts the liquid inclusions into solid chlorides and fluorides which are more easily removed from the metal and are less chemically reactive than simple chloride inclusions and therefore have less impact on cast metal quality.
Where gas injection in the treatment zone is accomplished by separate gas dispensers and gas dispersers, the introduction of a treatment gas containing the reactive gas (such as chlorine) via the fixed dispensers adjacent the dispersers, with introduction of inert gas via the moving dispersers will permit the chlorine to be dispersed as larger bubbles, whilst the inert gas will be dispersed as very fine bubbles.
This permits the effective reaction rates of the different gases to be adjusted separately. In addition, the use of fixed gas dispensers for the reactive gases provide for easier maintenance.
EXAMPLE 1
Molten metal treatment was carried out in a treatment zone as described in FIGS. 1 through 3, except that a total of six rotary gas injectors was used and all rotary gas injectors rotated in the same direction. Each rotary gas injector was as described in FIGS. 1 and 2 with the following specific features. The outer diameter of each rotor was 0.1 m. Eight rotary vanes were used. The outer face of the rotor had openings which covered 39.8% of the corresponding area swept by these openings when the rotor was rotated. The vanes were in the form of truncated triangles, with the outer faces having the same contour as the outer face of the overall rotor and the inner ends terminating on a circle of diameter 0.0413 m. The vanes were spaced to provide passages of constant rectangular cross-section for channelling metal and gas bubbles. The rotors were operated at 800 rpm.
The treatment zone was contained within a section of refractory trough between a casting furnace and a casting machine and had a cross-sectional area of approximately 0.06 m 2 and a length of approximately 1.7 metres. The metal depth in the treatment zone varied from 0.24 metres at the start of the treatment zone to 0.22 metres at the end of the treatment zone. The rotors were immersed so that the point of injection of the gas into the metal stream was approximately 0.18 metres below the surface of the metal. The metal volume contained in each treatment segment, defined as the length of trough equal to the width at the surface of the metal times the vertical cross-sectional area, was approximately 0.021 m 3 for each of the rotary gas injectors.
The treatment zone was fed with metal at a rate of 416 Kg/min. A mixture of Ar and Cl 2 was used in the treatment, fed at a rate of 55 litres/min per rotary gas injector, corresponding to an average gas consumption of 0.8 litres/Kg.
Although all rotary gas injectors operated without the formation of deep metal vortices, it was noted that the normal vortices present as a result of the rotation of the shafts was reduced for those injectors where the metal flow was principally directed counter to the direction of the rotation.
When an aluminum-magnesium alloy (AA5182) was treated in the treatment zone as described, a hydrogen removal efficiency of between 55 and 58% was obtained, which compares favourably with prior art degassers used under the same conditions. The treatment time (average metal residence time in the treatment zone) was 34 seconds. A conventional deep box degasser operating under similar conditions required 350 seconds treatment time, and used approximately 0.5 m 3 of metal for each of the two rotors in the degasser.
EXAMPLE 2
Metal treatment was carried out in aluminum alloy AA3004in a trough as illustrated in FIG. 15. The dimensions of the trough are given in Table 1. The treatment process was carried out using five different rotary gas injectors as shown in FIG. 16, with the critical rotor parameters given in Table 2. The metal depth in the trough was 8.76 inches.(222 mm), and the aluminum alloy flowrate was 450 kg/min. The performance of the metal treatment apparatus was determined in terms of its ability to effectively disperse gas throughout the treatment zone without excessive splashing. Excessive splashing not only creates unsafe operation, but contributes to excessive dross formation. The rotors were tested at three immersion depths and over a range of rotational speeds. No attempt was made to acquire data at rotational speeds above 850 rpm. FIG. 17 shows the operational ranges determined for each rotor type at different immersion levels. Rotors 1, 4 and 5 all represent rotors of the particularly of preferred embodiment of this invention. Rotor 2 does not have the "smooth top" of the preferred embodiment, and rotor 3 has an area ratio which exceeds the preferred value of 60%. The figure indicate that while all rotors can operate within the present invention, the preferred rotors (1, 4 and 5) provide the widest operating windows within the operating ranges of the degasser.
TABLE 1______________________________________Dimensions of Trough (FIG. 15)______________________________________Top opening (80) 339 mm (13.4 inches)Depth (81) 381 mm (15.0 inches)Bottom curvature (82) 152.4 mm (6.0 inches) radius______________________________________ The bottom of the trough is in the shape of a full semicircle.
TABLE 2______________________________________Rotor parameters (FIG. 16) Rotor Type (see FIG. 16)Dimension 1 2 3 4 5______________________________________Overall height 5.0" 5.0" 5.0" 3.0" 5.0"(90) 127 mm 127 mm 127 mm 76 mm 127 mmShoulder height 1.5" 1.5" 1.5" 1.5" 1.5"(91) 38 mm 38 mm 38 mm 38 mm 38 mmVane height 2.0" 2.0" 2.0" 1.5" 1.5"(92) 51 mm 51 mm 51 mm 38 mm 38 mmOverall diameter 4.0" 4.0" 4.0" 4.0" 4.0"(93) 102 mm 102 mm 102 mm 102 mm 102 mmShoulder diameter 4.0" 3.0" 4.0" 4.0" 4.0"(94) 102 mm 76 mm 102 mm 102 mm 102 mmOpen area of vanes 39.8% 39.8% 70.0% 39.8% 39.8%______________________________________
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A method of and apparatus for treating molten metal to achieve effective removal of such unwanted inclusions as gases, alkali metals, entrained solids, and the like. The method comprises continuously introducing molten metal into a container forming a trough or trough section, such as the trough provided between a melting furnace and a casting machine, providing at least one mechanically movable gas dispenser submerged within the metal in the container and introducing a gas into the metal adjacent to the gas disperser in a part of the trough forming a treatment zone such that the gas is broken into smaller bubbles by the gas dispenser and dispersed through the treatment zone. The trough or trough section is such that it exhibits a static to dynamic metal holdup of less than 50%.
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This application is a continuation of Patent Application, titled: FISH TANK CLEANING SYSTEM, Ser. No. 5,438, filed Jan. 22, 1979.
BACKGROUND OF THE INVENTION
This invention is in the field of cleaning systems for aquarium tanks as the cleaning of the rocks on the bottom of the tank has been a great problem.
Therefore, a main object of this invention is to provide a rock-stirring device for stirring the rocks on the bottom of an aquarium to cause the debris to raise therefrom so as to be drawn off by suction through a hose, the suction being applied to a small area for effective results and the area being bounded by the housing of the rock-stirring device, which latter has a stirring rod mounted in it.
SUMMARY OF THE INVENTION
A major goal of this invention is to provide a fish tank cleaning system comprising a water pump, a stone cleaning tool comprising a housing, the lower end of the housing being open to engage rocks on the bottom of an aquarium, a stirring rod moveably extending through the housing for stirring the rocks, the other end of the hose being connected to an outlet of said housing disposed above the bottom of the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a venturi pump of this invention with upper and lower portions of the housing wall broken away to show the interior in cross-section. A cap for the lower end of the pump is shown in place, as it would be if it is intended to deliver water from the pump through a hose to an aquarium. The cap is removed when pumping from the aquarium is desired.
FIG. 2 is a bottom plan view of the pump of FIG. 1.
FIG. 3 is a side elevation of a device now obsolete and so not further described.
FIG. 4 is a side elevation of a squeegee tool in position of use and shown engaging the side of an aquarium, which latter is shown in cross-section, the tool having a portion of its side wall broken away to show its hollow interior. FIG. 4 also shows an example of the position of a hose in an aquarium at a time when the aquarium is either being emptied or filled.
FIG. 5 is a view of the squeegee tool of FIG. 4 as it would be seen looking at its left side at a right angle to its handle.
FIG. 6 is a side elevation of the aquarium bottom cleaning tool of this invention showing rocks on the bottom being stirred by the tool, portions of the side wall of the tool being broken away.
FIG. 7 is a side elevation of the tool of FIG. 6 as seen from the right side, but without the rod showing.
FIG. 8 is a detail showing the grommet of FIG. 6 in frontal elevation with a portion thereof broken away.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The aquarium servicing system of this invention is generally indicated at 10 in FIG. 1, and comprises a pump as one of its parts, generally indicated at 20, which latter has an outer housing 24, to which a hose 26 of about one-half inch diameter is connected. The outer housing 24 has a coupling 28 attached to it of a type for reception on the faucet of a sink, whereby water from the faucet passes down into the interior of a constricted chamber 30, which has a constricted lower end and an enlarged upper end, the upper end 32 being adapted to receive the terminal end of a faucet therein, so that water from the faucet flows downwardly through the chamber 30 from an inlet port 33.
Since the chamber 30 is of gradually lesser and lesser area as its lower end is approached until a place of maximum constriction 38 is reached the water will, therefore, jet out from the lower end of the chamber 30 with considerable force.
The lower end of the chamber 30 has an inner wall 42 which is of the least horizontal cross sectional area at a point and then once again the area defined by the wall 42 becomes slightly larger in the last approximately one quarter inch or more of the length of the chamber 30.
The hose 26 connects to an inlet opening 43.
The chamber 30 has a wall 50 of which 42 defines the inner surface thereof, or, in other words, the inner surface of the chamber 30.
Between the wall 50 and the outer housing 24 a flow area 60 into which the hose 26 delivers water in the direction of an arrow 62, receiving the water from an aquarium, which latter could be located at a great distance from the pump 20, such as even two or three rooms away from the pump if desired, since the hose 26 can be of any length.
Such an aquarium is shown diagrammatically at 70 in FIG. 4, although it will be seen that only one wall 72 thereof is shown, and the other end 74 of the hose 26 can be seen in FIG. 4, disposed beneath the level of the water 78 in the tank.
Water flowing through the hose 26 from the aquarium is delivered into the flow area 60 and then it is drawn downwardly in the direction of the arrows and through an annular space 88, which latter is disposed between the outer side of the wall 50 at the lower terminal end 90 of the wall 50, and the annular surface of the inner wall 96 of the housing 24.
The annular surface 94 is disposed above the terminal end 90 of the chamber housing 50 and the inner wall 96 of the outer housing 24 is of a greater diameter in horizontal cross-section at the upper end of the flow area 60, and still greater at its center than it is at the annular surface 94 and inner wall 96 tapers inwardly gradually, as seen at 104, as the constricted annular surface 94 is approached from the top and, as seen at 106, the inner wall 96 gradually tapers outwardly to ever larger diameter as the lower end of the outer housing 24 is approached, as would be in horizontaly cross section downwardly from the constricted annular surface 94.
A flow divider 130 extends upwardly into the annular lower end 90 of the inflow chamber 30.
The flow divider 130 is substantially conical shape, having a pointed upper end and becoming larger in horizontal cross section toward its lower end.
The flow divider 130 is maintained centrally along a vertical axis 140 by means of a support structure 142 connected to the lower end of the flow divider 130 and connected to the inner side of the inner wall 96, and the support structure 142 is open for the most part to permit flow of water downwardly there across in the direction of the arrow 148 for flow out the bottom of the flow area 60, which is open during withdrawal of water from an aquarium, such opening being seen at 170, although this opening 170 can also be capped by a cap 180 when it is desired to fill the aquarium from water coming into the pump 20 from a faucet.
The cap 180 is removably secured by threads 182 so as to block flow through the opening 170 when the cap 180 is in place, and this has the effect that water will then flow outwardly through the hose 26 for filling the aquarium 70 of FIG. 4.
The support structure 142 is best seen in FIG. 2, and can be equidistantly spaced support legs 192.
Referring to FIG. 4 a suction squeegee of this invention is generally indicated at 200, and has a hollow handle 210 stiff enough for good control, while using the squeegee blade 220 to clean an inner wall of an aquarium such as the inner side of the wall 72, seen in FIG. 4.
The blade 220 has a surface 228 which generally faces a handle 210, the surface 228 being disposed at an acute angle of approximately 55 degrees with respect to the elongation of the straight handle 210, such angle being seen at 230, whereby the squeegee is effective in loosening algae from the aquarium wall, since the blade 220 is of rubber or of soft plastic with a substantial flexibility and resiliency.
Algae are then drawn with water through an elongated inlet 250 so as to flow upwardly in the direction of the arrow 254 through the hollow handle 200 and from thence through a hose such as the hose 26 which is suitably secured to the upper end of the handle 210 so that the algae are delivered back through the hose 26 and through the pump 20 down into a sink, not shown, below the pump 20.
The handle 210 is connected to an outwardly flared housing 290, as best seen in FIG. 5, so that the blade 220 and the inlet 250 can be of substantially the same length and of much larger transverse dimension than the handle 210 as measured transversely to an axis 270 extending through the handle 210 and at a right angle to the blade 220.
Referring to FIG. 6, an aquarium bottle cleaning tool is there generally shown at 400 and comprising an outer housing 410, having an open lower end 412, whereby the open lower end 412 can be placed onto rocks, shown in dotted lines at 414, at the bottom of an aquarium.
The lower edges 420 of the housing 410 are preferably in a horizontal plane and algae and manure on the rocks 414 can be stirred up by a stirring rod 422, which extends downwardly through a closed top of the housing 410 until the lower end of the rod 422 can be seen at 424 to be in a position for stirring the rocks 414.
The rod 422 extends through an opening 438 in a flexible rubber grommet 440 which connects the rod 422 with the upper wall 422 of the housing 410.
The grommet effectively seals the space between the upper wall 442 at an opening 448 therein and the outer surface of the rod 422.
The grommet 440 can be best seen in FIG. 8 to be of annular shape, having a central opening 438 for receiving the rod 422, the grommet having an annular notch 462 in the outer edge thereof for receiving edge portions of the upper wall 442 of the housing 410.
In operation, the lower end 423 of the rod 422 will effectively stir the rocks for raising debris into the water inside the housing 410 which is then drawn away through the hose 26.
A hose-receiving tube 470 is disposed partially on the inside of the housing 410 and partially on the outside thereof by extending through an opening 472 in the housing and suitable sealing means 474 is placed between the tube 470 and the wall 476 of the housing.
The hose-receiving tube 470 can be short or long but is designed to be of a size to receive the hose 26 thereover so that the aquarium end of the hose pulls water from the interior of the housing 410 through the tube 470.
The housing wall 476 takes on a special shape as seen at 482, in order to hold the tube 470.
In operation, the housing 410 is placed against the rocks 414 which are stirred by the stirring rod 422, the upper end of which is held in the operator's hands as the housing 410 is pressed against the bottom rocks 414 of the aquarium. Debris-laden water in the housing 410 is drawn through the tube 470 and the hose 26 into the pump of FIG. 1.
Referring to FIG. 3, a device is there shown at 500 which will not be further described because it is not necessary to the operation of the other parts of this invention.
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A fish tank cleaning system comprising a water pump, a hose connected to the water pump, a stone cleaning tool comprising a housing, the lower end of the housing being open to engage rocks on the bottom of an aquarium, a stirring rod moveably extending through the housing for stirring the rocks, the other end of the hose being connected to an outlet of said housing disposed above the bottom of the housing.
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BACKGROUND OF THE INVENTION
This invention relates to friction rotors for the false twisting of synthetic threads.
Utilization of friction rotors or disks for the production of false-twisted synthetic threads by utilizing a so-called false-twisting unit is generally known. Typically these friction rotors are constructed of a PUR-plasma-coating full ceramic or a nickel-diamond coating. In comparison with a nickel-diamond coated rotor, the life of a PUR-friction rotor is very short. As a practical matter, regeneration of these friction coverings is impossible.
The prior art has attempted to design a so-called throw-away disk for false-twisting of synthetic threads constructed so that the central base support portion of the disk can be reused. Federal Republic of Germany OS No. 29 01 408 describes a friction rotor which comprises a support part and a replaceable friction covering ring. Unfortunately, it has been found that with increasing speeds of rotation the friction covering ring in the construction of German OS No. 29 01 408 becomes loose from the support so that it no longer assures satisfactory operation of the false-twisting unit.
German Utility Model No. 76 23 421 discloses a friction rotor in which there is a shrink connection between the friction covering and the base support. Use of a shrink connection makes it inconvenient to replace a worn part, and with a shrink connection the friction covering loosens from its support as a result of temperature changes, different coefficients of expansion of the materials, and the action of corrosive scrooping agents. In the case of a three-part disk in which the support is placed on a sleeve, it has been observed that the latter becomes detached from the support after a relatively short period of operation.
SUMMARY OF THE INVENTION
In accordance with the instant invention a friction rotor consists of a central base support that is force-locked and form-locked to a composite ring by utilizing press fitted radially arranged shoulders or dovetail-shaped retainers. The composite ring is formed of an inner support part at least a portion of which is provided with a covering. When the friction covering has become worn, the composite ring can be separated from the base without great difficulty and replaced by a new one, yet the central base, support ring and friction covering remain tightly engaged over an extended period of use.
OBJECTS OF THE INVENTION
Accordingly, a primary object of the instant invention is to provide apparatus for the false-twisting of synthetic threads with a friction rotor that is convenient to replace and has a long operating life.
Another object is to provide a friction rotor of this type that consists of a central base and a replaceable composite ring that includes a friction covering along the periphery thereof.
Another object is to provide a friction rotor of this type having a base and composite ring that are form-locked and force-locked to each other.
A further object is to provide a friction rotor of this type in which locking is achieved by interengagement of cooperating shoulders on the base and composite member.
A still further object is to provide a friction rotor of this type in which the connection between the base and composite member is achieved by dovetail formations that project radially outward from the base and are achieved by complementary cutouts of the composite member.
BRIEF DESCRIPTION OF THE DRAWINGS
These objects as well as other objects of this invention shall become readily apparent after reading the following description of the accompanying drawings in which:
FIG. 1 is a perspective of a false-twisting unit that includes friction rotors constructed in accordance with teachings of the instant invention;
FIG. 2 is a perspective of one of the rotor supporting shafts of FIG. 1, together with elements that are mounted on said shaft;
FIG. 3 is a side elevation, partially sectioned, of one of the friction rotors in FIG. 1;
FIG. 4 is a perspective of a friction rotor constructed in accordance with a second embodiment of the instant invention;
FIG. 5 is a plan view of the base of the friction rotor illustrated in FIG. 4; and
FIG. 6 is a plan view of the replaceable composite ring of the rotor of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Now referring to the figures and more particularly to FIGS. 1-3. False-twisting unit 1 of FIG. 1 includes three vertical shafts 4, 5, 6, each mounting three composite friction disks or rotors. That, is rotors 1', 2', 3' are keyed to shaft 4, rotors 1", 2", 3" are keyed to shaft 5, and rotors 1"', 2"', 3"' are keyed to shaft 6.
Keyed to the respective shafts 4, 5, 6 below their respective bottom rotors 3', 3", and 3"' are the respective pinions 4a, 5a, 6a whose teeth are engaged by the teeth of closed loop timing belt 7. Driving power for false-twisting unit 10 is introduced through drive whorl 8 that is keyed to shaft 5 below pinion 5a so that whorl 8 drives shaft 5 directly, and acting through timing belt 7 and pinions 4a, 5a, 6a drives shafts 4 and 6 in synchronization with shaft 5.
All of the friction rotors 1', 2', 3' etc. of FIGS. 1 and 2 are of the same construction, which is explained in detail with reference to FIG. 3 which illustrates rotor 1'. The latter includes base disk 9 and replaceable composite ring 10 that is removably mounted on base 9. Ring 10 includes annular support part 11 having peripheral formation 11a that is embedded in friction covering 12. The inner edge of support part 11 is provided with annular shoulder 10' that is force-locked and form-locked to annular shoulder 9' of base 9. The connection between shoulders 9', 10' remains secure for extended periods of operation, yet is convenient to break so that expendable composite ring 10 may be replaced after friction covering 11a is worn away. The base 9 extends radially past one axial side of shoulder 10', and the ring 10 extends radially past one axial side of shoulder 9'. As a result, the base 9 and ring 10 are movable together into frictional engagement by relative axial movement in one direction and are separable by relative axial movement in the opposite direction.
Now referring more particularly to FIG. 4 which illustrates another embodiment of this invention wherein rotor 21 consists of base 91 (FIG. 5) and replaceable ring component 23 which includes plastic support 26 and friction coating 27 along the outer periphery of support 26. Dovetail projections 9.1, 9.2, 9.3 extend radially outward from base 91 and are received by dovetail recesses 10.1, 10.2, 10.3 which extend from the inner edge of member 26. Dovetail projections 9.1, 9.2 and 9.3 cooperate with recesses 10.1, 10.2, 10.3 to provide a force-fitted and force-locked connection between base 91 and ring 23, which connection may be broken when desired for replacement of composite member 27. As in the first embodiment of FIG. 3, the base 91 and the ring 23 are separable by relative axial movement of one off the other and are brought together by relative axial movement of one toward the other to bring them together and into frictional engagement.
Although the present invention has been described in connection with a preferred embodiment thereof, many variations will now become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
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A device for the false twisting of synthetic threads is provided with a plurality of friction rotors, each constructed of a reusable central bore and an expendable composite ring that is form-fitted and force-fitted to said base so as to be conveniently removable therefrom for replacement when the friction coating along the outer edge of the ring has worn.
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BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT
[0001] The present invention relates to a semiconductor optical sensor element and a method of producing the semiconductor optical sensor element. More specifically, the present invention relates to a semiconductor optical sensor element capable of being produced on a wafer level.
[0002] A semiconductor optical sensor element has been widely used for outputting a linear output according to environmental luminescence. In general, the semiconductor optical sensor element has an angular dependence in a light reception property. Accordingly, a light scattering plate is disposed on a housing of a conventional semiconductor optical sensor element, so that external light is irradiated on an optical-electric conversion element through the light scattering plate, thereby improving the light reception property (refer to Patent Reference 1).
[0003] In another conventional semiconductor optical sensor element, a luminescence sensor chip is disposed on one of a first electrode and a second electrode disposed on an insulation substrate. The luminescence sensor chip is connected to the one of the first electrode and the second electrode through a wiring portion. A sealing resin package is provided for sealing an entire portion of the conventional semiconductor optical sensor element, so that parts of the first electrode and the second electrode are exposed (refer to Patent Reference 2).
[0004] Patent Reference 1: Japanese Patent Publication No. 2006-287404
[0005] Patent Reference 2: Japanese Patent Publication No. 2002-176192
[0006] In the conventional semiconductor optical sensor element with the sealing resin package, after the luminescence sensor chip is attached to the insulation substrate, it is necessary to perform several steps for extending the wiring portion from the first electrode or the second electrode. Afterward, the sealing resin package is formed to obtain the conventional semiconductor optical sensor element. Accordingly, a manufacturing process becomes complicated, and it is difficult to reduce a size of the conventional semiconductor optical sensor element.
[0007] Further, as a mobile communication device has been miniaturized lately, it is necessary to produce a semiconductor optical sensor element using a W-CSP (Wafer Level Chip-size Package), thereby reducing a size and cost thereof.
[0008] In view of the problems described above, an object of the present invention is to provide a semiconductor optical sensor element and a method of producing the semiconductor optical sensor element capable of solving the problems of the conventional semiconductor optical sensor elements. In the invention, it is possible to minimize the number of manufacturing steps and improve yield.
[0009] Further objects and advantages of the invention will be apparent from the following description of the invention.
SUMMARY OF THE INVENTION
[0010] In order to attain the objects described above, according to a first aspect of the present invention, a method of producing a semiconductor optical sensor element includes the steps of: bonding a semiconductor wafer to a transparent optical wafer through an adhesive portion to form a bonded member; and cutting the bonded member at the adhesive portion to form the semiconductor optical sensor element formed of a sensor chip and a light scattering chip. The semiconductor wafer is provided with a sensor portion including a light reception portion of an optical-electric conversion element on a surface thereof. The transparent optical wafer includes a light scattering portion on a surface thereof.
[0011] According to a second aspect of the present invention, in the method of producing the semiconductor optical sensor element, a groove is formed in a dicing region, and a light blocking resin is disposed in the groove, thereby reducing cost.
[0012] According to a third aspect of the present invention, in the method of producing the semiconductor optical sensor element, a groove is formed in a dicing region, and a resin layer is disposed over an entire portion of the semiconductor chip. Then, a post forming step is performed for extending an electrode through the resin layer, thereby reducing the number of manufacturing steps.
[0013] According to a fourth aspect of the present invention, in the method of producing the semiconductor optical sensor element, a groove is formed such that the groove crosses the adhesive portion, and a light blocking resin layer is formed in the groove such that an outer side surface of the light blocking resin layer extends in parallel to a side surface of the light scattering chip and a side surface of the semiconductor chip. As a result, the light blocking resin layer is attached only to the side surface of the light scattering chip and the adhesive portion between the transparent optical wafer and the semiconductor wafer. Accordingly, it is possible to improve reliability of the semiconductor optical sensor element against moisture and reducing a size of the light blocking resin layer.
[0014] According to a fifth aspect of the present invention, the method of producing the semiconductor optical sensor element may include the step of grinding the semiconductor wafer of the bonded member after the bonded member is formed for adjusting a thickness of the semiconductor wafer. Accordingly, the transparent optical wafer supports the semiconductor to maintain strength thereof, thereby preventing the semiconductor wafer from being damaged during a bonded member processing step or transportation.
[0015] According to a sixth aspect of the present invention, a semiconductor optical sensor element includes a sensor chip including a sensor portion including a light reception portion of an optical-electric conversion element on a surface thereof; a light scattering chip bonded to the semiconductor chip with a specific distance therebetween and including a light scattering portion on a surface thereof; and an adhesive portion disposed between the semiconductor chip and the light scattering chip.
[0016] According to a seventh aspect of the present invention, in the semiconductor optical sensor element, the light scattering chip may be formed of a cover glass with transparency relative to light having a specific wavelength. The light scattering portion is formed on an outer surface of the light scattering chip through a sand blast process. The light scattering portion has roughness adjusted for scattering light having a specific wavelength.
[0017] In the semiconductor optical sensor element, when light is incident on the light reception portion of the optical-electric conversion element by a large angle relative to a direction perpendicular to the light reception portion, the light scattering portion scatters light to increase an amount of light received on the light reception portion, thereby expanding an incident range of the light reception portion.
[0018] When the light scattering chip formed of the cover glass scatters light, it is possible to provide the semiconductor optical sensor element with oblique incident light property having a substantially ideal cosign curve, thereby reducing manufacturing cost.
[0019] When a material or a roughness of the cover glass is optimized, the semiconductor optical sensor element is applicable to an ultraviolet light sensor or an infrared light sensor for detecting ultraviolet light or infrared light, in addition to visible light.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a schematic sectional view showing a semiconductor optical sensor element according to a first embodiment of the present invention;
[0021] FIG. 2 is a schematic plane view showing a semiconductor wafer according to the first embodiment of the present invention;
[0022] FIG. 3 is a schematic enlarged sectional view showing the semiconductor wafer according to the first embodiment of the present invention;
[0023] FIG. 4 is a schematic enlarged sectional view showing a glass wafer according to the first embodiment of the present invention;
[0024] FIG. 5 is a schematic perspective view showing a bonded member formed of the semiconductor wafer and the glass wafer according to the first embodiment of the present invention;
[0025] FIG. 6 is a schematic sectional view No. 1 showing the bonded member formed of the semiconductor wafer and the glass wafer in a manufacturing process of the semiconductor optical sensor element according to the first embodiment of the present invention;
[0026] FIG. 7 is a schematic sectional view No. 2 showing the bonded member formed of the semiconductor wafer and the glass wafer in the manufacturing process of the semiconductor optical sensor element according to the first embodiment of the present invention;
[0027] FIG. 8 is a schematic sectional view No. 3 showing the bonded member formed of the semiconductor wafer and the glass wafer in the manufacturing process of the semiconductor optical sensor element according to the first embodiment of the present invention;
[0028] FIG. 9 is a schematic sectional view No. 4 showing the bonded member formed of the semiconductor wafer and the glass wafer in the manufacturing process of the semiconductor optical sensor element according to the first embodiment of the present invention;
[0029] FIG. 10 is a schematic sectional view No. 5 showing the bonded member formed of the semiconductor wafer and the glass wafer in the manufacturing process of the semiconductor optical sensor element according to the first embodiment of the present invention;
[0030] FIG. 11 is a schematic sectional view No. 6 showing the bonded member formed of the semiconductor wafer and the glass wafer in the manufacturing process of the semiconductor optical sensor element according to the first embodiment of the present invention;
[0031] FIG. 12 is a schematic sectional view No. 7 showing the bonded member formed of the semiconductor wafer and the glass wafer in the manufacturing process of the semiconductor optical sensor element according to the first embodiment of the present invention;
[0032] FIG. 13 is a schematic sectional view No. 8 showing the bonded member formed of the semiconductor wafer and the glass wafer in the manufacturing process of the semiconductor optical sensor element according to the first embodiment of the present invention;
[0033] FIG. 14 is a schematic sectional view No. 9 showing the bonded member formed of the semiconductor wafer and the glass wafer in the manufacturing process of the semiconductor optical sensor element according to the first embodiment of the present invention;
[0034] FIG. 15 is a schematic sectional view showing a semiconductor optical sensor element according to a second embodiment of the present invention;
[0035] FIGS. 16(A) to 16(D) are schematic sectional views showing a bonded member formed of a semiconductor wafer and a glass wafer in a manufacturing process of the semiconductor optical sensor element according to the second embodiment of the present invention;
[0036] FIG. 17 is a schematic sectional view showing a semiconductor optical sensor element according to a third embodiment of the present invention; and
[0037] FIG. 18 is a schematic sectional view showing a semiconductor optical sensor element according to a fourth embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0038] Hereunder, embodiments of the present invention will be explained with reference to the accompanying drawings. In the following description, similar components are designated with the same reference numerals, and redundant explanations thereof are omitted. The embodiments simply represent examples, and do not limit the scope of the present invention.
First Embodiment
[0039] A first embodiment of the present invention will be explained. FIG. 1 is a schematic sectional view showing a semiconductor optical sensor element 100 according to the first embodiment of the present invention. The semiconductor optical sensor element 100 is formed of a sensor chip or a semiconductor chip 10 and a light scattering chip 40 bonded to the sensor chip 10 through an adhesive portion 9 .
[0040] As shown in FIG. 1 , the semiconductor optical sensor element 100 includes the light scattering chip 40 and the sensor chip 10 bonded to the light scattering chip 40 through the adhesive portion 9 . The light scattering chip 40 is provided for scattering light. The sensor chip 10 is formed of a silicon (Si) substrate, and includes a sensor portion including a light reception portion 11 of an optical-electric conversion element, and through electrodes 6 .
[0041] In the embodiment, the light scattering chip 40 includes a glass flat plate or a glass wafer 4 and a light scattering portion 121 formed on an outer main surface thereof. The light scattering chip 40 is individually cut from a transparent glass wafer (refer to as the glass wafer 4 ) together with the sensor chip 10 . More specifically, the light scattering chip 40 includes the light scattering portion 121 on a backside surface (an outer surface) thereof, and a front side surface (an inner surface) of the glass wafer 4 is flat.
[0042] In the embodiment, the adhesive portion 9 is disposed on the inner surface of the glass wafer 4 , and is formed of an adhesive material of an ultraviolet setting type, a thermal setting type, and the like. Further, the adhesive portion 9 is formed of a spacer (not shown) and adhesive layers (not shown) on both sides of the spacer.
[0043] In the embodiment, the adhesive portion 9 is attached to a first main surface of the sensor chip 10 . The light reception portion 11 is formed on the first main surface of the sensor chip 10 , and includes a light reception element (an optical-electric conversion element) such as a photo diode. The light reception portion 11 is connected to inner wiring portions 15 and metal pads 8 collectively formed as a sensor portion on the first main surface around the light reception portion 11 .
[0044] In the embodiment, the sensor chip 10 also has a second main surface (a backside surface) opposite to the first main surface. Outer wiring portions 18 and outer terminals 7 are formed in the second main surface at specific positions. An insulation film 14 covers the second main surface except the outer terminals 7 . Note that the sensor chip 10 has side surfaces. The side surfaces constitute edge portions of the sensor chip 10 crossing the first main surface and the second main surface. As shown FIG. 1 , the side surfaces are exposed, and may be coated with insulation paint if necessary.
[0045] In the sensor chip 10 , a through electrode 6 is formed below the metal pad 8 arranged near an outer circumference of the first main surface for connecting the inner wiring portion 15 and the outer wiring portion 18 . The through electrode 6 penetrates through the sensor chip 10 from the first main surface to the second main surface. Accordingly, it is possible to electrically connect to the light reception portion 11 through the outer wiring portion 18 without providing a wiring portion through the side surface of the sensor chip 10 . An insulation film 16 is disposed on an entire portion of the second main surface of the sensor chip 10 and an inner surface of the through electrode 6 , so that the through electrode 6 is electrically isolated. In the embodiment, the light scattering chip 40 may be attached to the first main surface of the sensor chip 10 through the adhesive portion 9 at a surrounding area of the light reception portion 11 , so that a space is created between the light scattering chip 40 and the light reception portion 11 . Further, a transparent adhesive material may be filled in the space between the light scattering chip 40 and the light reception portion 11 . It is suffice that the light scattering chip 40 is attached to the first main surface of the sensor chip 10 through the adhesive portion 9 at least at the surrounding area of the light reception portion 11 .
[0046] In the embodiment, light blocking resin layers 5 are disposed on the adhesive portion 9 and on side surfaces of the light scattering chip 40 . When the semiconductor optical sensor element 100 is individually cut with dicing, the sensor chip 10 and the adhesive portion 9 have commonly flat side surfaces. Further, the light blocking resin layers 5 are attached to the adhesive portion 9 and the side surfaces of the light scattering chip 40 , and have outer side surfaces flush with those of the sensor chip 10 . Accordingly, in a plan view of the semiconductor optical sensor element 100 , the light scattering chip 40 has an area smaller than that of the sensor chip 10 .
[0047] When light is incident on the semiconductor optical sensor element 100 , light passes through the light scattering portion 121 of the light scattering chip 40 and reaches the first main surface of the sensor chip 10 , so that the light reception portion 11 converts light to an electrical signal. When light is incident on the side surfaces of the light scattering chip 40 , the light blocking resin layers 5 block light. More specifically, the light blocking resin layers 5 are arranged on the side surfaces of the light scattering chip 40 , so that it is possible to block light from entering through side surfaces of the semiconductor optical sensor element 100 .
[0048] As described above, the light blocking resin layers 5 are arranged on the side surfaces of the light scattering chip 40 , it is possible to reduce a size of the light scattering chip 40 and block light from entering through side surfaces of the semiconductor optical sensor element 100 . Further, with the light blocking resin layers 5 , it is possible to prevent the light scattering chip 40 from partially cracking during a manufacturing process.
[0049] A method of producing the semiconductor optical sensor element 100 will be explained. FIG. 2 is a schematic plane view showing a semiconductor wafer 101 according to the first embodiment of the present invention.
[0050] As shown in FIG. 2 , a plurality of or an array of sensor portions 111 are formed on the first main surface of the semiconductor wafer 101 in a matrix pattern through a semiconductor manufacturing process. The semiconductor wafer 101 typically has a diameter of six or eight inches. In FIG. 2 , the sensor portions 111 are schematically represented as a rectangle element, and a shape and the number thereof are not limited.
[0051] FIG. 3 is a schematic enlarged sectional view showing the semiconductor wafer 101 according to the first embodiment of the present invention.
[0052] As shown in FIG. 3 , the light reception portion 11 including the optical-electric conversion element and the metal pads 8 arranged around the light reception portion 11 are formed on the first main surface of the semiconductor wafer 101 in each of the sensor portions 111 through the semiconductor manufacturing process. In this step, an amplifier (not shown) formed of several CMOS (Complementary Metal-Oxide Semiconductor) transistors may be disposed per the photo diode embedded in the light reception portion 11 . The metal pads 8 may be formed of a metal with good conductivity such as aluminum (Al).
[0053] In the next step, the inner wiring portions 15 are formed, so that the light reception portion 11 is connected to the metal pads 8 arranged around the light reception portion 11 . Through the steps described above, a plurality of or an array of the sensor portions 111 are formed on the first main surface of the semiconductor wafer 101 in the matrix pattern with a space in between to be a dicing region in a later step.
[0054] In the next step, the glass wafer 4 is prepared. The glass wafer 4 has a diameter the same as that of the semiconductor wafer 101 , i.e., six or eight inches, and a thickness of 300 to 2,000 μm. Further, the glass wafer 4 is formed of glass having a refractive index in a range of 1.45 to 2.00 according to a target wavelength. After the glass wafer 4 is prepared, a sand blast surface roughening process is performed as a physical etching process. More specifically, grinding particles with a specific index are blown against one of main surfaces of the glass wafer 4 with compressed air, so that an undulation surface is formed.
[0055] FIG. 4 is a schematic enlarged sectional view showing the glass wafer 4 of the semiconductor optical sensor element 100 processed with the sand blast surface roughening process according to the first embodiment of the present invention.
[0056] As shown in FIG. 4 , with the sand blast surface roughening process, the light scattering portion 121 with a roughness of 0.1 to 100 μm is formed on the entire surface of the glass wafer 4 . When the light scattering portion 121 has the roughness in the range of 0.1 to 100 μm, it is possible to scatter external light (oblique incident light property or cosine property).
[0057] In the embodiment, other than the physical etching process such as the sand blast surface roughening process, a chemical etching process may be adopted. In the chemical etching process, the surface of the glass wafer 4 contacts with a hydrogen fluoride solution to be dissolved, so that an undulation surface is formed. Further, after the sand blast surface roughening process, the chemical etching process may be performed.
[0058] In the next step, the semiconductor wafer 101 having the sensor portions 111 is attached to the glass wafer 4 with the adhesive portion 9 as shown in FIG. 5 . FIG. 5 is a schematic perspective view showing a bonded member formed of the semiconductor wafer 101 and the glass wafer 4 according to the first embodiment of the present invention.
[0059] As shown in FIG. 5 , the semiconductor wafer 101 is attached and fixed to the glass wafer 4 such that the light scattering portion 121 of the glass wafer 4 faces outside and the sensor portions 111 of the semiconductor wafer 101 face inside. The adhesive portion 9 is formed of a photosensitive polymer with high temperature resistance such as benzocyclobutene (BCB), a polyimide, and the like as the adhesive material. The adhesive material is an ultraviolet setting type or a thermal setting type. When the adhesive material is formed of a photosensitive polymer, light is irradiated from a side of the glass wafer 4 , so that the adhesive portion 9 is hardened through light irradiation. The adhesive portion 9 is provided for maintaining the specific distance between the semiconductor wafer 101 and the glass wafer 4 , and for sealing the sensor portions 111 during a grinding process, a through electrode forming process, a dicing process, and the like to be performed later.
[0060] In the next step, the backside surface (the exposed surface) of the semiconductor wafer 101 integrated with the glass wafer 4 is ground. FIG. 6 is a schematic sectional view No. 1 showing the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 in a manufacturing process of the semiconductor optical sensor element 100 according to the first embodiment of the present invention.
[0061] As shown in FIG. 6 , after a protective sheet for the backside surface grinding is attached to the light scattering portion 121 of the glass wafer 4 , the semiconductor wafer 101 is ground from an original thickness of 600 to 700 μm to a specific thickness of 50 to 100 μm. After the backside surface grinding, the protective sheet is removed, and may remain for protecting the light scattering portion 121 during the later steps.
[0062] In the next step, the through electrodes 6 , the outer wiring portions 18 , and the outer terminals 7 are formed in the second main surface of the semiconductor wafer 101 integrated with the glass wafer 4 . More specifically, through holes 61 are formed in the semiconductor wafer 101 with deep digging etching, and wiring portions are formed through copper plating and the like to form electrode pads.
[0063] FIG. 7 is a schematic sectional view No. 2 showing the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 in the manufacturing process of the semiconductor optical sensor element 100 according to the first embodiment of the present invention.
[0064] As shown in FIG. 7 , first, the through holes 61 with a diameter of 100 to 200 m are formed in the semiconductor wafer 101 from the second main surface (the backside surface) to reach the metal pads 8 . More specifically, the through holes 61 are formed with a reactive ion etching method in the semiconductor wafer 101 from the second main surface at positions of the metal pads 8 of the semiconductor wafer 101 , so that the through holes 61 have a size slightly smaller than that of the metal pads 8 .
[0065] In the reactive ion etching method, first, a mask (not shown) formed of a metal or a resist having openings corresponding to the through holes 61 is disposed on the second main surface of the semiconductor wafer 101 . Then, the semiconductor wafer 101 is etched through the openings through an SiF 4 generation reaction under an environment of a mix gas containing CF 4 , thereby forming the through holes 6 .
[0066] FIG. 8 is a schematic sectional view No. 3 showing the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 in the manufacturing process of the semiconductor optical sensor element 100 according to the first embodiment of the present invention.
[0067] As shown in FIG. 8 , the insulation film 16 formed of SiO 2 is formed on inner surfaces and bottom surfaces (for exposing the metal pad 8 ) of the through holes 61 and the second main surface of the semiconductor wafer 101 with a CVD (Chemical Vapor Deposition) method. More specifically, the insulation film 16 is formed such that a film thickness thereof on the bottom surfaces (for exposing the metal pad 8 ) thereof is smaller than that on the second main surface of the semiconductor wafer 101 . Accordingly, with subsequent reactive ion etching, opening portions 62 of the insulation film 16 are formed at the bottom surfaces of the through holes 61 to expose the metal pad 8 , and the insulation film 16 remains on the inner surfaces of the through holes 61 and the second main surface of the semiconductor wafer 101 .
[0068] FIG. 9 is a schematic sectional view No. 4 showing the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 in the manufacturing process of the semiconductor optical sensor element 100 according to the first embodiment of the present invention.
[0069] In the next step, a mask (not shown) having a specific pattern is formed on the insulation film 16 on the second main surface of the semiconductor wafer 101 . The mask has openings corresponding to the through holes 61 (in which the metal pads 8 are exposed), the through electrodes 6 around the through holes 61 , and the outer wiring portions 18 to be connected to the through electrodes 6 . Then, as shown in FIG. 9 , the outer wiring portions 18 and the through electrode 6 are formed.
[0070] FIG. 10 is a schematic sectional view No. 5 showing the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 in the manufacturing process of the semiconductor optical sensor element 100 according to the first embodiment of the present invention.
[0071] In the next step, as shown in FIG. 10 , an insulation film 14 is formed on an entire backside surface of the semiconductor wafer 101 . Then, the insulation film 14 is patterned through lithography, so that portions of the outer wiring portions 18 , where the outer terminals 7 for connecting to an external circuit are formed, are exposed.
[0072] FIG. 11 is a schematic sectional view No. 6 showing the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 in the manufacturing process of the semiconductor optical sensor element 100 according to the first embodiment of the present invention.
[0073] In the next step, a solder waste is coated and reflows on the portions of the outer wiring portions 18 thus exposed on the backside surface of the semiconductor wafer 101 . Then, remaining flux is removed, thereby forming the outer terminals 7 as shown in FIG. 11 . Before the outer terminals 7 are formed, a base metal film (not shown) may be formed.
[0074] In the embodiment, the insulation film 14 is formed of a material such as SiO 2 , SiN, and polyimide (PI). The outer wiring portions 18 are formed of a conductive material such as Cu, Al, Ag, Ni, Au, and the like. Further, the outer terminals 7 are formed of a material such as SnAg and NiAu.
[0075] FIG. 12 is a schematic sectional view No. 7 showing the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 in the manufacturing process of the semiconductor optical sensor element 100 according to the first embodiment of the present invention.
[0076] In the next step, as shown in FIG. 12 , the glass wafer 4 is cut until the adhesive portion 9 is exposed using a first dicing blade 51 with a blade dicing method, so that grooves 41 are formed in a dicing region. More specifically, the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 is placed on a supporting table of a dicing device (not shown), so that the first dicing blade 51 cuts the glass wafer 4 . It is preferred that the first dicing blade 51 cuts the glass wafer 4 in a cut width (a blade thickness) of 60 to 100 m, so that the same portion can be cut in a subsequent step.
[0077] As shown in FIG. 12 , the first dicing blade 51 cuts the bonded member from the side of the glass wafer 4 toward the semiconductor wafer 101 . Note that the grooves 41 may be formed with a laser method without using the first dicing blade 51 .
[0078] FIG. 13 is a schematic sectional view No. 8 showing the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 in the manufacturing process of the semiconductor optical sensor element 100 according to the first embodiment of the present invention.
[0079] In the next step, as shown in FIG. 13 , a light blocking resin is poured into the grooves 41 with a printing method or a dispensing method to form light blocking resin layers 5 . The light blocking resin layers 5 are formed of a polymer resin such as an epoxy resin containing a black colorant such as carbon black and iron (III) tetraoxide. Other than the black colorant, a dark color colorant with light blocking capability may be used.
[0080] FIG. 14 is a schematic sectional view No. 9 showing the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 in the manufacturing process of the semiconductor optical sensor element 100 according to the first embodiment of the present invention.
[0081] In the next step, as shown in FIG. 14 , the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 is cut using a second dicing blade 52 having a blade thickness smaller than that of the first dicing blade 51 . More specifically, the second dicing blade 52 cuts the bonded member from the side of the glass wafer 4 in a thickness direction thereof along a center of the dicing region of the light blocking rein layers 5 , so that a cut surface 411 is formed in the dicing region, thereby obtaining the semiconductor optical sensor element 100 individually.
[0082] In this step, the second dicing blade 52 has the blade thickness smaller than that of the first dicing blade 51 and cuts the bonded member at a specific position, so that it is possible to completely cut through the light blocking rein layers 5 , while the light blocking rein layers 5 remain on the side surfaces of the glass wafer 4 .
[0083] Before the bonded member is cut in the dicing device, a dicing tape (not shown) is attached to the semiconductor wafer 101 . Alternatively, the dicing tape (not shown) may be attached to the glass wafer 4 before the bonded member is placed in the dicing device, so that the second dicing blade 52 cuts the bonded member from the side of the semiconductor wafer 101 .
[0084] Through the steps described above, the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 is fully cut in a specific size, thereby obtaining the semiconductor optical sensor element 100 formed of the light scattering chip 40 , the adhesive portion 9 , and the sensor chip 10 shown in FIG. 1 individually.
[0085] As described above, the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 is fully cut in a specific size. Accordingly, it is possible to obtain the semiconductor optical sensor element 100 formed of the light scattering chip 40 , the adhesive portion 9 , and the sensor chip 10 shown in FIG. 1 capable of preventing light from entering from the side surfaces of the light scattering chip 40 with the light blocking resin layers 5 . In the embodiment, the light scattering chip 40 has at least two sides shorter than those of the sensor chip 10 , and the light blocking resin layers 5 cover all side surfaces of the light scattering chip 40 , and the configuration is not limited thereto. Further, the bonded member may be fully cut with a laser method, other than the blade dicing method, as far as the light blocking resin layers 5 remain on the side surfaces of the light scattering chip 40 after the cut.
[0086] In the embodiment, the light blocking resin layers 5 blocks light entering from the side surfaces of the light scattering chip 40 , thereby improving performance of the semiconductor optical sensor element 100 . Further, it is possible to reduce a scrub line width of the sensor chip 10 , even when the light blocking resin layers 5 have a large width. Accordingly, it is possible to form a large number of chips on one single wafer, thereby improving yield and reducing cost.
[0087] In the embodiment, the light blocking resin layers 5 with a large width are cut according to the scrub line width of the sensor chip 10 , and the light blocking resin layers 5 are simultaneously formed per the semiconductor optical sensor element 100 , thereby reducing the number of steps. Further, the light blocking resin layers 5 are formed on the side surfaces of the light scattering chip 40 having brittle nature, thereby making it possible to prevent the light scattering chip 40 from cracking or being damaged, and to easily handle the semiconductor optical sensor element 100 . Further, the light blocking resin layers 5 are formed on the side surfaces of the light scattering chip 40 , thereby eliminating a separate guide cover for blocking light and reducing cost. Accordingly, it is not necessary to attach a light blocking cover one by one in a conventional method, and it is possible to produce the semiconductor optical sensor element 100 including the light blocking film from the wafers.
Second Embodiment
[0088] A second embodiment of the present invention will be explained next. FIG. 15 is a schematic sectional view showing a semiconductor optical sensor element according to the second embodiment of the present invention.
[0089] As shown in FIG. 15 , the semiconductor optical sensor element includes the light scattering chip 40 as the transparent chip and the sensor chip 10 bonded to the light scattering chip 40 with the adhesive portion 9 . Further, the light blocking resin layers 5 are disposed on entire side surfaces of the light scattering chip 40 and entire side surfaces of the sensor chip 10 . Other configuration is similar to that of the semiconductor optical sensor element 100 in the first embodiment shown in FIG. 1 .
[0090] A method of producing the semiconductor optical sensor element will be explained next. FIGS. 16(A) to 16(D) are schematic sectional views showing a bonded member formed of the semiconductor wafer 101 and the glass wafer 4 in a manufacturing process of the semiconductor optical sensor element according to the second embodiment of the present invention.
[0091] In the second embodiment, the semiconductor optical sensor element is produced with a method similar to that in the first embodiment from the step of forming the bonded member of the glass wafer 4 and the semiconductor wafer 101 shown in FIG. 2 to the step of forming the outer terminals 7 shown in FIG. 11 .
[0092] In the next step, as shown in FIG. 16(A) , a dicing tape 200 is attached to an entire surface of the semiconductor wafer 101 , and then the bonded member of the glass wafer 4 and the semiconductor wafer 101 is placed in the dicing device.
[0093] In the next step, as shown in FIG. 16(B) , the glass wafer 4 , the adhesive portion 9 , and the semiconductor wafer 101 are fully cut up to an interface between the dicing tape 200 and the semiconductor wafer 101 from the side of the glass wafer 4 using the first dicing blade 51 with the blade dicing method (alternatively, the laser method), so that the grooves 41 are formed. It is preferred that the first dicing blade 51 cuts the glass wafer 4 , the adhesive portion 9 , and the semiconductor wafer 101 in the cut width (the blade thickness) of 60 to 100 m, so that the same portion can be cut in the subsequent step.
[0094] In the next step, as shown in FIG. 16(C) , the light blocking resin is poured into the grooves 41 with the printing method or the dispensing method to form light blocking resin layers 5 . Accordingly, the bonded member is integrated one more time without the grooves 41 .
[0095] In the next step, as shown in FIG. 16(D) , the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 is cut using the second dicing blade 52 in the thickness direction thereof along the center of the light blocking rein layers 5 , thereby obtaining the semiconductor optical sensor element individually.
[0096] In this step, the second dicing blade 52 has the blade thickness smaller than that of the first dicing blade 51 and cuts the bonded member at a specific position, so that it is possible to completely cut through the light blocking rein layers 5 , while the light blocking rein layers 5 remain on the side surfaces of the glass wafer 4 , the adhesive portion 9 , and the semiconductor wafer 101 .
[0097] Through the steps described above, the bonded member formed of the semiconductor wafer 101 and the glass wafer 4 is fully cut in a specific size. Accordingly, it is possible to obtain the semiconductor optical sensor element formed of the light scattering chip 40 , the adhesive portion 9 , and the sensor chip 10 shown in FIG. 15 capable of preventing light from entering from the side surfaces of the glass wafer 4 with the light blocking resin layers 5 .
[0098] In the embodiment, the light blocking resin layers 5 are disposed on the entire side surfaces of the semiconductor optical sensor element (the light scattering chip 40 , the adhesive portion 9 , and the sensor chip 10 ). Accordingly, it is possible to block light more securely, and to improve moisture resistance and sir tightness of an interface.
Third Embodiment
[0099] A third embodiment of the present invention will be explained next. FIG. 17 is a schematic sectional view showing a semiconductor optical sensor element 102 according to the third embodiment of the present invention.
[0100] As shown in FIG. 17 , the semiconductor optical sensor element 102 includes the light scattering chip 40 as the transparent chip and the sensor chip 10 bonded to the light scattering chip 40 with the adhesive portion 9 . Further, the side surfaces of the glass wafer 4 are formed in a two-stage step shape SP, and the light blocking resin layers 5 are disposed on the side surfaces of the light scattering chip 40 , so that the light blocking resin layers 5 protrude inside toward the light reception portion 11 to define an opening portion thereof. Other configuration is similar to that of the semiconductor optical sensor element 100 in the first embodiment shown in FIG. 1 .
[0101] In the embodiment, in the dicing step, a plurality of dicing blade having different thicknesses is used to form the two-stage step shape SP of the side surfaces of the light scattering chip 40 .
Fourth Embodiment
[0102] A fourth embodiment of the present invention will be explained next. FIG. 18 is a schematic sectional view showing a semiconductor optical sensor element 103 according to the fourth embodiment of the present invention.
[0103] As shown in FIG. 18 , the semiconductor optical sensor element 102 includes the light scattering chip 40 as the transparent chip and the sensor chip 10 bonded to the light scattering chip 40 with the adhesive portion 9 . Further, the side surfaces of the glass wafer 4 are formed in an inclined shape CL not perpendicular but inclined relative to the main surface, and the light blocking resin layers 5 are disposed on the side surfaces of the light scattering chip 40 , so that the light blocking resin layers 5 protrude inside toward the light reception portion 11 to define an opening portion thereof. Other configuration is similar to that of the semiconductor optical sensor element 100 in the first embodiment shown in FIG. 1 .
[0104] In the embodiment, in the dicing step, a dicing blade having a thickness gradually decreasing toward an outer circumferential edge thereof in a radial direction thereof is used to form the inclined shape CL of the side surfaces of the light scattering chip 40 .
[0105] When the side surfaces of the light scattering chip 40 are formed in the inclined shape CL, stray light tends to be reflected toward a circumference of the light reception portion 11 , thereby reducing noise due to stray light.
[0106] In the embodiments described above, in the light scattering chip 40 , the glass wafer 4 has one flat main surface (the inner surface) and the light scattering portion 121 formed on the backside surface (the outer surface). A second light scattering portion may be formed on the inner surface of the glass wafer 4 , as far as the light scattering portion 121 is formed on the backside surface (the outer surface). Further, the light reception portion 11 of the sensor chip 10 is attached to the light scattering chip 40 through the adhesive portion 9 . Alternatively, a space (a gap) may be provided above the light reception portion 11 , so that the sensor chip 10 is attached to the light scattering chip 40 through the adhesive portion 9 around the light reception portion 11 .
[0107] The disclosure of Japanese Patent Application No. 2008-333026, filed on Dec. 26, 2008, is incorporated in the application by reference.
[0108] While the invention has been explained with reference to the specific embodiments of the invention, the explanation is illustrative and the invention is limited only by the appended claims.
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A method of producing a semiconductor optical sensor element includes the steps of: forming an oxide film on a silicon carbide substrate; forming a gate electrode layer on the oxide film; patterning the gate electrode layer to form a gate electrode; and processing thermally the gate electrode layer or the gate electrode under an oxidation environment. Further, the gate electrode layer or the gate electrode is thermally processed under the oxidation environment at a temperature between 750° C. and 900° C.
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This application is a continuation of application Ser. No. 12/217,813, filed Jul. 9, 2008 now U.S. Pat. No. 7,789,065.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates generally to the modification of engine valve lift for producing an engine valve event in an internal combustion engine, particularly to engine braking apparatus and methods for converting an internal combustion engine from a normal engine operation to an engine braking operation.
2. Prior Art
It is well known in the art to employ an internal combustion engine as brake means by, in effect, converting the engine temporarily into a compressor. It is also well known that such conversion may be carried out by cutting off the fuel and opening the exhaust valve(s) at or near the end of the compression stroke of the engine piston. By allowing compressed gas (typically, air) to be released, energy absorbed by the engine to compress the gas during the compression stroke is not returned to the engine piston during the subsequent expansion or “power” stroke, but dissipated through the exhaust and radiator systems of the engine. The net result is an effective braking of the engine.
An engine brake is desirable for an internal combustion engine, particularly for a compression ignition type engine, also known as a diesel engine. Such engine offers substantially no braking when it is rotated through the drive shaft by the inertia and mass of a forward moving vehicle. As vehicle design and technology have advanced, its hauling capacity has increased, while at the same time rolling and wind resistances have decreased. Accordingly, there is a heightened braking need for a diesel-powered vehicle. While the normal drum or disc type wheel brakes of the vehicle are capable of absorbing a large amount of energy over a short period of time, their repeated use, for example, when operating in hilly terrain, could cause brake overheating and failure. The use of an engine brake will substantially reduce the use of the wheel brakes, minimize their wear, and obviate the danger of accidents resulting from brake failure.
There are different types of engine brakes. Typically, an engine braking operation is achieved by adding an auxiliary engine valve event called an engine braking event to the engine valve event for the normal engine operation. Depending on how the engine valve event is produced, an engine brake can be defined as:
(a) Type I engine brake—the engine braking event is produced by importing motions from a neighboring cam, which generates the so called Jake brake; (b) Type II engine brake—the engine braking event is produced by altering existing cam profile, which generates a lost motion type engine brake; (c) Type III engine brake—the engine braking event is produced by using a dedicated cam for engine braking, which generates a dedicated cam (rocker) brake; (d) Type IV engine brake—the engine braking event is produced by modifying the existing valve lift, which normally generates a bleeder type engine brake; and (e) Type V engine brake—the engine braking event is produced by using a dedicated valve train for engine braking, which generates a dedicated valve (the fifth valve) engine brake.
The engine brake can also be divided into two big categories, i.e., the compression release engine brake (CREB) and the bleeder type engine brake (BTEB).
Compression Release Engine Brake (CREB)
Conventional compression release engine brakes (CREB) open the exhaust valve(s) at or near the end of the compression stroke of the engine piston. They typically include hydraulic circuits for transmitting a mechanical input to the exhaust valve(s) to be opened. Such hydraulic circuits typically include a master piston which is reciprocated in a master piston bore by a mechanical input from the engine, such as the pivoting movement of the fuel injector rocker arm. Hydraulic fluid in the circuit transmits the motion of the master piston to a slave piston in the circuit, which in turn, reciprocates in a slave piston bore in response to the flow of hydraulic fluid in the circuit. The slave piston acts either directly or indirectly on the exhaust valve(s) to be opened during the engine braking operation. This is a Type I engine brake.
An example of a prior art CREB is provided by the disclosure of Cummins, U.S. Pat. No. 3,220,392 (“the '392 patent”), which is hereby incorporated by reference. Engine braking systems based on the '392 patent have enjoyed great commercial success. However, the prior art engine braking systems have certain inherent disadvantages that have limited their application to primarily larger vehicles such as heavy duty trucks (and typically, on engines having a displacement of about 10 liters or more), and their retrofit to existing engines is largely impossible without substantial modification of the engine cylinder head.
One of the disadvantages associated with the conventional prior art CREB system is due to the fact that the load from engine braking is supported by the engine components. Because the engine braking load is much higher than the normal engine operation load, many parts of the engine, such as the rocker arm, the push tube, the cam, etc. must be modified to accommodate the engine braking system. Thus, the overall weight, height, and cost of using the prior art CREB system are likely to be excessive, and limit its commercial application.
Another disadvantage associated with the conventional prior art CREB system is the high and unique noise generated by the releasing of high-pressure gas or “blow down” through the exhaust valve(s) during the compression stroke, near the top dead center position of the engine piston.
Additional disadvantages of the prior art systems reside in their relative complexity and the necessity for using precision components because they require accurate timing and hydraulic actuators capable of opening the exhaust valves precisely when required. Thus they may be comparatively expensive and difficult or impossible to install on certain engines.
Yet another disadvantage associated with the conventional prior art CREB system of hydraulic type is the compliance of the braking system, which may cause the braking valve lift to collapse at the peak braking load (near compression top dead center (TDC) of the engine piston) and further increase the braking load. The large reduction of braking valve lift due to compliance will reduce the braking performance and excessive braking load may cause engine damage.
Bleeder Type Engine Brake (BTEB)
The operation of a bleeder type engine brake (BTEB) has also long been known. During bleeder type engine braking, in addition to the normal exhaust valve lift, the exhaust valve(s) may be held slightly open during a portion of the cycle (partial-cycle bleeder brake) or open continuously throughout the non-exhaust strokes (intake stroke, compression stroke, and expansion or power stroke) (full-cycle bleeder brake). The primary difference between a partial-cycle bleeder brake and a full-cycle bleeder brake is that the former does not have exhaust valve lift during most of the intake stroke. An example of BTEB system and method is provided by the disclosure of the present inventor, U.S. Pat. No. 6,594,996, which is hereby incorporated by reference.
Usually, the initial opening of the braking valve(s) in a bleeder braking operation is far in advance of the compression TDC and then the braking valve lift is held constant for a period of time. As such, a BTEB may require much lower force to open the valve(s) due to early valve actuation, and generates less noise due to continuous bleeding instead of the rapid blow down of the CREB. Moreover, a BTEB often requires fewer components and can be manufactured at a lower cost. Thus, a BTEB can overcome some of the disadvantages of the CREB. Indeed, the BTEB systems have achieved certain commercial success, especially in the application to smaller vehicles, such as the middle and light duty trucks (and typically, on engines having a displacement of less than 10 liters). Following are some BTEB systems that are currently on the market.
(a) BTEB Operated by Rocker Arm with Eccentric Shift
U.S. Pat. No. 5,335,636 discloses a bleeder type engine brake (BTEB) system wherein the pivot center of the engine exhaust rocker arm is displaced or shifted in a downward direction by an eccentric that is connected to a hydraulic piston/actuator by a level arm. The displacement or shift of the rocker arm pivot center causes the exhaust valves to open during braking operation of the engine to create a partial cycle bleeder braking event. This is a Type IV engine brake.
The BTEB system of the type described above requires an extra mechanical component between the hydraulic piston or actuator and the rocker arm. The system also requires intermediate arms, a second rocker arm eccentric bore, features on the small end of the actuation/pivot arm and features on the mechanical actuation end of the piston. These parts and features all add cost and complexity, and reduce system reliability. Also, the system is integrated into the engine exhaust valve train. Load from engine braking by opening both exhaust valves is so high that other parts of the engine, such as the rocker arm, the push tube, the cam, etc. must be redesigned. Finally, such type of engine brakes cannot be retrofitted into existing engines.
(b) BTEB Operated by a Dedicated Engine Braking Valve
U.S. Pat. No. 5,168,848 discloses a bleeder type engine brake (BTEB) system that has an extra exhaust valve in addition to the normal engine exhaust valve(s). The extra exhaust valve is dedicated to engine braking and opened exclusively during braking operation of the engine. The dedicated engine braking valve is actuated by pneumatic or hydraulic means and held open to create a full cycle bleeder braking event. This is a Type V engine brake.
The BTEB system of the type described above is integrated into the cylinder head of the engine, thereby substantially conditioning its design and manufacture. The engine braking device is therefore dedicated to a particular type of engine. Moreover, the introduction of the extra exhaust valve creates an extra pocket in the combustion chamber, which increases engine emission. Also, such type of engine brakes can not be used in existing engines.
(c) BTEB Operated by Engine Valve Floating
U.S. Pat. No. 5,692,469 and U.S. Pat. No. 7,013,867 disclose a bleeder type engine brake (BTEB) system for engines with one and two exhaust valves per cylinder. The BTEB system includes a throttling device (also known as an exhaust brake) capable of raising exhaust pressure high enough to cause each exhaust valve to float near the end of each intake stroke. In this intermediate opening or floating of the exhaust valve, it is possible to intervene with the braking device so that the exhaust valve, which is about to close after the intermediate opening, is intercepted by a control piston charged with oil pressure and prevented from closing to create a partial cycle bleeder braking event. This is a Type IV engine brake.
The BTEB system of the type described above may not be reliable because it depends on the intermediate opening or floating of the braking exhaust valve, which is not consistent, both in timing and magnitude. As is well known in the art, exhaust valve floating is highly engine speed dependent and affected by the quality and control of the exhaust brake, and also the design of the exhaust manifold. There may be not enough or none valve floating for the actuation of the engine braking device at middle and low engine speeds when the engine brake is highly demanded since the engine is mostly driving at such speeds. Again, such type of engine brakes may not be able to retrofit into existing engines.
(d) BTEB Operated by High-Pressure Oil
U.S. Pat. No. 6,866,017 and U.S. Pat. No. 6,779,506 disclose a bleeder type engine brake (BTEB) that is actuated and controlled by high-pressure hydraulic fluid, or oil. The hydraulic fluid is supplied from a hydraulic rail, or oil rail, to a respective fuel injector at each engine cylinder to act on a piston in the fuel injector to force a charge of fuel into the respective combustion chamber during normal engine operation. A hydraulic actuator in the engine brake uses the already available high-pressure oil to actuate and hold one exhaust valve open to create a full cycle bleeder braking event. This is also a Type IV engine brake.
The BTEB system of the type described above is dedicated to a particular type of engine that has high-pressure oil rail (source), which greatly limits its application. Sophisticated electronic control is needed to eliminate excessive oscillations of the shared common high pressure source and to ensure a smooth transition between engine braking operation and normal engine operation. Also, such type of engine brakes cannot be retrofitted into existing engines.
It is clear from the above description that the prior-art engine brake systems have one or more of the following drawbacks:
(a) The system can only be installed on a particular type of engines;
(b) The system cannot be retrofitted to existing engines;
(c) The engine braking load is carried by the engine components;
(d) The system installment needs redesign of the engine or engine components;
(e) The system has too many components and is too complex;
(f) The system increases the manufacturing tolerance requirements and is too costly;
(g) The system is not reliable and only work at certain engine speeds; and
(h) The system affects normal engine performance (emission, oil rail pressure, etc.).
SUMMARY OF THE INVENTION
The engine braking apparatus of the present invention addresses and overcomes the foregoing drawbacks of prior art engine braking systems.
One object of the present invention is to provide an engine braking apparatus that can be installed on all types of engines, especially on smaller size engines.
Another object of the present invention is to provide an engine braking apparatus that can be retrofitted to existing engines.
Yet another object of the present invention is to provide an engine braking apparatus wherein the engine (valve train) components are not subject to the heavy engine braking loads so that the installment of the engine braking apparatus does not need redesign of the engine or engine components.
Still another object of the present invention is to provide an engine braking apparatus with fewer components, reduced complexity, lower cost, and increased system reliability.
A further object of the present invention is to provide such an engine braking apparatus that contains a braking valve lash adjusting mechanism so that it does not increase the manufacturing tolerance requirements of many of the components.
Still a further object of the present invention is to provide an engine braking apparatus that is rugged and simple in construction, easy to install, reliable in operation and effective at all engine speeds.
Yet a further object of the present invention is to provide engine brake actuation means that transmit force, or the engine braking load, through mechanical linkage means that does not have high compliance and overloading problems associated with hydraulic means. The mechanical linkage means includes rotatable devices, slidable devices, ball-locking devices, and a toggle device.
Still another object of the present invention is to provide an engine braking apparatus that will not interfere with the normal engine operation.
These and other advantages of the present invention will become more apparent from the following description of the preferred embodiments in connection with the following figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart illustrating the general relationship between a normal engine operation and an added engine braking operation according to one version of the present invention.
FIG. 2 is a schematic diagram of an engine braking apparatus with an exhaust valve train of the engine according to a first embodiment of the present invention.
FIG. 3 is a schematic diagram of an engine braking apparatus according to a second embodiment of the present invention.
FIG. 4A is a schematic diagram of an engine braking apparatus according to a third embodiment of the present invention.
FIG. 4B is a schematic diagram of a slidable plunger contained in the engine braking apparatus shown in FIG. 4A .
FIG. 5A is a schematic diagram of an engine braking apparatus according to a fourth embodiment of the present invention.
FIG. 5B is a schematic diagram of a slidable plunger contained in the engine braking apparatus shown in FIG. 5A .
FIG. 6 is a schematic diagram of an engine braking apparatus with an exhaust valve train of the engine according to a fifth embodiment of the present invention.
FIGS. 7A and 7B are schematic diagrams of an engine brake control mean at its “on” or “feeding” position and its “off” or “drain” position according to at least one embodiment of the present invention.
FIG. 8A is a schematic diagram of an engine braking apparatus according to a sixth embodiment of the present invention.
FIG. 8B is a schematic diagram of a slidable plunger contained in the engine braking apparatus shown in FIG. 8A .
FIGS. 8C and 8D are schematic diagrams of a spring used in the engine braking apparatus shown in FIG. 8A .
FIG. 8E is a schematic diagram showing the relationship between the spring shown in FIGS. 8C and 8D and the slidable plunger shown in FIG. 8B .
FIG. 9A is a schematic diagram of an engine braking apparatus with an exhaust valve train of the engine according to a seventh embodiment of the present invention.
FIG. 9B is a schematic diagram of a slidable plunger assembly contained in the engine braking apparatus shown in FIG. 9A .
FIG. 10 is a schematic diagram of an engine braking apparatus with an exhaust valve train of the engine according to an eighth embodiment of the present invention.
FIGS. 11A and 11B are schematic diagrams of an engine brake actuation means at its “off” and “on” position for an engine braking apparatus according to a ninth embodiment of the present invention.
FIGS. 12A and 12B are schematic diagrams of an engine brake actuation means at its “off” and “on” position for an engine braking apparatus according to a tenth embodiment of the present invention.
FIGS. 13A and 13B are schematic diagrams of an engine brake actuation means at its “off” and “on” position for an engine braking apparatus according to an eleventh embodiment of the present invention.
FIGS. 14A and 14B are schematic diagrams of engine brake actuation means at its “off” and “on” position for an engine braking apparatus according to an twelfth embodiment of the present invention.
FIGS. 15A and 15B are schematic diagrams of engine brake actuation means at its “off” and “on” position for an engine braking apparatus according to an thirteenth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation, not limitation, of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope and spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
FIG. 1 is a flow chart illustrating the general relationship between a normal engine operation 20 and an added engine braking operation 10 according to one version of the present invention. An internal combustion engine contains at least one exhaust valve 300 and an exhaust valve lifter 200 for cyclically opening and closing the exhaust valve during the normal engine operation 20 . The engine braking operation 10 is achieved through engine brake control means 50 and engine brake actuation means 100 that contains an inoperative position 0 and an operative position 1 . To convert the engine from its normal operation 20 to the braking operation 10 , the control means 50 will move the actuation means 100 from the inoperative position 0 to the operative position 1 , which takes place after the exhaust valve 300 is actuated by the exhaust valve lifter 200 . By default, the control means 50 is at its off position, the actuation means 100 at the inoperative position 0 , and the engine brake disengaged from the exhaust valve 300 .
FIG. 2 is a schematic diagram of an engine braking apparatus with an engine exhaust valve train according to one embodiment of the present invention. A typical truck engine has two exhaust valves 300 a and 300 b per engine cylinder. The two valves are biased upwards against their seats 320 on the engine cylinder head 500 by engine valve springs 310 a and 310 b to seal gas (air, during engine braking) from flowing between the engine cylinder and the exhaust manifolds 600 . The exhaust valve lifter 200 includes a rocker arm 210 pivotally mounted on a rocker shaft 205 for transmitting a mechanical input from a cam 230 to the exhaust valves through a cam follower 235 and a valve bridge 400 . The cam contains a lift profile 220 above the Cain inner base circle 225 for cyclically opening and closing the exhaust valves during the normal engine operation.
With continued reference to FIG. 2 , the engine brake actuation means 100 includes a brake housing 125 that is fixed on the engine block (not shown). In the brake housing there is a bore 120 , in which a rotatable device 135 with a stem 115 rotates. Underneath the rotatable device there are two surfaces 140 and 145 that have a height difference 130 . The first surface 140 is commensurate with the operative position for the engine braking operation and the second surface 145 commensurate with the inoperative position for the normal engine operation. The rotatable device 135 is biased to the inoperative position by an engine brake control means 50 that is also fixed on the engine block. The control means 50 comprises an electromechanical system that may contain an electric motor 51 , such as the well-known step motor, which has a predetermined rotational angle 53 . The electric motor is turned on and off by electric current through the positive and negative terminals 55 and 57 on the electric motor.
The actuation means 100 as shown in FIG. 2 is at its inoperative position and the engine brake is disengaged from the engine operation. When engine brake is needed, the control means 50 is turned on, which tends to rotate the actuation means 100 into the operative position. However, there is an intervention between the rotatable device 135 and the valve bridge 400 when the exhaust valve 300 a is at or near its seat 320 . The actuation means 100 is waiting for the lift or opening of the exhaust valve. Only after the exhaust valve 300 a is pushed down by the exhaust valve lifter 200 , the actuation means 100 can be rotated into its operative position at which the first surface 140 will be over the valve bridge surface 405 . When the exhaust valve 300 a returns, the valve bridge surface 405 will contact the first surface 140 on the actuation means 100 . Due to the height difference 130 between the first surface 140 and the second surface 145 , the exhaust valve 300 a pushed out by the exhaust valve lifter 200 cannot close or return to its seat 320 but is held open to create an engine braking event.
The engine brake according to the embodiment shown in FIG. 2 is a bleeder type or Type IV engine brake. The engine braking event is produced by modifying the existing engine valve lift. The modified lift of the engine braking valve 300 a by the actuation means 100 during non-exhaust strokes (intake stroke, compression stroke, and expansion or power stroke) is approximately 0.5 to 3.0 millimeters, much smaller than the lift of the same engine valve by the exhaust valve lifter 200 during the engine exhaust stroke. Such a small lift is within the regular valve seating ramp and the impact load between the actuation means 100 and the braking valve 300 a is small. However, we can further reduce such impact load by improving the existing exhaust valve lift profile with an even slower seating ramp starting before the valve 300 a contacts the actuation means 100 .
The load generated by the engine braking event according to the embodiment of the present invention is not passed to the exhaust valve lifter 200 , but to the engine block through a lash adjusting screw 110 that is secured to the brake housing 125 by a lock nut 105 , which avoids the excessive overall engine weight, height, and cost that were experienced with some prior art engine braking systems whose load is carried by the engine components.
A lash adjusting system with the lash adjusting screw 110 and the rotatable device 135 that is also slidable in the housing is designed for setting a lash between the actuation means 100 and the braking valve 300 a . The braking valve lash adjustment is necessary due to engine valve growth and manufacturing tolerance. The height difference 130 between the first surface 140 and the second surface 145 minus the braking valve lash determines the braking valve lift for the engine braking event or operation. Also, the lash adjusting screw 110 sits in a circumferential groove 150 in the rotatable device 135 , which forms a motion limiting means that can be used to control the rotational angle between the inoperative position and operative position.
Since the engine braking valve lift is controlled through the lash adjustment, not by a stroke limited piston, it is much less affected by the dimensional tolerance of the engine brake components. Therefore, the engine braking apparatus according to the embodiment of the present invention avoid using high cost precision components that some prior art engine braking systems require.
FIG. 3 shows a similar embodiment to that shown in FIG. 2 except that the engine brake control means 50 is an electrohydromechanical system that contains a three-way solenoid valve 51 a . The solenoid valve 51 a has a spool 58 with a predetermined stroke 53 a and is turned on and off by an electric current through the positive and negative terminals 55 and 57 . The control means 50 could be remotely located and used for controlling multiple cylinder engine brakes. A fluid circuit is formed in the engine brake actuation means 100 and in the engine for transmitting hydraulic fluid, for example, engine oil, from the control means 50 to the actuation means 100 . When the spool 58 slides in the brake housing 125 , it opens or closes a port (an orifice) 11 or 22 to allow the engine oil into or out of the fluid circuit including a flow passage 126 in the brake housing 125 . There is an annular cut or groove 127 on the stem 115 through which the pressurized engine oil can pass to a flow passage 128 and spray out of a bleeding orifice 129 in the rotatable device 135 when the engine brake is turned on.
The rotatable device 135 is biased against the adjusting screw 110 to the inoperative position by a spring 118 that can provide both compressional and torsional preload. One end of the spring 118 is fixed in the brake housing 125 and the other end in the rotatable device 135 . When the liquid flows out of the bleeding orifice 129 , it generates a jet propulsion force opposite to the flow jet direction, which overcomes the torsional preload by the spring 118 and rotates the rotatable device 135 from the inoperative position into the operative position when the engine braking valve is pushed down by the exhaust valve lifter 200 . The angle of rotation is controlled by a motion limiting means defined by the circumferential groove 150 in the rotatable device 135 , which has stop surfaces against the adjusting screw 110 .
When engine braking is not needed, the three-way solenoid valve 51 a is turned off and the spool 58 will close the oil supply port 11 and open the drain port 22 ( FIG. 3 ). There will be no oil jet flow out of the bleeding orifice 129 and thus no propulsion force on the rotatable device 135 so that it will return back to the inoperative position by the spring 118 , and the actuation means 100 will be disengaged from the normal engine operation. Note that the drain port 22 may be not needed for turning off the engine brake due to the bleeding orifice 129 . Therefore, a two-way solenoid valve plus the bleeding orifice may be used to replace the three-way solenoid valve 51 a.
Alternatively, the rotation of the rotatable device 135 can be achieved by other types of fluid and mechanical interaction, such as jet flow out of the brake housing 125 that impinges on the rotatable device 135 with an impulsion force; hydraulic piston in the brake housing 125 that acts on the rotatable device 135 ; or mechanical means, such as gear system or rope and pulley system; electric means; magnetic means; and a combination of two or more of the above means, such as the electrohydromechanical system.
FIG. 4A is a schematic diagram of an engine braking apparatus according to another embodiment of the present invention, in which the engine brake actuation means 100 contains a slidable device 135 a that will not rotate but only slide in the bore 120 of the brake housing 125 for the braking valve lash adjustment. The slidable device is biased up by a compression spring 118 a against the lash adjusting screw 110 . In the slidable device 135 a there is a horizontal bore 415 in which a braking plunger 136 shown with details in FIG. 4B can only slide due to an anti-rotation guide that is formed by two surfaces 136 a on the braking plunger fitting in a slot 139 cut underneath the bore 415 . The braking plunger contains a first surface 140 commensurate with the operative position and a second surface 145 commensurate with the inoperative position. The two surfaces are located on the protrusion portion of the braking plunger and have a height difference 130 . The braking plunger 136 is biased inwards to the inoperative position by a flat (or leaf) spring 177 . One end of the spring 177 is secured to the slidable device 135 a by at least one screw 179 and the other end is on the braking plunger surface 136 b and hooked onto the protrusion 136 c.
Note that the slidable device 135 a can have different shapes. If it is a piston, then there will be a bore 120 a in the brake housing 125 to match the piston, and also an anti-rotation mechanism that is formed by a hole or a radial groove 150 against the lash adjusting screw 110 for preventing the rotation of the slidable device. If it is a rectangular or square block, then 120 a will be a flat surface. The stem 115 can also take different shapes as long as it can slide up and down in the brake housing for the lash adjustment between the engine brake actuation means and the engine braking valve.
When engine braking is needed, the control means 50 containing the solenoid valve 51 a ( FIG. 3 ) is turned on. The pressurized engine oil gets into the flow passage 126 in the brake housing 125 , overcomes the preload by the spring 177 , and pushes the braking plunger 136 out after the exhaust valve 300 a is pushed down by the exhaust valve lifter 200 ( FIG. 4A ). There is a motion limiting means that controls the movement of the braking plunger 136 . The plunger movement or stroke is defined by the distance between the stop surface 420 at the left end of the slot or undercut 139 and the spring 177 whose stop surface contacts the stop surface 136 d on the braking plunger. Once the first surface 140 on the braking plunger 136 is over the valve bridge top surface 405 , the exhaust valve 300 a pushed out by the exhaust valve lifter 200 cannot close or return to its seat 320 but is held open to create an engine braking event.
The lash adjusting system for this engine braking apparatus comprises the lash adjusting screw 110 , the slidable device 135 a in the housing 125 , and the plunger 136 . It is designed for setting a lash between the brake actuation means 100 and the braking valve 300 a . The height difference 130 between the first surface 140 and the second surface 145 on the plunger minus the braking valve lash determines the braking valve lift for the engine braking event or operation.
FIGS. 5A and 5B show a similar embodiment to that shown in FIGS. 4A and 4B except that the braking plunger 136 is biased to the inoperative position by a compression spring 177 a . One end of the spring sits on the slidable device 135 a and the other end on the braking plunger. Another difference is the motion limiting means. A pin 142 on the slidable device fits into an axial groove 137 in the braking plunger for controlling the axial motion of the braking plunger. The pin and groove combination also forms an anti-rotation guide for the braking plunger. Also the operative and inoperative surfaces 140 and 145 are undercuts on the braking plunger as shown in FIG. 5B .
FIG. 6 shows another embodiment with a slidable device. Here the brake apparatus further comprises the valve bridge 400 . A braking plunger 136 as shown in FIG. 4B now is slidably disposed in a bore 415 in the valve bridge 400 . The plunger 136 is guided by an anti-rotation guide formed by two surfaces 136 a ( FIG. 4B ) on the plunger and a slot 139 that is cut on top of the bore 415 . The plunger 136 contains a first surface 140 (the operative position) and a second surface 145 (the inoperative position). Facing upwards to the lash adjusting screw 110 , the two surfaces are located on the protrusion portion of the braking plunger 136 and have a height difference 130 . The lash adjusting screw is secured to the brake housing 125 by a lock nut 105 . The braking plunger 136 is biased inwards to the inoperative position by the spring 177 . One end of the spring 177 is secured to the valve bridge 400 by at least one screw 179 and the other end is on the braking plunger surface 136 b ( FIG. 4B ).
FIGS. 7A and 7B are schematic diagrams of an engine brake control means 50 at its on and off positions. When engine braking is needed, the control means 50 containing a three-way solenoid valve 51 a is turned on as shown in FIG. 7A , and the port 11 is opened to allow engine oil to a fluid circuit comprising a flow passage 211 in the rocker shaft 205 of the engine. The engine oil flow passes a radial orifice 212 , through an undercut 213 , and into a flow passage 214 in the rocker arm 210 . Note that the control means 50 could be remotely located and used for controlling multiple cylinder engine brakes, and the fluid circuit may reach other components of the engine.
With reference back to FIG. 6 , the engine oil flows from the rocker arm 210 to a pressure chamber 425 in the valve bridge 400 through a flow passage 410 . The engine oil pressure overcomes the preload of the spring 177 , and pushes the braking plunger 136 out after the valve bridge 400 (and the braking valve 300 a ) is pushed away from the adjusting screw 110 by the exhaust valve lifter 200 . The movement of the braking plunger 136 is controlled by a motion limiting means with a plunger stroke defined by the distance between the stop surface 420 on the valve bridge 400 and the spring 177 whose stop surface contacts the stop surface 136 d ( FIG. 4B ) on the braking plunger 136 . Once the operative surface 140 is out and under the adjusting screw 110 , the exhaust valve 300 a pushed out by the exhaust valve lifter 200 cannot close or return to its seat 320 but is held open to create an engine braking event.
The lash adjusting system for this engine braking apparatus ( FIG. 6 ) comprises the lash adjusting screw 110 , the valve bridge 400 , and the braking plunger 136 slidable in the valve bridge. The height difference 130 between the first surface 140 and the second surface 145 on the plunger minus the braking valve lash determines the braking valve lift for the engine braking event or operation.
When engine braking is not needed, the three-way solenoid valve 51 a is turned off and the spool 58 will close the oil supply port 11 and open the drain port 22 as shown in FIG. 7B . Without oil pressure acting on the plunger 136 , it will be pushed back by the spring system 177 . Once the second surface 145 is under the adjust screw as shown in FIG. 6 , the engine brake means 100 is at the inoperative position and disengaged from the normal engine operation.
Note that the bleeding orifice 418 in the valve bridge is optional and used for turning off the engine brake faster or even totally eliminating the need of the drain port 22 . Therefore, a two-way solenoid valve plus the bleeding orifice 418 may be used to replace the three-way solenoid valve 51 a . Also a spring may be desirable to bias the rocker arm 210 against the valve bridge for a better sealing of the fluid from the passage 214 in the rocker arm to the passage 410 in the valve bridge.
FIG. 8A shows a similar embodiment to that shown in FIG. 6 except that the braking plunger 136 shown with details in FIG. 8B is biased to the inoperative position by a special spring device 138 that also acts as a stop and an anti-rotation guide to the braking plunger as shown in FIGS. 8C , 8 D and 8 E. Another difference is that the first and second surfaces 140 and 145 are not on the protrusion ( FIG. 4B ) but undercuts on the braking plunger as shown in FIG. 8B . The bleeding orifice 418 in the valve bridge as shown in FIG. 6 can still be used but is not shown here. Therefore the three-way solenoid valve with the drain port 22 in FIG. 7B is used for turning off the engine brake.
With continued reference to FIGS. 8A and 8B , the braking plunger 136 is slidable in the valve bridge 400 and biased to the inoperative position by a spring 138 a of the spring device 138 whose details are shown in FIGS. 8C and 8D . There is an anti-rotation guide and the braking plunger with guiding surfaces 136 a can only slide between the two legs 138 b of the spring device that are fixed into the valve bridge 400 . The spring 138 a acts on surface 136 b of the braking plunger. The slot or cut 138 c in the spring fits onto the protrusion 136 c on the plunger, which can also acts as a guide to the sliding of the braking plunger as shown in FIG. 8E . A motion limiting means controls the motion of the braking plunger 136 . The plunger stroke is defined by the distance between the stop surface 420 on the valve bridge 400 and the spring legs 138 b that contact the stop surface 136 d on the braking plunger as shown in FIGS. 8B to 8E .
FIG. 9A shows another embodiment with the braking plunger 136 shown with details in FIG. 9B sliding in the valve bridge 400 . The plunger 136 contains a first surface 140 commensurate with the operative position and a second surface 145 commensurate with the inoperative position. The two surfaces are on two cylindrical surfaces and have a height difference 130 ( FIG. 9B ). The braking plunger 136 is biased to the inoperative position ( FIG. 9A where surface 145 is under lash adjusting screw 110 ) by a coil spring 177 a . One end of spring 177 a sits on a spring seat 176 that is mounted on the braking plunger 136 . The other end of the spring sits on another spring seat 178 . Seat 178 is slidable in the bore 183 a but normally is stopped against a pin 142 fixed in the valve bridge 400 . There is a slot 137 or axial cut across the bore 183 a in the braking piston 136 , which has a width slightly larger than the pin 142 . The pin 142 and the slot 137 can form a motion limiting means to control the movement of the braking plunger 136 .
When engine braking is needed, the control means 50 is turned on as shown in FIG. 7A to allow engine oil to flow through the engine braking fluid circuit and into a pressure chamber 425 in the valve bridge 400 through a flow passage 410 ( FIG. 9A ). The engine oil pressure overcomes the preload of the spring 177 a , and pushes the braking plunger 136 out of the bore 415 after the valve bridge 400 (and the braking valve 300 a ) is pushed away from the adjusting screw 110 by the exhaust valve lifter 200 . When the surface 136 d in the slot 137 hits the pin 142 , the braking plunger 136 will stop moving. Now the braking plunger 136 is fully out or extended and the operative surface 140 is under the adjusting screw 110 , the exhaust valve 300 a pushed out by the exhaust valve lifter 200 cannot close or return to its seat 320 but is held open to create an engine braking event.
The lash adjusting system for this engine braking apparatus ( FIG. 9A ) comprises the lash adjusting screw 110 , the valve bridge 400 , and the braking plunger 136 slidable in the valve bridge. The height difference 130 between the first surface 140 and the second surface 145 on the plunger ( FIG. 9B ) minus the braking valve lash 132 ( FIG. 9A ) determines the braking valve lift for the engine braking event or operation.
When engine braking is not needed, the control means 50 is turned off and there will be no or little oil supplied to the engine braking fluid circuit. The oil pressure will not be high enough and plunger 136 will be pushed back into the valve bridge 400 by the spring 177 a . Once the second surface 145 is under the lash adjusting screw 110 as shown in FIG. 9A , the engine brake means 100 is at the inoperative position and disengaged from the normal engine operation. Again, the bleeding orifice 418 in the valve bridge is optional and used for turning off the engine brake.
FIG. 10 shows yet another embodiment with the braking plunger 136 slidably disposed in the valve bridge 400 . However, the plunger 136 only contains the first surface 140 commensurate with the operative position, while the second surface 145 commensurate with the inoperative position is on the valve bridge 400 and separated from the lash adjusting screw 110 by a lash 132 . The two surfaces 140 and 145 have a height difference 130 . The braking plunger 136 is biased to the inoperative position by a coil spring 177 a . One end of spring 177 a is on the braking plunger 136 and the other end on a spring seat 178 that is secured on the valve bridge 400 by at least one screw 179 . Seat 178 is also used as a stop to the braking plunger 136 , which limits the movement of the braking plunger 136 .
When engine braking is needed, the control means 50 is turned on ( FIG. 7A ) to allow engine oil to flow through the engine braking fluid circuit and into a pressure chamber 425 in the valve bridge 400 as shown in FIG. 10 . The engine oil pressure overcomes the preload of the spring 177 a , and pushes the braking plunger 136 out of the bore 415 after the valve bridge 400 (and the braking valve 300 a ) is pushed away from the adjusting screw 110 by the exhaust valve lifter 200 . The braking plunger 136 is stopped at the spring seat 178 and fully out or extended. The operative surface 140 is now under the adjusting screw 110 , and the exhaust valve 300 a pushed out by the exhaust valve lifter 200 cannot close or return to its seat 320 but is held open to create an engine braking event.
The lash adjusting system for this engine braking apparatus ( FIG. 10 ) comprises the lash adjusting screw 110 and the valve bridge 400 that contains the braking plunger 136 . The height difference 130 between the first surface 140 and the second surface 145 minus the braking valve lash 132 determines the braking valve lift for the engine braking event or operation. Instead of a cylindrical surface as shown in FIG. 10 , the first surface 140 can be a flat surface on the braking plunger 136 as shown in FIG. 8A .
When engine braking is not needed, the control means 50 is turned off and there will be no or little oil supplied to the engine braking fluid circuit. The oil pressure will not be high enough and the plunger 136 will be pushed back into the valve bridge 400 by the spring 177 a . The engine brake means 100 now is at the inoperative position and disengaged from the normal engine operation.
FIG. 11A shows a different embodiment of the engine brake actuation means 100 . It is a ball-locking device over the top surface 405 of the valve bridge 400 . The ball-locking device is contained in a lash adjusting system with the lash adjusting screw 110 secured to the brake housing 125 by a lock nut 105 . Depending on the position of the ball-locking device, a braking piston 160 can extend or retract to generate the operative position or inoperative position commensurate with the engine braking operation or the normal engine operation.
When engine braking is needed, the three-way solenoid valve 51 a ( FIG. 3 ) is turned on and the port 11 will be open to allow engine oil into the fluid circuit comprising a flow passage 126 in the brake housing 125 . The engine oil flows into a chamber 123 through an annular groove 121 , one or more orifices 122 and flow passage 180 as shown in FIG. 11B . The oil pressure pushes the braking piston 160 downwards with the ball-locking piston 165 against a spring 177 a . The spring is supported by a spring seat 178 that is secured to the lash adjusting screw by screws 179 . The braking piston 160 will slide in a bore 415 and stop at a clip ring 176 when a plurality of balls 175 contained in holes in the braking piston are aligned with an annular groove 170 in the bore 415 . The oil pressure overcomes the preload of spring 199 and pushes the ball-locking piston 165 down to the bottom of the bore 182 in the braking piston, which locks the balls in the groove 170 . Now the braking piston 160 is at its extended position with a lift 130 , and the exhaust valve 300 a pushed out by the exhaust valve lifter 200 ( FIG. 11A ) cannot close or return to its seat 320 but is held open by the braking piston 160 to create an engine braking event. The engine braking load from the braking piston is passed to the lash adjusting screw 110 through the balls 175 . Note that the bleeding orifice 168 is designed to drain the oil leaked to the backside of the ball-locking piston to avoid hydraulic lock.
The lash adjusting system for this engine braking apparatus comprises the lash adjusting screw 110 , the ball-locking system contained in the lash adjusting screw, and the valve bridge 400 . The height difference 130 between the retracted position and the extended position of the ball-locking device minus the braking valve lash determines the braking valve lift for the engine braking event or operation.
When engine braking is not needed, the solenoid valve 51 a is turned off and the spool 58 will close the oil supply port 11 and open the drain port 22 as shown in FIG. 3 . Without oil pressure acting on the ball-locking piston 165 , it will be pushed upwards by the spring 199 and the balls forced into the recess or annular cut of the ball-locking piston 165 under the upward push of the braking piston 160 by the spring 177 a . Once the balls are out of the annular groove 170 in the bore 415 , the braking piston 160 is free to move up and back to its retracted position when the engine brake actuation means 100 is disengaged from the engine operation, as shown in FIG. 11A .
FIGS. 12A and 12B show a similar embodiment to that shown in FIGS. 11A and 11B except that the balls 175 of the ball-locking device are contained in holes in the lash adjusting screw 110 and the ball-locking piston 165 is at the outside of the lash adjusting screw. When engine brake actuation means 100 is at its inoperative position, the braking piston 160 is biased up by the spring 177 or the returning braking valve 300 a and retracted in the bore 415 as shown in FIG. 12A . Note that the braking piston is part of the lash adjusting system, and the motion limiting means is formed by the ball-locking means.
When engine brake is needed, the engine brake control means 50 ( FIG. 3 ) is turned on and oil pressure pushes the braking piston 160 down against the spring 177 to a stop 176 so that the balls are aligned with an annular groove 170 a on the braking piston. Now the ball-locking piston 165 can be pushed down by the oil pressure against a spring 199 a and lock the balls into the groove 170 a as shown in FIG. 12B . The braking piston 160 is now at its extended position with a lift 130 , and the exhaust valve 300 a pushed out by the exhaust valve lifter 200 ( FIG. 12A ) cannot close or return to its seat 320 but is held open by the braking piston 160 to create an engine braking event. The engine braking load from the braking piston 160 is passed to the lash adjusting screw 110 through the balls 175 .
When engine braking is not needed, the engine brake control means 50 ( FIG. 3 ) is turned off and there will be no oil pressure acting on the ball-locking piston 165 , which will be pushed upwards by the spring 199 a toward the top of the bore 182 . Once the annular groove 170 on the ball-locking piston 165 is aligned with the balls 175 in the adjusting screw holes, they will move out of the annular groove 170 a and the braking piston 160 is free to be moved up in the bore 415 by the spring 177 and the upward valve motion. The braking piston 160 is now back to the retracted position and the actuation means 100 is disengaged from the engine operation, as shown in FIG. 12A .
FIGS. 13A and 13B show another ball-locking device with the balls 175 not contained in holes as in the previous embodiments but restrained by three elements or surfaces. The first surface is the tapered surface 192 on the bottom of the adjusting screw 110 . The second surface is the flat surface on the top of the braking piston 160 . The third surface is on the ball-locking piston 165 , either on the annular groove 170 when the ball-locking device is at the retracted position as shown in FIG. 13A or on the bore 415 when the ball-locking device is at the extended position as shown in FIG. 13B . Note that the braking piston 160 is also part of the motion limiting means incorporated into the ball-locking device.
When engine brake is needed, the control means 50 ( FIG. 3 ) is turned on and oil pressure pushes down both the ball-locking piston 165 and the braking piston 160 , while the balls 175 move down and inwards along the tapered surface 192 . Note that the adjusting screw stem 191 is smaller than the braking piston 160 that slides in the bore 415 inside the ball-locking piston. Once the balls are out of the annular groove 170 in the bore 415 , the ball-locking piston can move down further. The total travel of the system is limited by the spring 177 that acts as a spring and a stop. Now the braking piston is at its extended position and locked with the lift 130 as shown in FIG. 13B , which is finalized by the upward push of the returning braking valve 300 a . The engine braking load is passed from the braking piston 160 to the lash adjusting screw 110 through the balls 175 .
The lash adjusting system for the engine braking apparatus comprises the lash adjusting screw 110 , the ball-locking system in the housing, and the valve bridge 400 ( FIG. 11A ). The height difference 130 between the retracted position and the extended position of the ball-locking device minus the braking valve lash determines the braking valve lift for the engine braking event or operation.
When engine braking is not needed, the control means 50 ( FIG. 3 ) is turned off and there will be no oil pressure acting on the ball-locking piston 165 , which will be pushed upwards by the spring 199 a towards the top of the bore 182 . The balls are now aligned with and forced into the annular groove 170 in the ball-locking piston 165 and the braking piston 160 can be pushed up by the spring 177 or the returning braking valve 300 a and back to its retracted position as shown in FIG. 13A .
FIGS. 14A and 14B show another ball-locking device with balls 175 restrained by three elements or surfaces. The first surface is the tapered surface 192 on the braking piston 160 . The second surface is the bottom flat surface on the lash adjusting screw 110 and the third surface on the ball-locking piston 165 that slides in a bore 182 in the adjusting screw. Again, the braking piston 160 is part of the lash adjusting system and the motion limiting means is incorporated into the ball-locking device.
When engine brake is needed, the control means 50 ( FIG. 3 ) is turned on and oil pressure pushes down the braking piston 160 to a stop 178 , while the balls 175 move outward along the tapered surface 192 . Due to the oil pressure on the ball-locking piston 165 , it is pushed upward against the spring 199 . The venting orifice 168 on top of the adjusting screw 110 is designed to eliminate hydraulic lock of the ball-locking piston 165 . The tapered surface 192 and balls 175 are so designed that when the braking piston 160 is at its extended position, the ball-locking piston 165 is at the highest position and its large diameter surface locks the balls into a position shown in FIG. 14B . The height difference 130 between the retracted position and the extended position of the ball-locking device minus the braking valve lash determines the braking valve lift for the engine braking event or operation. The engine braking load is passed from the braking piston 160 to the lash adjusting screw 110 through the balls 175 .
When engine braking is not needed, the control means 50 ( FIG. 3 ) is turned off and there will be no oil pressure acting on the ball-locking piston 165 , which will be pushed downward by the spring 199 so that the balls 175 can move inward. The braking piston 160 can now slide upward in the bore 415 under the push of spring 177 or the returning braking valve 300 a . Note that the force by spring 177 on the braking piston 160 is higher than that by spring 199 on the ball-locking piston 165 so that the ball-locking device could be back to its retracted position as shown in FIG. 14A .
FIGS. 15A and 15B show a different embodiment of the engine brake actuation means 100 . It is a toggle device that contains two pins 184 and 186 , and a braking piston 160 that slides in a vertical bore 415 in the brake housing 125 . The upper pin 184 has two spherical ends; one engaged with a socket in the adjusting screw 110 , and the other with another socket in the lower pin 186 whose lower end sits in a third socket in the braking piston 160 . FIG. 15A shows the retracted position of the toggle device where the two pins guided in the slot 137 that is cut through a pin-locking piston 162 are pushed to the left by the spring 199 a . The pin-locking piston 162 slides in a horizontal bore 182 in the braking housing 125 . There is a smaller pin-locking piston 164 that slides in the larger pin-locking piston 162 . The slot 137 in piston 162 has a width that matches the diameter of the two pins and a length that is smaller than the diameter of the bore 415 . There will be always contact (no separation) among the braking piston, the lower pin, the upper pin, and the adjusting screw due to the upward force of the spring 177 that is secured to the brake housing 125 with at least one screw 179 .
When engine brake is needed, the control means 50 ( FIG. 3 ) is turned on and oil pressure can push both pin-locking pistons 162 and 164 to the right against the preload of the spring 199 a . Note that the small pin-locking piston 164 can be moved to the right further to lock the two pins in a vertical position, aligned with the adjusting screw and the braking piston, as shown in FIG. 15B . Now the toggle device is locked to its extended position. The motion limiting means for this toggle device is unique. The angle between the two pins decides the height difference 130 , while the angle itself is controlled by the two pin-locking pistons. The pin-locking piston 162 has a stroke 131 . The two bleeding orifices 168 and 169 are designed to eliminate hydraulic lock so that the two pistons can move freely. The orifice 169 is in a mounting screw 161 that acts as a spring seat and a stop to the large pin-locking piston 162 .
Again, a bleeding orifice could be added to the flow passage 126 in the engine braking fluid circuit for turning off the engine brake faster or even totally eliminating the need of the drain port 22 ( FIG. 3 ), so that a two-way solenoid valve plus the bleeding orifice may be used to replace the three-way solenoid valve 51 a.
The lash adjusting system is incorporated into the toggle device. The height difference 130 between the retracted position and the extended position of the toggle device minus the braking valve lash determines the braking valve lift for the engine braking event or operation. The engine braking load is passed from the braking piston 160 to the lash adjusting screw 110 through the two pins 184 and 186 .
CONCLUSION, RAMIFICATIONS, AND SCOPE
It is clear from the above description that the engine braking apparatus according to the embodiments of the present invention have one or more of the following advantages over the prior art engine braking systems:
(a) The system can be installed on all types of engines; (b) The system can be retrofitted to existing engines; (c) The engine braking load is not carried by the engine (valve train) components; (d) The system has no need for redesign of the engine or engine components; (e) The system has fewer components, reduced complexity, and lower cost; (f) The system has a braking valve lash adjusting system; (g) The system is more rugged and simple in construction, easier to install, more reliable in operation, and effective at all engine speeds; and (h) The system transmits force, or the engine braking load, through mechanical linkage means that does not have high compliance and overloading problems associated with hydraulic means used by some of the prior art engine brakes.
Due to the above advantages, the engine braking apparatus disclosed here can be used not only on truck engines, but also personal car engines; not only to slow down vehicles, but also to enhance vehicle cruise control, braking gas or exhaust gas recirculation control, and other engine or vehicle controls.
While my above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of the preferred embodiments thereof. Many other variations are possible. For example, instead of sitting over the top surface 405 of the valve bridge 400 for opening one exhaust valve 300 a for engine braking as shown in FIG. 2 and other figures, the engine brake actuation means 100 can sit over the top surface 215 of the rocker arm 210 or under the bottom surface of the rocker arm 210 on the cam follower 235 side for opening two exhaust valves 300 ( 300 a and 300 b ) for engine braking. The top surfaces could have different shape other than flat surface, for example, a spherical shape.
Also, instead of one plunger 136 in one side of the valve bridge 400 for opening one exhaust valve 300 a for engine braking as shown in FIG. 6 and other figures, two plungers 136 can be put in both sides of the valve bridge 400 for opening two exhaust valves 300 ( 300 a and 300 b ) for engine braking.
Also, the engine braking apparatus disclosed here can be applied to a push tube type engine (not shown here) instead the overhead cam type engine as shown in FIG. 2 and other figures, as well as to the engine's intake valve system (not shown here) instead the exhaust valve system.
Also, the engine brake actuation means 100 can be controlled (turned on and off) by other types of control means 50 , like a simple mechanical means, such as the wire control mechanism for a bicycle brake control. And a poppet type control valve could be used to replace the spool type valve 51 a of the control means 50 as shown in FIG. 3 .
Also, the two surfaces 140 and 145 commensurate with the operative and inoperative positions of the engine brake actuation means 100 as shown in FIG. 2 and other figures can be combined as one tapered or sloped surface, for example, a wedge type mechanism. And the tapered surface could be actively controlled to generated variable braking valve lift, which could be very useful for different engine braking needs, for example, at different engine speeds.
Also, the housing 125 can be different. It can be a rocker arm mounted on a rocker shaft; and there can be a different cam that has more than one lobe.
Further, two levels of oil supply pressure could be provided to the fluid circuit as shown in FIG. 6 so that during engine braking, the oil with full supply pressure flows into the braking circuit to actuate the engine braking actuation means 100 , while during the normal engine operation, the oil flowing through a pressure reduction device, for example, an orifice, into the braking fluid circuit does not have high enough pressure to actuate the actuation means 100 but can be used for system lubrication.
Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.
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Apparatus for modifying engine valve lift to produce an engine valve event in an internal combustion engine, the engine including at least one exhaust valve and an exhaust valve lifter for cyclically opening and closing the at least one exhaust valve, includes (a) an actuator for operating the at least one exhaust valve to produce said modified engine valve lift, said actuator having an inoperative position and an operative position; in said inoperative position said actuator being disengaged from the operation of the at least one exhaust valve, and in said operative position said actuator opening the at least one exhaust valve for said engine valve event; and (b) a controller for moving said actuator between said inoperative position and said operative position.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a ball joint having a dust cover thereon.
2. Description of the Prior Art
A ball joint shown in FIG. 4 is a known example of conventional ball joints.
In FIG. 4, numeral 1 denotes a socket made of steel or other metal. Socket 1 has a cylindrical through hole 2 formed therein and open at both ends. A recessed groove 3 is formed about the outer surface at one end of socket 1. A shank pestle 4 is integrally affixed to the outer surface of socket 1.
Numeral 5 denotes a ball stud made of steel or other metal having a ball portion 6 integrally formed with a shank portion 7. A stopper 8 is disport at middle part of shank portion 7. The diameter of stopper 8 is larger than the diameter of shank portion 7.
Numeral 9 denotes a ball seat made of a hard thermoplastic resin with a cylindrical outer surface fitted into socket 1. Ball seat 9 is open at one end and has flanges 10 and 11 formed on the outer surfaces of its opposed ends.
Numeral 12 denotes a cylindrical dust cover made of synthetic rubber. An attaching part 13 is disposed at one end of dust cover 12 to lock into the recessed groove 3 of socket 1. A slip 14 is formed at the other end of the dust cover to slidably attach dust cover 12 around the outer surface of shank portion 7 of ball stud 5.
Ball portion 6 of ball stud 5 is inserted, together with ball seat 9 positioned therearound, into through hole 2 of socket 1 with or without pressure. Ball portion 6 of ball stud 5 is slidably supported in ball seat 9. Shank portion 7 of ball stud 5 protrudes from ball seat 9. Flanges 10 and 11 at the ends of ball seat 9 lock over their respective ends of socket 1. Dust cover 12 is positioned to face the opening at one end of socket 1. An attaching part 13 of dust cover 12 is clamped into recessed groove 3 of socket 1 by a ring-shaped metal clip 15. Slip 14 is attached around shank 7 of ball stud 5 below stopper 8. When thus installed, dust cover 12 covers the opening of ball seat 9.
A ball joint of this type, with dust cover 12 excludeds dirt and muddy water in order to improve the life of the ball joint. However, this conventional ball joint presents a problem in that when load is applied at right angles to ball stud 5, there is a chance that a slight space may be formed between socket 1 and flange 11, thus permitting dirt and/or muddy water to enter the space between socket 1 and flange 11 and migrate along the surface of through hole 2 and into ball seat 9, where it can couse wear.
A ball joint shown in FIG. 5 is also a widely known example of conventional ball joints.
Unlike the above example shown in FIG. 4, instead of providing socket 1 with recessed groove 3 a thick catching receiver 16 is disposed at one end of ball seat 9. A flange 16 abuts one end of socket 1. A locking attaching part 13 of dust cover 12 is clamped into flange 16 by a metal clip. A recess 17 around the outer surface of the lower part of ball seat 9 provides relief to permit the ball seat 9 to easily inserted into through hole 2.
With this ball joint, part "a", where the diameter of the opening of ball seat 9 is smallest, is located beyond the end of socket 1, thus causing the drawing strength of ball stud 5 from socket 1 to be reduced. In order to improve the drawing strength of ball stud 5, it is necessary to position the smallest diameter part "a" of the opening of ball seat 9 as close as possible to the end of socket 1. However, doing this requires making socket 1 and ball stud 5 longer in the direction of the shank 7 and thereby increasing the fitting length H of ball stud 5. This is disadvantageous because the strength of ball stud 5 may suffer and the size of the entire ball joint is increased.
As described above, the conventional technique for fitting a dust cover on a ball joint has problems ability in its to seal the ball joint and in the drawing strength of the ball stud.
A major object of the present invention is to provide a ball joint with improved drawing strength of its ball stud from the socket, while maintaining satisfactory sealing with the dust cover.
SUMMARY OF THE INVENTION
Briefly stated, the present invention provides a ball joint having a ball seat fitted in a through hole in a socket. A recessed part of the socket has the same diamenter as a receiving part of the ball seat. An attaching part of a dust cover is clamped into the recess formed by the recessed part and the receiving past to seal the interior of the ball joint from the entry of moisture and dirt, and to provide lateral support to the ball seat. A double-ended version is disclosed wherein attaching parts of two dust covers seal and provide lateral support to opposed ends of the ball seat.
According to an embodiment of the invention, there is provided a ball joint comprising; a socket, a cylindrical through hole in the socket, a ball seat in the through hole, a ball stud with a ball portion slidably supported in the socket, at least one shank portion of the ball stud protruding from the through hole in at least one direction, at least one dust cover; a locking part for attaching the dust cover to the socket; a recessed part around an outer surface at an end of the socket; a receiving part on an outer surface near an end of the ball seat, an outer surface of the receiving part being disposed at a common level with that of the recessed part, an attaching part of the dust cover being clamped around surfaces of the recessed part and the receiving portion.
The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross section of an embodiment of a ball joint according to the present invention;
FIG. 2 is a curve of the drawing load of the ball joint of FIG. 1;
FIG. 3 is a longitudinal cross section of another embodiment of a ball joint according to the present invention;
FIGS. 4 and 5 are cross sections showing examples of conventional ball joints according to the prior are.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A detailed description of an embodiment of the present invention is given hereunder referring to FIG. 1:
A ball joint in FIG. 1 is similar to those explained above with reference to FIGS. 4 and 5, except for the manner of attaching the dust cover. Thus, parts corresponding to those of FIGS. 4 and 5 are given the same reference numerals in the following deseription.
A ball joint of the present embodiment of the invention includes a socket 1 made of steel or other metal having cylindrical through hole 2 that opens at both ends of the socket 1. A shank pestle 4 is integrally affixed to the exterior of socket 1. A ball stud 5, made of steel or other metal, includes a ball portion 6, a shank portion 7 and a stopper 8. The diameter of stopper 8 is larger than the diameter of shank portion 7. A ball seat 9, made of hard thermoplastic resin, includes a cylindrical outer surface and an opening at one end. Flanges 10 and 11 are disposed at opposed ends of an outer surface of ball seat 9. A recess 17 is formed in the outer surface of the bottom of ball seat 9. A cylindrical dust cover 12, made of synthetic rubber includes an attaching part 13 forming one end of said dust cover 12. A slip 14 forms the other end of the dust cover. A clip 15 engages attaching part 13, as will be explained.
To assembly the ball joint of FIG. 1, ball portion 6 of ball stud 5 is inserted into ball seat 9. Ball seat 9 is fitted into through hole 2 of socket 1 with or without pressure. Ball portion 6 of ball stud 5 is thus slidably supported with shank portion 7 protruding from ball seat 9. Flanges 10 and 11 at opposed ends of ball seat 9 face their respective ends of socket 1. Dust cover 12 is positioned to face the open end of socket 1, with its attaching part 13 lockingly fitted to the side of socket 1 and clamped by clip 15 and with its slip 14 fitted on shank 7 below stopper so that the opening of ball seat 9 is covered by dust cover 12.
Where dust cover 12 is attached to socket 1, a cylindrical wall 21 extends upon from socket 1. The inner diameter of cylindrical wall 21 is identical to that of through hole 2. An outer diameter of wall 21 is smaller than the diameter of socket 1, thus forming a recessed part 22 around one end of outer surface of socket 1. A receiving part 23 of ball seat 9 below flange 10 has an inner surface having the same diameter as an inner surface of the recessed part 22 of one end of the socket 1. Thus, a recess to receive attaching part 13 of dust cover 12 is formed by recessed part 22 of socket 1 and receiving part 23 of ball seat 9. The outer diameter of the formed recess being smaller than the outer diameter of socket 1 so that attaching part 13 of dust cover 12 is lockingly fitted and fixed by clamping around the outer surfaces of recessed part 22 and receiving part 23.
A height A of wall 21 (also recessed part 22 of socket 1) is set in the range of 1/4 to 3/4 of a height T of attaching part 13 of dust cover 12. For example, height A may be 1/2 of height T. Accordingly, the height of receiving part 23 of ball seat 9 is T minus A.
As described as above, recessed part 22 is formed by wall 21 extending from an end of socket 1. Attaching part 13 of dust cover 12 fits the vertical distance from recessed part 22 to receiving part 23. Therefore, can be positioned closed the smallest diameter part a of the opening of ball seat 9 to the end of socket 1, even within wall part 21, thereby limiting the required aperture of smallest diameter part a of the opening of ball seat 9 and increasing the drawing load. In addition, by setting the height A of recessed part 22 of socket A within the range from 1/4 to 3/4 of height T of attaching part 13 of dust cover 12, it is possible to select the best position of smallest diameter part a of the opening of ball seat 9 and its sealing ability.
Furthermore, as attaching part 13 of dust cover 12 abuts the outer surface of ball seat 9, the clamping effectiveness of clip 15 is improved, and improved sealing is therefore obtained.
With a conventional ball joint having a ball portion 6 of ball stud 5 with a diameter of 20 mm and a ball seat 9 made of polyacetyl resin, the resulting drawing strength is normally approx. 130 kg. A ball joint according to the present invention, however, provides a maximum drawing strength of 280 kg.
Referring now to FIG. 2, data is presented showing actual measurements of the relationship between the distance between the smallest diameter part and socket 1, and the drawing strength of ball stud 5. It will be noted that the drawing strength changes by a factor of about two over a distance of about 1 mm.
Referring now to FIG. 3, another embodiment of the present invention employs a ball stud 5 having a ball portion 6 with cylindrical shank portions 7 protruding from both ends of ball portion 6. A ball seat 9 is open at both ends. A dust cover 12 is attached between each shank portion 7 and its respective end of socket 1, thereby covering both openings of ball seat 9 with dust covers 12. In the same manner, the present invention is applicable to a ball joint wherein the shank is inserted through the center of ball stud 5.
According to the present invention, it is possible to position the smallest diameter part of the opening of the ball seat 9 close to or within the end of the socket 1, by forming a recessed part 22 around the outer surface of the end of the socket 1 and fitting the attaching part 13 of the dust cover 12 in the area from the recessed part 22 to the receiving part 23 of the ball seat 9. Therefore, the present invention makes it possible to limit the required aperture of the smallest diameter part of the opening of the ball seat 9 and thereby to maintain a large drawing load.
In addition, as the attaching part of the dust cover abuts the outer surface of the ball seat 9, clamping and sealing are both improved.
By setting the height of the recessed part 22 of the socket 1 within the range of from 1/4 to 3/4 of the height of the attaching part 13 of the dust cover 12, it is possible to select the best position of the smallest diameter part a of the opening of the ball seat as well as to improve the sealing.
Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.
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A ball joint has a ball seat fitted in a through hole of a socket. A recessed part of the socket has the same diameter as a receiving part of the ball seat. An attaching part of a dust cover is clamped into the recess formed by the recessed part and the receiving part to seal the interior of the ball joint from the entry of moisture and dirt, and to provide lateral support to the ball seat. A double-ended version is disclosed wherein attaching parts of two dust covers seal and provide lateral support to opposed ends of the ball seat.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent No. 62/331,962 entitled GuardSpark Covers and filed on May 4, 2016, which is specifically incorporated by reference herein for all that it discloses and teaches.
TECHNICAL FIELD
[0002] The invention relates generally to the field of commercial and residential electrical construction; and more particularly, to the field of preparing electrical wiring components prior to painting/texturing or otherwise finishing surrounding surfaces; and more particularly still, to electrical covers designed to fit over one or more electrical outlet(s) [[switches, and recessed light fixtures]] to protect said component during painting/texturing/finishing processes.
BACKGROUND
[0003] There are many products designed to cover and/or protect electrical outlets (hereinafter, “electrical components”) from receiving paint, texture, or other finishing materials (collectively, “finish materials”) during finishing projects. This is important as such materials can enter electrical components and cause malfunctions, be unsightly, reduce functionality, or even create electrical wiring hazards. In such situations, removing materials from electrical components can be time consuming and difficult; it is a much better approach to keep such materials from entering the electrical components in the first place. One common partial solution is to tape over the electrical components before commencing finish work. However, this is a laborious and time consuming process that ultimately yields unimpressive results as the gaps between rows or columns of tape allow materials to enter the electrical components. Furthermore, during the taping process, it is easy to accidentally make contact with the interior of the electrical components leading to potential electrical shock hazards. Tape is not reusable and often lets loose or fails when touched, vibrated, or otherwise moved—simple exposure to sunlight can also cause tape to fail. Not to mention the unsightly residue that tape often leaves behind. The prior art has seen the shortcomings of tape and attempted to address them with plastic paint shields. However, most such shields utilize prongs that either project into the outlets or into the electrical boxes. Many modern outlets have safety tabs that defeat insertion of such prongs causing such paint shields to be unusable. Further, depending on the installation of electrical components, there may be no room for insertion prongs to fit into an electrical box to the side of switches or outlets. Again, failure of such paint shields results. Additional problems with prior art paint shields is that they are flat, flimsy and prone to cracking, so they often gap or buckle, leaving spaces through which finish materials can enter. Thicker, more rigid shields fail to account for variations in manufacturing tolerances between electrical components, so may not fit all electrical components. What is needed is an electrical cover that is arched instead of flat so as to provide a better seal once installed, is able to be pressure-fit so that no insertion prongs are necessary, and is easy to quickly add or remove in order to save labor during finishing projects.
SUMMARY
[0004] The electrical cover comprises a friction-held electrical cover. Embodiments of the electrical cover described herein provide flexible finish material covers that guard outlets from paint, spackling, and other foreign materials. The frictionally-held finish material covers utilize specifically shaped features on the surfaces, such as negative draft, that contact the electrical components to increase the hold on the electrical device. Some of the shaped features of the frictionally-held covers also help minimize stress in the cover. The electrical covers are shaped with an arched rear surface that assists in minimizing edge warping when the electrical cover is positioned against the wall surface. Features are also molded into the parts to assist and strengthen the cover flatness once installed, and thus protect against the intrusion of finish material behind the cover.
[0005] The above summary provides a basic understanding of some aspects of the specification. This summary is not an extensive overview of the specification. It is intended to neither identify key or critical elements of the specification nor delineate any scope of particular embodiments of the specification, or any scope of the claims. Its sole purpose is to present some initial concepts in a simplified form as a prelude to the more detailed description that is presented later.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The aforementioned and other features and objects of the present invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following descriptions of a preferred embodiment and other embodiments taken in conjunction with the accompanying drawings, wherein:
[0007] FIG. 1 illustrates a front perspective view of an exemplary embodiment of an electrical cover in place on an outlet and electrical box;
[0008] FIG. 2 illustrates a front perspective view of an exemplary embodiment of an electrical cover shown about to be emplaced on an outlet and electrical box;
[0009] FIG. 3 illustrates a front perspective view of an exemplary embodiment of an electrical cover;
[0010] FIG. 4 illustrates a front elevation view of an exemplary embodiment of an electrical cover;
[0011] FIG. 5 illustrates a top plan view of an exemplary embodiment of an electrical cover; and
[0012] FIG. 6 illustrates a rear perspective view of the inside of an exemplary embodiment of an electrical cover.
DETAILED DESCRIPTION
[0013] In the following discussion, numerous specific details are set forth to provide a thorough understanding of the present disclosure. However, those skilled in the art will appreciate that embodiments may be practiced without such specific details. Furthermore, lists and/or examples are often provided and should be interpreted as exemplary only and in no way limiting embodiments to only those examples. Similarly, in this disclosure, language such as “could, should, may, might, must, have to, can, would, need to, is, is not”, etc. and all such similar language shall be considered interchangeable whenever possible such that the scope of the invention is not unduly limited. For example, a comment such as: “item X is used” can be interpreted to read “item X can be used”.
[0014] Exemplary embodiments are described below in the accompanying Figures. The following detailed description provides a review of the drawing Figures in order to provide an understanding of, and an enabling description for, these embodiments. One having ordinary skill in the art will understand that in some cases well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments. Further, examples described herein are intended to aid in understanding the principles of the embodiments, and are to be construed as being without limitation to such specifically recited examples and conditions. As a result, the inventive concepts are not limited to the specific embodiments or examples.
[0015] Referring now to the drawings, FIG. 1 illustrates a front perspective view of an exemplary embodiment of an electrical cover 10 in place on an outlet 92 and electrical box 90 . The main body of the electrical cover 10 extends vertically and curves horizontally so as to form an arch when viewed from above (see later FIGs.). The materials comprising the electrical cover in this embodiment can be transparent, other embodiments may utilize translucent and/or opaque components. Running vertically along both sides of the of the main body is a plurality of scored cut-lines 20 and 22 , these provide a simple guide for the user to cut away excess materials when using multiple electrical covers 10 on multiple side-by-side outlets. In other embodiments, the scored cut-lines 20 and 22 can be deep enough that a user can simply bend the cover along those lines and snap off the excess rather than requiring cutting.
[0016] Note that FIG. 1 illustrates the electrical cover in place on an outlet and mated electrical box 90 . As such, the un-installed arch of the rear surface of the electrical cover is difficult to make out, see later FIGs. for more detail of the arch.
[0017] In the embodiment illustrated in FIG. 1 , a raised plateau 40 is shown surrounding the outlet 92 (not visible in FIG. 1 , see FIG. 2 ). The raised plateau 40 provides clearance for outlet bracketry and helps to sustain contact between the rear surface of the cover and the box and/or surrounding surfaces/walls. Extending up from the plateau 40 is the receptacle guard 30 , comprising an upper receptacle grasp 31 and a lower receptacle grasp 32 . The receptacle grasps 31 and 32 are designed to surround the individual receptacles and pressure-fit over them in order to hold the electrical cover in place. See later FIGs. for additional explanation of the subcomponents that help the receptacle grasps 31 and 32 grip and hold the outlet.
[0018] Note that as the electrical cover 10 is pressed onto the outlet, the receptacles grasps 31 and 32 grip the electrical receptacles from the top, sides, and bottom with a friction fit. The arched shape of the back surface of the electrical cover is pressed approximately flat so that no gaps are available through which finish materials can enter either the outlet or the electrical box. The electrical covers protect not only the outlet itself, but associated wiring, wiring connections, and the walling materials (e.g., drywall) that surrounds the perimeter of the outlet. The electrical covers shield the electrical components from paint and/or other surface finishing materials such as plastering or spackling that is sprayed and/or rolled onto a wall surface or surface finishing treatments such as grouting tiles. The electrical covers may be reused, and may be washable or disposable. The electrical covers can be fabricated from a low-cost thermally formed polymer plastic. The covers utilize negatively drafted contact surfaces to improve the overlapping friction holding force while minimizing material stress. A second arched surface formed into the center of the electrical covers improves the holding force as well. Rounded surfaces are designed into the covers to minimize the risk of cracking, make the covers easier to form during fabrication, and improve the covers' holding frictional force as well as the life-cycle for reusability.
[0019] FIG. 2 illustrates a front perspective view of an exemplary embodiment of an electrical cover 10 shown about to be emplaced on an outlet 92 and electrical box 94 . The same components from FIG. 1 are illustrated and referenced but since the electrical cover 10 is spaced away from the outlet 92 , the various relationships can be better seen and understood.
[0020] FIG. 3 illustrates a front perspective view of an exemplary embodiment of an electrical cover 10 . In this view, the arch that is formed into the rear surface of the electrical cover 10 can be seen in the top rim 80 . The arch is more easily discernable here than in FIG. 1 as this electrical cover is not installed. See FIG. 5 for an additional depiction of this feature. The right side rim 81 and left side rim 83 are depicted in this FIG., as is the bottom rim 84 . As can be seen in the illustration, the rims are preferably somewhat thin so that they can be flexible and mold to the underlying surfaces once installed in order to minimize any gapping therebetween.
[0021] Moving from the top down, the first feature that is encountered on the raised plateau 40 is the fastener clearance 50 . This feature allows the cover to clear any screws or other fasteners used to install the outlet 92 in the electrical box 90 . A second fastener clearance 52 is present near the bottom edge of the raised plateau 40 . Between the two fastener clearances 50 and 52 is the receptacle guard 30 , comprising an upper receptacle grasp 31 and a lower receptacle grasp 32 . Between the two is a strengthening bridge 75 which strengthens resistance against pinching the plurality of finger holds 74 and 76 and increases the cover holding force to the outlet. The outer front face surfaces of the grasps 31 and 32 can be arched as well (see first grasp arch 72 and second grasp arch 78 in FIG. 3 ) to strengthen the electrical cover and assist in the grasping functionality.
[0022] FIG. 4 illustrates a front elevation view of an exemplary embodiment of an electrical cover 10 . In addition to all the subcomponents discussed above, FIG. 4 highlights a number of additional components that are instrumental in the grasping functionality that provides the pressure-fit of the electrical cover 10 to the outlet.
[0023] The standard outlet is made up of two, vertically-stacked receptacles. The upper receptacle grasp 31 can utilize a top grasp wall 37 to grasp the upper edge of the top receptacle. Similarly, a right side grasp wall 73 grasps the right side of the top receptacle and a left side grasp wall 71 grasps the left side of the top receptacle. These grasp walls 37 , 71 and 73 work in combination with each other and with those of the lower receptacle grasp 32 to securely grip and hold the outlet receptacles. The lower receptacle grasp 32 has grasp walls similar to those detailed above: a right side grasp wall 79 grasps the right side of the bottom receptacle, a left side grasp wall 77 grasps the left side of the bottom receptacle, and a bottom grasp wall 38 grasps the bottom edge of the bottom receptacle. The grasp walls 37 , 38 , 71 , 73 , 77 and 79 all angle slightly inwards as they extend out from the raised plateau 40 in order to accommodate outlet receptacles of various sizes due to manufacturing tolerances, etc.
[0024] Additionally, the contact surfaces of the grasp walls may incorporate a modified surface friction material (such as a laminate material, tape, additional layer of plastic, etc.), coating (such as lacquer, polyurethane, etc.), or roughening (during or after formation). Modifying the surface roughness further enhances the electrical cover's ability to accommodate size variations in the outlet receptacles without introducing too much overlap.
[0025] The cover is designed with pressure points that allow the user to engage and disengage the friction surfaces that hold to the electrical device. In FIG. 4 , these pressure points comprise the plurality of finger holds 74 and 76 . By squeezing at these key points, the user causes the grasp walls to separate and release the electrical cover from the receptacles. The plurality of top spacer corners 33 and 35 and bottom spacer corners 34 and 36 provide flexibility to the grasp walls therebetween and help the finger holds 74 and 76 function properly. As noted above, the cover utilizes surfaces that are negatively drafted relative to other drafted features on the surfaces that contact the electrical device to increase the overlap and help minimize stress in the cover.
[0026] FIG. 5 illustrates a top plan view of an exemplary embodiment of an electrical cover 10 . Note the accentuated arch shape apparent in the top rim 80 . The perimeter of the electrical cover is approximately flattened against the installation surface (wall, outlet box, etc.) once installed and the arch causes constant pressure to be applied to the top, left, right, and bottom rims forcing them against the installation surface and minimizing gaps therebetween.
[0027] FIG. 6 illustrates a rear perspective view of the inside of an exemplary embodiment of an electrical cover 10 . Note that components referenced on earlier Figures are referenced here. This view is showing the rear of these components; said view can also be termed as an inside view as the previous views showed the front or external surface of the electrical cover while this view shows the internal surfaces.
[0028] While particular embodiments have been described and disclosed in the present application, it is clear that any number of permutations, modifications, or embodiments may be made without departing from the spirit and the scope of this disclosure. Particular terminology used when describing certain features or aspects of the embodiments should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects with which that terminology is associated. In general, the application should not be construed to be limited to the specific embodiments disclosed in the specification, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the inventions encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the claimed subject matter.
[0029] The above detailed description of the embodiments is not intended to be exhaustive or to limit the disclosure to the precise embodiment or form disclosed herein or to the particular fields of usage mentioned above. While specific embodiments and examples are described above for illustrative purposes, various equivalent modifications are possible within the scope of the disclosure, as those skilled in the relevant art will recognize. Also, the teachings of the embodiments provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments.
[0030] Any patents, applications and other references that may be listed in accompanying or subsequent filing papers, are incorporated herein by reference. Aspects of embodiments can be modified, if necessary, to employ the systems, functions, and concepts of the various references to provide yet further embodiments.
[0031] In light of the above “Detailed Description,” the Inventors may make changes to the disclosure. While the detailed description outlines possible embodiments and discloses the best mode contemplated, no matter how detailed the above appears in text, embodiments may be practiced in a myriad of ways. Thus, implementation details may vary considerably while still being encompassed by the spirit of the embodiments as disclosed by the inventor. As discussed herein, specific terminology used when describing certain features or aspects should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the embodiments with which that terminology is associated.
[0032] The above specification, examples and data provide a description of the structure and use of exemplary implementations of the described systems, articles of manufacture and methods. It is important to note that many implementations can be made without departing from the spirit and scope of the disclosure.
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The electrical cover is a flexible, friction-held electrical cover that guards outlets from finish materials such as paint, spackling, and other foreign materials. The frictionally-held finish material electrical covers utilize specifically shaped features on the surfaces, such as negative draft, that contact the electrical components to increase the hold on the electrical device. Some of the shaped features of the frictionally-held covers also help minimize stress in the cover. The electrical covers are shaped with an arched rear surface that assists in minimizing edge warping when the electrical cover is positioned against the wall surface. Features are also molded into the parts to assist and strengthen the cover flatness once installed, and thus protect against the intrusion of finish material behind the cover.
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This is a continuation of application Ser. No. 201,447, filed Jun. 2, 1989, now abandoned.
BACKGROUND OF THE INVENTION
This invention concerns a device for sizing extended cross-sectionally shaped or profiled elements, profiles or bars comprising a plane surface along longitudinal axis of the element.
The invention is particularly well adapted to the groove moulds used in the production of arc-shaped bars made of composite materials constituting flexible hollow shafts.
A process and apparatus for producing reinforced cross-linkable shaped section bars are described, for example, in the French patent FR-2.312.356, wherein a sectional groove mould corresponding to the section of the profile to be obtained is used, with reinforcement elements impregnated with cross-linkable resin rolled up onto a mandrel in a groove mould. Then, the cross-linkable material is cross-linked before separating the reinforced arc-shaped bar from the mandrel. In some applications of this process, the groove mould is not separated from the bar obtained and it is even desirable that both be properly linked.
SUMMARY OF THE INVENTION
The aim of this invention resides in providing a process and apparatus for sizing the internal walls of the groove mould, especially the lateral walls.
The invention provides an apparatus for sizing a shaped extended element having a longitudinal axis, with the element comprising at least one lateral surface.
According to advantageous features of the present invention, the apparatus comprises a wheel having an axis, with the lateral surface being roughly parallel to the longitudinal axis, at least locally near to the wheel, and with the wheel being driven by a rotation movement and comprising at least one ring-shaped surface centered on the wheel axis. The ring-shaped surface is adapted to cooperate with the lateral surface of the extended element during a displacement of the wheel relatively to the extended element along an axis parallel to the longitudinal axis of the element. The apparatus also comprises coating means adapted to deposit, at least on an outer circumference of the ring-shaped surface, a sufficient amount of glue allowing for sizing of the lateral surface of the extended element.
When the extended element also includes a groovebottom surface different from a shaped section lateral surface along the axis of the the extended element, such as the bottom surface of a groove or even a surface roughly perpendicular to the lateral surface, the wheel could include a circumferential surface adapted to cooperate with the surface of the groove bottom. The coating means could be adapted to deposit on the the circumferential surface of the wheel a sufficient quantity of glue to allow for sizing of the groove bottom surface.
The groove bottom surface could be roughly inscribed on a cone and possibly on a cylinder whose axis is included inside a plane perpendicular to the longitudinal axis, and the circumferential surface of the wheel may be conical.
The groove bottom surface could be roughly perpendicular to the lateral surface and the circumferential surface of the wheel could be roughly perpendicular to the ring-shaped surface.
The wheel could include an antiadhesive coating on the ring shaped surface and/or circumferential surface of the wheel adapted to respectively cooperate with the lateral and/or groove bottom surfaces of the extended element.
The extended element could be applied against the said wheel by at least one press roller or press-cylinder roller.
The coating means could include two mixing rollers between which is disposed the glue, with at least one of the rollers being coated with glue on one part of its outer surface, the wheel being in contact with the said roller coated with glue.
The element could include several lateral surfaces parallel to each other and the wheel could include as many lateral ring-shaped surfaces adapted to cooperate with the lateral surfaces of the extended element as are needed to size them.
At least one of the lateral surfaces of the extended element could be planar and at least one of the ring-shaped surfaces, adapted to cooperate with the lateral surfaces of the element, could be planar and be perpendicular to the wheel axis.
The invention also provides a process for sizing a shaped extended element having a longitudinal axis and comprising at least one lateral surface parallel to the longitudinal axis. This process comprising the steps of providing a wheel having an axis in at least one lateral ring-shaped surface substantially or roughly perpendicular to the axis of the wheel and centered on the axis, with the ring-shaped surface having an outer circumference, and with the wheel being rotatably driven. The extended or elongated element is moved relative to the wheel along an axis parallel to the axis longitudinal to the extended or elongated element, and the lateral surface of the extended or elongated element is made to cooperate with the lateral ring-shaped surface of the wheel. At least the outer circumference of the wheel is coated with a glue by a suitable coating means.
The invention also provides for an apparatus for sizing an extended element having a longitudinal axis and a groove bottom surface needing to be sized.
The apparatus includes a wheel and coating means, with the wheel having a circumferential surface osculating from a groove bottom surface, and with the coating means including two mixing rollers adapted to produce a glue film. One part of the glue film is transferred by the circumferential surface of the wheel onto the groovebottom surface by the contact of the wheel onto one of the two mixing rollers.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in connection with the accompanying drawings which show, for the purpose of illustration only, one embodiment in accordance with the present invention, and wherein:
FIG. 1 is a front view, on an enlarged scale, of a portion of the sizing apparatus constructed in accordance with the present invention;
FIG. 2 is a top view of a sizing apparatus constructed in accordance with the present invention; and
FIG. 3 is a side-face view of a glue-spreading or sizing wheel of the sizing apparatus of the present invention.
DETAILED DESCRIPTION
Referring now to the drawings wherein like reference numerals are used throughout the various views to designate like parts and, more particularly, to FIG. 1, according to this figure, a shaped flexible extended or elongated element 1 to be sized is penetrated by a sizing wheel generally designated by the reference numeral 2 and maintained on the sizing wheel 2 by a press-cylinder roller 3. The sizing wheel 2 is driven by a continuous rotating movement around an axis generally designated by the reference numeral 5 by contact with a coating means generally designated by the reference numeral 4; whereas, the extended or elongated element 1 is driven by a directional displacement corresponding approximately or roughly to that of the tangential speed of a contact between the sizing wheel 2 and the extended or elongated element 1.
The sizing wheel 2 comprises two plane lateral annular or ring shaped surfaces 6 which are perpendicular to the axis 5 of the sizing wheel 2 or nearly so. A portion of these ring-shaped surfaces 6 cooperates with plane lateral surfaces generally designated by the reference numeral 7 (FIG. 3) of the extended or elongated element 1, with the plane lateral surfaces 7 extending along the longitudinal axis of the extended or elongated element 1.
These ring-shaped surfaces 6 are placed on both sides of the sizing wheel 2 and the plane lateral surfaces 7 of flexible extended on elongated element 1 are placed opposite the ring-shaped surfaces 6.
The outer surface of the sizing wheel 2, or the circumferential surface generally designated by the reference numeral 8, is adapted to cooperate with the shaped extended element 1 along a groove bottom surface generally designated by the reference numeral 9 disposed perpendicular to the two plane lateral surfaces 7 and forming with the plane lateral surfaces 7 the internal walls of a U-shaped groove of the extended or elongated element 1.
The sizing wheel 2 comprises on its lateral walls two end shields designed to maintain and/or guide the sizing wheel 2 so as to, in particular, ensure proper cooperation of the sizing wheel 2 with the extended or elongated element 1, correct drive, and sizing at the level of the coating means 4.
The coating means 4 include two mixing rollers 11, 12 rotatably synchronized by a train of gears 13 (FIG. 2) and driven by a reducer and motor unit 14 (FIG. 2).
Above and between the mixing rollers 11 and 12, turning in the opposite direction and at the same speed, a glue mass 15 is disposed intended for sizing.
This glue mass 15, which may be liquid, pasty or indeed solid, is kept inside the inter-rollers upper space by two centering tools or glue mass limit devices 16 (FIG. 2).
The flexible extended or elongated element is delivered from a coil generally designated by the reference numeral 17 (FIG. 2), routed towards the sizing wheel 2, then when once coated is discharged to a receiving coil generally designated by the reference numeral 18.
The process for sizing the plane lateral surfaces 7 of the groove bottom surface 9 of the section is carried out by placing the glue mass 15 between the mixing rollers 11 and 12 with the glue mass 15 being rolled by the mixing rollers 11, 12 into a very fine layer which adheres to the mixing rollers 11, 12. One part of the fine glue layer is then recovered by the osculating surface 8 of the sizing wheel 2, possibly via slight contact pressure being exerted between the sizing wheel 2 and the mixing roller 12.
A peripheral cylindrical glue cord 19 (FIG. 3) is provided on the outer circumferences of the ring-shaped surfaces 6, with enough glue to coat the lateral surfaces 7 of the flexible shaped extended or elongated element 1. By rotating the sizing wheel 2, the peripheral cylindrical glue cord 19 is then routed towards the plane lateral surfaces 7 where it spreads out due to the ring-shaped surfaces 6 and the combined movements of the wheel 2 and the element 1.
The size of the peripheral cylindrical glue cord 19 results in particular from the spacing combination of the mixing rollers 11, 12 defining the thickness of the film of glue on the rollers, the type and geometry of the sizing wheel 2 and contact pressure with the mixing roller 12 of the mixing rollers 11, 12.
The size of the peripheral cylindrical glue cord 19, like the different relative speeds of the moving elements and their geometry, determines the thickness of the film of glue on the lateral surfaces 7 and groove bottom 9 of the flexible shaped extended or elongated element 1.
Without involving any restriction concerning the type of elements used to implement the process of the invention, it is possible to use steel or aluminium mixing rollers 11, 12, Teflon centering tools or gum-limit devices 16, a Teflon, neoprene or silicon rubber sizing wheel 2 reinforced by metal wheel disks 10 to size a polyamide shaped element 11 (generally designed by the Rilsan manufacturing brand) with, for example, the epoxide glue SCOTCH-WELD 2216 B/A which is a brand registered by the Minesota Mining and Manufacturing Company in accordance with the proportions proposed by the manufacturer.
For example, a cord with a diameter of 1/10th to 1/100th of a millimeter enables thicknesses to be obtained with sufficient glue over a width of one of the plane lateral surfaces 7 of the extended or elongated element 1 of about one centimeter.
When the groove bottom surface 9 is not planar, it is possible, with a material of an adapted sizing wheel, to design the circumferential surface 8 with an proper form so that this surface can cooperate firstly with the greater bottom surface 9 and secondly with the outer surface of the mixing roller 12 with which it comes into contact. Thus, the association of the choice of hardness of the wheel and the form of the circumferential surface 9 enables the surface 8 to fit both the sizing cylindrical revolution surface of the roller 12 and the non-cylindrical groove bottom surface 8.
In the embodiment described above, the flexible extended or elongated element 1 comprises two lateral plane surfaces 7 perpendicular to the groove bottom surface 9 and the sizing wheel 2 includes two plane ring-shaped surfaces 6. It is also within the scope of this invention to use it when at least one of the plane lateral surfaces 7 is not perpendicular to the axis of the sizing wheel 2 and when it could cooperate at least with one outer circumference of a ring-shaped surface 6, either without deformation of the sizing wheel 2 and/or the flexible extended or elongated element 1, or with deformation of one and/or the other, especially when they are elastic. Thus, the plane lateral surfaces 7 of the extended or elongated element 1 might tend to close or open the extended or elongated element 1.
Thus, the lateral surfaces of the element might tend to close the element or open it.
Similarly, the ring-shaped surface(s) 6 need not necessarily be planar and could be truncated. The top of the cone on which rests the ring-shaped surface 6, which is the axis 5 of the sizing wheel 2, could be either on one *side, or on the other of the plane in which occurs the outer contour of the ring-shaped surface 6.
The material of the sizing wheel 2 could enable the ring-shaped surface 6 to be adapted to the lateral surface 7 by deforming the sizing wheel 2 and/or the profiled or shaped extended or elongated element 1, especially as regards the contact of the sizing wheel 2 with the extended or elongated element 1.
The ring-shaped surface 6 could be composed of sections of cones and could also coat varied forms allowing the ring-shaped surface 6 to be adapted to the lateral surfaces of the shaped or profile of the extended or elongated element 1.
For example, when the profile or shape of the extended or elongated element 1 comprises at least one lateral surface 7 perpendicular to the axis 5 and when the sizing wheel 2 includes a hollow conical ring-shaped surface 6 (as opposed to relief), the coating of the plane lateral surface 7 shall be effected by the outer contour of the ring-shaped surface 6.
Generally speaking, in order to carry out proper sizing of the plane lateral surfaces 7 of profile or shape of the elongated or extended element 1, it is essential that the outer circumferences of the ring-shaped surfaces 6 of the sizing wheel 2 are quite close to, or indeed even touch via a suitable clamping, the plane lateral surfaces 7 to be sized.
According to the same process, it is possible to size as many lateral surfaces 7 as desired, this possibly being the case for a shaped or profiled elongated or extended element 1 including several parallel grooves.
Also, it is possible, by preventing the circumference of the ring-shaped surface 6 being fed by a glue cord 19, to avoid carrying out sizing on a lateral surface of the elongated element.
It is possible to use scrapers disposed on the mixing rollers 11, 12 in order to concentrate or disperse the glue near to the circumferential surface of the sizing wheel 2 peripheral cylindrical glue, so that the cord 19 has the correct dimensions. Moreover, a coating means may be provided which does not employ mixing rollers.
It is possible to size only the groove bottom surface 9 of the shaped or profile extended or elongated element 1 and use the mixing rollers 11, 12 for this purpose, and it is also possible to press the profile or shaped extended or elongated element 1 againts the sizing wheel 2 by using several pressing rollers.
The mixing rollers 11, 12 with coating means 4 need not be synchronized in rotation relative to each other and/or with the sizing wheel 2, or be synchronized at different speeds in order to obtain a friction 25 force when such a force has beneficial consequences.
Especially, at the level of contact of the mixing roller 12 with the sizing wheel 2, it is possible to tranversally guide the shaped or profiled elongated or extended element 1 with the aid of the rollers leaning against the lateral faces of the shaped or profiled extended or elongated element 1.
The invention is more particularly applicable to the groove mould sizing used in the production of composite armors for flexible extended bodies.
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A method and apparatus for the sizing of a shaped extended element having a longitudinal axis and including lateral surfaces extending substantially parallel to axis. The apparatus includes a wheel rotatable about an axis and with the wheel including at least one planar ring-shaped surface extending perpendicular to the axis of the wheel and centered on the surface. The ring-shaped surface is adapted to cooperate with the lateral surface of the shaped elongated element during a displacement of the wheel relative to the element along an axis parallel to the longitudinal axis of the element. A coating means is adapted to deposit, at least on the outer circumference of the wheel a sufficient amount of glue for allowing a sizing of the lateral surface of the shaped element.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a system for detecting intruders.
[0002] More particularly, it relates to a system for detecting an intruder, which can distinguish between intruders of different types. The known systems do provide detection of intruders, however they can not distinguish walking intruders of different types. In many instances it is very important not only to detect a presence of an intruder, but also to obtain information about the nature of the intruders.
SUMMARY OF THE INVENTION
[0003] Accordingly, it is an object of present invention to provide a system of detecting intruders, which makes possible detection of walking intruders of different types.
[0004] In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in a system for detecting an intruder, which has at least one sensor which sense the presence of intruders and at least a processing means connected with said sensor, said processing means being operative for determining a plurality of parameters, analyzing the parameters, and making a decision from a determined value as to what type of intruder is present.
[0005] When the system is designed in accordance with the present invention, it is possible to distinguish the intruders from one another. In particular, if the system is used for example during hunting, etc., the system allows to determine whether a detected object is a human being or an animal. This significantly increases the safety of hunting, to avoid hitting of a human being, instead of an animal.
[0006] The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] [0007]FIG. 1 is a view schematically showing a plurality of sensors of the inventive system covering a corresponding area; and
[0008] [0008]FIG. 2 is a view schematically showing a block diagram of the inventive system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0009] A system for detecting an intruder in accordance with the present invention includes a plurality of sensors which are identified as a whole with reference numeral 1 and provided in an area 2 . The sensors can be connected with one another and identified in FIG. 2 generally a sensing means 2 . The sensing means 2 are connected with an amplifier 3 , which in turn is connected to the analog/digital convertor 4 . The analog-digital convertor is connected with a processing unit 5 .
[0010] The central processing unit 5 is operative for determining a speed of movement of the intruder which can be represented as a number of steps per time unit or a time between the steps. It also determines a stability of movement of the intruder which is determined as a percentage of deviation of time intervals between the steps from an average interval. It also determines a level of a signal obtained from a sensor which is a level of an amplitude of voltage produced by the sensor. The sensor can be an acoustic sensor, a seismic sensor or a combined acoustic/seismic sensor which produces a signal in form of a voltage. Finally, the processing unit 5 determines a speed of change from one step to the other, or a speed of change of the amplitude.
[0011] The present invention can be used for example as a system for determining whether an intruder in an area is a human being or an animal, in particular a bear. The speed of movement of the human being is 0.25-1.5 seconds between the steps, while the speed of movement of the bear is 1.4-1.8 less time between the steps. The stability of the movement of a human being is 3-10%, while the stability of the movement of bear is 8-20%. A level of signal received from the sensor is for a human being 1.5-2.5 mV, while for the bear the level of signal is 4-6 times greater. Finally, the speed of change from step to step is 15-25% for a human being, and 30-50% for a bear. The central processing unit determines the numerical values of the above mentioned parameters. The specific operations for determining each of this parameters are not germaine to the present invention, and can be performed in any suitable way.
[0012] The central processing unit 5 is connected with an indicating device 6 . The indicating device can be formed for example as a screen, in which as a result of the processing in the processing unit 5 , it is shown a picture of a human being or a bear thus clearly indicating the type of the intruder. Also, on the screen there can be words saying “human being” or “bear”. Also, the indicating unit can be formed as an alarm which produces different alarms, for example a sound “human being” or “bear”, or alarms which do not include words, but instead signals of different pitch, type, etc.
[0013] Thus, the system in accordance with the present invention provides the possibility of distinguishing the type of the intruder for many purposes, including hunting purposes, etc.
[0014] 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 constructions differing from the types described above.
[0015] While the invention has been illustrated and described as embodied in system for detecting intruders, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
[0016] 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.
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A system for detecting a walking intruder has at least one sensor which senses the presence of intruders, and a processing unit connected with the sensor and operative for determining a plurality of parameters, analyzing the parameters, and making a decision from the determined value about a type of intruder present.
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FIELD OF THE INVENTION
[0001] The disclosure relates to controlling the display of a computer device.
BACKGROUND OF THE INVENTION
[0002] One technical area where there are particular challenges in controlling the display of a computer device is in the design of computer-implemented games. Not only is there a requirement to create fun and compelling games, these games need to be delivered to a player in a seamless and engaging fashion, while adhering to complex game rules.
[0003] Gameplay should be engaging and rewarding to players. This typically requires games to be easily understood at their simplest or introductory levels, providing rewarding gameplay with quite simple game mechanics, but becoming progressively more challenging so that players are not bored, but remain engaged and develop rewarding skills. Effective engagement requires various forms of feedback to reinforce players' sense of success and accomplishment.
[0004] A ‘match-3 game’ is a type of casual puzzle game where the player is required to find patterns on a seemingly chaotic board. The player then has to match three or more of the same type of game element on the game board and those matched elements will then disappear.
[0005] One type of match-3 games are the so-called ‘switcher’ games where the player switches place on two adjacent game elements on the game board so that one or both of them create a chain of at least three adjacent game elements of the same type. Those matched game elements will then disappear. In a typical switcher game the game board will be repopulated with game objects from the top of the board with the physics of the game board being that the game pieces are falling downwards on the board.
[0006] Another type of match-3 game are the so-called ‘shooter’ games where the player launches for instance a ball or bubble on to the game board tying to aim at groups of similar game elements already on the game board. If the launched ball hits or forms a group of more than 3 similar game elements then that group of game elements are removed from the game board. In a typical shooter game the physics of the game board being that the game pieces are falling downwards on the board.
[0007] This patent specification describes not only various ideas and functions, but also their creative expression A portion of the disclosure of this patent document therefore contains material to which a claim for copyright is made and notice is hereby given: Copyright King.com Limited 2012 and 2013 (pursuant to 17 U.S.C. 401). A claim to copyright protection is made to all screen shots, icons, look and feel and all other protectable expression associated with the games illustrated and described in this patent specification.
[0008] The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but reserves all other copyright rights whatsoever. No express or implied license under any copyright whatsoever is therefore granted.
SUMMARY OF THE INVENTION
[0009] The present application is directed to controlling the display of a computer device to deliver functions of a new type of match-3 game, in which players can slide game objects past each other to create line combinations of three or more. A sliding match-3 game as described herein presents particular technical challenges because matches are acknowledged in any direction on a game board, and not just in the direction that a game object is moving (or sliding). These challenges are addressed by described embodiments of the present invention.
[0010] One aspect of the invention provides a method of controlling a display of a computer device comprising: rendering on the display a game board having a plurality of selectable game objects having respective characteristics, each at a respective tile location in an array; detecting a user input to select a game object to cause the game object to move in a direction, wherein when a game object is moved to an adjacent new tile location, the game object at that tile location is swapped with the selected game object; generating match data for the selected game object if moved in that direction, the match data indicating whether the move results, at any potential new tile location of the selected game object or swapped objects resulting from the move, in at least three game objects of the same characteristic occupying adjacent tile locations in the game board, and, if so, implementing the move and rendering an animation of the move on the display, wherein the selected game object slides in the direction up to a blocking condition which prevents further movement.
[0011] In some embodiments of the present invention which are described herein, the game objects are referred to as ‘plushies’. A match check is performed when a plushie has actually changed its position, that is when a move has been implemented and the plushie is “sliding”. Matches of more than three game objects of the same characteristics are acknowledged by removal of those game objects from the rendered image of the game board, and from the data structure representing the game board itself. In addition, embodiments of the present invention provide a match check to test what would happen if a plushie were to slide in the direction indicated by a user. Only valid moves will be implemented, and in order for a move to be valid at least one match would need to occur. Tile data is stored in a data structure in a memory wherein the tile data identifies the characteristics of each game object at a respective tile location represented in the data structure, such as a matrix or grid. In the embodiments of the invention, the grid is three-dimensional. That is, two dimensions represent the two dimensions of the plane of the game board, and a third dimension provides multiple object layers, each holding data managing a different function of the game.
[0012] The characteristic of a game object can be its colour. In that case, the colours of game objects in the data structure are copied into a “colour grid”, and the potential new position of the plushie represents a starting point of a check for matches. The check is performed by detecting colour matches in and around that position. The characteristic of a game object can be indicated by one or a set of characteristics identifiers, such as a colour identifier. A grid of characteristic identifiers can be used to detect matches.
[0013] This check is carried out when a move is actually implemented to acknowledge all matches which occur as the plushie slides. It is also implemented when a player tries to make a move (switch). In that case, an algorithm implemented in game code executed by a processor performs a match check for each position that the plushie would pass and all reversing moves (swaps) of the plushies that it passes. If any match is detected, the algorithm stops and the move will start (actually be implemented). When a move is actually performed, the grid might have changed due to a refill or some of the moves, so there is no certainty that the anticipated match will occur. Therefore, when the move is actually implemented, the check is carried out again for “real” matches.
[0014] Aspects of the invention also provide a computer device in which the method is implemented, and a computer readable medium holding instructions for implementing the method. The code can be executed on a client device to control a display of the device. Parts or all of the code can be executed remotely, for example at a server, and generate data which is transmitted to a client device for controlling a display of the client device.
DESCRIPTION OF THE DRAWINGS
[0015] Embodiments of the invention will now be described by way of the accompanying drawings in which:
[0016] FIGS. 1 a to 1 g illustrate a plushie slide in one game board configuration;
[0017] FIG. 2 illustrates a z-axis refill;
[0018] FIGS. 3 a to 3 f illustrate a plushie slide in another game board configuration;
[0019] FIGS. 4 a to 4 c illustrate a z-axis refill sequence with a combo;
[0020] FIGS. 5 a to 5 d illustrate a 6-combo;
[0021] FIG. 6 is a schematic illustration of a computer device;
[0022] FIG. 7 is an exemplary computer environment;
[0023] FIG. 8 is a schematic diagram of code components for controlling the display;
[0024] FIG. 9 illustrates the four layer data structure;
[0025] FIGS. 10 to 12 show a game board displayed to a user; and
[0026] FIG. 13 is a flow chart of a match detector.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The terms user and player are used interchangeably throughout this document and no specific meaning is intended using one or the other unless the context suggests otherwise.
[0028] In the following description of various implementations of the invention, reference is made to the accompanying drawings which form part thereof, and in which is shown by way of illustration various implementations in which the invention may be utilized. It is to be understood that the other implementations may be utilized, and structural and functional modifications may be made without departing form the scope of the present invention.
[0029] FIG. 6 shows a schematic picture of a computing device, containing a Central Processing Unit 172 and Random Access Memory 174 . The CPU 172 acts according to input given from input devices 170 such as a keyboard, mouse or touchscreen. Computer buses 178 are used to communicate, both between input devices 170 and the CPU 172 , but also between different controllers within the computer device, such as a graphics controller 180 and a network controller 182 . These controllers in turn communicate with external devices, such as a display 184 for video output with which the graphics controller 180 communicates to present the game board, and the network controller 182 communicates with for instance the Internet 122 , through wireless or wired connections. A user can interact with the computing device through input devices 170 such as a pointing device (e.g. mouse) and a keyboard.
[0030] FIG. 7 portrays an exemplary overall environment in which the present invention can be utilized. A virtual game is stored on for instance a game server 205 . The virtual game is to be played on a client device, such a computer 220 , 225 or a smartphone or other handheld device 230 . The client device can also be a kiosk, arcade gaming station, smart TV or other device with computing capabilities, input devices and a screen that can present the game to a user. The client device communicates with the game server 205 and a social network server 215 , for instance through the Internet 220 or other network. It should be understood that the social network server 215 and the game server 210 do not have to be located in different places, they could be on the same server or on a plurality of servers located in different locations. People skilled in the art will understand that other devices than the exemplary ones listed can also be used without departing from the spirit and scope of the invention.
Different Implementations
[0031] The techniques described in this patent can be deployed in many different gameplay architectures. For example, a computer game can be implemented as a computer program that is stored and runs entirely locally on the processor of a PC, games console, tablet or mobile telephone or other computing device. The game can be implemented solely as a computer program that is stored and runs entirely on one of many processors in a remote server, and data streams or updates are supplied to the client device (e.g. tablet, smartphone, etc.) to enable the client to render and display graphics and sounds; this ‘web services’ approach is increasingly common.
[0032] Another aspect is a hybrid one, in which back-end servers handle some elements of the gameplay, and for instance a Java game applet is provided to client devices and it is the locally running Java applet that generates the graphics/sounds/user interaction for gameplay on the player's client device. Some data may be fed back to the back-end servers to enable scoring, interaction with other players and cross-platform synchronisation. Generally, the techniques described in this specification are not specific to any one game architecture but can be deployed on any suitable game architecture.
[0033] The game can be implemented allowing a user to interact with it in different ways depending on the capabilities of the device which the user is accessing the game with. A user can interact with the game through using a touch screen where the user can select and/or move elements on the game board with a finger or for instance with a stylus. The game can also be played with a pointing device such as a mouse or other interaction devices such as keyboard.
[0034] Mobile devices may have a touch screen interface where the player can interact with the game using a finger or a pointing device such as a stylus. Some mobile devices have hard keys that complement the touch screen interface. Such hard keys may be in the form of a button or in the form of a joystick type of interaction.
[0035] Over the course of players playing the game, data will be produced. This data can for instance be related to a player's game performance or to game information related to a social network to which the game is connected. It is possible to gather this data, store it and make use of it for instance to improve the game.
Game Description
[0036] Stitcheroo is a level-based action puzzle game in which players slide coloured bricks, or plushies, past each other to create line combinations of three or more. The game is played on a series of 9×9 game boards of plushies in 5-6 different colours with automatic refills along the z-axis to ensure a constantly filled game board. Three or more plushies of the same colour in a line or L/T-formation will create a combo, and refills may in turn generate chain combos. Any playable plushie may be swiped up, down, left or right and will pass under all other plushies in the same row or column until coming to a full stop against another plushie of the same colour, an obstacle or a wall. All passed plushies will naturally be moved one step in the opposite direction; enabling chain reactions among other plushie constellations. All passed plushies will naturally be moved one step in the opposite direction; enabling chain reactions among other plushie constellations.
[0037] Combos in Stitcheroo are made by sliding plushies to create groups of three or more of the same colour. Once a combo has been created, the group disappears, leaving room for new, random plushies to be refilled from above. Refills can, in turn, create further combos as they land, which will lead to further refills, and so on. All passed plushies will naturally be moved one step in the opposite direction, enabling further chain reactions among other plushie constellations behind the passing plushie.
[0038] Slide-by combos in Stitcheroo are made by sliding plushies past rows or columns of the same kind, momentarily forming a line combo. All slide-by combos are activated instantly, visualized by an animation of a wave of energy travelling from the sliding plushie to the ends of the combo line. The sliding plushie may then travel on to create further slide-by combos, regular combos or simply come to a stop against a wall or a plushie of the same colour. Either way, the sliding plushie always disappears. Upon disappearing, the squares left empty by the combos are refilled by random plushies as usual.
Golden Buttons
[0039] Golden buttons in Stitcheroo are score bonuses present on the game board, carrying a set amount of points when collected. To collect a golden button, a played plushie must pass or be placed on the square carrying it. Each level holds three randomly placed golden buttons, either appearing exposed from the start or hidden beneath an obstacle. To reveal a hidden golden button, the obstacle hiding it must first be removed, upon which the golden button may be collected as normal. If not collected before the end of a level, any exposed golden buttons will be transferred to the next level, while hidden ones are lost. Golden buttons which are transferred between levels can never be re-hidden.
Obstacles & Boundaries
[0040] Obstacles in Stitcheroo are either destructible or indestructible. Indestructible obstacles are just another name for level boundaries, which may appear anywhere and in any shape on the game board. Destructible obstacles, however, are actual objects present on the game board. Visually represented as thimbles, the obstacles have two basic states; silver and bronze. To clear an obstacle, combos need to be made adjacent to it, upon which the obstacle goes from bronze to silver before completely vanishing. By clearing obstacles, the freed up squares will automatically fill up with plushies and enable the player to pass unhindered.
Special Combos
4-Combo
[0041] Creating a 4 line-combo instantly causes an animation of all combined plushies to contract in a generic smoke effect. From the effect, the two end plushies slide off in opposite directions without hesitation, possibly creating chain combos.
5-Combo
[0042] Creating a 5 line- or L/T-combo instantly causes an animation of all combined plushies to contract in a generic smoke effect. From the effect, the last added plushie continues on without delay at the same time as all plushies of the same colour start to slide along in the same direction, able to create reverse combos on the way, before ultimately exploding without radius (i.e. without involving other plushies) against any obstacles or wall.
6-Combo
[0043] Creating a 6 T-combo instantly causes an animation of all combined plushies to contract in a generic smoke effect. From the effect, the last added plushie carries on uninterrupted in the same direction until reaching an obstacle or wall, clearing all plushies in its way. Upon impact, the plushie bounces while changing columns or rows and sliding back the same way it came. This repeats until reaching the far corner of the wall in the general direction of movement, where the plushie ultimately explodes without radius.
[0044] 7-Combo
[0045] Creating a 7 T-combo instantly causes an animation of all combined plushies to contract in a generic smoke effect. From the effect, a plushie of the combination's colour emerges and grows rapidly on the square of the last added plushie, until reaching the size of 3×3 squares. Finally exploding in a big cloud of dust while shaking the camera violently, the super-sized plushie then sends all plushies on the game board flying cheerily off screen. Naturally, all obstacles are removed in the blast, revealing and collecting any hidden golden buttons, along with already exposed ones.
[0046] FIGS. 1-5 show an edited version of the game board as it will be rendered to a user on the display of his computer device. The board has been reduced to a 5×5 grid and only partially filled for illustrative purposes. The game objects are represented by simplified shapes in this instance, and are called ‘plushies’. When operated by a user input device in the form of a mouse, a plushie can be moved by clicking and holding it, then dragging the plushie in any of the 4 axis parallel directions within the x-y plane of the board (up, down, left or right). The plushie will only slide if, by moving in the selected direction, it will make a group of at least 3 matching plushies in a combo at some point before stopping. The plushie will slide even if it is not directly involved in the combo if the movement of another plushie causes a combo, as in to make a reverse combo. A plushie will stop if it meets an obstacle, or another plushie of the same colour, or the edge of the board. If it reaches any of these having been directly involved in a slide-by combo it will explode.
[0047] Plushies have characteristics, such as colour and shape, which can be used to identify matches.
[0048] FIG. 1 a shows a section of a typical board, a domed plushie P 1 in tile T 15 has been chosen and dragged in the negative x direction (to the left) on the board. This is an allowed move as a 3 line combo will be made as a result.
[0049] FIG. 1 b shows the first move the plushie T 15 will make. The domed plushie of T 15 will move to the left, under the triangular plushie in tile T 14 . The triangular plushie in tile T 14 will move to the right, to fill the tile previously occupied by the sliding domed plushie, T 15 . This is referred to as a ‘swap’ or ‘reverse swap’.
[0050] FIG. 1 c shows the result of the first move. The next element movement is indicated with arrows. The triangular plushie, having moved to tile T 15 , has made a 3 line combo in the y direction at tiles T 10 , T 15 , and T 20 . This is a reverse combo. The domed plushie continues across the board and slides under the next cylindrical plushie at T 13 .
[0051] FIG. 1 d shows the domed plushie having moved under the cylindrical plushie to T 13 . The cylindrical plushie having taken the place the domed plushie left behind at T 14 . The 3 matched triangular plushies (at T 10 , T 15 , and T 20 ) have now exploded denoted by a wavy line, which represents an animation which would be displayed. The domed plushie at T 13 now creates a new group of 3 in the y direction. This is a slide-by combo. The domed plushie at T 13 continues to slide to the left. Arrows indicate the next element movement.
[0052] FIG. 1 e shows the board after the domed plushie has moved under the next, ‘u’ plushie to T 12 . The ‘u’ plushie has moved to tile T 13 . The two stationary domed plushies that were at T 8 and T 18 in FIG. 1 d have exploded. The domed plushie at T 12 continues to slide.
[0053] FIG. 1 f shows the domed plushie reaching the edge of the board at T 11 . The domed plushie has moved past the cube plushie at T 11 , which has moved into the hole left behind at T 12 . The domed plushie makes another group of 3 in the y direction at T 6 , T 11 , and T 16 . The domed plushie at T 11 cannot slide any further as it has reached the board edge.
[0054] FIG. 1 g shows the board after the whole slide of the domed plushie is completed. All of the events in FIGS. 1 a - f occur without any further user input after the original click and drag of the domed plushie at T 15 in FIG. 1 a . The final group of 3 has vanished, the central domed plushie also vanishing as it has reached the edge of the board, and thus the end of its slide.
[0055] FIG. 2 shows the refilling of the holes left in the board after the plushies forming the combos outlined by dashed lines in FIGS. 1 c 1 c , 1 d , and 1 f have exploded.
[0056] Holes are filled with plushies selected at random. The board is refilled along the z-axis (from above). Here all holes are shown refilling at the same time for illustrative purposes. In the actual gameplay, holes may be filled while other combos are being made elsewhere on the board.
[0057] Refilling the board is postponed during the outcomes of 4, 5, 6 and 7 combos so as not to obscure the player's vision with falling plushies.
[0058] FIG. 3 a shows another typical board arrangement. The domed plushie in T 15 is held and dragged to the left. The arrow shows the plushie's entire slide.
[0059] FIG. 3 b shows the first move the domed plushie will make indicated with arrows. The domed plushie at T 15 will move to the left, under the triangular plushie at T 14 . The triangular plushie will move to the right to T 15 , to fill the tile previously occupied by the sliding domed plushie.
[0060] FIG. 3 c shows the board after the domed plushie has moved to T 14 . The next move is indicated with arrows.
[0061] FIG. 3 d shows the domed plushie at T 13 having swapped places with the cylindrical plushie now at T 14 . The domed plushie now makes a slide-by combo with the domed plushies at T 8 and T 18 . This slide-by combo is outlined using a dashed line. The arrows show the next move for the sliding domed plushie.
[0062] FIG. 3 e shows the result of the domed plushie continuing to T 12 , having swapped places with the ‘u’ plushie now at T 13 . The two stationary domed plushies from T 8 and T 18 involved in the Slide-by combo have exploded. The sliding domed plushie now comes to a stop at T 12 . This is because it has reached a plushie of the same type (colour/shape).
[0063] FIG. 3 f shows the board after the sliding domed plushie has disappeared from T 12 . The plushie previously at T 12 has exploded as a result of having been directly involved in a combo. By which it is meant that at some point during the slide it formed a combo which included it and at least 2 other plushies of the same type (colour/shape).
[0064] FIG. 4 a shows the refilling of the holes left in the board from the Slide-by combo outlined by a dashed line in FIG. 3 d . This is done along the z-axis as shown previously in FIG. 2 . Refilling the board from the z-axis allows for minimal changes to the board between moves. This enables a player to make a new combo by sliding another plushie while holes are being refilled elsewhere on the board.
[0065] FIG. 4 b shows a group of three red plushies being made at tiles T 8 , T 9 , and T 10 as a result of the random refilling of the holes on the board. This combo disappears as part of the original move, with no extra input required from the player.
[0066] FIG. 4 c shows the board after the 3 combo of red plushies has exploded. No plushies were moving so the refilling of these 3 holes will be the only change to the board. Refilling is along the z-axis.
[0067] FIG. 5 a shows the board set where the next move will create a 6-combo. The move to create the 6-combo is shown using arrows. A cube plushie at T 22 will switch with a ‘u’ plushie at T 17 . Part of the board has not been filled with plushies for illustrative purposes only.
[0068] FIG. 5 b shows the 6-combo outlined by a dashed line. The 6-combo encompasses plushies in tiles T 7 , T 12 , T 16 , T 17 , T 18 , and T 19 . The ‘u’ plushie now occupies tile T 22 .
[0069] FIG. 5 c shows the board immediately after the 6-combo is made. The 6-combo instantly causes an animation of all combined plushies to contract in a generic smoke effect. From the effect, the last added plushie at tile T 17 carries on uninterrupted in the same direction, until reaching an obstacle or wall, clearing all plushies in its way, for example the plushie at T 2 . Blasting plushies resulting from 4 and 6 combos can pass holes, move out of the grid and cross each other's paths.
[0070] FIG. 5 d shows how the last added plushie at T 17 carries on sliding uninterrupted in the same direction. When reaching a wall or the board edge, the boosted plushie bounces upon impact, and continues in the opposite direction in the adjacent column or row. The boosted plushie clears all plushies in its way. Cleared plushies 502 can be seen flying off in various directions having previously occupied tiles T 2 , T 3 , T 8 , T 13 , T 23 and T 4 . Cleared plushies leave the board completely. This continues until the boosted plushie 504 reaches the far corner of the wall in the general direction of movement, where the plushie ultimately explodes without radius. No plushies are spawned during the booster motion, so as not to obscure the player's vision with falling plushies.
[0071] FIG. 9 is a schematic diagram showing components of software used to implement the game and control the display. The game software is executed on a processor by code stored in a memory, locally at the computer device or remotely. The game comprises a game logic component 2300 which incorporates the rules, etc. of the game. An input detection component 2302 detects user inputs by the input devices 170 to detect where a user has clicked and what action a user has just taken. A rendering component 2304 is responsible for rendering each screen after a user move, and for displaying the explosions and other animations arising in the game. The rendering component is also responsible for displaying the refill in the z-axis to animate a refill as though the plushies are arriving from above the screen to refill the game board. A matrix component 2308 stored in a memory provides a matrix representation of the game board as shown schematically in FIG. 8 . In reality the matrix component can be supplied by any suitable data structure, held in local memory or remote memory accessible by the device, and is responsible for identifying for each tile location on the board information about what is to be displayed at that tile location. This information is provided to the rendering component to control the display.
[0072] In described embodiments of the present invention, the matrix 2308 is implemented as a three-dimensional grid. That is, the board is shown with two dimensions x and y, and there is a third dimension which is denoted here as dimension n (so that it does not become confused with the third dimension in the real world which is denoted z). The ‘n’ for dimension comprises four layers which are shown schematically in FIG. 8 and denoted a ButtonLayer BL, NormalLayer NL, ExplodeLayer EL and FallLayer FL. The NormalLayer NL of the data structure is the layer that holds data concerning the moving plushies. So referring back to FIGS. 1 through 5 , the tile numbers T 1 , T 2 , etc., can be considered to represent grid positions in the NormalLayer of the data structure. The position of a game object in the data structure is either where it is or where it is going (the next tile location). When it starts to move it changes position to its destination even though it is closer to its start at that point. Obstacles (such as thimbles) are held in the grid structure in the NormalLayer.
[0073] Providing a multi-layer grid structure in the n dimension allows the display to be controlled so that the game mechanics discussed above can readily be made visible to a user in an engaging and simplified fashion.
[0074] The layers act as logical layers. The provision of the layers allow simultaneous activity at one tile. For example, there could be a button hidden in the ButtonLayer while a thimble is in the NormalLayer at the same tile position. A plushie can be moving in a tile position in the NormalLayer, while another tile is exploding at that tile position, in the ExplodeLayer. Note that when a plushie moves into a tile location occupied by another plushie of a different characteristic, this is detected in the NormalLayer. The animation of one plushie moving ‘under’ the adjacent plushie is effected by the rendering component. A tile can be exploding in a tile position in the ExplodeLayer while another tile is falling towards that position in the FallLayer. A plushie can be passing through a position the NormalLayer while another plushie is falling towards that tile position in the FallLayer.
[0075] To render the game board on the display of a computer device, data is extracted for each tile position from each of the four layers of the data structure and supplied to the rendering component 2304 to allow each tile position to be rendered. Thus, a tile can simultaneously show a plushie moving, another one exploding and another one falling, for example. The game logic handles these are distinct events, while the rendering component can amalgamate them to display all active functions at a particular tile location.
[0076] FIG. 9 illustrates four cases of possible game piece configurations with respect to the layers of the grid. They are each separated into a case 1 - 4 . Case 1 , there can be a button 602 hidden in ‘Button Layer’ while a Thimble 604 is in ‘Normal Layer’. Case 2 , a plushie 606 can be moving in a position in ‘Normal Layer’, while another plushie 608 is exploding in ‘Explode Layer’. Case 3 , a plushie 608 can be exploding in a position in ‘Explode Layer’, while another plushie 610 is falling towards that position in ‘Fall Layer’. Case 4 , a plushie 606 can be passing through a position in ‘Normal Layer’, while another plushie 610 is falling towards it in ‘Fall Layer’. Note that if the thimble 604 is removed by game play, the button 602 is revealed, and the rendering component changes the graphical image on the display to change the thimble to a button at that location, although the button stays in the logical Button Layer.
[0077] FIG. 10 shows how these four layers are presented to the player in real game play. Plushies fill the board around obstacles, in this case both bronze 702 and silver 704 thimbles. Bronze thimbles are presented as sitting over silver thimbles. Buttons 706 also occupy some tiles instead of plushies. Two explosion clouds 708 can be seen around the recently created holes in the board due to the latest move. Two bronze thimbles 710 can be seen flying out of the frame. The thimbles are thrown off the board when plushies explode next to them.
[0078] FIG. 11 shows plushies 902 falling in from the fall layer, along the z-axis, to refill the board.
[0079] Data for rendering the images on the display is managed in layers in the graphics component, to allow for the action associated with one plushie to be ‘overlaid’ on the action associated with another plushie in an image rendered to a user.
[0080] The main layers of the playing area from bottom to top are:
[0081] shadowLayer,
[0082] moveLayer (plushies moving below other plushies),
[0083] gridLayer (plushies, thimbles and buttons),
[0084] slideByEffectLayer (yarn animation),
[0085] combo 7 Layer (the plushie that grows),
[0086] trailLayer (particle effects trailing moving plushies),
[0087] genericCloudLayer (cloud particle effect after some combos),
[0088] bigCloudLayer (combo 7 cloud),
[0089] colorFlightLayer (flash lightning for combo 5 ),
[0090] flightLayer (plushies flying off screen),
[0091] fallLayer (plushies, buttons and thimbles falling in),
[0092] buttonFlightLayer (buttons flying to GUI on the side),
[0093] scoreTrailLayer (particles flying to zipper),
[0094] scorePopLayer
[0095] Some graphics are simply set to not render when below other things. i.e. buttons below thimbles.
[0096] FIG. 12 shows the starting game board as well as the statistics band which is presented down the right hand side of the board. Vital information is presented to the player along the right-hand side of the screen. At the top is presented a target score 902 to complete the level. Below this is a timer 904 that counts down the total playing time remaining. Each stitch around the edge of the pink circle represents a second within the current minute. Below this is the number of remaining moves 906 . Underneath this is the number of buttons collected 908 out of the total available to collect on the current level.
[0097] FIG. 13 illustrates a flow diagram of operation of a match detector component 2310 . The match detector component 2310 has a responsibility for performing two different kinds of match checks. A match check is performed when a plushie has changed its position in a game move, and a match is also formed to test what would happen if a plushie were to move in the direction indicated by a user. The data in NormalLayer of the grid is used to detect matches. The colours of plushies in the NormalLayer of the grid are copied into a colour grid, the corresponding colour of each plushie being copied into the corresponding tile position. When a plushie has been selected, the next position (adjacent tile in the direction which has been chosen by the player) is the starting position of the check. The check is performed, detecting colour matches in and around that position. After detecting user selection of a plushie S 1300 , this check S 1302 is carried out. When a player tries to make a move, the algorithm performs a match check for each position that the plushie would pass and all reversing moves of the plushies that it passes. If any match is detected, the algorithm will stop and the move will start. Thus, in Step S 1304 , a check is made to see whether any combination has resulted with the plushie in the next starting position. If a match has resulted, the move is permitted S 1306 . If no combination has been detected on the game board, then the position of the plushie in the next adjacent tile in the direction of the move is checked and the process repeats S 1308 . When the game performs a check for potential combos before allowing a plushie to move, there is no guarantee that an anticipated combo will occur. This is because other combos may have been completed in the meantime, and resulted in plushies exploding which would have been involved in the anticipated combo. Thus, after the move has been implemented, at Step S 1310 checks are made again for reverse or slide by combos on the game board. If a combo is detected Step S 1312 , the appropriate animation is activated as described earlier. If no combination is detected, the plushie is slid to its end condition and no further action is taken. Note that the end condition could be an edge of the game board, a hole in the game board (created by removal of a plushie), an obstacle (such as a thimble) or a game object having a matching characteristic. This may mean that a plushie cannot complete a slide it has started, due to changes in the game board while it is sliding.
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A computer implemented method of controlling a display of a computer device comprising: rendering on the display a game board having selectable game objects and detecting a user input to select a game object to cause the game object to move in a direction. When a selected game object is moved to an adjacent new tile location, the game object at that tile location is swapped with the selected game object. Match data for the selected game object is generated indicating whether the move results in at least three game objects of the same characteristic occupying adjacent tile locations in the game board, and, if so, the move is implemented and an animation of the move is rendered, wherein the selected game object slides in the direction up to a blocking condition which prevents further movement.
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BACKGROUND AND SUMMARY
[0001] Diesel powertrains may have a particulate filtration system referred to as a Diesel Particulate Filter (DPF), where engine generated soot may be collected. The collection, or loading, of soot leads to an increase in exhaust pressure, which may degrade engine performance. As such, collected soot can be periodically combusted (e.g., regenerated, or purged) to clean the device and reduce the performance impact.
[0002] It may be advantageous to vary when a particulate filter is regenerated to reduce fuel consumption and extend filter usable life. In some examples, filter soot loading may be inferred and/or correlated to a measure of filter flow restriction, such as based on upstream and/or downstream pressures. However, the restriction over the DPF may depend heavily on the amount of flow, which in turn may vary with temperature in and around the DPF. Further, since temperature may vary both along the length of the filter and/or across the filter width, especially during transients, using a measure or estimate of DPF temperature and/or exhaust temperature may produce errors, especially during low flow conditions (e.g., idle) where errors in models may be amplified. Such errors may lead to unnecessary regeneration, thus increasing fuel usage and decreasing durability.
[0003] Thus, in one approach, the restriction and/or the decision and timing of the regeneration may be correlated to loading taking into account temperature and/or flow distribution along and/or across the DPF. Further, in one embodiment, such correlation may be used during higher flow and/or higher temperature conditions to provide improved accuracy and address the problem of low flow restriction variability.
[0004] The inventors herein have recognized the above issues and approaches, which will be more fully described herein with reference to the description and/or figures.
BRIEF DESCRIPTION OF THE FIGURES
[0005] FIG. 1 is a schematic diagram of an engine;
[0006] FIG. 2 is a schematic diagram of exemplary emission control system;
[0007] FIGS. 3 and 7 are example routines for managing particulate filter regeneration;
[0008] FIG. 4 shows an example flow model for a DPF;
[0009] FIGS. 5-6 , and 8 show example filter flow data.
DETAILED DESCRIPTION
[0010] Internal combustion engine 10 , comprising a plurality of cylinders, one cylinder of which is shown in FIG. 1 , is controlled by electronic engine controller 12 . Engine 10 includes combustion chamber 30 and cylinder walls 32 with piston 36 positioned therein and connected to crankshaft 40 . Combustion chamber 30 is shown communicating with intake manifold 44 and exhaust manifold 48 via respective intake valve 52 and exhaust valve 54 . Engine 10 is shown as a direct injection engine with injector 80 located to inject fuel directly into cylinder 30 . Fuel is delivered to fuel injector 80 by a fuel system (not shown), including a fuel tank, fuel pump, and high pressure common rail system. Fuel injector 80 delivers fuel in proportion to the pulse width of signal FPW from controller 12 . Both fuel quantity, controlled by signal FPW and injection timing may be adjustable. Engine 10 may utilize compression ignition combustion under some conditions, for example.
[0011] Controller 12 is shown in FIG. 1 as a microcomputer including: microprocessor unit 102 , input/output ports 104 , read-only memory 106 , random access memory 108 , and a conventional data bus. Controller 12 is shown receiving various signals from sensors coupled to engine 10 , in addition to those signals previously discussed, including: engine coolant temperature (ECT) from temperature sensor 112 coupled to cooling sleeve 114 ; a measurement of manifold pressure (MAP) from pressure sensor 116 coupled to intake manifold 44 ; a measurement (AT) of manifold temperature from temperature sensor 117 ; an engine speed signal (RPM) from engine speed sensor 118 coupled to crankshaft 40 .
[0012] An emission control system 20 is coupled to an exhaust manifold 48 and several exemplary embodiments of the system in accordance with the present invention are described with particular reference to FIGS. 2A-2C .
[0013] In one example, engine 10 may be a diesel fueled engine that operates with stratified charge combustion in excess oxygen conditions. Alternatively, fuel timing adjustments, and multiple fuel injections, can be utilized to obtain homogeneous charge compression ignition combustion. While lean operation may be utilized, it is also possible to adjust engine conditions to obtain stoichiometric or rich air-fuel ratio operation.
[0014] In another alternative embodiment, a turbocharger can be coupled to engine 10 via the intake and exhaust manifolds. The turbocharger may include a compressor in the intake and a turbine in the exhaust coupled via a shaft. Further, the engine may include a throttle and exhaust gas recirculation.
[0015] Referring now to FIG. 2 , the emission control system 20 optionally includes a catalyst system 13 upstream of the particulate filter 15 . Various types of catalysts can be optionally used, such as, for example: a urea based Selective Catalytic Reduction (SCR) catalyst, an oxidation catalyst, and/or a NOx absorber, or these catalysts could be combined with the particulate filter. In the case of an SCR catalyst, in one example, it may include a base metal/zeolite formulation with optimum NOx conversion performance in the range of 200-500° C. Reductant, such as aqueous urea, can be stored on-board and injected in the exhaust system upstream of the SCR catalyst. Alternatively, any other structure known to those skilled in the art to deliver reductant to an exhaust gas aftertreatment device may be used, such as late injection in a direction injection type engine.
[0016] Alternatively, catalyst system 13 may include (separate or in addition to the SCR catalyst) an oxidation catalyst, which may include a precious metal catalyst, preferably one containing platinum, for rapid conversion of hydrocarbons (HC), carbon monoxide (CO) and nitric oxide (NO) in the engine exhaust gas. The oxidation catalyst may also be used to supply heat in the exhaust system, wherein an exotherm is created when extra HC is reduced over the oxidation catalyst. This can be accomplished through, for example, in-cylinder injection during either or both of a power or exhaust stroke of the engine (in a direct injection engine) or any of a number of other alternatives, such as retarding injection timing, increasing EGR and intake throttling, or another approach to increase the HC concentration in the exhaust gas. Alternatively, hydrocarbons may be injected directly into the exhaust gas stream entering the oxidation catalyst. Reductant delivery system 19 may be used to deliver HC from the fuel tank or from a storage vessel to the exhaust system to generate heat for heating the particulate filter 15 for regeneration purposes.
[0017] Particulate filter 15 , in one example a diesel particulate filter (DPF), may be coupled downstream of the catalyst system and may be used to trap particulate matter (e.g., soot) generated during the drive cycle of the vehicle. The DPF can be manufactured from a variety of materials including cordierite, silicon carbide, and other high temperature oxide ceramics. Once soot accumulation has reached a predetermined level, regeneration of the filter can be initiated. Filter regeneration may be accomplished by heating the filter to a temperature that will burn soot particles at a faster rate than the deposition of new soot particles, for example, 400-600° C. In one example, the DPF can be a catalyzed particulate filter containing a washcoat of precious metal, such as Platinum, to lower soot combustion temperature and also to oxidize hydrocarbons and carbon monoxide to carbon dioxide and water.
[0018] Further note that a temperature sensor 21 is shown coupled to the DPF. The sensor, or additional temperature sensors, could also be located within the DPF, or upstream of the filter, or DPF temperature (or exhaust temperature) can be estimated based on operating conditions using an exhaust temperature model. In one particular example, multiple temperature sensors can be used, e.g. one upstream and one downstream of the DPF.
[0019] Also, a differential pressure signal (Δp) is shown being determined from pressure sensors 124 and 126 . Note that a single differential pressure can also be used to measure the differential pressure across DPF 15 . A single port gauge pressure sensor (SPGS) may also be used. In yet another alternative embodiment, the DPF can be located in an upstream location, with an optional catalyst (or catalysts) located downstream.
[0020] As will be appreciated by one skilled in the art, the specific routines described below in the flowcharts may represent one or more of any number of processing strategies such as event-driven, interrupt-driven, multi-tasking, multi-threading, and the like. As such, various acts or functions illustrated may be performed in the sequence illustrated, in parallel, or in some cases omitted. Likewise, the order of processing is not necessarily required to achieve the features and advantages, but is provided for ease of illustration and description. Although not explicitly illustrated, one or more of the illustrated acts or functions may be repeatedly performed depending on the particular strategy being used. Further, these Figures graphically represent code to be programmed into the computer readable storage medium in controller 12 .
[0021] Referring now to FIG. 3 , a routine is described for controlling particulate filter regeneration, such as based on a determined flow restriction that may be correlated to soot loading. In one example, where restriction over the DPF depends heavily on volumetric flow, which in turn depends on temperature, a distributed correlation may be used. Temperature (and restriction) may be modeled as a distributed quantity over the length of the DPF, especially during transients, rather than a single “lumped” temperature/restriction. However, this is just one approach, and various other may be alternatively used, or used in additional to distributed temperature modeling.
[0022] While improved determinations of the restriction using a distributed approach can provide more appropriately timed DPF regeneration, errors may still persist in the determination. Further, in some cases, such improved estimation approaches may not be used due to timing restrictions, processing power restrictions, system degradation, etc. As such, flow variability may persist. Thus, alternatively, or in addition, the DPF scheduling routine of FIG. 3 may impose conditions to be satisfied before the updating and/or applying an estimate of flow restriction. Specifically, the routine may limit updating the measured restriction only when post DPF temperature>minimum threshold and exhaust volumetric flow rate>minimum threshold.
[0023] Specifically, first in 310 , the routine reads operating parameters, such as differential pressure temperatures, etc.
[0024] Then, in 312 , the routine determines whether the temperature downstream of the DPF (T_postDPF) is less than a minimum temperature value (T_min) and whether exhaust volumetric flow (Q_v) is less than a minimum flow value (Q_min). Alternatively, the routine may determine whether temperature downstream of the DPF (T_postDPF) is less than a minimum temperature value (T_min) or whether exhaust volumetric flow (Q_v) is less than a minimum flow value (Q_min).
[0025] If the answer to 312 is yes, the routine continues to 314 to freeze the estimated restriction value (R) at its previous vale (R_prev), which would be zero upon initialization. Otherwise, the routine continues to 316 to update the estimated restriction (R) based one or more approaches, such as using a Darcy model, and/or a distributed model as described below with regard to FIGS. 4-6 . Further, in one particular example, a filter constant, which is a function of the temperature gradient across the particulate filter) may be used to modify a restriction value, where the restriction is based on Darcy's law, as noted below. Alternatively, the filter constant may be used with a simplified lumped model may also be used
[0026] Next, in 318 , the routine regenerates the DPF based on the determination of 310 , such as by increasing exhaust temperature to a regeneration temperature. The exhaust temperature may be increased, as noted herein, by increasing throttling, late injection, etc. Additionally, the routine may further identify degradation based on the soot loading, such as degradation of the particular filter, and indicate such degradation to an operator, and/or set a code that can be communicated from the vehicle controller.
[0027] While the routine of FIG. 3 imposes the flow and temperature boundary conditions, various alternative approaches may also be used. For example, such conditions may be avoided in some examples by using alternative estimation techniques, such as described with regard to FIGS. 7-8 .
[0028] Turning now to FIGS. 4-7 , information is provided relating to determining flow restriction in a DPF using a distributed approach. Specifically, distributed temperature/flow of the DPF may be modeled as illustrated in FIG. 4 , and then used to obtain a more accurate restriction correlation. The figure shows an example model of the DPF flow using a circuit analogy. The DPF is approximated as several “parallel” segments exposed to different temperatures, where the temperature of each layer may be a function of inlet and outlet temperature, and each layer is exposed to a fraction of the total flow (e.g., a fraction of the total flow passes through each layer). Darcy's law may be applied to this system, in which:
[0000] q =( k/ μ)( dp/dx )=( k/ μ)( Δp/x ), q=v w [m/s], k=m 2
[0000] Δ p=xq (μ/ k )= q ( xμ/k ), Δ p =wall pressure drop
[0000] V=IR
[0000] R w,i =x i μ( T i )/ k
[0029] where:
[0030] q=heat transfer
[0031] k=area
[0032] p=pressure
[0033] x=distance
[0034] μ is viscosity
[0035] R=restriction
[0036] V=flow
[0037] In one example, DPF flow can be assumed to be comprised of multiple (n=number of slices>=2) flow paths. Lumping channel losses with wall losses, the network of FIG. 4 reduces to a simple parallel network of restrictions (however, in an alternative embodiment, channel losses may be separately modeled). The equivalent restriction can then be calculated as
[0000] 1 /R soot,eq =1/ R 1 +1/ R 2 +1/ R 3 +1/ R 4 + . . . +1/ R n =Σ(1/ Ri ),,
[0000] R i =( Δp−c 0− c 2*ρ( Ti )* Qî 2))/ c 1μ( Ti ) Qi, where μ is viscosity and ρ is density
[0000] Qi =α i *mex h/ ρ( Ti ), mex h =exhaust mass flow rate, α i belongs to {α 1 , α 2 , α 3 , α 4 , . . . , α n }, Σα i =1, which then dictates the fraction of flow seeing temperature Ti.
[0000] Ti=T ( i,t ), where, assuming linear temperature drop between T in and T out,
[0000] T ( i,t )= T in( t )+( i− 1)( T out( t )− T in( t ))/( n− 1), i= 1,2, . . . , n
[0038] The coefficients c0, c1, and c2 can be obtained from experimental flow testing of the DPF. Further, the density and viscosity of exhaust gas can be estimated based on exhaust gas temperature and experimental test data. The restriction R i is a monotonic function of the soot load in grams/liter. In this way, measured pressure across the DPF can be correlated to a restriction.
[0039] Note that taking a linear temperature profile is without loss of generality. It can be interpreted as adopting a non-linear (e.g. logarithmic) axial grid spacing that samples the linear increments of temperature. Since the results do not (explicitly) depend on axial length, the grid spacing can change dynamically.
[0040] FIG. 6 shows example simulation results for different numbers of slices (2,3) and different distribution of flow at different temperatures (α) The graph shows a normalized restriction (where the restriction is artificially normalized to 1 by dividing by the first value R(0). A comparison metric (100*σ(R)/μ(R)) can be generated for each simulation, which is independent of normalization constant of the restriction and provides a measure of the variance in the restriction.
[0000]
Case
num_slices
alpha
Metric (%)
0
1
N/A*
7.9762
1
2
[.5 .5]
6.9653
2
2
[.3 .7]
5.4673
3
3
[.1 .1 .8]
6.2697
4
3
[.33 .01 .66]
5.7001
5
3
[.45 .1 .45]
7.5119
6
3
[.01 .33 .66]
6.4144
7
3
[.33 .33 .34]
8.1006
8
3
[.45 .33 .22]
8.7540
9
3
[.1 .45 .45]
7.0568
10
3
[.33 .45 .22]
8.2187
11
3
[.45 .45 .1]
8.8337
[0041] As indicated above, it may be possible to further improve the correlation between flow restriction and loading by including channel losses. As indicated below, by including the channel losses, the restriction calculation may be further stabilized. Specifically, the correlation may be modified to include the temperature offset between gas at the end of the inlet channel and the exit temperature (t_postdpf). The offset exists for heat transfer to occur at the wall towards dpf outlet, and affects the results as shown in the simulation data of FIG. 6 and table below.
[0042] Specifically, the channel losses may be modeled as:
[0000] dΔp= 4 f* ( dx — dpf/D _cell)*(½) ρV ( x — dpf )̂2, where f= 64/ Re (Reynolds number),
[0043] since channel Re<2000 almost always, and 0<x_dpf<L_dpf, and Δpchannel_loss=∫dΔp.
[0044] The temperature offset between gas at the end of the inlet channel and the exit temperature (t_postdpf) may be modeled as:
[0000] T ( i,t )= T in( t )+( i− 1)( T _offset( t )+ T out( t )− T in( t ))/( n− 1), where I= 1, 2, . . . , n, A is a constant offset of 75 deg C.
[0000] The simulation data including channel losses used n=2 slices with alpha=[0.3 0.7], and again R artificially normalized to 1, with the same comparison metric. As indicated, including the channel losses further improved the correlation.
[0000]
Case
t_offset_c
channel loss
Metric (%)
0
N/A
N/A
7.9762
1
0
Not incl.
5.4673
2
75
Not incl.
4.4815
3
75
included
3.8158
[0045] Referring now to FIGS. 7-8 , still another approach to determining filter restriction is provided. In particular, the approach may include applying a Darcy model to gas flows for lower flow soot load estimation. Specifically, variability at lower flows can be avoided during in some examples by avoiding determining the restriction estimate at such conditions (as noted in FIG. 3 ) and using a lumped parameter estimate in the example where temperature gradients may be an in-significant noise factor for high-flow restriction variability. However, during lower flow conditions such as idle or tip-out, the restriction is frozen and as such may not be updated for a significant duration, depending on the vehicle drive cycle, such as during an extended idle.
[0046] Thus, in still another approach, a first mapping approach (which may include a first estimation routine) can be used during higher flow and higher temperature conditions, and an alternative mapping may be used during lower flow (and/or lower temperature) conditions, such as described with regard to FIG. 7 . For example, the approach of FIGS. 4-6 may be used during the higher conditions, or other mappings may be used, as noted below.
[0047] Specifically, FIG. 7 shows an example flow chart of a routine that may be used. During higher flow conditions, a lumped approach may be used. However, during lower flow conditions, a mapping using Darcy's law and a linear transformation may be used, where:
[0000]
R
D
=
(
1
p
1
Q
exh
μ
)
(
p
1
2
-
p
2
2
)
2
R
D
0
,
with
R
d
0
=
1.44
e
5
[0048] where p1 is upstream DPF pressure, p2 is downstream DPF pressure, and Qexh is exhaust flow, and:
[0049] the linear transformation follows the equation, R=RD*1.79−0.78. Note that the value Rd0 may vary with system component specifications. In particular, Rd0 represents a normalization constant Rd for a clean (no soot) DPF to a fixed number, e.g. 1. This also applies to the linear transformation.
[0050] Then, during higher flow conditions, the restriction may be determined as:
[0000] R =(Δ p−c 0− c 2*ρ( T )* Q exĥ2))/ c 1μ( T ) Q exh.
[0051] Specifically, referring to FIG. 7 , in 710 , the routine reads operating parameters, such as differential pressure, temperatures, flow (e.g. engine flow), etc.
[0052] Then, in 712 , the routine determines whether the temperature downstream of the DPF (T_postDPF) is less than a minimum temperature value (T_min). If so, the routine continues to 714 to freeze the estimated restriction value (R) at its previous vale (R_prev), which would be zero upon initialization. Otherwise, the routine continues to 716 to determine whether exhaust volumetric flow (Q_v) is less than a minimum flow value (Q_min). If so, the routine continues to 718 to determine RD using the above second mapping, and then in 720 , transforms RD to R using the linear transformation. Alternatively, when the answer to 716 is no, the routine continues to 722 to determine the restriction (R) based on a first mapping, such as illustrated above using parameters c0, c1, and c2. From either 722 , 720 , or 714 , the routine continues to 724 to determine whether to regenerate the DPF based on R and various operating conditions, such as vehicle speed, ambient temperature, desired engine output, etc.
[0053] Referring now to FIG. 8 , data illustrates results for the approach illustrated in FIG. 7 , where different sized restrictions are shown versus mass flow for a 6.4 L engine having a 9″×12″ sized DPF. The data illustrate that the combination of different estimation routines for different flow and/or temperature conditions can provide improved estimation results for determining flow restriction of a DPF in an engine exhaust.
[0054] It will be appreciated that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments are not to be considered in a limiting sense, because numerous variations are possible. The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various systems and configurations, and other features, functions, and/or properties disclosed herein.
[0055] The following claims particularly point out certain combinations and subcombinations regarded as novel and nonobvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure.
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In one example, a method of operating an engine having a diesel particulate filter in a vehicle, the particulate filter having a length and depth, includes performing particulate filter regeneration in response to temperature variation across the length and/or depth of the particulate filter.
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The invention described herein may be manufactured and used by or for the Government for governmental purposes without payment of any royalty thereon.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is in the field of excavating apparatus.
2. Description of the Prior Art
It is known in the art to elevate vehicular tracks to accommodate an auxiliary power means as demonstrated by W. R. Bertelsen, U.S. Pat. No. 3,095,938. M. B. Kurkpatrick, U.S. Pat. No. 2,864,600 teaches a method of employing radially adjustable wheels on a curved platform to guide his mining machine. The prior art does not show a method of primary propulsion on angularly adjustable crawler tracks.
An invention by E. C. Seward, U.S. Pat. No. 3,202,243, although arising out of an entirely different context, teaches two platforms moving relative to one another by means of a piston with both horizontal and vertical capabilities. W. Tiblin, U.S. Pat. No. 3,314,724 employs hydraulic rams to move a main shaft relative to the crawler tracks and H. H. Gardner, U.S. Pat. No. 2,821,374 teaches a pivot actuated steering mechanism which permits vertical movement. The present invention is capable of varying the horizontal, vertical and lateral attitudes of the shaft to fashion a tunnel, and this is new to the art.
W. Tinlin, U.S. Pat. No. 3,314,725 teaches a method of making a rotatable pneumatic drilling head to reciprocate horizontally and vertically within a rectangular frame by means of a plurality of screw jacks. The prior art does not teach a frame mounted movable bearing assembly.
James G. Patrick, U.S. Pat. No. 3,887,236 teaches a tension cutting method wherein undisturbed rock is broken from the inplace mass by a breaking force acting in a radial direction or one otherwise transverse to the direction of excavation dependent upon the cantilevered echelon cut. The prior art does not teach a tension cutting method without the utilization of a cantilevered echelon cut.
L. W. Anderson, U.S. Pat. No. 1,462,997 added to the art the use of rotating pick-up buckets with a central recovery hopper, but nowhere in the art is taught a continuous belt conveyor which rotates with the drilling head. The prior art does not teach a vehicle mounted, kerf cutting and tension wedge breaking drilling head as presented herein.
SUMMARY OF THE INVENTION
The vehicle has many desirable features improving the prior art. The crawler track assemblies support the vehicle and impart the required thrust to the tracks for propulsion on the tunnel floor or walls. The track assemblies are easily adjusted for any size tunnel within the vehicle's range. Each track is propelled by its own hydraulic motor and reduction gear mechanism.
Two large bearing assemblies support the shaft on which is affixed the drill head assembly. The bearing assemblies are affixed to the platform, and a pin connects a double-action hydraulic ram to the platform. This double-action hydraulic ram is attached to the base frame, and the ram will move the platform left or right of the tunnel centerline. Another double-action hydraulic ram affixed to the base frame causes rotation of the platform about the pin.
The drill head assembly is supported by and rotated with the shaft. The drill head assembly has four main groups: the pneumatic drills which are expansible within the range of the vehicle; the fluid actuated rock breakers; muck buckets which help gather the broken rock on the first conveyor; and the rotatable first conveyor which passes the tunnel muck back lead to the second conveyor. Except for the air systems required to drive the drills and to operate the pneumatic motor which turns the rotatable conveyor, the vehicle is hydraulically powered. All major controls for the operation of the vehicle are in the operators cab at the rear of the vehicle.
It is, accordingly, a primary objective of the invention to produce a vehicle which is highly efficient and extremely practical in performing tunnelling operations.
Another object is to provide a vehicle which is readily adaptable to use in short tunnels, adits and tunnels with variable rock formations.
It is a further object of this invention to provide a vehicle in which most of the tunnel face may be seen as the tunnelling is in progress.
A further object of the invention is to provide a vehicle which takes up less space in the section of tunnel where it is working, therefore, allowing more room for workmen to perform other essential functions such as setting support steel.
Another objective of this invention is to provide a vehicle which permits setting of support steel very close to the tunnel face being excavated.
Yet another objective of this invention is to provide a vehicle relatively adaptable for use in an unsupported tunnel.
It is an object of this invention to provide a vehicle which can easily correct vertical or horizontal alignment and which is crawler mounted so that there is no loss of time for the stroking cycles as in prior art tunnelling machines.
A further object is to provide a vehicle which will easily permit entry to the front for performing functions as consolidation grouting without removing the vehicle from the tunnel.
Still another object is to provide a vehicle which is readily accessible to the front for inspection of the head or replacement of parts.
It is an object of this invention to provide a vehicle which can be readily retracted through a lined or supported section of the tunnel by virtue of its collapsible frame adjusting feature.
It is a further object of the invention to provide a vehicle which can be reused economically on various sizes of tunnels, thereby eliminating the practice of expending costly machines at the conclusion of a single job.
These and other objects will become apparent from the following description, wherein:
FIG. 1 is a perspective view of the self-propelled excavating vehicle;
FIG. 2 is a side elevational view of the self-propelled excavating vehicle;
FIG. 3 is a view on lines 3--3 of FIG. 2 showing the extendable frame support;
FIG. 4 is a view taken on line 4--4 of FIG. 2;
FIG. 5 is a partial horizontal sectional view on the line 5--5 of FIG. 4;
FIG. 6 is an enlarged view of a thrust bearing for the drive shaft;
FIG. 6a is a view on the line 6a-6b of FIG. 6;
FIG. 7 is a plan view of the drill head assembly;
FIG. 8 is a front view of the drill head assembly;
FIG. 9 is an elevational view of a fluid actuated breaker assembly; and
FIG. 10 is a view on line 10--10 of FIG. 2.
FIG. 11 is a view on line 11--11 of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The crawler track assemblies are shown generally at 1 in FIGS. 1 and 2. They are used for supporting the vehicle and imparting the required forward and reverse thrust. They are each individually powered through reduction gear by a hydraulic motor (motor and reduction gears are not shown). The crawler track assemblies 1 are attached to the frame extension 2 by a suitable hinge 3. The frame extension 2 (see FIG. 10) is capable of telescoping outwardly from the base frame 4. With the adjustment of the horizontal brace 5 the crawler track assemblies 1 can be angled from vertical to at least 45° . The adjustment lugs 6 are affixed to independent and threaded shafts 7 which are mated into the horizontal brace 5 to allow the angling of the crawler track assemblies. There are variously sized horizontal braces which can be adopted for use with the crawler track assemblies. At least two horizontal braces 5 are affixed to the base frame 4. The hydraulic motors for the tracks 1 are controlled from the operator's cab 8. The operator's cab 8 will house all operating controls (not shown) and will, in addition, have an accurate level bubble (not shown) to check against the vertical attitude of the shaft 10. This is possible since the operator's cab 8 is firmly affixed to the rear bearing assembly 11 (FIG. 2) and will respond to changes in direction of the main shaft 10.
The shaft 10 is supported to the rear bearing assembly 11 and the front bearing assembly 12. These bearing assemblies are affixed to double-action hydraulic rams 13 braced in slide brackets 14. The brackets 14 are firmly affixed to the platform 15. The platform 15 pivotally rests upon the base frame 4. The platform 15 is capable of left and right movement around pins 16a and 16b, shown in FIG. 3. The pin 16b with one end firmly affixed to the platform 15 cooperates with a bearing (not shown) and is moved by the double-action hydraulic ram 18 which is attached to the frame 4 by pins 18a. The ram 18 is used to regulate the position of the pin 16b with respect to left or right of the tunnel centerline. In addition, affixed to the underside of platform 15 by pin 17a and affixed to the base frame 4 by pin 16a is a double-action hydraulic ram 17 which causes rotation about the pin 16a of the platform 15 in relationship to the base frame 4. The front and rear bearing assemblies 11 and 12, respectively, are supported by a horizontal shaft 19 which rests in a bearing 20. The shaft can be raised or lowered by a double-action hydraulic ram 13 which is housed inside a slide 14 that is firmly affixed inside slide brackets 21, as in FIG. 4, which are firmly affixed to the platform 15.
In FIG. 4, resting in the rear bearing assembly 11 and FIG. 10 the front bearing assembly 12 is the shaft 10. The shaft 10 is supported in the front bearing assembly 12 by four bearings which are bolted through the bearing assembly 12. The rear bearing assembly 11 supports the rear end of the shaft 10 and enters a milled section (not shown) at the end of the shaft 10. The shaft 10 is supported in the rear bearing assembly by four bearings (not shown). The front bearing assembly 12 and the rear bearing assembly 11 will keep the same orientation of the shaft 10 regardless of the height of one bearing assembly to the other. The shaft 10 has a bull gear 22 firmly affixed to it and is rotated by a pinion gear 23 which passes through the bearing assembly 11 to a reduction gear and hydraulic motor generally shown at 24. The hydraulic motor 24 has the ability to go in a forward or reverse direction and is controlled at the operator's cab 8. The rear bearing assembly 11 houses the thrust bearings 25 (one of which is shown in FIG. 4) which are mounted on the thrust bearing shaft 26. The thrust bearings 25 work directly against the rear end of the milled section of the shaft 10. Reverse thrust is possible by the action of the rearward end of the thrust bearings 25 acting against the butt plate 9 which is bolted onto the rearward end of the shaft 10.
The main conveyor 27 is firmly affixed to the bearing assemblies 11 and 12. A hydraulic motor 28 drives the conveyor 27 and is controlled from the operator's cab 8. The hydraulic pumps (not shown) for all hydraulic motors are situated near the end of the platform 15 and are driven by electric motors. Ample space for additional motors is available under the base frame 4. Not shown, but included in the hydraulic system, are storage tanks for the hydraulic oil and coolers. Ample space exists above the platform 15 for these units. The drill head assembly is generally shown at FIGS. 7 and 8. The assembly mount 29 is firmly affixed to the shaft 10 onto which is firmly affixed the main air chamber 30 to which is firmly affixed the inner drill assembly 31. The rotatably mounted conveyor 32 is affixed to the front of the drill head assembly. The muck bucket 60 scoops fallen rock and carries it until it is dumped onto conveyor 32. The muck chute 33 is mounted on each side of conveyor 32 to prevent the muck from falling over the sides of the conveyor 32. A hinge mechanism affixes the main air chamber 30 to the back end of the outer drill assemblies 34 (see FIG. 7). The turning of the adjustment lugs 35, FIGS. 7 and 8, fixes the inward and outward position of the front end of the outer drill assemblies 34. In addition to the bracing afforded by the threaded shaft 36, there are installed and firmly affixed to the inner drill assemblies 31 spacer braces 37 which give support to the outer drill assemblies 34. Further bracing is accomplished by tying together the upper and lower sections of the outer drill assemblies 34 by bolts 38. Other braces 39 and 40 are also installed and can be eliminated by removing pins 41 (see FIG. 8). Different tunnel sizes require a change in location of the conveyor 32 which is movable inwardly or outwardly. The conveyor 32 is affixed to the fluid actuated breaker 42 (FIG. 8) at the front and the air chamber 30 at the rear. The conveyor 32 rotates with the drill head. When the conveyor 32 is over the conveyor 27, a spring loaded trip lever (not shown) on the revolving drill head strikes the stationary conveyor 27 and causes air to flow to the air motor 43 (FIG. 2) which activates the conveyor 32 and unloads onto the chute 33. After the conveyor 32 passes the chute 33, the spring loaded trip lever returns to the closed position and the conveyor 32 stops.
Firmly affixed to the inner drill assemblies 31 are two fluid actuated breakers 42 supported by brace 81 which point in opposite directions (see FIG. 8). A breaker arm 45 extends from each breaker 42, and affixed on these arms are metal lugs 46 which enter the kerfs cut by the pneumatic drills 47, whereby the rock is broken by the striking of the lugs 46 against the ridge of rock between the kerfs. The direction of the smashing blows is outward, and the arm 45 is braced by a slide 48 supported by brace 81. Bolted on the leading and trailing sides of the drill assemblies are wedge-like members 49 which also enter the kerfs and dislodge any rock fragments which may be in the path of the drills 47.
A pilot drill 50 near the center of the tunnel head is off and centered by the diameter of the drill bit and cuts a hole twice the diameter of the bit as the machine revolves. Just opposite this bit is a conical rolling rock breaker 51 which breaks a thin web or ridge of rock which remains outside of the center hole cut by the drill 50 and inside the kerf cut by the first row of drills 47. The hydraulic oil for the fluid actuated breakers 42 is supplied from the main hydraulic pumps (not shown) through the operator's control panel (not shown) to the intake swivel 52 at the rear of shaft 10 (see FIG. 2). The hydraulic oil for the breakers 42 travels through line 53 inside the air supply channel 54 of the main shaft 10 to the fluid actuated breakers 42 and from there back over the outside of line 53 through line 55 to the swivel 56 and then to the oil reservoir tanks (not shown).
The path of air travel to the drills follows the air line 55 of the air swivel 58, then through the air supply channel 54 of the main shaft 10. The outlet of the air supply channel 54 is attached so that air is supplied to the main air chamber 30 (see FIG. 7) and the through flexible hoses 59 to the outer drill assemblies 34. To control dust in the tunnel, water will be injected into the air line 55 and emerge at the drills 47 and 50.
The drills 47 and 50 are down-the-hole pneumatic hammers, and they will be constructed so as to be threaded on the outside near the top end for a suitable distance, and they will in turn be screwed into the drill assemblies. The threading of the outside of the drills will permit fine adjustments for depth of penetration as some drills will have to be farther forward than others. A suitable device is provided to prevent the drill from unscrewing during drilling. A metal plug will be inserted into the drill holes which are not being used.
CUTTER OPERATION
The machine approaches the wall to be drilled by activating the tracks 1. When the drill head contacts the wall, the pilot drill 50 is activated and begins drilling. As the wall is penetrated the pneumatic drills 47 contact the wall and are activated. The bull gear 23 begins to rotate the main shaft 10 and, consequently, the drill head. Leading and trailing members 49 enter the kerfs cut by the drills and dislodge the rock fragments therein. As the drill head continues to rotate, the kerfs become deep enough for penetration by the lugs 46 of the breaker bars 45. At this point the breakers 42 are actuated forcing the breaker arms 45 outward which results in the breaking of the rocks between the kerfs. The conical rock breaker 51 is also actuated and breaks the ridge of rock between the innermost drills and the pilot drill 50. As the drill head rotates, the muck buckets scoops fallen rock. When the drill head rotates to a point where a muck bucket is in the top position, the rock in the bucket begins to fall into the chute 33 and onto the conveyor 32. When the conveyor 32 is located over the main conveyor 27, the conveyor 32 is activated and unloads the chute.
Although a particular embodiment and form of this invention has been illustrated, it is obvious to those skilled in the art that modifications may be made without departing from the scope and spirit of the foregoing disclosure.
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A vehicle which can easily be dismantled into transportable units and reassembled readily at the tunnel site is provided. A major advantage of this vehicle is the requirement of low thrust during operation and adaptability to use in short tunnels and tunnels with variable rock formations. With only minor adjustments to the drill head assembly and crawler carriage, it is capable of conforming to variable diameters of tunnel sizes. Pneumatic drills in the drill head assembly are guided along the vehicle's path to cut kerfs into the rock. Fluid activated breaker elements enter the kerfs and break out the ridges of rock through smashing blows. The drill head assembly rotates as the kerf cutting process is repeated. The excavated rock is conveyed to the rear of the vehicle for easy disposal. The drills are capable of boring any type of rock, therefore, it is envisioned that this vehicle can excavate soft through very hard formations.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to German Patent Application No. DE 10 2011 008 381.2, entitled “Piston-Cylinder Unit with Device for Determining Position”, filed Jan. 12, 2011, which is hereby incorporated by reference in its entirety for all purposes.
TECHNICAL FIELD
[0002] This present disclosure relates to a piston-cylinder unit with a device for determining position.
BACKGROUND AND SUMMARY
[0003] Determining the position of a cylinder piston represents a necessary and important task in a series of technical applications. In particular, the exact position of the cylinder piston often plays a major role in targeted control of the piston-cylinder unit. Moreover, determining the position can decisively increase the operational reliability of a piston-cylinder unit, since the intake of the hydraulic medium, in particular the hydraulic fluid, at the extreme positions of the cylinder piston can be exactly controlled and consequently stopped at the right time.
[0004] Precise position determination is also important in the automatic control of the piston-cylinder units in construction machines and hoisting equipment. The piston-cylinder unit actuates the working devices of the construction machine or hoisting equipment in the usual manner. Sufficiently precise determination of the position of the piston-cylinder unit increases the quality of the control, and therefore is absolutely essential.
[0005] The high control pressures prevailing within the piston-cylinder unit, which occur especially in hydraulic cylinder units, often allow only slight modification of the piston or the cylinder jacket without interfering with the entire system in a way that is relevant to safety. For this reason, setting up a suitable position measuring device often turns out to be especially difficult and cost-intensive.
[0006] Numerous piston-cylinder units pick up the instantaneous position of the cylinder piston by cable potentiometers.
[0007] Processes are also known that work according to a magnetostrictive principle. These involve picking up the position of the piston using a ring magnet attached at a specific piston position in combination with a sensor built into the piston rod.
[0008] However, one thing that all known processes have in common is that they require elaborate and cost-intensive modifications of the piston-cylinder unit. Additional transducers and sensors must first be integrated into the piston-cylinder unit.
[0009] The present disclosure has the goal of pointing out a piston-cylinder unit with a device for determining position that has satisfactory stability and robustness but is nevertheless simple and economical to produce and attach.
[0010] This is accomplished by a piston-cylinder unit with a device for determining position. It is possible for the piston-cylinder unit to be made in the form of a hydraulic cylinder and for it to use a hydraulic oil as its hydraulic medium.
[0011] The device for determining position comprises at least one exciter that is electrically connected, indirectly or directly, with the cylinder jacket and with the cylinder piston of the piston-cylinder unit. In this arrangement, the cylinder jacket and cylinder piston function as the electrodes of a series-resonant circuit. The piston rod and cylinder jacket form a series inductance. Opposite surfaces of the piston and cylinder jacket form a capacitance with hydraulic media. Accordingly, the complete piston-cylinder unit can be understood as an oscillating circuit.
[0012] The exciter according to the present disclosure serves to excite the electrical series-resonant circuit to oscillate at its resonant frequency. In theory, the resonant frequency that is set up in an oscillating circuit is a function of the capacitance and inductance. Consequently, it is possible to deduce the variable capacitance of the piston-cylinder unit from the resonant frequency, the capacitance and inductance depending on the instantaneous position of the piston. Thus, it is possible to determine the exact instantaneous position of the piston from the resonant frequency. To accomplish this, it is also possible to measure an electrical signal characterizing the resonant frequency on the device according to the present disclosure.
[0013] The present disclosure utilizes the advantage that the piston-cylinder unit is suitable, without modification, to form an electrical oscillating circuit. In contrast to the prior art, it is not necessary to arrange any external sensors or transducers or additional electrodes on or inside the piston-cylinder unit. The known components of a piston-cylinder unit, such as the cylinder jacket and the cylinder piston, are used to form a series-resonant circuit. Thus, in one example, the piston-cylinder is without an external sensor or transducer or additional electrodes on or inside the piston-cylinder unit for position detection.
[0014] The exciter advantageously comprises an oscillating circuit that is electrically connected with the piston-cylinder unit. A Hartley oscillating circuit is especially advantageous.
[0015] The resonant frequency of the oscillating circuit is a high-frequency signal, known from experience to lie in the megahertz frequency band. The piston-cylinder unit can act as an antenna that emits electromagnetic waves. In this connection, it can be expedient for at least part of the device for determining position to be advantageously arranged inside of the cylinder housing or cylinder jacket. In particular, the exciter is arranged inside the piston-cylinder unit or a hollow space in the piston-cylinder unit provided for this purpose. The shielding effect of the cylinder jacket has an advantageous effect on the EMC characteristics [electromagnetic compatibility] of the device or the piston-cylinder unit.
[0016] Alternatively, it is possible that at least one additional shield to be provided that covers the externally arranged device for determining position, in particular the exciter, and prevents the emission of electromagnetic waves. It turns out to be advantageous for the shield to be magnetic, in particular made from a ferromagnetic material. Of course other shielding materials are also conceivable that are suitable to cover and shield the device for determining position. It also turns out to be advantageous to use at least one EMI filter [electromagnetic interference filter].
[0017] It is possible for the measured signal characterizing the resonant frequency to be an electrical voltage. This voltage has an oscillating signal shape during the oscillation of the piston-cylinder unit; it is advantageously electrically insulated, and is used as a square wave signal for digital evaluation.
[0018] Under some circumstances, the oscillating circuit components or external influences are damped and interfere with the oscillation behavior. To keep the oscillation amplitude constant, it can be advantageous for there to be a circuit device to stabilize the measurable voltage. External influences include, for example, moisture, dust deposits, etc. This measure stabilizes the resonant frequency and makes it possible to determine the position with sufficient accuracy.
[0019] It is possible to provide an evaluation device that is suitable to evaluate the signal and output the current piston position. The evaluation device can be an appropriately configured microcontroller or a suitable analog circuit device having computer readable storage media and code therein to carry out the various actions described herein. The evaluation device is either solidly or detachably connected with the piston-cylinder unit.
[0020] To reduce the resonant frequency, it can be advantageous to arrange an additional inductance between the exciter and the piston or between the exciter and the cylinder jacket. This can be advantageous for technical reasons involving EMC.
[0021] It is advantageous for the contact between the exciter and the piston-cylinder unit to be a sliding contact. The contact between the moving part of the piston-cylinder unit, in particular the piston rod, may be made by a sliding contact. It has turned out to be expedient for the contact between the piston rod and the exciter to be a brush type of contact, the brush sliding along the surface of the piston rod as the piston moves. it is possible for the brush to consist of carbon, bronze, or another suitable material.
[0022] Alternatively, the contact between the piston rod and the exciter can be made by a capacitive or conducting ring. The ring is arranged so that it can slide coaxially on the surface of the piston rod. Using a capacitive ring creates an additional constant capacitance, which is connected in series with the oscillating circuit.
[0023] It is possible for the ring to consist of a conductive material that is indirectly or directly connected with the exciter, a dielectric being arranged between the ring and the piston rod, or the conductive ring being directly electrically connected with the piston rod. It is also possible to isolate the piston-cylinder unit from the oscillator or the exciter by inserting a transformer. The leakage inductance of the transformer can also be used to reduce the resonant frequency.
[0024] Moreover, the present disclosure relates to a construction machine or a piece of hoisting equipment with a piston-cylinder unit described in one of the preceding advantageous embodiments. The construction machine or a piece of hoisting equipment according to the present disclosure has the same advantages and properties as the piston-cylinder unit described above, for which reason it is not explained again here.
[0025] The use of the piston-cylinder unit is not in any way limited to construction machines or hoisting equipment. Possible areas of application are found in aircraft or generally in all machines/equipment with hydraulic/pneumatic technology.
[0026] Further advantages and details of the present disclosure will be explained detail below using the sample embodiments shown in the drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0027] FIG. 1 shows the piston-cylinder unit according to the present disclosure with a device for determining position.
[0028] FIG. 2 shows a circuit diagram of the device according to the present disclosure for determining position.
[0029] FIG. 3 shows an advantageous further development of the piston-cylinder unit according to the present disclosure.
[0030] FIG. 4 shows the piston-cylinder unit according to the present disclosure with an additional shield.
[0031] FIG. 5 shows an alternative embodiment of the piston-cylinder unit according to the present disclosure.
[0032] FIG. 6 shows the piston-cylinder unit according to the present disclosure with a capacitive ring arranged on it
[0033] FIG. 7 shows a sectional illustration of the capacitive ring or the piston rod along the cutting line A-A.
[0034] FIG. 8 shows another advantageous embodiment of the piston-cylinder unit according to the present disclosure.
[0035] FIG. 9 shows an exemplary method of determining the position of the piston of the piston-cylinder unit according to the present disclosure.
DETAILED DESCRIPTION
[0036] FIG. 1 shows the piston-cylinder unit 10 according to the present disclosure with a device for determining position. The piston-cylinder unit 10 may be included in a machine or equipment 1 , such as a construction machine or a piece of hoisting equipment. The body of piston-cylinder unit 10 resembles a known piston-cylinder unit. In particular, unit 10 comprises a tubular cylinder jacket 20 , whose hollow space holds a piston 30 with attached piston rod 31 that can move in a line.
[0037] Piston-cylinder unit 10 may be used in construction machines or hoisting equipment 1 , wherein piston-cylinder unit 10 drives an attached working device. The automatic operation of the working device requires precise determination of the position of piston 30 .
[0038] Making it possible to determine the exact position does not require the installation of additional sensors, electrodes, or transducers on or in piston-cylinder unit 10 . Instead, the fact that appropriate excitation causes the entire piston-cylinder unit 10 to act as an electrical oscillating circuit is used to advantage. In particular, piston 30 forms the first electrode of a series-resonant circuit and cylinder jacket 20 forms its second electrode. Neither piston 30 nor piston rod 31 have a conductive connection with cylinder jacket 20 ; instead they are mounted so that they can slide over seals between piston 30 and cylinder jacket 20 and in the opening area of cylinder jacket 20 and protruding piston rod 31 . A hydraulic cylinder has, between piston 30 and cylinder jacket 20 , a hydraulic medium 32 , in particular hydraulic oil, that acts as an dielectric between the two electrodes.
[0039] The oscillating circuit is excited by an exciter such as oscillator 50 that is connected through electrical lines 40 first with cylinder jacket 20 and also with piston rod 31 . Oscillator 50 is structured to generate electrical excitation to excite the electrical oscillating circuit formed by the piston-cylinder unit and contact lines to oscillate at its resonant frequency. For example, oscillator 50 may be structured to generate an electrical excitation signal characterizing the resonant frequency of the piston-cylinder unit.
[0040] After the oscillating circuit is excited through oscillator 50 , it oscillates at its resonant frequency. The impedance formed from piston 30 and cylinder jacket 20 depends on the respective position of piston 30 in the hollow space of the cylinder. Since the capacitance and inductance of the oscillating circuit affect the resonant frequency that is set up, it is possible to deduce the impedance of piston-cylinder unit 10 from the resonant frequency that is picked up.
[0041] To accomplish this, a corresponding output voltage V out is measured in the area of oscillator 50 and analyzed or interpreted by a corresponding evaluation device 11 , and possibly indicated visually or acoustically by output device 12 . For example, output device 12 may be a speaker or display device connected to or included within evaluation device 11 such that evaluation device 11 may output or display the piston position on output device 12 . The evaluation device 11 may be in the form of an appropriately configured controller or a suitable analog circuit device having computer readable storage media and code stored thereon to carry out the various actions described herein. Exemplary actions carried out by the evaluation device 11 are further described with reference to FIG. 9 below. The evaluation device 11 is either solidly or detachably connected with the piston-cylinder unit.
[0042] The electrical contact between oscillator 50 and moving piston rod 31 is made using a sliding contact. To accomplish this, the end of lead 40 of oscillator 50 that goes to piston rod 31 has a brush contact, which slides on the surface of piston rod 31 . The brushes of this point of contact may be made of carbon, bronze, or another suitable material.
[0043] FIG. 2 shows a circuit diagram of the piston-cylinder unit 10 according to the present disclosure with the corresponding device for determining position connected. The output voltage labeled V out has an oscillating signal shape describing the current resonant frequency of the entire oscillating circuit. This voltage or voltage curve changes as a function of the corresponding piston position of piston-cylinder unit 10 .
[0044] FIG. 3 shows the piston-cylinder unit 10 according to the present disclosure known from FIG. 1 , with an inductance added between oscillator 50 and cylinder jacket 20 . Since the oscillating circuit formed oscillates in a high-frequency region, the inductance 60 that is also connected in series can substantially reduce the resonant frequency.
[0045] Under some circumstances, the use of piston-cylinder unit 10 in construction machines or hoisting equipment 1 must satisfy high EMC requirements. As was already mentioned above, the arrangement according to the present disclosure produces especially high-frequency oscillations, which under some circumstances can extend into the megahertz frequency band. To meet the necessary EMC requirements, additional shielding 70 is installed, as shown in FIG. 4 , covering the area around oscillator 50 and shielding the electromagnetic waves released into the environment because of the radiation pattern of piston-cylinder unit 10 . Such shielding 70 is made out of a ferromagnetic material, for example. Of course all materials that ensure sufficient shielding of the electromagnetic waves are conceivable.
[0046] In an advantageous embodiment, cylinder jacket 20 can be repurposed as a shield. As is shown in FIG. 5 , oscillator 50 is installed in the hollow space in cylinder jacket 20 . Furthermore, radio interference suppression filters can be connected to the outputs of oscillator 50 .
[0047] An alternative to the embodiment of the piston-cylinder unit with sliding contacts is to implement the connection between oscillator 50 and piston rod 31 using a capacitive or conducting ring 80 . As shown in FIG. 6 , such a ring 80 runs coaxial to piston rod 31 and slides on its surface.
[0048] A sectional illustration along cutting line A-A is shown in FIG. 7 . This figure shows capacitive ring 80 , which is made out of a conductive material. Piston rod 31 and capacitive ring 80 have a dielectric 90 between them. Ring 80 and piston rod 31 form a constant capacitance that is connected in series to the oscillating circuit.
[0049] FIG. 8 shows a possible decoupling of oscillator 50 from piston-cylinder unit 10 . The electrical connection is made through a transformer 100 . The internal inductance of the transformer 100 acts as an additional series inductance in the oscillating circuit, further reducing the resonant frequency that is set up. Transformer 100 also provides electrical insulation between the cylinder and oscillator 50 .
[0050] FIG. 9 shows an exemplary method of determining an instantaneous position of the piston 30 of piston-cylinder unit 10 . The method begins at step 110 , when the exciter, such as oscillator 50 , excites the electrical series-resonant circuit, causing it to resonate at its resonant frequency at step 120 . The output voltage at the exciter 50 is measured, for example with an evaluation device 11 , at step 130 . This voltage is then analyzed by the evaluation device 11 at step 140 , as discussed above with reference to FIG. 2 , as the voltage describes the current resonant frequency of the entire oscillating circuit. The voltage or voltage curve changes as a function of the corresponding piston position of piston-cylinder unit 10 . Therefore, at step 150 , the instantaneous position of the piston may be determined based on the measured voltage.
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The present disclosure relates to a piston-cylinder unit with a device for determining position, the device comprising at least one exciter that is indirectly or directly electrically connected with the cylinder jacket and the cylinder piston of the piston-cylinder unit, and that excites the electrical oscillating circuit formed by the piston-cylinder unit and the contact lines to oscillate at its resonant frequency, it being possible to measure an electrical signal characterizing the resonant frequency on the piston-cylinder unit. The invention also relates to a construction machine or piece of hoisting equipment with such a piston-cylinder unit.
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BACKGROUND OF THE INVENTION
The invention relates to a device for drilling a bore in the ground.
A device of this type is disclosed by WO 97/34070. The percussive tools are in this case connected directly in a plurality to the tool head, so the percussive energy is transferred via the drive medium to the tools sunk in the bore and from said tools directly to the base of the bore, so that the connecting rod assembly remains largely unaffected thereby. The tool head is connected via the connecting rod assembly to a drive device, normally arranged outside the bore and having a rotary drive, so that the tools arranged on the tool head operate at points on the base of the bore which are always new. The devices mentioned are mostly used to operate in solid rock.
In practice, this type of drilling is of increasing importance since, firstly, the quality of the bores is better and the direction of the bores can be maintained virtually exactly; secondly, because of the sound-absorbing method of use in the bore without any substantial external effect, environmental criteria such as noise nuisance are satisfied considerably better.
In installations of this type, transporting the rock material separated and excavated away at the face or the base of the bore out of the bore can be carried out within the hollow connecting rod assembly in the manner of what is known as “reverse circulation”. For instance, the air lift method can be used for this purpose, in which air as a flushing medium is blown into the drilling assembly above the tool head, so that the air rising in the connecting rod assembly produces a pressure difference in the connecting rod assembly between bore and surface, which induces a flow velocity in the connecting rod assembly, with which the rock material is driven out through the connecting rod assembly.
In the case of the known device, percussive hammers are used as tools. Although, by using this device, satisfactory drilling progress is achieved, in particular in hard rock, it is disadvantageous that the drilling efficiency decreases, in particular in softer strata.
SUMMARY OF THE INVENTION
The invention is therefore based on the object of providing a device which ensures satisfactory drilling progress in an extremely wide range of rock formations.
This object is achieved by the invention in that each of the tools comprises an excavation disk and means which set the excavation disk oscillating in operation means that each tool simultaneously exerts on the face or the base of the bore a percussive action which loosens hard rock and also an excavating action which carries away loosened hard rock and softer soil formations. Different rock formations can thus be loosened and carried away efficiently with the device according to the invention.
Pins or disk rollers, in particular, can be used as removal means.
Particularly preferred is an embodiment of the device according to the invention in which at least one drive device is provided, by means of which the tool head can be set rotating about the bore longitudinal axis. The drive device can both be arranged outside the bore and the torques can be transmitted via the connecting rod assembly. However, it is likewise possible to mount the connecting rod assembly nonrotatably and to provide the drive device in or on the tool head. The rotational movement of the tool head ensures that the excavation disks operate at different points on the face or the base of the bore.
The drive device for the tool head can be equipped in such a way that the rotation takes place in a fixed direction of rotation, that is to say either in or counter to the clockwise direction.
However, it is likewise possible to configure the drive device in such a way that the rotation takes place in alternating directions of rotation, for example through rotational angles between 90° and 270°. This embodiment has the advantage that it is possible to dispense with complicated rotary leadthrough seals, such as would be necessary in order to supply fluid media to the tool head, or wiping contact arrangements such as would be necessary in order to introduce electric currents, for example in order to drive the tools. The seal and wiping contact arrangements can be replaced by simple flexible lines which are not susceptible to faults.
In a particularly preferred embodiment of the device according to the invention, means are provided which set the excavation disk of each tool rotating during the operation of the device. This measure intensifies the excavation action on the rock to be loosened, the drilling efficiency increases. The means are, for example, hydraulic, pneumatic or electric rotary drives.
Trials have shown that the drilling efficiency is particularly high if the rotational frequency of the excavation disk of each tool is lower than its oscillation frequency. The ratio between rotational frequency and oscillation frequency is preferably 1:30 to 1:60.
In a particularly preferred refinement of the device according to the invention, each tool comprises a rotationally driven main shaft which has a shaft journal whose axis forms an acute angle with the axis of the main shaft, and a head carrying the excavation disk, which is mounted such that it can rotate about the axis of the shaft journal and has a circumferential region which runs on an opposing circumferential region. As a result of this measure, the excavation disk is set in oscillation movement by the main shaft at a frequency which corresponds to the rotational frequency of the main shaft. As a result of the circumferential region of the head running on the opposing circumferential region, the rotation of the main shaft simultaneously sets the excavation disk into a rotation whose rotational frequency depends on the configurations of the circumferential region and of the opposing circumferential region. A fixed relation between oscillation and rotational frequency of the excavation disk can therefore be predefined by design.
However, in order to be able to adapt the device according to the invention optimally to different rock formations, it is particularly desirable to be able to vary the ratio of oscillation to rotation. In the particularly preferred embodiment of the device, this is made possible by the opposing circumferential region itself being capable of being set rotating. Depending on the direction of rotation of the opposing circumferential region, with a constant rotational speed of the main shaft, an increase or reduction in the resultant rotational speed of the excavation disk is thus effected.
The opposing circumferential region and the circumferential region running on it can be configured in any way which ensures the running action during operation. Because of the simplicity of production and the operational reliability, however, it is preferred for the circumferential region to have external toothing and for the opposing circumferential region to have internal toothing.
The opposing circumferential region is preferably formed by a hollow gear which is arranged concentrically with respect to the main shaft axis and which, according to the particularly preferred embodiment of the invention, can be set rotating.
It has been shown that the ratio of the oscillation frequency and the rotational frequency which can be achieved with a nonrotatable opposing circumferential region is not optimal for a large number of applications. Normally, a speed of the drill head with a lower ratio would be more advantageous for the drilling progress. A preferred embodiment of the device according to the invention therefore provides for the opposing circumferential region to be set rotating by means of an epicyclic gear mechanism which is in engagement with the main shaft. This embodiment has the advantage that it requires no further drive motors.
However, it is likewise possible to set the opposing circumferential region rotating by means of a separate drive, independently of the main shaft, that is to say not to couple the opposing circumferential region and main shaft. The separate drive is particularly preferably configured such that it can be controlled or regulated, which means that, during operation, adaptation of the ratio between the drill head rotational speed and oscillation frequency to the type of rock occurring in each case is possible.
BRIEF DESCRIPTION OF THE DRAWING
Exemplary embodiments of the device according to the invention are illustrated in the drawing, in which:
FIG. 1 shows, in perspective form, a first embodiment of a drive system of a device according to the invention;
FIG. 1 a shows a rotary drive which, in the embodiment of the drive unit according to FIG. 1 , can be used as alternative to the rotary drive illustrated herein;
FIG. 2 shows, in schematic form, the action of the air lift system in a device according to the invention;
FIG. 3 shows, schematically, a side view of a tool head having a plurality of tools;
FIG. 4 shows a view according to FIG. 3 from below;
FIG. 5 shows the construction of one of the tools in longitudinal section;
FIG. 6 shows, in perspective form, a view corresponding to FIG. 1 of a second embodiment of the drive system of a device according to the invention;
FIGS. 7 and 8 show two further embodiments of the drive system in a view corresponding to FIG. 6 ;
FIG. 9 shows an oscillating drive, such as can be used in the embodiment according to FIG. 8 ;
FIG. 10 shows the construction of a further embodiment of a tool in an illustration corresponding to FIG. 5 ; and
FIG. 11 shows, in schematic form, a preferred arrangement of tools according to FIG. 10 on a tool head.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a first embodiment of a part of a device according to the invention which is arranged outside a bore to be drilled in the ground. The drive system of the device, designated overall by 3 , is fixed to a supporting device 2 which is supported on a working platform designated overall by 1 . A rotary drive head 4 , shown schematically, acts on a connecting rod assembly 5 having segments that can be connected to one another, of which only the upper part is shown and which extends (indicated only dashed) through the working platform 1 into the bore to be drilled in the ground and as far as the tool head. The drive of the connecting rod assembly 5 having the rotary drive head 4 can be carried out in a conventional manner known from the prior art, for example via a hydraulic motor.
Alternatively, however, it is likewise possible, instead of the rotary drive head 4 arranged at the upper end of the connecting rod assembly 5 , to use a rotary drive 4 ′ illustrated in FIG. 1 a , such as is known in design terms per se from piping devices.
This rotary drive 4 ′ comprises a stationary, outer part 4 ″, opposite which an annular inner part 4 ′″, whose internal diameter is matched to the external diameter of the connecting rod assembly 5 and can optionally be connected to the latter, at least in the drive direction, in an operative connection, that is to say by a force fit or form fit, can be driven in rotation. The drive can be carried out, for example, by a hydraulic motor. With its stationary part 4 ″, the rotary drive 4 ′ can be operatively connected to variable-length force generators 2 ′, such as spindles or piston/cylinder units, provided on the supporting device 2 . If the connecting rod assembly 5 and the inner part 4 ′″ of the rotary drive 4 ′ are configured in such a way that a force-transmitting connection between the connecting rod assembly 5 and the inner part 4 ′″ can also be achieved in the longitudinal direction of the former, then a forward drive force can also be introduced into the connecting rod assembly via the rotary drive 4 ′. However, it is likewise possible to mount the rotary drive 4 ′ on the supporting device so as to be fixed and to configure the inner part 4 ′″ and connecting rod assembly 5 in such a way that the connecting rod assembly 5 can be displaced in the inner part 4 ′″ in its longitudinal direction. In this case, the forward drive forces have to be introduced into the connecting rod assembly, for example, by acting on the first rotary connecting head 10 , yet to be described.
Arranged at the upper end of the connecting rod assembly 5 is a first rotary connecting head, designated by 10 , via which the material loosened at the base of the bore in the ground is carried away to the outside via an outlet pipe 21 and compressed air is introduced into the connecting rod assembly by means of a first feed line 13 . Arranged under the first rotary connecting head 10 is a second rotary connecting head, designated overall by 20 . The supporting device 2 can be swiveled about a horizontal axis A and is connected to swiveling drives 6 , so that it can be inclined and it is also possible for bores in the ground to be drilled in a manner deviating from the vertical.
FIG. 2 explains in schematic terms the method by which the drilled material loosened by tools 41 of a tool head 40 is conveyed outward from the base 16 of the bore 9 in the ground, partially filled with water, for example as far as a level 9 ′. The interior of the connecting rod assembly 5 forms a flushing pipe 8 , which is normally filled with water, into which air is blown in above the tool head 40 through an inlet valve 43 , having been compressed outside the drilling apparatus by a compressor, not shown, and is led downward along the connecting rod assembly 5 by means of a first feed 12 via a first feed line 13 on the first rotary connecting head 10 . The air blown in effects an upward flow within the flushing pipe 8 as a result of the difference in density between the liquid interspersed with air bubbles in the flushing pipe 8 and the external liquid in the bore 9 in the ground, with which upward flow the drilled material 7 is transported upward and flushed out of the device via the outlet pipe 11 . Via a second feed line 23 in the second connecting head 20 of the second feed 22 , shown in one piece with the first connecting head, the operating medium is supplied and, via the latter, is led downward along the connecting rod assembly 5 in order to drive the tools 41 of the tool head 40 . The operating medium used can be hydraulic fluid under pressure. However, it is likewise possible to configure the drive for the tools electrically. Instead of the second connecting head, a wiping contact arrangement can then be used in order to feed the electrical energy in.
In FIGS. 3 and 4 , a tool head 40 , which is provided for a hydraulic drive, for example, is shown schematically. The tools 41 driven by the hydraulic medium are connected via supports 44 to a mounting plate 42 , which is fitted to the lower end of the connecting rod assembly 5 . The excavation disks 45 arranged on the tools 41 act downward on the base 10 of the bore 9 in the ground and fragment the rock there. The respective point of action moves onward in the circumferential direction as a result of the rotation of the tool head. By fitting the tools 41 at different radii, it is possible to sweep over the entire bore cross section. The number and arrangement of the tools 41 can be matched to the diameter of the bore 9 in the ground and the material to be removed. At their lower ends, the tools 41 are held and guided on a guide plate 46 shaped like a circular disk with a diameter corresponding to the diameter of the bore in the ground.
FIG. 5 shows a tool 41 in a detailed illustration. It comprises a head 46 which carries the excavation disk 45 . The excavation disk 45 is fixed to the head 46 by a plurality of cylindrical-head bolts 47 , of which only one is illustrated in the drawing.
The excavation disk 45 is provided with a central cutter 48 . The excavation disk 45 in the exemplary embodiment demonstrated has three arms 50 which extend radially outward and which, as can be seen in the case of the arm illustrated on the left in the drawing, are filled with a plurality of chisels 51 .
The head 46 is rotatably mounted by means of tapered roller bearings 52 , 53 on a shaft journal 54 of a main shaft 55 . The shaft journal 54 , having a substantially cylindrical outer circumferential surface, is integrally molded on the main shaft 55 in such a way that its axis B forms an acute angle w of about 3° with the axis of rotation AA.
The main shaft 55 is in turn mounted by means of tapered roller bearings 56 , 57 in a machine housing 58 such that it can rotate about the axis of rotation AA and is driven in rotation by a hydraulic motor 59 flange-mounted at the end.
The part of the head 46 facing away from the excavation disk 45 is formed as a gear wheel, called the oscillating gear 60 in the following text, arranged concentrically with the axis B of the shaft journal 54 , and therefore formed as a circumferential region 61 which, during rotation of the main shaft 55 , runs in internal toothing 63 acting as an opposing circumferential region 62 .
The internal toothing 63 is formed on a hollow gear 64 arranged concentrically with respect to the main shaft axis and mounted such that it can rotate with respect to the latter.
At the end opposite to the internal toothing 63 , the hollow gear has further internal toothing 65 , which is part of an epicyclic gear mechanism designated overall by 71 . The toothing of the parts of smaller diameter 67 of the planet gears 66 engages in the internal toothing 65 . The parts 68 of larger diameter of the planet gears 66 engage with their toothing in external toothing 69 provided on the main shaft 55 and also in internal toothing 70 provided in the machine housing 58 , so that, during the rotary drive of the main shaft 55 , the planet gears circulate around the axis of rotation AA in the same direction of rotation. Here, the hollow gear 64 is set rotating in the direction opposite to the excavation disk 45 , whose rotation is moved as a result of the oscillating gear 60 running on the internal toothing 63 . It goes without saying that, by selecting the ratios in the epicyclic gear mechanism 71 , the rotational speed of the hollow gear 64 relative to the main shaft 55 and thus, as a result, the ratio of oscillation frequency to rotational frequency of the excavation disk 45 can be predefined.
FIG. 6 shows a second embodiment of a drive device. Mutually functionally corresponding parts are provided with designations increased by 100. The basic structure largely corresponds to that of FIG. 1 . To this extent, the description there also applies to the present embodiment.
The drive system of the device, designated overall by 103 , is fixed to a supporting device 102 which is supported on a working platform designated overall by 101 . A rotary drive head 104 , shown schematically, acts on a connecting rod assembly 105 which extends through the working platform 101 into the bore to be drilled in the ground and as far as the tool. The drive of the connecting rod assembly 105 by means of the rotary drive head 104 can be carried out in a conventional manner known from the prior art.
Arranged at the upper end of the connecting rod assembly 105 is a first connecting head, designated by 110 , via which material loosened at the base of the bore in the ground is carried away outward via the outlet pipe 121 , and a flushing fluid, normally air, is introduced into the connecting rod assembly 105 by means of a first feed line 113 . Arranged underneath the first connecting head 110 is a second connecting head, designated overall by 120 . The supporting device 102 can be inclined about a horizontal axis A by means of a swiveling drive 106 , so that it is also possible for bores in the ground to be drilled in a manner deviating from the vertical.
In the second embodiment of the drive device, the second connecting head 120 can rotate as a whole with the connecting rod assembly 105 , and only the first rotary connecting head 110 is mounted so as to be stationary. The rotary drive 104 is designed in such a way that it rotates the connecting rod assembly 105 having the second connecting head 120 for the drive medium of the hammers in the tool to and fro in an oscillatory manner through a predetermined angle about the axis of rotation of the assembly 105 . This swept angle is less than 360° and is chosen on the basis of the number and position of the tools 41 located on the same radius. In the case of only one tool 41 per radius, 360° are needed, in the case of two tools offset by 180° from each other per radius, a to and fro rotation of 180° suffices. However, it is likewise within the scope of the invention to rotate the tool head to and fro through an angle which is limited but greater than 360°.
As a result of the limited rotational angle, it is possible to operate a fixedly installed feed line for the drive medium that also participates in the rotational angle, without requiring a rotary seal or wiping contact arrangement. In the exemplary embodiment shown, the drive medium is introduced into the second feed 122 of the connecting rod assembly 105 by means of a flexible hose 115 . The hose 115 is mounted between the second feed line 123 and the second feed 122 . The length of the hose 115 is chosen such that the hose 115 can follow the rotation of the connecting rod assembly 105 without hindering the latter.
In a further embodiment, illustrated in FIG. 7 , in which mutually functionally corresponding parts are provided with designations increased by 200 with respect to FIG. 1 , the feed line 223 for the operating medium, the feed line 213 for the compressed air and the outlet pipe 221 are formed as flexible hoses. The two feed line pipes 213 and 223 are connected under the rotary drive 204 , at the points 213 ′, 223 ′, via flange arrangements not illustrated in detail, to the lines 212 , 222 running on the connecting rod assembly 205 , through which the compressed air is fed to the inlet opening ( 43 in FIG. 2 ) and the operating medium to the tool head ( 40 in FIG. 2 ). The advantage of this embodiment is that the rotary drive head 204 , which, however, in this case effects only an oscillatory movement, merely has to comprise a rotary mounting for the connecting rod assembly 205 but it is possible to dispense entirely with rotary leadthroughs and rotary seals.
In this connection, it should be pointed out that it is not absolutely necessary to connect the flexible hoses 213 , 223 to the lines 212 , 222 at the points 213 ′ and 223 ′. Instead, it is likewise possible to dispense entirely with the rigid lines 212 , 222 and to lead the hoses 213 , 223 as far as the corresponding connecting points, located in the bore, on the connecting rod assembly and, respectively, on the tool head. Furthermore, it is obvious that, depending on the operation of the tools 41 , flexible electric cables could also be used instead of the flexible lines.
Instead of the rotary drive head 204 always acting on the upper end of the upper segment of the connecting rod assembly 205 , in this embodiment it is also possible to provide a rotary drive 4 ′ which acts on the connecting rod assembly 205 on the outside and whose mode of action and function also otherwise corresponds to that of the rotary drive 4 ′ but which effects only a to and fro movement of the connecting rod assembly.
A further embodiment of the device according to the invention is illustrated in FIG. 8 . Mutually functionally corresponding elements are provided with designations increased by 300 relative to the embodiments in FIG. 1 . In the case of this embodiment, an upper mounting in the context of the rotary drive 204 in FIG. 7 or a rotary connecting head have been dispensed with completely. A drive unit 304 , which in terms of its function corresponds to that illustrated in FIG. 9 and is yet to be described further below, is used for the oscillatory drive.
The hose lines 313 , 323 are connected to the feeds 312 , 322 and the hose line 321 is connected to the interior of the connecting rod assembly 305 with the aid of a flange head 360 which is arranged at the upper end of the upper segment of the connection rod and is constructed in such a way that connections provided on the latter for the hose lines 313 , 323 , 321 communicate with the lines 312 , 322 and the interior of the connecting rod assembly.
The drive unit 304 is mounted on the supporting unit 302 via adjustable-length force generators 302 ′, such that the forward drive force can also be introduced into the connecting rod assembly via the drive unit 304 by lowering the drive unit 304 . Once the drive unit 304 has reached its lower position, further forward drive can be effected by “re-gripping”, by being released and fixed again after it has been displaced into a higher position with the aid of the force generator, and the procedure begins again. Since, in this device, no supporting unit whose length corresponds at least to that of one segment of the connecting rod assembly 5 is necessary, this embodiment is distinguished by a particularly low overall height.
The rotary drive 304 ′ illustrated in FIG. 9 , which is known per se from piping machines and therefore is not to be described in detail, comprises a part 304 ′″ which can be set into an oscillatory movement with the aid of two piston/cylinder units and which is configured such that it can be folded up in many parts over its circumference. In order to connect it to the connecting rod assembly 305 , the part 304 ′″ pushed onto the latter is closed, so that it is operatively connected to the circumferential surface of the connecting rod assembly 205 .
A further embodiment of one of the tools 41 is illustrated in FIG. 10 . In this tool, the carrier device for the removal means, implemented as a double arm 72 , executes only an oscillatory movement but no rotational movement. The mechanical construction of this tool is therefore simplified substantially as compared with that according to FIG. 5 , since it is possible to dispense with an opposing circumferential surface on which the circumferential surface runs in order to produce the rotation, and therefore with the entire gear mechanism.
In addition, it is possible to dispense with individual drives for producing the oscillatory movement in each tool and, instead, to provide a central drive which is coupled to the tools. The central drive can contain a gear mechanism having drive shafts for each tool, in order in this way also to be able to vary oscillation frequencies.
The tools according to FIG. 10 are arranged in the tool head in such a way that their double arms 72 extend at right angles to the tangents to the circles or circular sections which they sweep over on account of the rotation of the tool head. In addition, as illustrated schematically in FIG. 11 , they are arranged to be offset laterally, so that individual cutting tools 451 operate in different tracks.
In this way, as compared with arrangements in which the excavation disks of the tools rotate and/or a plurality of cutting tools operate in one track, a coarser drilled material is obtained. The energy balance is more beneficial on account of the coarser drilled material, since the proportion of energy required for further comminution is dispensed with.
In the above text, only exemplary embodiment of devices according to the invention which are suitable for driving forward bores running substantially vertically have been shown. It goes without saying that the invention is not restricted to such bores but is also suitable for driving forward tunnel bores which run substantially in the horizontal direction.
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The invention relates to a device for drilling a bore in the ground, comprising a drive system with a connecting rod assembly that extends from the drive system into the ground. The end of said assembly pointing towards the face or base of the bore is connected to a tool head ( 40 ). The device also comprises several tools ( 41 ) that are located on the tool head ( 40 ) and work on the face or the base of the bore. The inventive device is characterised in that each tool ( 41 ) comprises an excavation disc ( 45 ) and elements that cause the excavation disc ( 45 ) to oscillate during operation.
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BACKGROUND OF THE INVENTION
The present invention relates to pumping fluids such as viscous crude oil from high productivity deep wells utilizing a submersible pump suspended from a rod string disposed in a production tube within the well casing.
Conventionally, the annular space between the casing and the production tubing string below the pump is sealed from the lower portion of the well formation by a packing or a gland. The production tube is perforated near the discharge side of the pump so that production fluid is advanced upwardly by the pump through the production tube and through the annular space. The pump is suspended usually from a rod string or sucker rod and there is but one operative pumping system. That is, there is no alternative flow path other than through the production tube and through the annular space simultaneously.
While arrangements of this type are operative they have the disadvantage of generating excessive down time and considerable expense when trouble develops in the well or when production diminishes. In such situations, the rod string and the suspended pump must be pulled from the well. Depending upon the difficulty it may even be necessary to pull the production tubing string.
Furthermore, it is frequently desirable when the fluid pump is of a high viscosity to maintain a supply of low viscosity fluid in the production tube for lubrication and dilution while producing high viscosity fluid, solely through the annular space.
Obviously to accomplish a change in pumping flow paths in prior art systems, it is necessary to pull the rod string and the tubing string to shift from one pumping mode to another at a substantial loss of time and with concomitant addition expense.
SUMMARY OF THE INVENTION
Consequently, it is a principal object of the present invention to provide a slotted housing which facilitates production of well fluids through a plurality of different flow paths, selectively, without having to pull the pump, the rod string and the tubing string from the well.
More explicitly, it is a principal feature of the present invention to provide a pumping system operative selectively to pump (1) through the production tube and the annular space between the production tube and the well casing simultaneously, (2) through the production tube solely or (3) through the annular space solely, as desired, without having to pull the rod string and/or the tubing string.
A further feature of the invention is the provision of slotted housing in the form of a tubular element or a sleeve which is operable to connect in series with the conventional production tubing string.
A further feature of the invention is the provision of a slotted housing which includes a plurality of seat means for engaging, supporting and locating a submersible pump where each seat means in combination with the pump housing develops a valve action and a distinct fluid flow path.
A further feature of the invention is the provision of a plurality of through apertures in the slotted housing in a region between at least two of said seat means.
A still further feature of the present invention is the provision of a slotted housing in the form of a tubular element adapted to make a threaded connection in series with the production tubing string where the slotted housing includes a plurality of seat means operable to engage, support and position a submersible pump and a stuffing box or seal means, said tubular element including at least one through aperture providing communication from the interior of the tubing string to the annular space between the tubing string and the well casing so that depending upon the position of the pump housing and the stuffing box relative to the several seat means, the flow of product fluid may take, selectively, one of three different paths, i.e. through the production tube solely, through the production tube and the annular space simultaneously or through the annular space solely. All these selective flow paths can be developed rapidly and economically without the need to dismantel and pull the rod and tubing strings.
A further feature of the invention is the novel cooperation between a slotted housing and the housing or casing of a submersible pump.
A still further feature of the invention is a provision of a valve system which involves a minimum number of piece parts.
Among other advantages and features of the invention are the following:
1. Small number of moving parts;
2. The pump casing in combination with the slotted housing cooperate to effect a valve action;
3. Three different valve settings are possible selectively and rapidly without having to resort to pulling the system from the well;
4. The slotted housing is a relatively uncomplicated tubular structure which is inexpensive to fabricate;
5. The slotted housing, by virtue of its threaded ends, facilitates inclusion in the tubing string at any point along the string;
6. The system, by virtue of the choice of flow paths, reduces "down" time greatly by reducing the necessity and frequency of pulling the system; and
7. The slotted housing, in its tubular form, with inwardly protuberant seat means serves to position the pump in place securely and concentrically relative to the production tube.
A fluid production pumping system for oil wells and the like embracing certain principles of the invention may include a well casing, a fluid production tube within the casing spaced from the casing to define an annular space between the casing and the tube, slotted housing in series with a production tube said slotted housing defining a sleeve having at least one aperture leading from the interior of the tube to the annular space, stope or seat means for locating and seating a submersible pump in at least two distinct positions relative to said aperture whereby said pump is operable selectively to assume a first position relative to said slotted housing effective to discharge product through the said annular space and said tube and to assume a second position to discharge product through said tube without the need to withdraw and dismantel the pumping system.
A method of effecting a valve action within the well embracing certain other principles of the invention may comprise the steps of incorporating a length of tubing in the tubing string having a through aperture, lowering the tubing string until the aperture arrives at the region of the surface of the fluid to be pumped, thereafter lowering a submersible pump inside the tubing string and effecting a valve action by changing the location of the pump relative to said aperture.
A slotted housing embracing additional principles of the invention may comprise a hollow tubular element having threaded ends and an intermediate through slot said element having a plurality of seat means on the interior thereof for locating a pump means disposed therein.
Other features and advantages of the present invention will become more apparent from the examination of the succeeding specification when read in conjunction with the appended drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical section of the slotted housing.
FIG. 2 is a schematic illustration of the well hole casing, production tube and the bottom of the formation with the pumping system set for pumping product through the annular space and the production tube simultaneously.
FIG. 3 is an enlarged view of the valve arrangement of FIG. 3 showing the submersible pump, suspended by a rod string, seated below through apertures permitting flow dually through the annular space and the production tube as indicated by the arrows.
FIG. 4 is similar to FIG. 3 showing the submersible pump seated in a second position above the apertures in which the flow path is limited to the production tube, and,
FIG. 5 shows the submersible pump in the position of FIG. 3 with a stuffing box or seal means seated on an upper seat means blocking flow through the production tube while directing flow through the annular space.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, in particular FIG. 2, reference numeral 10 designates a typical deep well arrangement in which the present invention is operative including a casing 11, a production tubing string 12, an annular space 13 between the casing 11 and the production tubing string 12, a submersible pump 16 and a packing 17 for sealing the annular space from the bottom of the formation 18.
The reference numeral 19 designates through slots providing communication between the interior of the production tube and the annular space 13 whereby the arrangement of FIG. 2 is operative to pump fluid upwardly through the production tube 12 and through the annular space 13 simultaneously as indicated by the arrows.
A reference to FIGS. 1 and 3 provides an enlarged view of the slotted housing indicated generally at 21 and its cooperation with the pump P to effect the flow paths of FIG. 2.
The slotted housing 21 defines a hollow cylindrical body or sleeve 22 making a threaded connection at 23 and 24 with the tubing string T. The slotted housing includes a plurality of through apertures 26 and 27 straddled by seat means 28 and 29.
The seat means are generally of the same configuration and include inwardly projecting, annular beads 5 or protuberances 31 and 32 bounded by bevelled margines 33, 34 36 and 37.
The bevelled margins provide seats or positioning points for engagement with mating bevels 38 and 39 formed on the housing 41 of the submersible pump P.
Obviously the angle of the bevel is not critical so long as there is a neat fit between the seat means and the pump housing to effect a seal and to position the pump concentrically and at the correct vertical distance from the slots or apertures 26-27.
The pump P is suspended and moved up and down vertically by means of the rod string R.
Note that in FIG. 3 the pump is positioned below the slots 26-27 which, for purposes of claiming the invention, is termed the first position and the seat means 28 is termed the first seat means.
In the first position the upper bevel 34 of seat means 28 engages mating lower bevel 38 on the pump housing 41. In this position fluid product is discharged upwardly through the tube T and through the annular space 13 via the slots 26-27 as indicated by the arrows of FIGS. 2 and 3.
Referring to FIG. 4, the pump P is shown in the second position in contact with the seat means 29, referred to in the succeeding claims as the second seat means.
In this position the upper bevel 39 of the pump housing 41 is nested into the lower bevelled margin 36 of the upper or second seat means 29.
Thus, in the second position of the pump means valving action between the pump housing 41 and the slotted housing is effective to cut off flow through slots 26 and 27 and flow is directed solely through the product tubing string T as indicated by the arrows of FIG. 4.
FIG. 5 shows the pump means and its housing 41 in the first position as described previously with respect to FIG. 3.
In the system of FIG. 5 a gland or stuffing box 42 is dropped downwardly, guided by the rod string R where upon the stuffing box seats itself on the upper bevel 37 of upper seat means 29. The stuffing box is suitably bevelled to match or mate with the upper seat means to form a seal which is impervious to viscous fluids such as heavy crude oil but somewhat pervious to low viscosity fluids such as light oil.
Thus, in the valving arrangement of FIG. 5 the product tubing string T is blocked and fluid discharging from pump P flows solely through the annular space 13 via slots or apertures 26 and 27 as indicated by the arrows.
In the arrangement of the pumping system shown in FIG. 5 it is sometimes desirable to fill the product tubing string T with low viscosity fluid to hold the stuffing box 42 in place.
In addition a slight weeping or seeping of low viscosity fluid through the stuffing box into the discharge side of the pump P acts to create favorable flow characteristics in the relatively viscous fluid being pumped solely through the annular space 13.
It is to be understood that the invention is not limited to the illustrations described and shown herein, which are deemed to be merely illustrative of the best modes of carrying out the invention, and which are susceptible of modification of form, size, arrangement of parts and details of operation. The invention rather is intended to encompass all such modifications which are within its spirit and scope as defined by the claims.
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A well pumping system operative selectively to pump fluids (1) through the production tube and the annular space between the production tube and the well casing simultaneously (2) through the production tube solely or (3) through the annular space solely, without having to pull the rod string and/or the tube string.
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PRIORITY INFORMATION
[0001] This application is a divisional of U.S. patent application Ser. No. 10/679,032 filed on Oct. 3, 2003 which claims priority to U.S. Provisional Patent Appln. No. 60/421,067, filed Oct. 25, 2002, Swedish Patent Application No. 0302312-4, filed Aug. 27, 2003 and Swedish Patent Application No. 0202959-3, filed Oct. 4, 2002 all of which are incorporated herein in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to new recombinant human antibodies raised against peptides being derivatives of apolipoprotein B, in particular antibodies to be used for immunization therapy for treatment of atherosclerosis, method for their preparation, and method for passive immunization using said antibodies.
In Particular the Invention Includes:
[0004] The use of any isolated recombinant antibody raised against an oxidized form of the peptides listed in table 1, in particular MDA-modified peptides, preferably together with a suitable carrier and adjuvant as an immunotherapy or “anti-atherosclerosis “vaccine” for prevention and treatment of ischemic cardiovascular disease.
[0005] 2. Description of the Prior Art
[0006] The protective effects of humoral immunity are known to be mediated by a family of structurally related glycoproteins called antibodies. Antibodies initiate their biological activity by binding to antigens. Antibody binding to antigens is generally specific for one antigen and the binding is usually of high affinity. Antibodies are produced by B-lymphocytes. Blood contains many different antibodies, each derived from a clone of B-cells and each having a distinct structure and specificity for antigen. Antibodies are present on the surface of B-lymphocytes, in the plasma, in interstitial fluid of the tissues and in secretory fluids such as saliva and mucous on mucosal surfaces.
[0007] All antibodies are similar in their overall structure, accounting for certain similarities in physico-chemical features such as charge and solubility. All antibodies have a common core structure of two identical light chains, each about 24 kilodaltons, and two identical heavy chains of about 55-70 kilodaltons each. One light chain is attached to each heavy chain, and the two heavy chains are attached to each other. Both the light and heavy chains contain a series of repeating homologous units, each of about 110 amino acid residues in length which fold independently in a common globular motif, called an immunoglobulin (Ig) domain. The region of an antibody formed by the association of the two heavy chains is hydrophobic. Antibodies, and especially monoclonal antibodies, are known to cleave at the site where the light chain attaches to the heavy chain when they are subjected to adverse physical or chemical conditions. Because antibodies contain numerous cysteine residues, they have many cysteine-cysteine disulfide bonds. All Ig domains contain two layers of beta-pleated sheets with three or four strands of anti-parallel polypeptide chains.
[0008] Despite their overall similarity, antibody molecules can be divided into a small number of distinct classes and subclasses based on physicochemical characteristics such as size, charge and solubility, and on their behavior in binding to antigens. In humans, the classes of antibody molecules are: IgA, IgD, IgE, IgG and IgM. Members of each class are said to be of the same isotype. IgA and IgG isotypes are further subdivided into subtypes called IgA1, IgA2 and IgG1, IgG2, IgG3 and IgG4. The heavy chains of all antibodies in an isotype share extensive regions of amino acid sequence identity, but differ from antibodies belonging to other isotypes or subtypes. Heavy chains are designated by the letters of the Greek alphabet corresponding to the overall isotype of the antibody, e.g., IgA contains .alpha., IgD contains .delta., IgE contains .epsilon., IgG contains .gamma., and IgM contains .mu. heavy chains. IgG, IgE and IgD circulate as monomers, whereas secreted forms of IgA and IgM are dimers or pentamers, respectively, stabilized by the J chain. Some IgA molecules exist as monomers or trimers.
[0009] There are between 10 8 and 10 10 structurally different antibody molecules in every individual, each with a unique amino acid sequence in their antigen combining sites. Sequence diversity in antibodies is predominantly found in three short stretches within the amino terminal domains of the heavy and light chains called variable (V) regions, to distinguish them from the more conserved constant (C) regions.
[0010] Atherosclerosis is a chronic disease that causes a thickening of the innermost layer (the intima) of large and medium-sized arteries. It decreases blood flow and may cause ischemia and tissue destruction in organs supplied by the affected vessel. Atherosclerosis is the major cause of cardiovascular disease including myocardial infarction, stroke and peripheral artery disease. It is the major cause of death in the western world and is predicted to become the leading cause of death in the entire world within two decades.
[0011] The disease is initiated by accumulation of lipoproteins, primarily low-density lipoprotein (LDL), in the extracellular matrix of the vessel. These LDL particles aggregate and undergo oxidative modification. Oxidized LDL is toxic and cause vascular injury. Atherosclerosis represents in many respects a response to this injury including inflammation and fibrosis.
[0012] In 1989 Palinski and coworkers identified circulating autoantibodies against oxidized LDL in humans. This observation suggested that atherosclerosis may be an autoimmune disease caused by immune reactions against oxidized lipoproteins. At this time several laboratories began searching for associations between antibody titers against oxidized LDL and cardiovascular disease. However, the picture that emerged from these studies was far from clear. Antibodies existed against a large number of different epitopes in oxidized LDL, but the structure of these epitopes was unknown. The term “oxidized LDL antibodies” thus referred to an unknown mixture of different antibodies rather than to one specific antibody. T cell-independent IgM antibodies were more frequent than T-cell dependent IgG antibodies.
[0013] Antibodies against oxidized LDL were present in both patients with cardiovascular disease and in healthy controls. Although some early studies reported associations between oxidized LDL antibody titers and cardiovascular disease, others were unable to find such associations. A major weakness of these studies was that the ELISA tests used to determine antibody titers used oxidized LDL particles as ligand. LDL composition is different in different individuals, the degree of oxidative modification is difficult both to control and assess and levels of antibodies against the different epitopes in the oxidized LDL particles can not be determined. To some extent, due to the technical problems it has been difficult to evaluate the role of antibody responses against oxidized LDL using the techniques available so far, but, however, it is not possible to create well defined and reproducible components of a vaccine if one should use intact oxidized LDL particles.
[0014] Another way to investigate the possibility that autoimmune reactions against oxidized LDL in the vascular wall play a key role in the development of atherosclerosis is to immunize animals against its own oxidized LDL. The idea behind this approach is that if autoimmune reactions against oxidized LDL are reinforced using classical immunization techniques this would result in increased vascular inflammation and progressive of atherosclerosis. To test this hypothesis rabbits were immunized with homologous oxidized LDL and then induced atherosclerosis by feeding the animals a high-cholesterol diet for 3 months.
[0015] However, in contrast to the original hypothesis immunization with oxidized LDL had a protective effect reducing atherosclerosis with about 50%. Similar results were also obtained in a subsequent study in which the high-cholesterol diet was combined with vascular balloon-injury to produce a more aggressive plaque development. In parallel with our studies several other laboratories reported similar observations. Taken together the available data clearly demonstrates that there exist immune reactions that protect against the development of atherosclerosis and that these involves autoimmunity against oxidized LDL.
[0016] These observations also suggest the possibility of developing an immune therapy or “vaccine” for treatment of atherosclerosis-based cardiovascular disease in man. One approach to do this would be to immunize an individual with his own LDL after it has been oxidized by exposure to for example copper. However, this approach is complicated by the fact that it is not known which structure in oxidized LDL that is responsible for inducing the protective immunity and if oxidized LDL also may contain epitopes that may give rise to adverse immune reactions.
[0017] The identification of epitopes in oxidized LDL is important for several aspects:
[0018] First, one or several of these epitopes are likely to be responsible for activating the anti-atherogenic immune response observed in animals immunized with oxidized LDL. Peptides containing these epitopes may therefore represent a possibility for development of an immune therapy or “atherosclerosis vaccine” in man. Further, they can be used for therapeutic treatment of atherosclerosis developed in man.
[0019] Secondly, peptides containing the identified epitopes can be used to develop ELISAs able to detect antibodies against specific structure in oxidized LDL. Such ELISAs would be more precise and reliable than ones presently available using oxidized LDL particles as antigen. It would also allow the analyses of immune responses against different epitopes in oxidized LDL associated with cardiovascular disease.
[0020] U.S. Pat. No. 5,972,890 relates to a use of peptides for diagnosing atherosclerosis. The technique presented in said U.S. patent is as a principle a form of radiophysical diagnosis. A peptide sequence is radioactively labelled and is injected into the bloodstream. If this peptide sequence should be identical with sequences present in apolipoprotein B it will bind to the tissue where there are receptors present for apolipoprotein B. In vessels this is above all atherosclerotic plaque. The concentration of radioactivity in the wall of the vessel can then be determined e.g., by means of a gamma camera. The technique is thus a radiophysical diagnostic method based on that radioactively labelled peptide sequences will bound to their normal tissue receptors present in atherosclerotic plaque and are detected using an external radioactivity analysis. It is a direct analysis method to identify atherosclerotic plaque. It requires that the patient be given radioactive compounds.
[0021] Published studies (Palinski et al., 1995, and George et al., 1998) have shown that immunisation against oxidised LDL reduces the development of atherosclerosis. This would indicate that immuno reactions against oxidised LDL in general have a protecting effect. The results given herein have, however, surprisingly shown that this is not always the case. E.g., immunisation using a mixture of peptides #10, 45, 154, 199, and 240 gave rise to an increase of the development of atherosclerosis. Immunisation using other peptide sequences, e.g., peptide sequences #1, and 30 to 34 lacks total effect on the development of atherosclerosis. The results are surprising because they provide basis for the fact that immuno reactions against oxidised LDL, can protect against the development, contribute to the development of atherosclerosis, and be without any effect at all depending on which structures in oxidised LDL they are directed to. These findings make it possible to develop immunisation methods, which isolate the activation of protecting immuno reactions. Further, they show that immunisation using intact oxidised LDL could have a detrimental effect if the particles used contain a high level of structures that give rise to atherogenic immuno reactions.
SUMMARY OF THE INVENTION
[0022] The technique of the present invention is based on quite different principles and methods. In accordance with claim 1 the invention relates to antibodies raised against oxidized fragments of apolipoprotein B, which antibodies are used for immunisation against cardiovascular disease.
[0023] As an alternative to active immunisation, using the identified peptides described above, passive immunisation with pre-made antibodies directed to the same peptides is an attractive possibility. Such antibodies may be given desired properties concerning e.g. specificity and crossreactivity, isotype, affinity and plasma half-life. The possibility to develop antibodies with predetermined properties became apparent already with the advent of the monoclonal antibody technology (Milstein and Köhler, 1975 Nature, 256:495-7). This technology used murine hybridoma cells producing large amounts of identical, but murine, antibodies. In fact, a large number of preclinical, and also clinical trials were started using murine monoclonal antibodies for treatment of e.g. cancers. However, due to the fact that the antibodies were of non-human origin the immune system of the patients recognised them as foreign and developed antibodies to them. As a consequence the efficacy and plasma half-lives of the murine antibodies were decreased, and often side effects from allergic reactions, caused by the foreign antibody, prevented successful treatment.
[0024] To solve these problems several approaches to reduce the murine component of the specific and potentially therapeutic antibody were taken. The first approach comprised technology to make so called chimearic antibodies where the murine variable domains of the antibody were transferred to human constant regions resulting in an antibody that was mainly human (Neuberger et al. 1985, Nature 314:268-70). A further refinement of this approach was to develop humanised antibodies where the regions of the murine antibody that contacted the antigen, the so called Complementarity Determining Regions (CDRs) were transferred to a human antibody framework. Such antibodies are almost completely human and seldom cause any harmful antibody responses when administered to patients. Several chimearic or humanised antibodies have been registered as therapeutic drugs and are now widely used within various indications (Borrebaeck and Carlsson, 2001, Curr. Opin. Pharmacol. 1:404-408).
[0025] Today also completely human antibodies may be produced using recombinant technologies. Typically large libraries comprising billions of different antibodies are used. In contrast to the previous technologies employing chimearisation or humanisation of e.g. murine antibodies this technology does not rely on immunisation of animals to generate the specific antibody. In stead the recombinant libraries comprise a huge number of pre-made antibody variants why it is likely that the library will have at least one antibody specific for any antigen. Thus, using such libraries the problem becomes the one to find the specific binder already existing in the library, and not to generate it through immunisations. In order to find the good binder in a library in an efficient manner, various systems where phenotype i.e. the antibody or antibody fragment is linked to its genotype i.e. the encoding gene have been devised. The most commonly used such system is the so called phage display system where antibody fragments are expressed, displayed, as fusions with phage coat proteins on the surface of filamentous phage particles, while simultaneously carrying the genetic information encoding the displayed molecule (McCafferty et al., 1990, Nature 348:552-554). Phage displaying antibody fragments specific for a particular antigen may be selected through binding to the antigen in question. Isolated phage may then be amplified and the gene encoding the selected antibody variable domains may optionally be transferred to other antibody formats as e.g. full length immunoglobulin and expressed in high amounts using appropriate vectors and host cells well known in the art.
[0026] The format of displayed antibody specificities on phage particles may differ. The most commonly used formats are Fab (Griffiths et al., 1994. EMBO J. 13:3245-3260) and single chain (scFv) (Hoogenboom et al., 1992, J Mol. Biol. 227:381-388) both comprising the variable antigen binding domains of antibodies. The single chain format is composed of a variable heavy domain (VH) linked to a variable light domain (VL) via a flexible linker (U.S. Pat. No. 4,946,778). Before use as analytical reagents, or therapeutic agents, the displayed antibody specificity is transferred to a soluble format e.g. Fab or scFv and analysed as such. In later steps the antibody fragment identified to have desirable characteristics may be transferred into yet other formats such as full length antibodies.
[0027] Recently a novel technology for generation of variability in antibody libraries was presented (WO98/32845, Soderlind et al., 2000, Nature BioTechnol. 18:852-856). Antibody fragments derived from this library all have the same framework regions and only differ in their CDRs. Since the framework regions are of germline sequence the immunogenicity of antibodies derived from the library, or similar libraries produced using the same technology, are expected to be particularly low (Soderlind et al., 2000, Nature BioTechnol. 18:852-856). This property is expected to be of great value for therapeutic antibodies reducing the risk for the patient to form antibodies to the administered antibody thereby reducing risks for allergic reactions, the occurrence of blocking antibodies, and allowing a long plasma half-life of the antibody. Several antibodies derived from recombinant libraries have now reached into the clinic and are expected to provide therapeutic drugs in the near future.
[0028] Thus, when met with the challenge to develop therapeutic antibodies to be used in humans the art teaches away from the earlier hybridoma technology and towards use of modern recombinant library technology (Soderlind et al., 2001, Comb. Chem. & High Throughput Screen. 4:409-416). It was realised that the peptides identified (PCT/SE02/00679), and being a integral part of this invention, could be used as antigens for generation of fully human antibodies with predetermined properties. In contrast to earlier art (U.S. Pat. No. 6,225,070) the antigenic structures i.e. the peptides used in the present invention were identified as being particularly relevant as target sequences for therapeutic antibodies (PCT/SE02/00679). Also, in the present invention the antibodies are derived from antibody libraries omitting the need for immunisation of lipoprotein deficient mice to raise murine antibodies (U.S. Pat. No. 6,225,070). Moreover, the resulting antibodies are fully human and are not expected to generate any undesired immunological reaction when administered into patients.
[0029] The peptides used, and previously identified (PCT/SE02/00679) are the following:
[0000] TABLE 1 A. High IgG, MDA-difference P 11. FLDTVYGNCSTHFTVKTRKG (SEQ. ID NO: 39) P 25. PQCSTHILQWLKRVHANPLL (SEQ. ID NO: 40) P 74. VISIPRLQAEARSEILAHWS (SEQ. ID NO: 41) B. High IgM, no MDA-difference P 40. KLVKEALKESQLPTVMDFRK (SEQ. ID NO: 42) P 68. LKFVTQAEGAKQTEATMTFK (SEQ. ID NO: 43) P 94. DGSLRHKFLDSNIKFSHVEK (SEQ. ID NO: 44) P 99. KGTYGLSCQRDPNTGRLNGE (SEQ. ID NO: 45) P 100. RLNGESNLRFNSSYLQGTNQ (SEQ. ID NO: 46) P 102. SLTSTSDLQSGIIKNTASLK (SEQ. ID NO: 47) P 103. TASLKYENYELTLKSDTNGK (SEQ. ID NO: 48) P 105. DMTFSKQNALLRSEYQADYE (SEQ. ID NO: 49) P 177. MKVKIIRTIDQMQNSELQWP (SEQ. ID NO: 50) C. High IgG, no MDA difference P 143. IALDDAKINFNEKLSQLQTY (SEQ. ID NO: 51) P 210. KTTKQSFDLSVKAQYKKNKH (SEQ. ID NO: 52) D. NHS/AHP, IgG-ak > 2, MDA-difference P1. EEEMLENVSLVCPKDATRFK (SEQ. ID NO: 53) P 129. GSTSHHLVSRKSISAALEHK (SEQ. ID NO: 54) P 148. IENIDFNKSGSSTASWIQNV (SEQ. ID NO: 55) P 162. IREVTQRLNGEIQALELPQK (SEQ. ID NO: 56) P 252. EVDVLTKYSQPEDSLIPFFE (SEQ. ID NO: 57) E. NHS/AHP, IgM-ak > 2, MDA-difference P 301. HTFLIYITELLKKLQSTTVM (SEQ. ID NO: 58) P 30. LLDIANYLMEQIQDDCTGDE (SEQ. ID NO: 59) P 31. CTGDEDYTYKIKRVIGNMGQ (SEQ. ID NO: 60) P 32. GNMGQTMEQLTPELKSSILK (SEQ. ID NO: 61) P 33. SSILKCVQSTKPSLMIQKAA (SEQ. ID NO: 62) P 34. IQKAAIQALRKMEPKDKDQE (SEQ. ID NO: 63) P 100. RLNGESNLRFNSSYLQGTNQ (SEQ. ID NO: 64) P 107. SLNSHGLELNADILGTDKIN (SEQ. ID NO: 65) P 149. WIQNVDTKYQIRIQIQEKLQ (SEQ. ID NO: 66) P 169. TYISDWWTLAAKNLTDFAEQ (SEQ. ID NO: 67) P 236. EATLQRIYSLWEHSTKNHLQ (SEQ. ID NO: 68) F. NHS/AHP, IgG-ak < 0.5, no MDA-difference P 10. ALLVPPETEEAKQVLFLDTV (SEQ. ID NO: 69) P 45. IEIGLEGKGFEPTLEALFGK (SEQ. ID NO: 70) P 111. SGASMKLTTNGRFREHNAKF (SEQ. ID NO: 71) P 154. NLIGDFEVAEKINAFRAKVH (SEQ. ID NO: 72) P 199. GHSVLTAKGMALFGEGKAEF (SEQ. ID NO: 73) P 222. FKSSVITLNTNAELFNQSDI (SEQ. ID NO: 74) P 240. FPDLGQEVALNANTKNQKIR (SEQ. ID NO: 75)
or an active site of one or more of these peptides.
[0030] In Table 1 above, the following is due:
[0000] (A) Fragments that produce high levels of IgG antibodies to MDA-modified peptides (n=3),
(B) Fragments that produce high levels of IgM antibodies, but no difference between native and MDA-modified peptides (n=9),
(C) Fragments that produce high levels of IgG antibodies, but no difference between native and MDA-modified peptides (n=2),
(D) Fragments that produce high levels of IgG antibodies to MDA-modified peptides and at least twice as much antibodies in the NHP-pool as compared to the AHP-pool (n=5),
(E) Fragments that produce high levels of IgM antibodies to MDA-modified peptides and at least twice as much antibodies in the NHP-pool as compared to the AHP-pool (n=11), and
(F) Fragments that produce high levels of IgG antibodies, but no difference between intact and MDA-modified peptides but at least twice as much antibodies in the AHP-pool as compared to the NHP-pool (n=7).
[0031] The present invention relates to the use of at least one recombinant human antibody or an antibody fragment thereof directed towards at least one oxidized fragment of apolipoprotein B in the manufacture of a pharmaceutical composition for therapeutical or prophylactical treatment of atherosclerosis by means of passive immunization.
[0032] Further the invention relates to the recombinant preparation of such antibodies, as well as the invention relates to method for passive immunization using such antibodies raised using an oxidized apolipoprotein B fragment, as antigen, in particular a fragment as identified above.
[0033] The present invention utilises a recombinant antibody fragment library to generate specific human antibody fragments against oxidized, in particular MDA modified peptides derived from Apo B100. Identified antibody fragments with desired characteristics may then rebuilt into full length human immunoglobulin to be used for therapeutic purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIGS. 1A-1C are ELISA results from Screen II;
[0035] FIGS. 2A-2F are graphs of dose response for ELISAs;
[0036] FIG. 3 are the DNA sequences of various regions;
[0037] FIGS. 4A and 4B are light and heavy-chain vectors;
[0038] FIG. 5 is a graph of ELISA results;
[0039] FIG. 6 is a graph of Oil Red 0 Stained area in aortas;
[0040] FIG. 7 is a graph of Oil Red 0 stained area in aortas versus antibody product;
[0041] FIGS. 8 a and 8 b are graphs of LDL uptake; and
[0042] FIG. 9 are graphs of the Ratio MDA/na LDL and ApoB
DETAILED DESCRIPTION OF THE INVENTION
[0043] Below will follow a detailed description of the invention exemplified by, but not limited to, human antibodies derived from a recombinant antibody fragment library and directed towards two MDA modified peptides from ApoB 100.
EXAMPLE 1
Selection of scFv Against MDA Modified Peptides IEIGL EGKGF EPTLE ALFGK (SEQ. ID NO: 70) (P45, Table 1) and KTTKQ SFDLS VKAQY KKNKH (P210, Table 1)
[0044] The target antigens were chemically modified to carry Malone-di-aldehyde (MDA) groups on lysines and histidines. The modified peptides were denoted IEI (P45) and KTT (P210).
[0045] Selections were performed using BioInvent's n-CoDeR™scFv library for which the principle of construction and production have been described in Soderlind et al. 2000, Nature BioTechnology. 18, 852-856. The library contains approximately 2×10 10 independent clones and a 2000 fold excess of clones were used as input for each selection. Selections were performed in three rounds. In selection round 1, Immunotubes (NUNC Maxisorb™-444202) were coated with 1.2 ml of 20 g/ml MDA-modified target peptides in PBS (137 mM NaCl, 2.7 mM KCl, 4.3 mM Na 2 HPO 4 , 1.4 mM KH 2 PO 4 ) with end over end agitation at +4° C. over night. The tubes were then blocked with TPBSB5% (5% BSA, 0.05% Tween 20, 0.02% sodium Azide in PBS) for 30 minutes and washed twice with TPBSB3% (3% BSA, 0.05% Tween 20, 0.02% sodium Azide in PBS) before use. Each target tube was then incubated with approximately 2×10 13 CFU phages from the n-CodeR™ library in 1.8 ml TPBSB3% for 2 h at room temperature, using end over end agitation. The tubes were then washed with 15×3 ml TPBSB3% and 2×1 ml PBS before the bound phages were eluted with 1 ml/tube of 2 mg/ml trypsin (Roche, 109819) for 30 minutes at room temperature. This procedure takes advantage of a specific trypsin site in the scFv-fusion protein to release the phage from the target. The reaction was stopped by the addition of 100 of Aprotein (0.2 mg/ml, Roche, cat.236624), and the immunotubes were washed with 300 ul PBS, giving a final volume of 1.4 ml.
[0046] For amplification of the selected phage E. Coli HB101F′ cells were grown exponentially in 10 ml of LB medium (Merck, cat. 1.10285) to OD 600 =0.5 and infected with the selected and eluted phage principally as described (Soderlind et al., 2000, Nature BioTechnol. 18, 852-856. The resulting phage supernatant was then precipitated by addition of ¼ volume of 20% PEG 6000 in 2.5 M NaCl and incubated for 5 h at +4° C. The phages were then pelleted by centrifugation for 30 minutes, 13000×g, re-suspended in 500 l PBS and used in selection round 2.
[0047] The amplified phagestock was used in selection round 2 in a final volume of 1.5 ml of 5% BSA, 0.05% Tween 20, 0.02% sodium Azide in PBS. Peptide without MDA modification (4×10 −7 M) was also included for competition against binders to MDA-unmodified target peptide. The mixture was incubated in immunotubes prepared with antigen as described above, except that the tubes were blocked with 1% Casein instead of TPBSB3%. The incubations and washing of the immunotubes were as described for selection 1. Bound phages were then eluted for 30 minutes using 600 l of 100 mM Tris-Glycine buffer, pH 2.2. The tubes were washed with additional 200 l glycin buffer and the eluates were pooled and then neutralised with 96 l of 1 M Tris-HCl, pH 8.0. The samples were re-natured for 1 h at room temperature and used for selection round 3.
[0048] For selection round 3, BSA, Tween 20 and Sodium Azide were added to the renaturated phage pool to a final concentration of 3%, 0.05% and 0.02%, respectively. Competitor peptides, MDA modified unrelated peptides as well as native target peptides without modification were added to a concentration of 1×10 −7 M. The phage mixtures (1100 l) were added to immunotubes coated with target antigen as described in selection 1 and incubated over night at 4° C. with agitation. The tubes were then washed with 3×3 ml TPBSB 3%, 5×3 ml PBS and eventually bound phages were eluted using trypsin as described in selection round 1 above. Each eluate was infected to 10 ml of logarithmically growing HB101F′ in LB containing 100 g/ml ampicillin, 15 g/ml tetracycline, 0.1% glucose, and grown over night at 30° C., 200 rpm in a shaker incubator.
[0049] The over night cultures were used for mini scale preparation of plasmid DNA, using Biorad mini prepp Kit (Cat. 732 6100). To remove the phage gene III part from the expression vector, 0.25 g of the plasmid DNA was cut for 2 h at 37° C. using 2.5 U Eag-1 (New England Biolabs, cat. R050) in the buffer recommended by the supplier. The samples were then heat inactivated for 20 minutes at 65° C. and ligated over night at 16° C. using 1 U T4 DNA ligase in 30 l of 1× ligase buffer (Gibco/BRL). This procedure will join two Eag-1 sites situated on opposite sides of the phage gene III fragment, thus creating a free scFv displaying a terminal 6xhis tag. After ligation the material was digested for 2 h at 37° C. in a solution containing 30 ul ligation mix, 3.6 l 10×REACT3 stock, 0.4 l 1 M NaCl, 5 l H 2 O 2 , in order to destroy clones in which the phage gene III segment had been religated. Twenty (20) ng of the final product were transformed into chemical competent Top10F′ and spread on 500 cm 2 Q-tray LA-plates (100 μg/ml Amp, 1% glucose), to enable the picking of single colonies for further screening.
[0000] Screening of the n-CoDeR™scFv Library for Specific Antibody Fragments Binding T0 MDA Modified Peptides from Apolipoprotein B-100
[0050] In order to identify scFv that could discriminate between MDA modified IEI (P45) peptide and native IEI and between MDA modified KTT (P210) and native KTT respectively screenings were performed on bacterial supernatants from selected scFv expressing clones.
[0051] Colony picking of single clones, expression of scFv and screening number 1 was performed on BioInvent's automatic system according to standard methods. 1088 and 831 single clones selected against the MDA modified IEI and KTT peptides respectively were picked and cultured and expressed in micro titre plates in 100 l LB containing 100 g ampicillin/ml.
[0052] For screening number 1 white Assay plates (Greiner 655074) were coated with 54 pmol peptide/well in coating buffer (0.1 M Sodium carbonate, pH 9.5), either with MDA modified peptide which served as positive target or with corresponding unmodified peptide which served as non target. In the ELISA the expressed scFv were detected through a myc-tag situated C-terminal to the scFv using 1 g/ml of anti-c-myc monoclonal (9E10 Roche 1667 149) in wash buffer. As a secondary antibody Goat-anti-mouse alkaline phosphatase conjugate (Applied Biosystems Cat # AC32ML) was used at 25000 fold dilution. For luminescence detection CDP-Star Ready to use with Emerald II™-Tropix®-(Applied Biosystems Cat # MS100RY) were used according to suppliers recommendation.
[0053] ScFv clones that bound MDA modified peptide but not native peptide were re expressed as described above and to screening another time in a luminescent ELISA (Table 2 and FIG. 1 ). Tests were run both against directly coated peptides (108 pmol/well coated with PBS) and the more physiological target, LDL particles (1 g/well coated in PBS+1 mM EDTA) containing the ApoB-100 protein with and without MDA modification were used as targets. Positive clones were those that bound oxidised LDL and MDA modified peptide but not native LDL or peptide. The ELISA was performed as above except that the anti-His antibody (MaB050 RαD) was used as the detection antibody. Twelve IEI clones and 2 KTT clones were found to give more than three fold higher luminescence signal at 700 nm for the MDA modified form than for the native form both for the peptide and LDL.
[0054] The identified clones were further tested through titration against a fixed amount (1 g/well) of MDA LDL and native LDL in order to evaluate the dose response of the scFv ( FIG. 2 ).
[0000]
TABLE 2
Screening results. The number of clones tested in each screening step
for each target. The scored hits in percent are shown within brackets.
Target
IEI
KTT
Screening
Tested Clones
1088
831
number 1
Scored Hits
64
33
(%)
(5.9%)
(4.0%)
Screening
Tested Clones
64
33
number 2
Scored Hits
12
2
(%)
(1.1%)
(0.2%)
Dose
Tested Clones
12
2
response
Scored Hits
8
2
(%)
(0.7%)
(0.2%)
[0055] The sequences of the chosen scFv clones were determined in order to find unique clones. Bacterial PCR was performed with the Boeringer Mannheim Expand kit using primers (5′-CCC AGT CAC GAC GTT GTA AAA CG-3′) (SEQ. ID NO: 76) and (5′-GAA ACA GCT ATG AAA TAC CTA TTG C-3′) (SEQ. ID NO: 77) and a GeneAmp PCR system 9700 (PE Applied system) using the temperature cycling program 94° C. 5 min, 30 cycles of 94° C. 30 s, 52° C. for 30 s and 68° C. for 2 min and finally 5 min at 68 min. The sequencing reaction was performed with the bacterial PCR product (five fold diluted) as template, using Big Dye Terminator mix from PE Applied Biosystems and the GeneAmp PCR system 9700 (PE Applied system) and the temperature cycling program 25 cycles of 96° C. 10 s, 50° C. for 5 s and 60° C. for 4 min. The extension products were purified according to the supplier's instructions and the separation and detection of extension products was done by using a PRISM® 3100 Genetic analyser (PE Applied Biosystems). The sequences were analysed by the in house computer program. From the sequence information homologous clones and clones with inappropriate restriction sites were excluded, leaving six clones for IgG conversion. The DNA sequence of the variable heavy (VH) and variable light (VL) domains of the finally selected clones are shown in FIG. 3 .
EXAMPLE 2
Transfer of Genes Encoding the Variable Parts of Selected scFv to Full Length Human IgG1 Vestors
[0056] Bacteria containing scFv clones to be converted to Ig-format were grown over night in LB supplemented with 100 g/ml ampicillin. Plasmid DNA was prepared from over night cultures using the Quantum Prep, plasmid miniprep kit from Biorad (# 732-6100). The DNA concentration was estimated by measuring absorbance at 260 nm, and the DNA was diluted to a concentration of 2 ng/ l.
[0057] VH and VL from the different scFv-plasmids were PCR amplified in order to supply these segments with restriction sites compatible with the expression vectors (see below). 5′ primers contain a BsmI and 3′ primers contain a BsiWI restriction enzyme cleavage site (shown in italics). 3′ primers also contained a splice donor site (shown in bold).
Primers for Amplification of VH-Segments:
[0058]
[0000]
5′VH:
(SEQ. ID. NO: 13)
5′-GGT GTGCATTC CGAGGTGCAGCTGTTGGAG
3′VH:
(SEQ. ID. NO: 14)
5′-GA CGTACG ACTCACCT GAGCTCACGGTGACCAG
Primers for Amplification of VL-Segments:
[0059]
[0000]
5′VL:
(SEQ. ID. NO: 15)
5′-GGT GTGCATTC CCAGTCTGTGCTGACTCAG
3′VL:
(SEQ. ID. NO: 16)
5′-GA CGTACG TTCT ACTCACCT AGGACCGTCAGCTT
[0060] PCR was conducted in a total volume of 50 μl, containing 10 ng template DNA, 0.4 □M 5′ primer, 0.4 M 3′ primer and 0.6 mM dNTP (Roche, #1 969 064). The polymerase used was Expand long template PCR system (Roche # 1 759 060), 3.5 upper reaction, together with each of the supplied buffers in 3 separate reactions. Each PCR amplification cycle consisted of a denaturing step at 94° C. for 30 seconds, an annealing step at 55° C. for 30 seconds, and an elongating step at 68° C. for 1.5 minutes. This amplification cycle was repeated 25 times. Each reaction began with a single denaturing step at 94° C. for 2 minutes and ended with a single elongating step at 68° C. for 10 minutes. The existence of PCR product was checked by agarose gel electrophoresis, and reactions containing the same amplified material (from reactions with different buffers) were pooled. The PCR amplification products were subsequently purified by spin column chromatography using S400-HR columns (Amersham-Pharmacia Biotech # 27-5240-01).
[0061] Four (4) l of from each pool of PCR products were used for TOPO®-TA cloning (pCR 2.1 TOPO®-, InVitrogen #K4550-01) according to the manufacturers recommendations. Bacterial colonies containing plasmids with inserts were grown over night in LB supplemented with 100 g/ml ampicillin and 20 g/ml kanamycin. Plasmid DNA was prepared from over night cultures using the Quantum Prep, plasmid miniprep kit from Biorad (# 732-6100). Plasmid preparations were purified by spin column chromatography using S400-HR columns (Amersham-Pharmacia Biotech # 27-5240-01). Three plasmids from each individual VH and VL cloning were subjected to sequence analysis using BigDye®-Cycle Sequencing (Perkin Elmer Applied Biosystem, # 4303150). The cycle sequencing program consisted of a denaturing step at 96° C. for 10 seconds, an annealing step at 50° C. for 15 seconds, and an elongating step at 60° C. for 4 minutes. This cycle was repeated 25 times. Each reaction began with a single denaturing step at 94° C. for 1 minute. The reactions were performed in a volume of 10 l consisting of 1 M primer 5′-CAGGAAACAGCTATGAC (SEQ. ID NO:78), 3 l plasmid DNA and 4 l Big Dye®-reaction mix. The reactions were precipitated according to the manufacturer's recommendations, and samples were run on a ABI PRISM®-3100 Genetic Analyzer. Sequences were compared to the original scFv sequence using the alignment function of the OMIGA sequence analysis software (Oxford Molecular Ltd).
[0062] Plasmids containing VH and VL segments without mutations were restriction enzyme digested. To disrupt the pCR 2.1 TOPO® vector, plasmids were initially digested with DraI (Roche # 1 417 983) at 37° C. for 2 hours. Digestions were heat inactivated at 70° C. for 20 minutes and purified by spin column chromatography using S400-HR columns (Amersham-Pharmacia Biotech # 27-5240-01). The purified DraI digestions were subsequently digested with BsmI (Roche # 1 292 307) and BsiWI (Roche # 1 388 959) at 55° C. over night. Digestions were purified using phenol extraction and precipitation. The precipitated DNA was dissolved in 10 l H 2 O and used for ligation.
[0063] The expression vectors were obtained from Lars Norderhaug (J. Immunol. Meth. 204 (1997) 77-87). After some modifications, the vectors ( FIG. 4 ) contain a CMV promoter, an Ig-leader peptide, a cloning linker containing BsmI and BsiWI restriction sites for cloning of VH/VL, genomic constant regions of IgG1 (heavy chain (HC) vector) or lambda (light chain (LC) vector), neomycin (HC vector) or methotrexate (LC vector) resistance genes for selection in eukaryotic cells, SV40 and ColEI origins of replication and ampicillin (HC vector) or kanamycin (LC vector) resistance genes for selection in bacteria.
[0064] The HC and LC vectors were digested with BsmI and BsiWI, phosphatase treated and purified using phenol extraction and precipitation. Ligation were set up at 16° C. over night in a volume of 10 l, containing 100 ng digested vector, 2 l digested VH/VL-pCR 2.1 TOPO®-vector (see above), 1 U T4 DNA ligase (Life Technologies, # 15224-025) and the supplied buffer. 2 l of the ligation mixture were subsequently transformed into 50 l chemocompetent top10F′ bacteria, and plated on selective (100 g/ml ampicillin or 20 g/ml kanamycin) agar plates.
[0065] Colonies containing HC/LC plasmids with VH/VL inserts were identified by colony PCR:
[0000]
Forward primer:
5′-ATGGGTGACAATGACATC
(SEQ. ID NO: 17)
Reverse primer:
5′-AAGCTTGCTAGCGTACG
(SEQ. ID NO: 18)
[0066] PCR was conducted in a total volume of 20 l, containing bacterias, 0.5 M forward primer, 0.5 M reverse primer and 0.5 mM dNTP (Roche, #1 969 064). The polymerase used was Expand long template PCR system (Roche # 1 759 060), 0.7 Upper reaction, together with the supplied buffer #3. Each PCR amplification cycle consisted of a denaturing step at 94° C. for 30 seconds, an annealing step at 52° C. for 30 seconds, and an elongating step at 68° C. for 1.5 minutes. This amplification cycle was repeated 30 times. Each reaction began with a single denaturing step at 94° C. for 2 minutes and ended with a single elongating step at 68° C. for 5 minutes. The existence of PCR product was checked by agarose gel electrophoresis. Colonies containing HC/LC plasmids with VH/VL inserts were grown over night in LB supplemented with 100 g/ml ampicillin or 20 g/ml kanamycin. Plasmid DNA was prepared from over night cultures using the Quantum Prep, plasmid miniprep kit from Biorad (# 732-6100). Plasmid preparations were purified by spin column chromatography using S400-HR columns (Amersham-Pharmacia Biotech # 27-5240-01). To confirm the integrity of the DNA sequence, three plasmids from each individual VH and VL were subjected to sequence analysis using Big Dye®-Cycle Sequencing (Perkin Elmer Applied Biosystem, # 4303150). The cycle sequencing program consisted of a denaturing step at 96° C. for 10 seconds, an annealing step at 50° C. for 15 seconds, and an elongating step at 60° C. for 4 minutes. This cycle was repeated 25 times. Each reaction began with a single denaturing step at 94° C. for 1 minute. The reactions were performed in a volume of 10 l consisting of 1 M primer (5′-AGACCCAAGCTAGCTTGGTAC) (SEQ. ID NO:79), 3 l plasmid DNA and 4 μl Big Dye® reaction mix. The reactions were precipitated according to the manufacturer's recommendations, and samples were run on a ABI PRISM® 3100 Genetic Analyzer. Sequences were analysed using the OMIGA sequence analysis software (Oxford Molecular Ltd). The plasmid DNA was used for transient transfection of COS-7 cells (see below) and were digested for production of a joined vector, containing heavy- and light chain genes on the same plasmid.
[0067] Heavy and light chain vectors containing VH and VL segments originating from the same scFv were cleaved by restriction enzymes and ligated: HC- and LC-vectors were initially digested with MunI (Roche # 1 441 337) after which digestions were heat inactivated at 70° C. for 20 minutes and purified by spin column chromatography using S200-HR columns (Amersham-Pharmacia Biotech # 27-5120-01). HC-vector digestions were subsequently digested with NruI (Roche # 776 769) and LC-vector digestions with Bst11071 (Roche # 1 378 953). Digestions were then heat inactivated at 70° C. for 20 minutes and purified by spin column chromatography using S400-HR columns (Amersham-Pharmacia Biotech # 27-5240-01). 5 l of each digested plasmid were ligated at 16° C. over night in a total volume of 20 l, containing 2 U T4 DNA ligase (Life Technologies, # 15224-025) and the supplied buffer. 2 l of the ligation mixture were subsequently transformed into 50 μl chemocompetent top10F′ bacteria, and plated on selective (100 g/ml ampicillin and 20 g/ml kanamycin) agar plates.
[0068] Bacterial colonies were grown over night in LB supplemented with 100 g/ml ampicillin and 20 g/ml kanamycin. Plasmid DNA was prepared from over night cultures using the Quantum Prep, plasmid miniprep kit from Biorad (# 732-6100). Correctly joined vectors were identified by restriction enzyme digestion followed by analyses of fragment sizes by agarose gel-electrophoreses
[0069] Plasmid preparations were purified by spin column chromatography using S400-HR columns (Amersham-Pharmacia Biotech # 27-5240-01) and used for transient transfection of COS-7 cells.
[0070] COS-7 cells (ATCC # CRL-1651) were cultured at 37° C. with 5% CO 2 in Dulbeccos MEM, high glucose+GlutamaxI™-(Invitrogen # 31966021), supplemented with 0.1 mM non-essential amino acids (Invitrogen # 11140035) and 10% fetal bovine sera (Invitrogen # 12476-024, batch # 1128016). The day before transfection, the cells were plated in 12-well plates (Nunc™-, # 150628) at a density of 1.5×10 5 cells per well.
[0071] Prior to transfection, the plasmid DNA was heated at 70° C. for 15 minutes. Cells were transfected with 1 g HC-plasmid+1 g LC-plasmid, or 2 g joined plasmid per well, using Lipofectamine™-2000 Reagent (Invitrogen, # 11668019) according to the manufacturers recommendations. 24 hours post transfection, cell culture media was changed and the cells were allowed to grow for 5 days. After that, medium was collected and protein production was assayed for using ELISA.
[0072] Ninetysix (96)-well plates (Costar # 9018, flat bottom, high binding) were coated at 4° C. over night by adding 100 l/well rabbit anti-human lamda light chain antibody (DAKO, # A0193) diluted 4000 times in coating buffer (0.1 M sodium carbonate, pH 9.5). Plates were washed 4 times in PBS containing 0.05% Tween 20 and thereafter blocked with 100 l/well PBS+3% BSA (Albumin, fraction V, Roche # 735108) for 1 h. at room temperature. After washing as above, 100 l/well of sample were added and incubated in room temperature for 1 hour. As a standard for estimation of concentration, human purified IgG1 (Sigma, # 15029) was used. Samples and standard were diluted in sample buffer (1×PBS containing 2% BSA and 0.5% rabbit serum (Sigma # R4505). Subsequently, plates were washed as described above and 100 l/well of rabbit anti-human IgG ( -chain) HRP-conjugated antibody (DAKO, # P214) diluted 8000 times in sample buffer was added and incubated at room temperature for 1 hour. After washing 8 times with PBS containing 0.05% Tween 20, 100 l/well of a substrate solution containing one OPD tablet (10 mg, Sigma # P8287) dissolved in 15 ml citric acid buffer and 4.5 l H 2 O 2 (30%) was added. After 10 minutes, the reaction was terminated by adding 150 l/well of 1M HCl. Absorbance was measured at 490-650 nm and data was analyzed using the Softmax software.
[0073] Bacteria containing correctly joined HC- and LC-vectors were grown over night in 500 ml LB supplemented with ampicillin and kanamycin. Plasmid DNA was prepared from over night cultures using the Quantum Prep, plasmid maxiprep kit from Biorad (# 732-6130). Vectors were linearized using PvuI restriction enzyme (Roche # 650 129). Prior to transfection, the linearized DNA was purified by spin column chromatography using S400-HR columns (Amersham-Pharmacia Biotech # 27-5240-01) and heated at 70° C. for 15 minutes.
EXAMPLE 3
Stable Transfection of NSO Cells Expressing Antibodies Against MDA Modified Peptides Form Apolipoprotein B-100
[0074] NS0 cells (ECACC no. 85110503) were cultured in DMEM (cat nr 31966-021, Invitrogen) supplemented with 10% Fetal Bovine Serum (cat no. 12476-024, lot: 1128016, Invitrogen) and 1×NEAA (non-essential amino acids, cat no. 11140-053, Invitrogen). Cell cultures are maintained at 37° C. with 5% CO 2 in humidified environment.
[0075] DNA constructs to be transfected were four constructs of IEI specific antibodies (IEI-A8, IEI-D8, IEI-E3, IEI-G8), two of KTT specific antibodies (KTT-B8, KTT-D6) and one control antibody (JFPA12). The day before transfection, the cells were trypsinized and counted, before plating them in a T-75 flask at 12×10 6 cells/flask. On the day of transfection, when the cells were 85-90% confluent, the cells were plated in 15 ml DMEM+1×NEAA+10% FBS (as above). For each flask of cells to be transfected, 35-40 μg of DNA were diluted into 1.9 ml of OPTI-MEM®-I Reduced Serum Medium (Cat no. 51985-026, lot: 3062314, Invitrogen) without serum. For each flask of cells, 114 μl of Lipofectamine™-2000 Reagent (Cat nr. 11668-019, lot: 1116546, Invitrogen) were diluted into 1.9 ml OPTI-MEM®-I Reduced Serum Medium in another tube and incubated for 5 min at room temperature. The diluted DNA was combined with the diluted Lipofectamine™-2000 Reagent (within 30 min) and incubated at room temperature for 20 min to allow DNA-LF2000 Reagent complexes to form.
[0076] The cells were washed with medium once and 11 ml DMEM+1×NEAA+10% FBS were added. The DNA-LF2000 Reagent complexes (3.8 ml) were then added directly to each flask and gently mixed by rocking the flask back and forth. The cells were incubated at 37° C. in a 5% CO 2 incubator for 24 h.
[0077] The cells were then trypsinized and counted, and subsequently plated in 96-well plates at 2×10 4 cells/well using five 96-well plates/construct. Cells were plated in 100 l/well of DMEM+1×NEAA+10% FBS (as above) containing G418-sulphate (cat nr.10131-027, lot: 3066651, Invitrogen) at 600 g/ml. The selection pressure was kept unchanged until harvest of the cells.
[0078] The cells were grown for 12 days and assayed for antibody production using ELISA. From each construct cells from the 24 wells containing the highest amounts of IgG were transferred to 24-well plates and were allowed to reach confluency. The antibody production from cells in these wells was then assayed with ELISA and 5-21 pools/construct were selected for re-screening (Table 3). Finally cells from the best 1-4 wells for each construct were chosen. These cells were expanded successively in cell culture flasks and finally transferred into triple layer flasks (500 cm2) in 200 ml of (DMEM+1×NEAA+10% Ultra low IgG FBS (cat.no. 16250-078, lot.no. 113466, Invitrogen)+G418 (600 μg/ml)) for antibody production. The cells were incubated for 7-10 days and the supernatants were assayed by ELISA, harvested and sterile filtered for purification.
EXAMPLE 4
Production and Purification of Human IgG1
[0079] Supernatants from NSO cells transfected with the different IgG1 antibodies were sterile filtered using a 0.22 μm filter and purified using an affinity medium MabSelect™ with recombinant protein A, (Cat. No. 17519901 Amersham Biosciences).
[0080] Bound human IgG1 was eluted with HCL-glycine buffer pH 2.8. The eluate was collected in 0.5 ml fractions and OD 280 was used to determine presence of protein. The peak fractions were pooled and absorbance was measured at 280 nm and 320 nm. Buffer was changed through dialysis against a large volume of PBS. The presence of endotoxins in the purified IgG-1 preparations was tested using a LAL test (QCL-1000®-, cat. No. 50-647U Bio Whittaker). The samples contained between 1 and 12 EU/ml endotoxin. The purity of the preparations were estimated to exceed 98% by PAGE analysis.
[0000]
TABLE 3
Summary of Production and Purification of human IgG1
Volume
culture
Total IgG1 in
Total IgG1
Clone
supernatant
supernatant
Purified
name
(ml)
(mg)
(mg)
Yield (%)
IEI-A8
600
68
42
61.8
IEI-D8
700
45
21
46.7
IEI-E3
700
44.9
25.6
60
IEI-G8
600
74
42.4
57.3
KTT-B8
1790
77.3
37.6
48.6
KTT-D6
1845
47.8
31.8
66.5
JFPA12
2000
32.2
19.2
59.6
[0081] The purified IgG1 preparations were tested in ELISA for reactivity to MDA modified and unmodified peptides ( FIG. 5 ) and were then used in functional in vitro and in vivo studies.
EXAMPLE 5
Analysis of Possible Anti-Atherogenic Effect of Antibodies are Performed Both in Experimental Animals and in Cell Culture Studies
[0082] 1. Effect of Antibodies on Atherosclerosis in Apolipoprotein E Knockout (apo E−) Mice.
[0083] Five weeks old apo E− mice are fed a cholesterol-rich diet for 15 weeks. This treatment is known to produce a significant amount of atherosclerotic plaques in the aorta and carotid arteries. The mice are then given an intraperitoneal injection containing 500 g of the respective antibody identified above. Control mice are given 500 g of an irrelevant control antibody or PBS alone. Treatments are repeated after 1 and 2 weeks. The mice are sacrificed 4 weeks after the initial antibody injection. The severity of atherosclerosis in the aorta is determined by Oil Red O staining of flat preparations and by determining the size of subvalvular atherosclerotic plaques. Collagen, macrophage and T cell content of subvalvular atherosclerotic plaques is determined by Masson trichrome staining and cell-specific immunohistochemistry. Quantification of Oil Red O staining, the size of the subvalvular plaques, trichrome staining and immunohistochemical staining is done using computer-based image analysis.
[0084] In a first experiment the effect of the antibodies on development of atherosclerosis was analysed in apo E−/− mice fed a high-cholesterol diet. The mice were given three intraperitoneal injections of 0.5 mg antibody with week intervals starting at 21 weeks of age, using PBS as control. They were sacrificed two weeks after the last antibody injection, and the extent of atherosclerosis was assessed by Oil Red O staining of descending aorta flat preparations. A pronounced effect was observed in mice treated with the IEI-E3 antibody, with more than 50% reduction of atherosclerosis as compared to the PBS group (P=0.02) and to a control group receiving a human IgG1 antibody (FITC8) directed against a non-relevant fluorescein isothiocynate (FITC) antigen (P=0.03) ( FIG. 6 ). The mice tolerated the human antibodies well and no effects on the general health status of the mice were evident.
[0085] To verify the inhibitory effect of the IEI-E3 antibody on development of atherosclerosis we then performed a dose-response study. The schedule was identical to that of the initial study. In mice treated with IEI-E3 antibodies atherosclerosis was reduced by 2% in the 0.25 mg group (n.s.), by 25% in the 0.5 mg group (n.s.) and by 41% (P=0.02) in the 2.0 mg group as compared to the corresponding FITC antibody-treated groups ( FIG. 7 ).
[0086] 2. Effect of antibodies on neo-intima formation following mechanical injury of carotid arteries in apo E− mice. Mechanical injury of arteries results in development of fibro-muscular neo-intimal plaque within 3 weeks. This plaque resembles morphologically a fibro-muscular atherosclerotic plaque and has been used as one model for studies of the development of raised lesion. Placing a plastic collar around the carotid artery causes the mechanical injury. Five weeks old apo E− mice are fed a cholesterol-rich diet for 14 weeks. The mice are then given an intraperitoneal injection containing 500 g of the respective antibody. Control mice are given 500 g of an irrelevant control antibody or PBS alone. The treatment is repeated after 7 days and the surgical placement of the plastic collar is performed 1 day later. A last injection of antibodies or PBS is given 6 days after surgery and the animals are sacrificed 15 days later. The injured carotid artery is fixed, embedded in paraffin and sectioned. The size of the neo-intimal plaque is measured using computer-based image analysis.
[0087] 3. Effect of Antibodies on Uptake of Oxidized LDL in Cultured Human Macrophages.
[0088] Uptake of oxidized LDL in arterial macrophages leading to formation of cholesterol-loaded macrophage foam cells is one of the most characteristic features of the atherosclerotic plaque. Several lines of evidence suggest that inhibiting uptake of oxidized LDL in arterial macrophages represent a possible target for treatment of atherosclerosis. To study the effect of antibodies on macrophage uptake of oxidized c are pre-incubated with 125 I-labeled human oxidized LDL for 2 hours. Human macrophages are isolated from blood donor buffy coats by centrifugation in Ficoll hypaque followed by culture in presence of 10% serum for 6 days. The cells are then incubated with medium containing antibody/oxidized LDL complexes for 6 hours, washed and cell-associated radioactivity determined in a gamma-counter. Addition of IEI-E3 antibodies resulted in a five-fold increase in the binding (P=0.001) and uptake (P=0.004) of oxidized LDL compared to FITC-8 into macrophages, but had no effect on binding or uptake of native LDL ( FIGS. 8 a and 8 b ).
[0089] 4. Effect of antibodies on oxidized LDL-dependent cytotoxicity. Oxidized LDL is highly cytotoxic. It is believed that much of the inflammatory activity in atherosclerotic plaques is explained by cell injury caused by oxidized LDL. Inhibition of oxidized LDL cytotoxicity thus represents another possible target for treatment of atherosclerosis. To study the effect of antibodies on oxidized LDL cytotoxicity cultured human arterial smooth muscle cells are exposed to 100 ng/ml of human oxidized LDL in the presence of increasing concentrations of antibodies (0-200 ng/ml) for 48 hours. The rate of cell injury is determined by measuring the release of the enzyme LDH.
[0090] The experiment shown discloses an effect for a particular antibody raised against a particular peptide, but it is evident to the one skilled in the art that all other antibodies raised against the peptides disclosed will behave in the same manner.
[0091] The antibodies of the present invention are used in pharmaceutical compositions for passive immunization, whereby the pharmaceutical compositions primarily are intended for injection, comprising a solution, suspension, or emulsion of a single antibody or a mixture of antibodies of the invention in a dosage to provide a therapeutically or prophylactically active level in the body treated. The compositions may be provided with commonly used adjuvants to enhance absorption of the antibody or mixture of antibodies. Other routes of administration may be the nasal route by inhaling the antibody/antibody mixture in combination with inhalable excipients.
[0092] Such pharmaceutical compositions may contain the active antibody in an amount of 0.5 to 99.5% by weight, or 5 to 90% by weight, or 10 to 90% by weight, or 25 to 80% by weight, or 40 to 90% by weight.
[0093] The daily dosage of the antibody, or a booster dosage shall provide for a therapeutically or prophylactically active level in the body treated to reduce or prevent signs and symptoms of atherosclerosis by way of passive immunization. A dosage of antibody according to the invention may be 1 g to 1 mg per kg bodyweight, or more.
[0094] The antibody composition can be supplemented with other drugs for treating or preventing atherosclerosis or heart-vascular diseases, such as blood pressure lowering drugs, such as beta-receptor blockers, calcium antagonists, diurethics, and other antihypertensive agents.
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The present invention relates to passive immunization for treating or preventing atherosclerosis using an isolated human antibody directed towards at least one oxidized fragment of apolipoprotein B in the manufacture of a pharmaceutical composition for therapeutical or prophylactical treatment of atherosclerosis by means of passive immunization, as well as method for preparing such antibodies, and a method for treating a mammal, preferably a human using such an antibody to provide for passive immunization.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to German Patent Application No. 10 2011 115 587.6, filed Oct. 11, 2011, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
The technical field pertains to a car body with a shear element on one side.
BACKGROUND
A front frame of a motor vehicle with a crossmember and a pair of left and right longitudinal braces that are arranged symmetric relative to the crossmember is known, for example, from DE 10 2005 043 707 A1. Nowadays, car bodies generally are at least partially symmetric along the plane of the longitudinal and the vertical vehicle axis.
In certain instances, such as during a collision with lateral components such as, e.g., the 10° load scenario according to the RCAR test protocol, in which a corner of the motor vehicle collides with a barrier that is inclined relative to the lateral vehicle axis by 10°, the forces introduced into the car body on one side in the collision area can lead to an asymmetric load distribution and consequently to a lateral displacement of car body elements, such as, the crossmembers.
In this context, FIG. 1 schematically shows a conventional car body with several crossmembers 1 . 1 to 1 . 5 -L and several pairs of left (index “-L”) and right (index “-R”) braces 2 . 1 to 2 . 3 , and FIG. 2 shows the car body after a collision with a barrier that is inclined relative to the lateral vehicle axis by 10°. The lateral loads and lateral displacements in the crossmembers are indicated with arrows and result in an expansion of the assemblage, particularly the asymmetric deformation of the car body.
Accordingly, it can be desirable to provide an improved car body. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.
SUMMARY
According to one practice, shear plates are mounted on crossmembers and braces, wherein these shear plates absorb forces and reduce or prevent a lateral displacement and/or assemblage expansion. Since it cannot be predicted on which side of the vehicle a collision occurs and corresponding forces are introduced, shear plates of this type are symmetrically distributed such that, in pairs of left and right braces, the left as well as the right brace is respectively connected to the crossmember by means of a shear plate. However, this reduces the available structural space in the area of the car body, particularly when using plate-like shear elements. For example, if shear plates 20 ′ are respectively arranged symmetrical or on both sides of the front frame according to FIG. 1 as indicated with broken lines in FIG. 1 , the structural space in the front section of the car is restricted and therefore can no longer be used for accommodating a water reservoir, a horn, electronic components or the like.
According to one of various aspects of the present disclosure, provided is a one-sided shear element that is mounted on only one brace of a pair of left and right braces, which can significantly reduce the lateral displacement and assemblage expansion. Consequently, structural space for accommodating vehicle components such as water reservoirs, a horn or the like remains on the opposite side, on which no symmetrical shear element is provided.
According to another exemplary aspect of the present disclosure, a car body, for example, a front frame or rear frame, features one or more central crossmembers relative to, for example, the plane of the longitudinal and the vertical vehicle axis, as well as one or more pairs of left and right braces that are arranged at least substantially symmetric to such a crossmember. According to one of various exemplary embodiments, the braces may extend at least substantially in the longitudinal, the vertical and/or the lateral direction of the vehicle. In the context of the present disclosure, the crossmembers extend at least substantially in the lateral direction of the vehicle in one example, but may also be inclined relative to the lateral direction of the vehicle.
According to this exemplary aspect of the present disclosure, one or more shear elements are provided in order to absorb shear forces during a collision. In this case, one or more shear elements are arranged between the one brace of a pair of left and right braces and a crossmember and mounted on the brace and another car body element, for example, the crossmember, wherein no shear element is provided symmetrically thereto between the crossmember and the other brace of this pair.
In this way, structural space for vehicle components is cleared on the side of the other brace such that, according to one exemplary enhancement, one or more vehicle components such as water reservoirs, a horn or the like can be accommodated in the space between the other brace of a pair of left and right braces and the crossmember symmetric to the shear element that is mounted on the one brace of the pair. As mentioned above, the lateral displacement and the assemblage expansion can also be significantly reduced with this one-sided shear element.
One or more shear elements may be respectively arranged between a crossmember and a brace of a first pair of left and right braces that are arranged at least substantially symmetric to the crossmember and between the same or another crossmember and a brace of a second pair of left and right braces that are arranged at least substantially symmetric to this crossmember, wherein no shear element is provided symmetrically thereto between the respective crossmember and the respective other brace of the first and second pair. The one-sided shear elements of the first and second pair may be arranged on the same side of the vehicle or on opposite sides of the vehicle. Two or more shear elements may be additionally or alternatively arranged between a crossmember and one brace of a pair of left and right braces that are arranged at least substantially symmetric to this crossmember, wherein no shear element is provided symmetrical to one or more of these shear elements between the crossmember and the other brace of this pair. It would therefore be possible, for example, to provide one side of the vehicle with two shear elements while the other side of the vehicle is provided with only one shear element or no shear element at all. According to one exemplary embodiment, one or more shear elements are mounted on one brace of a pair of left and right braces and no shear element is provided between the crossmember and the other brace of this pair.
A shear element may be arranged on the left or the right side of the vehicle. It may extend in the longitudinal, the vertical and/or the lateral direction of the vehicle between the crossmember and one brace of the pair. According to one of various exemplary embodiments, it extends in the longitudinal, the vertical and the lateral direction of the vehicle and therefore is inclined relative to the longitudinal, the lateral and the vertical vehicle axis, i.e., it extends diagonal to a generally frame-like car body.
According to one exemplary embodiment, a shear element is realized in a rod-like or plate-like fashion. In comparison with a plate-like shear element or a frame-like or solid shear element, a rod-like shear element or a shear rod occupies less structural space, is able to adequately absorb and transmit forces in the (longitudinal) direction of rod and also has a lower weight. However, a plate-like shear element may have the advantage of being able to better absorb and transmit lateral forces and moments.
According to another exemplary embodiment, the shear element features a tubular center part, wherein a flattening for respectively mounting the shear element on the crossmember and one brace of the pair is realized on one or both end faces of the center part. Such a shear element can be easily manufactured and mounted and has a low weight. A bore may be arranged in a flattening in order to screw down the shear element.
According to another exemplary embodiment, the shear element is permanently mounted on the crossmember and/or one brace of the pair. It may be mounted, for example, by means of welding, soldering, bonding, riveting and/or caulking. This advantageously makes it possible to produce a permanent connection that is less sensitive to vibrations. A shear element may likewise be separably mounted on the crossmember and/or one brace of the pair. In this case, it may be mounted, for example, by means of screws. This simplifies the mounting of the shear element, as well as its replacement, e.g., in case of a defect.
According to another exemplary embodiment, the shear element is rigidly mounted on the crossmember and/or one brace of the pair in order to enable the shear element to also transmit moments. It may likewise be mounted on the crossmember and/or one brace of the pair in an articulated fashion in order to compensate, for example, distortions of the car body.
According to another exemplary embodiment, the crossmember and/or the one brace feature a holding bracket for mounting the shear element. This makes it possible to compensate for an offset between, for example, the orientation of the mounting surfaces on the crossmember and on the brace.
A shear element therefore may be directly or indirectly mounted on a brace and/or a crossmember. It would be possible, for example, to arrange at least one additional brace that extends in the longitudinal, vertical and/or lateral direction of the vehicle between a crossmember and a shear element such that the shear element is indirectly mounted on the crossmember by means of this (these) additional brace(s). In the context of the present disclosure, an arrangement of a shear element between a brace and a crossmember generally refers, for example, to an arrangement in the force flow such that the shear element transmits tensile, compressive and/or lateral forces and/or bending moments and/or torsional moments between the crossmember and the brace. In the context of the present disclosure, an arrangement of a shear element between a brace and a crossmember likewise refers, for example, to the shear element spatially bordering on the brace and the crossmember, wherein at least one additional brace may also be intermediately arranged between the crossmember and the shear element as described above. In the context of the present disclosure, an arrangement between a brace and a crossmember furthermore refers, for example, to an arrangement in a space that is at least partially defined by the brace and the crossmember.
A person skilled in the art can gather other characteristics and advantages of the disclosure from the following description of exemplary embodiments that refers to the attached drawings, wherein the described exemplary embodiments should not be interpreted in a restrictive sense.
BRIEF DESCRIPTION OF THE DRAWINGS
The various embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
FIG. 1 shows a conventional car body;
FIG. 2 shows the car body according to FIG. 1 during a 10° load scenario;
FIG. 3 shows a car body according to an exemplary embodiment of the present disclosure in the form of an illustration that corresponds to that in FIG. 1 ;
FIG. 4 shows the car body according to another exemplary embodiment of the present disclosure in the form of an illustration that corresponds to that in FIG. 3 ; and
FIG. 5 shows part of the car body according to FIG. 3 in the form of a perspective view.
DETAILED DESCRIPTION
The following detailed description is merely exemplary in nature and is not intended to limit the present disclosure or the application and uses of the present disclosure. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.
As initially mentioned, FIG. 1 shows a conventional car body with three central crossmembers 1 . 1 to 1 . 3 and two pairs of left and right crossmembers 1 . 4 -L, 1 . 4 -R and 1 . 5 -L, 1 . 5 -R. The car body furthermore features three pairs of left and right braces 2 . 1 -L and 2 . 1 -R, 2 . 2 -L and 2 . 2 -R, as well as 2 . 3 -L and 2 . 3 -R. These braces may respectively extend in the longitudinal and/or vertical direction of the vehicle such that FIG. 1 may represent a front view in the longitudinal direction of the vehicle or a top view in the vertical direction of the vehicle. Accordingly, the reference symbol “A” identifies a longitudinal or vertical vehicle axis that is illustrated in the form of a dot-dash line. In this context, it should be emphasized that the schematically indicated braces may also extend in the lateral direction of the vehicle that is indicated in the form of a dot-dot-dash line in FIG. 1 and identified by the reference symbol “Q.” The pairs of left and right crossmembers 1 . 4 -L, 1 . 4 -R and 1 . 5 -L, 1 . 5 -R, for example, accordingly could also be interpreted as pairs of left and right braces in the context of the present disclosure.
As initially mentioned, FIG. 2 shows the car body according to FIG. 1 during a 10° load scenario. The arrows indicate lateral displacements of car body elements in the lateral direction of the vehicle Q and the expansion of the assemblage. The structural space for other vehicle components would be significantly restricted if plate-like shear elements 20 ′ would be arranged on both sides as indicated in FIG. 1 .
In the car body according to an exemplary embodiment of the present disclosure that is illustrated in FIG. 3 , a shear rod 10 consequently is arranged on one side between the right crossmember 1 . 4 -R and the right brace 2 . 1 -R or the crossmember 1 . 1 , respectively, while no shear rod is provided symmetrically thereto, i.e., in the lower right corner of FIG. 3 . In this way, structural space for accommodating a water reservoir, horn and/or other vehicle components, collectively and/or individually schematically represented by structure 30 in FIG. 3 , is made available at this location while the one-sided shear rod 10 simultaneously reduces a lateral displacement and assemblage expansion during an offset collision such as, e.g., the 10° load scenario according to RCAR. In other respects, the design corresponds to the embodiment according to FIG. 1 , wherein corresponding elements are identified by identical reference symbols such that only the differences between these embodiments are discussed. The frame in FIG. 3 may be a front frame or a rear frame, depending on perspective, with crossmember 1 . 4 being interior to crossmember 1 . 1 .
FIG. 4 shows a car body according to another exemplary embodiment of the present disclosure in the form of an illustration that corresponds to that in FIG. 3 , wherein corresponding elements are once again identified by identical reference symbols such that only the differences between these exemplary embodiments are discussed.
In the exemplary embodiment according to FIG. 4 , a one-sided shear element 20 realized in a plate-like fashion is arranged on the other, left side of the vehicle (on the right in FIG. 4 ). This shear element can absorb moments in a superior fashion. On the other side, a shear element with a rod-like design, e.g., of the type used in the exemplary embodiment according to FIG. 3 may make it possible to also accommodate (not-shown) smaller vehicle components, for example, electronic components, at this location.
FIG. 5 shows part of the car body according to FIG. 3 in the form of a perspective view. This figure shows the shear rod 10 that extends in the longitudinal, lateral and vertical direction of the vehicle, i.e., diagonally. It features a tubular center part, both sides of which transform into a flattening with a through-bore arranged therein. Screws 11 that are respectively screwed to the brace and the crossmember directly or by means of a holding bracket 12 extend through these through-bores. The holding bracket 12 compensates the offset between the orientations of the two car body mounting surfaces for the shear rod 10 and is generally welded or bonded to the car body.
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the present disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the present disclosure as set forth in the appended claims and their legal equivalents.
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A car body, for example, a front or rear frame is provided. The car body includes at least one crossmember and at least one pair of left and right braces that are arranged at least substantially symmetric to the crossmember. The car body also includes a shear element that is designed for absorbing shear forces during a collision and that is mounted on a brace of the pair, wherein no shear element is provided symmetrically thereto on the other brace of this pair.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 09/762,606, filed May 21, 2001, now U.S. Pat. No. 6,705,405 which is the National Stage of International Application No. PCT/GB99/02708, filed Aug. 16, 1999, which claims benefit of Great Britain Patent Application No. GB9818360.1, filed Aug. 24, 1988. Each of the aforementioned related patent applications is herein incorporated by reference.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
This invention relates to an apparatus for facilitating the connection of tubulars using a top drive and is more particularly, but not exclusively, intended for facilitating the connection of a section or stand of casing to a string of casing.
SUMMARY OF THE INVENTION
In the construction of oil or gas wells it is usually necessary to line the borehole with a string of tubulars known as a casing. Because of the length of the casing required, sections or stands of say two sections of casing are progressively added to the string as it is lowered into the well from a drilling platform. In particular, when it is desired to add a section or stand of casing the string is usually restrained from falling into the well by applying the slips of a spider located in the floor of the drilling platform. The new section or stand of casing is then moved from a rack to the well centre above the spider. The threaded pin of the section or stand of casing to be connected is then located over the threaded box of the casing in the well and the connection is made up by rotation there between. An elevator is then connected to the top of the new section or stand and the whole casing string lifted slightly to enable the slips of the spider to be released. The whole casing string is then lowered until the top of the section is adjacent the spider whereupon the slips of the spider are re-applied, the elevator disconnected and the process repeated.
It is common practice to use a power tong to torque the connection up to a predetermined torque in order to make the connection. The power tong is located on a platform, either on rails, or hung from a derrick on a chain. However, it has recently been proposed to use a top drive for making such connection. The normal use of such a top drive maybe the driving of a drill string.
A problem associated with using a top drive for rotating tubulars in order to obtain a connection between tubulars is that some top drives are not specifically designed for rotating tubulars are not able to rotate at the correct speed or have non standard rotors.
According to the present invention there is provided an apparatus for facilitating the connection of tubulars using a top drive, said apparatus comprising a motor for rotating a tool for drivingly engaging a tubular, and means for connecting said motor to said top drive, the apparatus being such that, in use, said motor can rotate one tubular with respect to another to connect said tubulars.
Other features of the invention are set out in claims 2 et seq.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention and in order to show how the same may be carried into effect reference will now be made, by way of example, to the accompanying drawings, in which:
FIG. 1 is a front perspective view of an apparatus in accordance with the present invention; and
FIG. 2 is a rear perspective view of the apparatus of FIG. 1 in use.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 there is shown an apparatus which is generally identified by reference numeral 1 .
The apparatus 1 comprises a connecting tubular 2 , a suspension unit 3 and a hydraulic motor 4 and 4 ′. The hydraulic motor 4 , 4 ′ has a stator 5 and a rotor 6 and is driven by a supply of pressurised hydraulic fluid (the fluid supply lines are not illustrated in the Figures). The suspension unit 3 suspends the hydraulic motor 4 , 4 ′ from the connecting tubular 2 .
The suspension unit 3 comprises a plate 7 which is fixed to the connecting tubular 2 by a collar 8 . The plate 7 has two projections 9 and 10 which have holes 11 and 12 for accommodating axles 13 and 14 , which arc rotationally disposed therein. The axles 13 and 14 are integral with a rigid body 15 . A slider 16 is arranged on runners 17 and (not shown) on the rigid body 15 . Arms 18 and 19 are connected at one end to the slider 16 via spherical bearings 20 and at the other end to each side of the stator 5 via spherical bearings 21 and 21 ′. The arms 18 and 19 are provided with lugs 22 and 22 ′ to which one end of a piston and cylinder 23 , 24 is attached and are movable thereabout. The other end of each piston and cylinder 23 , 24 is attached to lugs 25 , 26 respectively and is movable thereabout. A mud pipe 27 is provided between the plate 7 and the stator 5 for carrying mud to the inside of a tubular therebelow. The mud pipe 27 comprises curved outer surfaces at both ends (not shown) which are located in corresponding recesses in cylindrical sections 28 , 29 , thus allowing a ball and socket type movement between the plate 7 and the stator 5 .
Referring to FIGS. 1 and 2 , the apparatus 1 is suspended from a top drive 110 via connecting shaft 2 . A tool 30 for engaging with a tubular is suspended from beneath the rotor 6 of the hydraulic motor 4 . Such a tool may be arranged to be inserted into the upper end of the tubular, with gripping elements of the tool being radially displaceable for engagement with the inner wall of the tubular so as to secure the tubular to the tool.
In use, a tubular (not shown) to be connected to a tubular string held in a spider (not shown) is located over the tool 30 . The tool 30 grips the tubular. The apparatus 1 and the tubular are lowered by moving the top drive so that the tubular is in close proximity with the tubular string held in the spider. However, due to amongst other things manufacturing tolerances in the tubulars, the tubular often does not align perfectly with the tubular held in the spider. The suspension unit 3 allows minor vertical and horizontal movements to be made by using alignment pistons 31 and 32 for horizontal movements, and piston and cylinders 23 and 24 for vertical movements. The alignment piston 31 acts between the rigid body 15 and the plate 7 . The alignment piston 32 acts between the slider 16 and the arm 19 . The alignment pistons 31 and 32 and pistons and cylinders 23 , 25 are actuated by hydraulic or pneumatic means and controlled from a remote control device.
The piston and cylinders 23 , 24 are hydraulically operable. It is envisaged however, that the piston and cylinders 23 , 24 may be of the pneumatic compensating type, i.e. their internal pressure may be adjusted to compensate for the weight of the tubular so that movement of the tubular may be conducted with minimal force. This can conveniently be achieved by introducing pneumatic fluid into the piston and cylinder 23 , 24 and adjusting the pressure therein.
Once the tubulars are aligned, the hydraulic motor 4 and 4 ′ rotate the tubular via 15 gearing in the stator 5 thereby making up the severed connection. During connection the compensating piston and cylinders 23 , 24 expand to accommodate the movement of the upper tubular. The alignment pistons 31 and 32 can then be used to move the top of the tubular into alignment with the top drive. If necessary, final torquing can be conducted by the top drive at this stage, via rotation of the pipe 27 , and the main elevator can also be swung onto and connected to the tubular prior to releasing the slips in the spider and lowering the casing string. It will be appreciated that the suspension unit 3 effectively provides an adapter for connecting a top drive to the tubular engaging tool 30 .
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An apparatus for facilitating the connection of tubulars using a top drive, said apparatus comprising a motor ( 4, 4 ′) for rotating a tool ( 30 ) for drivingly engaging a tubular, and means ( 3 ) for connecting said motor ( 4, 4 ′) to said top drive, the apparatus being such that, in use, said motor ( 4, 4 ′) can rotate one tubular with respect to another to connect said tubular.
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BACKGROUND OF THE INVENTION
The present invention relates to a method of producing a pulse width modulated signal, and more particularly to a method of producing such signal using only digital techniques and digital apparatus.
Pulse width modulation of an electrical signal is a common method of encoding information. This type of modulated signal is often used to drive some sort of electromotive power unit, such as a servo-motor. A typical system might employ a servo-motor, driven by such signal, to control; a manufacturing process, the flight of an airplane, or some other real-time event. This type of servo-control is extensively employed in many drone environments; i.e., those in which no operator is actually present, such as guided missiles or the like. An early pulse width modulation system used on guided missiles simply combined an analog ramp wave with an analog command signal received from an autopilot. With the advent of more sophisticated electronic apparatus and the general trend toward digitalization, this analog method became less and less compatible with the rest of the overall system. However, totally digital systems have proved less than perfect, with such imperfections evidenced by a lack of smooth airframe response, resolution deficiencies and inexactitudes in the performance of command signals.
To further show some of the problems presented by a totally digital system, a prior hybrid (analog and digital) system might be examined. To pulse width modulate a command signal, say, a digital one at some frequency f m , this command signal may be compared to a modulation reference wave having a typical period of 1/f m . A typical system employs an analog ramp wave as the modulation reference and a comparator to indicate when both waves are of equal value, i.e., when one wave crosses the other. Each time the comparator detects such crossing a binary command may be sent to an on-off actuator connected to the particular servomechanism under control. No resultant command signal errors will be introduced whether the initial command signal is in analog or digital form, provided the modulation reference is an analog signal. However, when the modulation reference wave is in digital form and the command signal is in digital form, resolution problems arise. A typical digital modulation reference signal might consist of a series of discrete steps of increasing amplitude arranged to approximate an analog ramp wave. In other words, instead of the modulation reference being a smooth wave it is more like a staircase wave. In this case, when the command signal intercepts the reference wave and the comparator indicates that the waves are of equal value, the indicated actual point of intercept will lead or lag (in time) the ideal intercept point obtained by use of an analog ramp wave.
Therefore, it is an object of the invention to provide a digital method of pulse width modulation.
It is a further object of the invention to provide a digital pulse width modulation method having an effective resolution which is not primarily determined by the ratio of computational frequency to modulation frequency.
It is a still further object of the invention to provide a digital pulse width modulation method capable of being performed on a general purpose digital computer.
SUMMARY OF THE INVENTION
To eliminate the intercept uncertainty which obtains when utilizing a digital wave, composed of a number of steps, as a modulation reference wave, the invention provides a method to calculate the ideal intercept points. If an intercept is seen to occur between the (n th ) and (n th + 1) steps of the digital modulation reference (incremental ramp wave) the exact time of the ideal intercept may be computed.
Regarding the effective resolution problem, assume a typical autopilot has a computation frequency of f c and a pulse width modulation frequency of f m . If this autopilot is capable of giving only binary commands at the modulation frequency f m , which do not vary in phase, then the intrinsic resolution of the method of modulation of this example is given by:
r.sub.i = f.sub.c /2f.sub.m ( 1)
Of course f c will be greater than f m , and for practical values of f c and f m if the intrinsic resolution lies between 2 and 10, unsatisfactory airframe response will result. In the method of this invention, whereby the ideal intercept is calculated rather than actually detected, the following information must be known: the value of the command signal for the n th interval, the value of the incremental modulation reference at the (n th ) and (n th + 1) interval, and the desired resolution required for each sampling interval. Assuming that each sampling interval is divided into 2 n parts, the effective resolution of the proposed method would be:
r.sub.e = 2.sup.n r.sub.i = 2.sup.n f.sub.c /2f.sub.m = 2.sup.(n .sup.- 1) f.sub.c /f.sub.m ( 2)
Accordingly, the method of the present invention accepts a digital command signal, develops an incremental modulation reference, then checks to see if an intercept has occurred between the modulation reference and the command signal during the (n th ) and (n th + 1) intervals. If it does occur, a properly scaled number will be computed having a value proportional to the time of intercept. Also, if an intercept should have occurred in the (n th ) interval but was not detected, then we should advance into the (n th + 1) interval and again compute a number proportional to the ideal time of intercept.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a prior art hybrid (analog and digital) pulse width modulation system;
FIG. 2 is a block diagram of a digital pulse width modulation system utilizing the method of the present invention;
FIG. 3 is a plot of an analog modulation reference waveform and a digital command signal waveform;
FIG. 4 is a waveform of the resultant pulse width modulated signal formed by the signals in FIG. 3;
FIG. 5 is a plot of a digital modulation reference waveform and a digital command signal waveform;
FIG. 6 is a waveform of the resultant pulse width modulated signal formed by the signals of FIG. 5;
FIG. 7 shows a portion of the digital modulation waveform; and
FIG. 8 is a logical flow chart which outlines the steps of the method of the present invention;
FIG. 9 is a schematic diagram of a correction counter as utilized in the embodiment of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1 which shows a typical application using a pulse width modulated signal produced by a hybrid (analog and digital) system, a conventional ramp wave generator 10 is used to produce an analog ramp wave signal on line 12, and a digital command signal generator 14 produces a signal on line 16 containing the information to be encoded. These signals, on lines 12 and 16, are fed to a conventional comparator 18 which detects when the two signals intersect and produces an output signal on line 20. This signal, which is now pulse width modulated, is then fed to a conventional ON/OFF actuator 22. The ON/OFF actuator 22 is mechanically connected to the device desired to be controlled, which might be, for example, an airplane or missile control surface 28. This shows how a command signal containing information can be modulated to perform the actual control function. This type of system will produce no appreciable resolution problems nor accuracy errors due to the modulation ramp.
A block diagram of a digital pulse width modulation system is shown in FIG. 2. A digital command generator 36 is again used to provide a signal on line 38 containing the information to be encoded, but the analog ramp wave is now a digital incremental ramp wave supplied by a general purpose computer 40. To avoid overloading the computer with the production of an incremental ramp wave that approaches the resolution of an analog ramp wave, the incremental ramp wave is necessarily coarse in resolution. The digital command signal on line 38 is fed to the general purpose computer 40 or digital processor or the like which has been programmed in accordance with the method of the instant invention. Any of several wellknown general purpose digital computers, such as the Honeywell DDP-316 for example, may be used to implement the proposed digital pulse width modulation process. It may not be necessary to employ a separate digital command signal generator 36, if the general purpose computer 40 is of sufficient size. It is a relatively simple matter to program a general purpose computer to generate the digital command signal, shown here for clarity on line 38. The signal on line 41, which is now pulse width modulated, and which has been produced by the method of the invention may then be fed to a correction counter 42 which serves to correct the timing of the command signal. The correction counter 42 is a special purpose digital output device serving as a programmable clock and producing an output signal on line 43 which is readily acceptable by an ON/OFF actuator 44. The correction counter 42 of the preferred embodiment is described in more detail in FIG. 9. However, if the general purpose computer 40 contains a real-time clock that can operate on an interrupt basis, then the apparatus of FIG. 9 is not required. The ON/OFF actuator 44 is mechanically connected to a control surface 50 or the like which operates in accordance with the information contained in the pulse width modulated signal on line 42.
To better understand the manner in which the desired signals are produced by the systems of FIGS. 1 and 2 attention is now turned to FIGS. 3, 4, 5, 6 and 7. The waveforms of FIGS. 3 and 4 are those associated with the conventional hybrid method of pulse width modulation shown in FIG. 1. Waveform 60 is an analog ramp wave and waveform 62 represents a digital command signal, these waves are compared and their intercept points 64 are detected and used to produce the resultant pulse width modulated signal. FIG. 4 is a plot of the resultant pulse width modulated waveform 65, with the pulses being indicated respectively at 66, 67, and 68. The axis of FIG. 4 corresponds in time with the axis of FIG. 3.
Referring now to FIG. 5 the waveforms of a totally digital system, as shown in FIG. 2, are plotted on the same time base as FIGS. 3 and 4. An incremental ramp wave 70 is shown as a dotted line and is an approximation of an analog ramp wave 72 which is shown as a light solid line. The digital command signal 62 is shown again as in FIG. 3. The intercept points 74 between the two signals 70 and 62 may or may not be identical to those points of intercept 64 between the analog ramp wave and the digital command signal. Therein reside the errors discussed above. In order to better show the errors or inaccurate intercept points which obtain when using an all digital system, FIG. 6 is referred to.
FIG. 6 is placed in the same time reference as FIGS. 3, 4 and 5. The exact points of intercept obtained in FIG. 3, and hence the exact modulation of the digital signal, are shown in relation to all the figures by the vertical dashed lines 80, 82, 84, 86, 88, 90. These dashed lines are superimposed on the actual resultant signal 91 produced by the totally digital system of FIG. 2, the waveforms of which are shown in FIG. 5. If the pulses of FIG. 6, 92, 94, 96 have been accurately produced they will correspond exactly with pulses 66, 67, and 68 of FIG. 4. The dashed lines 80, 82, 84, 86, 88 and 90 will show where possible errors reside. As mentioned earlier, it is possible that a digital system will produce an accurate pulse, such as that which occurred in pulse 92, as can be seen from dashed lines 80 and 82. Pulse 94, however, does not line up with the correctly produced pulse 67. The pulse 94 is displaced in time as can be seen by the shaded areas 98 and 100. Similarly, the pulse 96 also is displaced in time from the true pulse 68, this is shown by the shaded areas 102 and 104. It is these errors, represented by the shaded areas 98, 100, 102, and 104, which the method of the subject invention eliminates.
FIG. 7 shows a portion of the digital incremental ramp wave, shown as dotted line 70 in FIG. 5, with its critical points or values labelled. R min is the minimum ramp wave value, R max is the maximum ramp wave value, and Δ represents the incremental increase per time unit of the ramp wave, in either increasing or decreasing direction. R n indicates some particular point of interest on the ramp wave, and (R n + 1) indicates the point immediately following R n on the ramp wave. Note that (R n + 1) follows R n in time only, and does not indicate the amplitude of the wave, i.e., it will not indicate that the ramp is increasing or decreasing. A digital command signal C, represented as 62 in FIGS. 3 and 5, is also shown.
Referring now to FIG. 8, which is a flow chart of the method of the present invention, it can be seen to consist of two legs which relate to the positive and negative slopes of the ramp modulation reference wave. The first function of the method is to develop an incremental modulation reference such that its value at each increment is known. Assuming a portion of a conventional incremental ramp wave is entered at point 120, the first step is to generate a slope sign bit, this will indicate if the ramp is increasing or decreasing in value. Depending upon the slope of the wave at that instant, the ramp value R n will be compared to either the highest ramp value R max or the lowest ramp value R min . If either end point has been reached then the signal will be incremented (or decremented) one step (Δ) and crossed over to the opposite leg of the flow chart corresponding to either positive or negative slope. As indicated in FIG. 7 the next step after R n is R n + 1. If a maximum or minimum value has not been reached then the reference slope sign bit is added to the ramp value R n . This is generally accomplished by replacing R n with R n plus the reference slope sign bit. The modulation reference has now been generated in such a way that the value at any step is known and the slope direction at that value is also known.
It is now desired to determine if an intercept has occurred or will occur between the two waves. The ramp amplitude increment (Δ) is added to the ramp amplitude R n and compared with the value of the digital command signal (C n ). In the positive slope leg, if the command signal minus the ramp wave value plus the amplitude increment, C n - (R n + Δ), is not less than zero then the remainder of the loop is circumvented and the method is begun again. Note that this NO signal is shown at the bottom as arrow 120 which is the same as the input arrow 120 at the start of this method. If C n - (R n + Δ) is less than zero then the next step is to determine if the command signal C n minus the ramp value R n is greater than or equal to zero, if not then the computed tail command or control surface command TC takes the value of an immediate tail command in the positive direction TC + . Since this preferred embodiment was intended for use in a guided missile environment, with the modulated data signal driving movable tail fins, the notation TC representing a tail command has been retained. If C n - R n is greater than or equal to zero then the computed tail command TC is replaced by the command signal C n minus the ramp value R n times a predetermined scale factor SF, (C n - R n ) × SF. This scale factor SF is arrived at as follows:
SF = f/f.sub.c /R.sub.max - R.sub.min (3)
where: R max - R min is the peak-to-peak value of the ramp wave, f c is the computation frequency, and f is the clock frequency of the correction counter. This computed tail command TC is then used by the correction counter to time the correct time to intercept.
The comparisons between C n and R n + Δ and between C n and R n act as intercept detections and predictions, i.e., does the command signal lie between the ramp value under consideration and the ramp value plus an amplitude increment? It should be noted that a value not yet reached is checked first, that is, R n + Δ is first examined and if the command signal is found to be less than that value then the command signal is compared to the ramp value at R n without the previous increment Δ. At the first decision stage in this intercept detection and prediction test, provision is made to return to the beginning if an intercept will not occur within that increment. At the second decision of this test provision is made to determine the sign of the computed command, that is, to determine if a leading or lagging edge of the pulse has been detected. The magnitude and hence the pulse width error correction is then determined in the following step.
The correction counter 42 of FIG. 2 is not shown in more detail in FIG. 9. This special purpose digital output device is loaded with an (n + 1) bit number whenever intercept is computed by the general purpose computer 40 of FIG. 2 using the flow diagram of FIG. 8. A sign bit is required to determine switching direction and an n-bit number is needed to divide the sampling interval into 2 n parts. A load command signal from a digital autopilot or the like on line 200 is used to load a direction flip-flop 202 and a binary pre-settable counter 204. The load command on line 200 is also fed to a control flip-flop 206 having a SET output on line 208 which is fed to a gate device 210. A second input to the gate device 210 is supplied by a clock on line 212. The gate device output signal on line 214 is fed to the pre-settable counter 204 and serves to start the counting. The clock signal on line 212 has a frequency given by 2 n f c and is synchronous with the load command on line 200. At the completion of the count of the Up-Counter 204 (1111), a command flip-flop 216 is set to the state determined by the direction flip-flop 202 and will produce the pulse width modulated tail command on line 43.
As mentioned previously, many applications needing a digitally produced pulse width modulation waveform have a general purpose digital computer available, and this method is ideally suited for implementation by such computer. Moreover, because of the very few decisional steps in the method of this invention a special purpose logic circuit could easily be constructed to accomplish this method.
Various other modifications, adaptations, and alterations are of course possible in light of the above teachings. It should therefore be understood at this time that within the scope of the appended claims the invention may be practiced otherwise than is specifically described hereinabove.
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Disclosed is a method of encoding information in a pulse width modulated nal using totally digital techniques. An incremental ramp wave is utilized as a modulation reference, and intercepts between the modulation reference and a signal to be encoded are detected and/or predicted logically by examining the values of these two signals at predetermined intervals.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Patent Application No. 61/594,727 filed Feb. 3, 2012, the disclosure of which is hereby incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] Embodiments of the present invention generally relate to storage covers, and more particularly to tarp covers.
[0003] Various types of protective covers have been developed for covering piles or mounds of particulate material, such as salt, sand, grain and the like, from the effects of the weather while the material is in outside storage.
[0004] While prior art covers are capable of protecting a pile or mound of materials covered thereby, they possess a number of shortcomings. For example, in order to counteract the effects of aerodynamic lift exerted on such cover by the wind, a large number of ballast weights, such as automobile tires, were attached to the cover at fixed attachment points so that the ballast weights rested on the cover between the top or apex and the lower margin of the pile. However, if the pile had an atypical size or shape, the height of the pile diminished, or as particulate matter was removed from the pile, the fixed attachment points ended up so close to the ground that the ballast weights rested on the ground which reduced or eliminated the effectiveness of the weights in maintaining the cover on the pile.
[0005] The wind may also enter beneath the cover through a removal opening or otherwise get beneath the cover and exert tensile forces on the cover. In addition, the canvas material would develop rips if the stress became too great. However, once a canvas panel formed a rip, the rip had a tendency to propagate and extend the entire length of the panel, resulting in a substantial cost to repair the rip. Such ripping may also occur in vinyl or polyethylene panels of a cover under certain stress conditions.
[0006] Bulk storage pile covers have been in use for a long time. However there are some problems holding the covers down. The covers attach around the perimeter and in some cases also attach in the center. The cover is then held down by vacuum fans. Relying on vacuum fans to hold down the covers leaves them vulnerable to power outages. Any interruption in electrical service leaves the cover subject to damage, although some users have backup generators and others have tried external strapping systems. When used, external strapping systems are installed after the piles are full. However, new worker safety regulations on the use of fall protection, limits the use of external strapping systems.
[0007] Thus, there is a need for a cover for a pile of particulate material which protects the pile from the elements and resists the effects of wind and rain on the cover. A related need is for a cover which allows for the attachment of ballast weights at desired locations on the cover and also allows for each ballast attachment point to be shifted, compensating for changes in the shape and height of the pile.
[0008] There is a further need for a cover for a pile of particulate material which prevents rips which may form in the panels compromising the cover from propagating for more than a desired short length that is easy to repair.
SUMMARY OF THE INVENTION
[0009] The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. Rather than specifically identify key or critical elements of the invention or to delineate the scope of the invention, its purpose, inter alia, is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.
[0010] In accordance with one embodiment, a system for storing commodities is provided. The system may include a tarpaulin. The tarpaulin may further have an internal strapping.
[0011] In accordance with one embodiment, a method for storing commodities is provided. The method may include providing a tarpaulin. In one embodiment, the method for storing commodities may include configuring the tarpaulin to provide internal strapping. In accordance with another embodiment, a method of securing a tarpaulin and maintaining a weather resistant cover is provided.
[0012] While the subject matter disclosed herein was designed for bulk grain piles, the system for storing commodities may be used for any bulk storage of commodities. The system provides storage for commodities in moisture resistant ways. For example, the tarpaulin may be used to keep the rain off of a stored commodity.
[0013] Optionally, the system for storage may be used to store salt, compost, silage, contaminated soil and the like. In an alternate embodiment, the storage system may be used for storage tank covers such as water tanks. Optionally, the storage system may be used for providing partitioning or compartments inside a storage tank.
[0014] In yet another embodiment of the subject matter disclosed herein the system may be used for temporary work enclosures. Optionally, the system for storage may be used in any other scenario where a tarpaulin with weather resistant material may be used. The system disclosed herein may employ a plurality of tarpaulin designs. For example, the tarpaulin may be round, square, rectangular oval, kidney bean shaped and the like, or may be adaptable to any suitable shape, depending upon other factors, such as the shape of the storage area, type of particulate material being protected, local terrain, incidence of inclement weather, susceptibility to wild animal foraging, and the like. In addition, the tarpaulin may be in the form of sections that will be assembled to create an entire cover.
[0015] The storage system may allow the storage area to be filled without the need for end-user workers to get on the storage area surface after the tarpaulin is raised and the ground pile is filled. The workers may be required to get on the tarpaulin where an external strapping system or other ballast may be employed. Thereby, the subject matter disclosed herein may eliminate the risk of workers falling off the pile. In yet another embodiment, the system may be manufactured using weather resistance material.
[0016] The internal strapping system may eliminate the need for a worker to climb on top of the pile as the pile is filling or after filling is complete. In one embodiment, the subject matter disclosed herein may include webbing. For example, the webbing may be part of the tarpaulin material. In an alternate embodiment, a plurality of webbing straps may be provided.
[0017] In a preferred embodiment, the system is used in connection with a ground surface that is surrounded by a retaining wall. In one embodiment, the wall is between 6′ and 8′ in height, although in other embodiments the wall may be higher or lower, depending upon the size, shape, and type of particulate to be stored. The wall may be fabricated of steel, concrete, wood, or any other suitable material that will contain the particulate and withstand the outward pressure of the contents when the storage area is full. The retaining wall may be tilted outwardly at the top edge such that the perimeter of the top edge of the retaining wall is larger than the perimeter of the bottom edge of the retaining wall to form a frustoconical structure, and may also have supporting angle iron braces drilled and ratchet mounted to the exterior the wall (or any other anchoring source that may be available), that bolster the wall from further tilting under the internal pressure generated by the stored particulate. In a preferred embodiment, the top of the retaining wall may be tilted outwardly at an angle of about 30°.
[0018] In other embodiments, the storage system may be used without a retaining wall. In this case, the tarpaulin may be secured to anchors embedded in the ground. If the storage area includes a flat surface of concrete or other man-made substance, anchors may be embedded in or otherwise securely attached to the substance so that the tarpaulin may be tightened or released as required to permit loading, unloading, and storage.
[0019] In a preferred embodiment of the system, the straps may be connected to a tensioning device at both the first end and the second end. In this embodiment, the straps are anchored to a winch or similar tension ratcheting device which is attached to an angle iron brace. Alternatively, the straps may be directly anchored to a winching system that is situated on the ground or may simply be anchored to a grounded stake or similar device whereby the straps can be tightened or loosened as desired.
[0020] The strap system may assist in keeping the tarpaulin in place with respect to the outer walls in the event of high winds and/or loss of power to aeration fans. The strap system may further allow keeping the tarp in place in relation to the outer walls while the reverse suction of an aeration fan may be turned off during fumigation process. The subject matter disclosed herein may allow holding the tarp in place if the aeration fans are turned off or should lose electricity from a power grid.
[0021] Depending upon the terrain, the type of particulate to be stored, and other related factors, the storage area may be circular or oval in shape. Although other shapes are possible, the preferred embodiments use tarpaulins that are round or oval largely because those shapes permit the most efficient use of the strapping system used with the invention.
[0022] In a preferred embodiment, the tarpaulin will be provided in sections that will be assembled and tensioned in accordance with the invention. The assembled tarpaulin is attached to the wall around the circumference of the storage area. In a preferred embodiment, the edges of the tarpaulin will be sandwiched between two wooden beams, one of which is mounted and secured to the top of the wall below the tarpaulin, and the second wood beam being above the tarpaulin and attached to the first with a tightening mechanism. The edges of the tarpaulin are placed between the two wooden beams which are then tightened together to hold the tarpaulin securely.
[0023] The tarpaulin sections are constructed with tunnel-like pockets running lengthwise or crosswise through the tarpaulin. A securing strap is passed through each pocket, and generally extends outwardly from the edges of the tarpaulin. Where two tarpaulin sections meet, the straps are connected using a connector such as a carabiner, ring, or if the strap ends have grommets, they could be connected using a plastic tie wrap, a bolt, cable, padlock, other any other strong connector. In some embodiments, the straps may be tied securely to one another. Where the strap extends from a tarpaulin edge at the retaining wall, it may be secured to an external point beside the tarpaulin where it can be anchored or otherwise securely affixed to a non-movable point. In a preferred embodiment, a winch may be attached to one of the angle iron braces, and will receive the end of the strap in a manner that permits the strap to be tensioned by a ratchet. When the storage area is filled, the straps may be ratcheted or otherwise tensioned so as to hold the tarpaulin tightly against the material being stored. Handles attached to the underside of the tarpaulin may allow grab points for workers to pull sections together on while deploying the storage system.
[0024] The tarpaulin sections may be configured for simple attachment to one another using plastic tie-wraps or similar closing mechanism passed through grommets in the tarpaulin. Alternatively, sections may be attached using clips, wires, laces, hook and loop fasteners, bolts, or any other equivalent fastening mechanism. A rain flap may extend over the seam between two sections, and the flap may be secured using snaps or a hook and loop or other suitable fastener. Handles may be provided on the interior surface of the tarpaulin to allow workers assembling the sections to have a better grip and apply leverage when pulling two seams sections together to form a seam. Once the tarpaulin sections have been assembled, the resulting tarpaulin may be used to cover grain or any other suitable particulate material, and may be tightened with winches and ratchets to hold the tarpaulin against the material being stored.
[0025] In the prior art, vacuum fans have been situated so as to suck air from within the tarpaulin-enclosed storage area serve to further tighten the tarpaulin against the storage material, and help to prevent the tarpaulin from flapping when blown by wind outside the tarpaulin. However, in the event of power failures, which common experience dictates occur most frequently during storms that generate high winds, the vacuum fans fail, thereby exacerbating the conditions which cause the tarpaulin to flap. In higher force winds, the flapping can cause the tarpaulin to rip or fail, and the contents of the storage area to be destroyed or disbursed by the high winds. Although the invention contemplates the use of vacuum fans to enhance the effects of straps and the perimeter attachment system, the invention represents an improvement over the prior art since the tarpaulin of the invention will provide adequate storage and protection from wind and rain even in the absence of electricity to power the vacuum fans.
[0026] The following description and the annexed drawings set forth in detail certain illustrative aspects of the invention. These aspects are indicative, however, of but a few of the various ways in which the principles of the invention may be employed and the present invention is intended to include all such aspects and their equivalents. Other advantages and novel features of the invention will become apparent from the following description of the invention when considered in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The drawings, in which like numerals represent similar parts, illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.
[0028] FIG. 1 is a front view of an embodiment of a storage tarpaulin and retaining wall with angle iron braces.
[0029] FIG. 2 illustrates a plan view of an embodiment of a tarpaulin as depicted in FIG. 1 .
[0030] FIG. 2 a is a detailed diagram of the edge of the tarpaulin of FIG. 1 , showing the strapping within a pocket of the tarpaulin.
[0031] FIG. 3 is a front view of an alternative embodiment of a storage tarpaulin and retaining wall with angle iron braces.
[0032] FIG. 4 illustrates a plan view of an embodiment of a tarpaulin as depicted in FIG. 3 .
[0033] FIG. 5 is a plan view of another embodiment of a round tarpaulin.
[0034] FIG. 6 is a plan view of an embodiment of a tarpaulin in the shape of an oval with straps running crosswise to the longitudinal axis of the oval.
[0035] FIG. 7 is a plan view of an embodiment of a tarpaulin in the shape of an oval with straps running parallel to the longitudinal axis of the oval.
[0036] FIG. 8 is a plan view of another embodiment of a round tarpaulin in which the straps terminate at a mid-point in the tarpaulin.
[0037] FIG. 9 illustrates a retaining wall and angle iron brace in cross section with a tarpaulin sandwiched between a board and the retaining wall, and a strap attached to a winch.
[0038] FIG. 10 illustrates a method of connecting two tarpaulin sections.
[0039] FIG. 11 depicts two straps attached using a carabiner.
[0040] FIG. 12 depicts an embodiment of the storage system in which a retaining wall is not used.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] FIG. 1 is a front view of a storage surface area having a perimeter with a tarpaulin 10 secured to a retaining wall 12 extending around the perimeter of the storage surface area. Straps 14 extend through internal tunnels or pockets (not visible) integral to the tarpaulin. Angle iron braces 18 extend around the outside perimeter of the retaining wall 12 . A top opening 20 allows particulate, preferably grain, to be loaded to the storage area using an overhead conveyor (not shown). In FIG. 1 , straps are passed generally across the tarpaulin from one side to another and are secured on either side of the storage area. Internal straps 14 are encased in lengthwise pockets that are integral to the tarpaulin, and may be secured to an external anchor where they extend through the tarpaulin. The straps can be made from any suitable material, including but not limited to rope, cord, webbing or cable.
[0042] In the invention, straps are placed under tension to provide a generally downwardly directed force to secure the tarpaulin and the underlying particulate material being stored against undesired movement during the period of storage. Pockets are provided to hold the straps in place with respect to the tarpaulin, and the pockets do not experience tension along the length of the pocket.
[0043] In a preferred embodiment, the plurality of pockets and straps extending in a generally parallel direction may be spaced apart by between about 3 feet up to about 24 feet. Alternate embodiments may have variable spacing between adjacent straps and pockets.
[0044] FIG. 2 is a plan view of a round tarpaulin 10 in which parallel pockets 16 and straps 14 extend across the tarpaulin. One or more lifting rings 50 may be attached at or near the top of the tarpaulin to assist in installation and removal. A center opening 20 is used for filling the storage area. The tarpaulin depicted in FIG. 2 may be comprised of a plurality of sections which can be adjoined together to create a larger surface area.
[0045] FIG. 2 a depicts the detail of the tarpaulin 10 and pocket 16 through which a strap 14 is passed. Pockets may be used wherever it is necessary to secure a strap such that the strap must physically pass from within a pocket to the outside of the tarpaulin where it may be fastened to some other object. FIG. 2 a is an enlarged, detailed view showing the structure of the tarpaulin 10 in the vicinity of straps 14 , which, in a preferred embodiment, may be enclosed in pockets 16 . The straps may of any material, including rope, cord, webbing, or cable. In a preferred embodiment, the straps 14 may be between 1 and 3 inches in width. In some embodiments, the straps 14 may be fully movable longitudinally within the pocket 16 . In some embodiments, the pockets 16 may be thermally bonded to the tarpaulin 10 . Optionally, any other suitable method such as stitching or adhesive may be used to bond the pockets to the tarpaulin. It should be noted that the word “tarp” and “tarpaulin” may be used interchangeably.
[0046] FIG. 3 depicts another embodiment of the storage system in which straps 14 within a tarpaulin 10 run at an angle before passing over the top of the storage area. In the configuration shown in FIG. 3 , additional strength is provided on one side of the storage area by the higher incidence of straps on one side.
[0047] FIG. 4 is a plan view of the storage system of FIG. 3 . Straps 14 generally provide support in a localized section of the tarpaulin. Such localized support might be desirable in situations in which there is a prevailing wind that constantly wears against one side of the tarpaulin.
[0048] Other strap and webbing configurations may be used as circumstances require. FIG. 5 shows an alternative embodiment of the tarpaulin and strap system depicted in FIGS. 1 and 2 . In FIG. 5 , parallel pockets run across of the tarpaulin and straps 14 are within the pockets. A perpendicular cross-strap 26 provides strength and tensioning ability in a direction that is perpendicular to the parallel straps. A center hole 20 may have a reinforced collar or other device to allow perpendicular strap 26 and one of the parallel straps to meet and connect at the center hole.
[0049] FIG. 6 depicts a plan view of another embodiment of a storage tarpaulin. In this embodiment, pockets and straps 14 run crosswise to the long axis of the oval tarpaulin. This configuration may be suitable for a storage area in which material is to be deposited or removed from either or both ends. As material is added, straps at the vicinity of the area where material is added can be adjusted by loosening until the particulate has been added, or by tightening to secure the tarpaulin against the material. This can be done in a localized area without the need to adjust straps in other parts of the storage area.
[0050] Another oval embodiment is shown in the plan view of FIG. 7 . In FIG. 7 , the pockets run lengthwise on the long axis of the oval tarpaulin. Straps 14 are be used to tension the tarpaulin against the stored material.
[0051] FIG. 8 is a plan view depicting an alternative embodiment of a round tarpaulin that may be assembled in four sections. In this configuration, parallel straps 14 intersect and join perpendicular straps 26 . Pockets enclose all straps. In each section, parallel straps extend from the edge of the tarpaulin about half of the distance across the tarpaulin, only as far as a perpendicular strap where they are joined and terminate.
[0052] FIG. 9 depicts the retaining wall 12 (in cross section) and demonstrates how the tarpaulin 10 and strap 14 may be anchored to angle iron brace 28 which is situated adjacent to retaining wall 12 . In this embodiment, board 32 runs lengthwise along the top of the retaining wall 12 . Just before the tarpaulin reaches the board 32 the strap 14 leaves the tarpaulin through a hole in the pocket 16 and passes over the board 32 . The tarpaulin 10 extends between the top of the retaining wall 12 and the board 32 , and is pressed between the retaining wall 12 and board 32 when the board is tightened against the retaining wall with screws, clamps, or some other suitable tightening mechanism. Strap 14 runs over the board and terminates at a winch 30 , ratchet, or other suitable device that may be used to tension the strap. As depicted in FIG. 9 , angle iron brace 28 further supports winch 30 . In this embodiment, the winch 30 and supporting angle iron brace 28 are the anchors which tighten and secure tarpaulin 10 .
[0053] FIG. 10 depicts a seam between two tarpaulin sections 10 , and also shows an integral handle 44 for closing the two sections. A rain flap 38 is used to keep water out of the storage area. The rain flap 38 may be attached to the tarpaulin by stitching 40 , or preferably by heat bonding. A hook and loop fastener 42 , 46 may be used to seal the rain flap against becoming unsecured by wind or the elements. Where the respective edges of two adjacent sections meet, opposing grommets 34 are used to hold the sections together and are tied with a plastic tie wrap 36 , a cord, cable, chain, carabiner or any other suitable closing mechanism.
[0054] At times, it may be necessary to secure two straps 14 to one another. When this is done as shown in FIG. 11 , a carabiner 48 may be used to pass through opposing loops in the straps 14 . A carabiner may have a quick release or spring loaded link that may be opened to secure or loose the straps. Optionally, straps may have grommets or other reinforcements embedded at the end, and two straps may be connected by a screw or nut and bolt.
[0055] FIG. 12 depicts an embodiment of the storage system in which a retaining wall is not used. Although any suitable ground anchoring component may be used, one of the simplest, which is depicted in FIG. 12 , is stakes 50 that may be embedded in the ground or may be embedded in or otherwise secured to a ground covering 52 . In an embodiment, the ground covering may be a tarpaulin material that attaches to the tarpaulin 10 around the base perimeter of the storage area, thereby preventing the material being stored from escaping below the tarpaulin 10 , or allowing wind or rain to enter the storage area from beneath the tarpaulin 10 .
[0056] In yet another embodiment of the present invention, the tarpaulin engages a ground covering section. The ground covering section is laid on the ground, whereupon particulate material is piled on top of the ground covering. Once the particulate material has been piled on the ground covering, the perimeter of the tarpaulin is secured to the perimeter of the ground covering using a hook and loop fastener, or by sewing the perimeters together, or by using any other equivalent structure for securing the perimeter of the tarpaulin to the perimeter of the ground covering. Once the tarpaulin and ground covering have been secured to one another, an internal strapping system—as described herein—may then be utilized to tighten and further secure the ground covering and tarpaulin to the particulate material contained therein.
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In accordance with one embodiment, a system for storing commodities is provided. The system may include a tarpaulin. The tarpaulin may further have an internal strapping. In accordance with one embodiment, a method for storing commodities is provided. The method may include providing a tarpaulin. In one embodiment, the method for storing commodities may include configuring the tarpaulin to provide internal strapping.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is in the field of fuel injection systems for internal combustion engines, wherein the fuel is injected into the engine intake manifold.
2. Description of the Prior Art
The prior art of four stroke cycle internal combustion engines, using intake manifold fuel injectors, is described in U.S. Pat. No. 5,456,232, Col. 1, line 57, through Col. 4, line 15, and this material is incorporated herein by reference thereto. Some types of intake manifold fuel injectors proportion the instantaneous fuel injection rate to the instantaneous air flow rate, during each engine intake process, so that the resulting engine intake air-fuel mixture is essentially of a constant fuel to air ratio throughout the air mass quantity going into each engine cylinder during each intake process. An example of such a gasoline engine fuel injection system is described in U.S. Pat. No. 5,456,232, Col. 4, line 35, through Col. 19, line 9, and this material is incorporated herein by reference thereto. These manifold fuel injectors of U.S. Pat. No. 5,456,232, are described therein as useable on four stroke cycle internal combustion engines, but are also useable on two stroke cycle internal combustion engines, by setting the timing of fuel injection to coincide with the timing of air intake flow, during each engine air intake process.
Manifold fuel injector systems need compensator schemes, when engine speed and load vary over a wide range. Examples of prior art compensators, for manifold fuel injectors are described in the following references:
A. U.S. Pat. No. 5,456,232; Col. 13, line 40, through Col. 18, line 51:
B. U.S. Pat. No. 5,483,937
C. U.S. Pat. No. 5,613,475
These compensator schemes are relatively complex mechanically. It would be beneficial to have available a compensator scheme capable of adequately compensating a manifold fuel injector over a wide range of engine speed and load, of relative mechanical simplicity.
SUMMARY OF THE INVENTION
The compensators of this invention are intended to be used on those gasoline engine manifold fuel injectors which use a gas pressure cycler to vary the liquid fuel injection pressure, and thus vary the instantaneous liquid fuel flow rate in proportion to the instantaneous engine intake air flow rate into each engine cylinder during each intake stroke. Examples of such manifold fuel injectors are described in U.S. Pat. No. 5,456,232. Each compensator comprises at least one bleed volume and each bleed volume is connected into the variable volume chamber of the gas pressure cycler via a separate orifice and bleed valve and driver for opening and closing the valve. Each bleed volume is additionally and separately connected into the variable volume chamber of the gas pressure cycler via a return flow passage, with a check valve permitting flow only from the bleed volume into the variable volume chamber. A controller is used responsive to a sensor of engine intake air mass per intake stroke, and a sensor of gas pressure cycler pressure rise, and operates upon the drivers of the bleed valves so that the bleed valves are opened only during the pressure rise portion of the cycle of pressure rise and pressure decrease of the gas pressure cycler. The controller adjusts the number of times the bleed valve is opened, and also the duration of each valve opening, so that the mass of air bled out of the variable volume chamber of the gas pressure cycler during pressure rise is increased as engine intake air mass decreases, and is decreased as this air mass increases. During the pressure decrease portion of the gas pressure cycler cycle, the bled mass of air is returned into the variable volume chamber to maintain an essentially symmetrical cycle of pressure rise and decrease, in conformity with the essentially symmetrical engine intake air flow rate rise and decrease during each intake stroke. In this way the compensator of this invention adjusts liquid fuel injection pressure, and hence instantaneous liquid fuel flow rate, to be proportional to instantaneous engine intake air flow rate. Thus an essentially constant mixture ratio of air to fuel is maintained throughout each intake mixture mass for each engine cycle. The compensators of this invention are of greater mechanical simplicity than prior art compensators for these manifold fuel injectors and this is a principal beneficial object of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
A schematic diagram of a compensator of this invention is shown on a manifold fuel injector and gasoline engine in FIG. 1.
A detailed drawing of one form of manifold fuel injector is shown in FIG. 2 with a compensator of this invention.
A modified form of compensator is shown in FIG. 3 on a manifold fuel injector.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The combination of the invention described herein comprises the following three components, each of which, in turn, comprises several differing elements:
1. An internal combustion engine mechanism, as described in the material incorporated herein by reference thereto;
2. A manifold fuel injection system, as also described in the material incorporated herein by reference thereto;
3. A compensator of this invention, for the manifold fuel injection system as described herein below;
One example arrangement of the devices of this invention on a four stroke cycle internal combustion engine mechanism is shown schematically in FIG. 1 and comprises the following:
1. A four stroke cycle, single cylinder, engine, 1, is shown with piston, 2, cylinder, 3, crankshaft, 4, connecting rod, 5, variable volume chamber, 6, air intake valve, 7, exhaust valve, 8, air supply manifold, 9, exhaust gas manifold, 10, fuel supply source, 11, and fuel supply pressure pump, 12, ignition means, 13.
2. The valve drive means is shown separated from the engine for clarity and comprises: a drive gear, 14, connected to the crankshaft, 4, and rotated at crankshaft speed, a valve drive gear, 15, rotated at half crankshaft speed by the drive gear, 14, and driving in turn the intake valve cam, 16, and the exhaust valve cam, 17. The intake and exhaust valves are opened by these cams and closed by springs, 18, 19. In FIG. 1 the intake valve is shown open and the exhaust valve is shown closed with the piston descending on the intake stroke and increasing the volume of the variable volume chamber, 6, and intake air is flowing through the intake manifold, 9, and into the variable volume chamber, 6.
3. A gasoline engine manifold fuel injection system, 20, is shown in FIG. 1 and comprises:
a. A fuel injector nozzle, 21, is injecting liquid fuel into the intake manifold, 9, whenever intake air is flowing into the engine cylinder. This liquid fuel flows from the liquid fuel chamber of the fuel injector means, 22.
b. A gas pressure cycling means, 23, is driven by a pressure cycler drive means, 24, which is in turn driven at twice crankshaft speed from the inter drive means, 25, driven in turn from the crankshaft drive gear, 14.
c. A pressure transmitter means, 26, transmits pressure from the gas pressure cycler, 23, to the liquid fuel chamber of the fuel injector, 22.
d. An intake stroke sensor, 27, is one input to a fuel valve controller means, 28, which controls the opening and closing of a nozzle valve and a fuel supply valve within the fuel injector means, 22, so that: the fuel injector nozzle, 21, is connected to the liquid fuel chamber of the fuel injector, 22, only whenever air is flowing into the variable volume chamber, 6, during the intake stroke; the engine fuel supply source is connected via pipe, 29, to the liquid fuel chamber of the fuel injector, 22, only when the nozzle valve is closed.
A particular example fuel injection system, 20, of this invention is shown in detail in cross section in FIG. 2 and FIG. 1 and comprises the following:
4. The gas pressure cycler, 23, comprises a variable volume chamber, 30, enclosed between the fixed cylinder container, and the moveable sealed piston, 32, which is driven by the pressure cycler drive means cam, 33, and spring, 34, driven in turn from the inter drive means, 25. When the piston, 32, is moved by the cam, 33, to decrease the volume of the variable volume chamber, 30, the gas pressure therein rises, and when the piston, 32, is moved by the spring, 34, and the cam, 33, to increase the volume of the variable volume chamber, 30, the gas pressure therein decreases. In this way a cycle of pressure increase followed by pressure decrease is created at each revolution of the pressure cycler drive cam, 33, and this cycle is timed by the inter drive means, 25, to occur during and throughout each engine intake stroke. The pressure in the variable volume chamber, 30, at the start of each pressure cycle is equalized to that in the engine air intake manifold, 9, via the vent connections, 35 and 36.
5. The fuel injector means for injecting liquid fuel, 22, into the engine intake manifold, 9, comprises a liquid fuel chamber, 37, connectable and disconnectable to the fuel injector nozzle, 21, via the nozzle valve, 38, with nozzle valve drive means, 39, and connectable and disconnectable to the fuel supply source pipe, 29, via the fuel supply valve, 40, with supply valve drive means, 39. The fuel injector nozzle, 21, connects into the engine air intake manifold, 9.
A particular example of pressure transmitter is shown in cross section in FIG. 2 and FIGS. 1, suitable for use on internal combustion engines operated over a wide range of speed and torque output, and comprises:
1. The liquid fuel pressurizer liquid piston, 66, is connected to the end, 68, of a pivoted lever, 67, whose opposite end, 69, is connected to the pressure transmitter gas piston, 70, so that the pressure created in the variable volume chamber, 30, of the gas pressure cycler, 23, is transmitted to the liquid fuel in the liquid fuel chamber, 37. The pivoted lever, 67, is pivoted about the pivot, 71, so that the force transmitted from the pressure transmitter piston, 70, to the liquid fuel pressurizer piston, 66, can be adjusted by moving the pivot, 71, in the directions, 72, relative to the ends, 69, and 68, of the lever, 67, where the gas piston, 70, and the liquid piston, 66, respectively connect to the lever, 67. When the pivot, 71, is moved toward the liquid piston, 66, the net force transmitted to the liquid fuel in the liquid fuel chamber, 37, is increased relative to the net force acting on the gas piston, 70, the reverse effect occurring when the pivot, 71, is moved toward the gas piston, 70.
In this way the ratio of net liquid pressure on the liquid fuel in the liquid fuel chamber, 37, to the net gas pressure on the gas piston, 70, can be adjusted by varying the position of the pivot, 71, relative to the liquid piston, 66, and the gas piston, 70. Also in this way the instantaneous mass rates of flow of liquid fuel can be increased by moving the pivot toward the liquid piston, 66, and away from the gas piston, 70, and vice versa. When the instantaneous mass rates of flow of liquid fuel are thusly increased or decreased the mass rate of fuel flow per intake stroke is also correspondingly increased or decreased and thus the mean value of air fuel ratio for each intake stroke can be adjusted by adjusting the position of the pivot, 71, relative to the liquid piston, 66, and the gas piston, 70.
2. An example pivot adjustment means for moving the pivot, 71, of the lever, 67, is shown in FIG. 2 and comprises: a threaded pivot holder, 73, fitted to the adjustment screw, 74, which can be rotated by the pivot drive means, 75, so that the pivot, 71, can be moved in the directions, 72, but does not move at right angles to this direction. A rotary pivot drive means, 75, is shown in this FIG. 2 example, such as an electric motor or electric stepping motor, but other pivot drive means, such as hydraulic or pneumatic drive means can alternatively be used as is well known in the art of controllers.
3. An example electronic fuel flow control means, 76, is shown in FIG. 2 which can be responsive to an engine speed sensor, 79, and operates upon the pivot drive means, 75, to adjust the position of the pivot, 71, relative to the gas piston, 70, and the liquid piston, 66. The control means, 76, operates via the pivot drive means, 75, so that the pivot, 71, is moved closer to the liquid piston when engine speed increases.
For an essentially constant mean value of air fuel ratio over a range of engine speeds, the proper relation between pivot position and engine speed is best determined experimentally.
4. The fuel valve controller, 28, receives an input signal from the intake stroke sensor, 27, and operates to open and close the nozzle valve, 38, and the fuel supply valve, 40, via their combined drive means, 39, so that the nozzle valve, 38, is open only during and throughout the intake stroke, and so that the fuel supply valve, 40, is open only when the nozzle valve is closed. The fuel valve controller, 28, also operates to close the pressure and vent valve, 80, only during and throughout the engine intake stroke, so that pressure rise is developed in the variable volume chamber, 30, of the gas pressure cycler, 23, and to open the pressure and vent valve, 80, only during and throughout the engine compression, expansion, and exhaust strokes, so that no pressure rise is developed in the variable volume chamber, 30. The pressure and vent valve, 80, vents the variable volume chamber, 30, to the engine intake manifold, 9, when open, via passages, 81, 36. The form of this invention shown in FIG. 2 can be used on a single cylinder internal combustion engine. If used on a multicylinder engine, this FIG. 2 form of the invention will require a separate gas pressure cycler, 23, for each engine cylinder. But each gas pressure cycler can serve 4 engine cylinders by use of a selector valve as described in the referenced material.
A. Basic Compensator
An example compensator of this invention, for the manifold fuel injector described hereinabove, is shown in FIG. 1, and in more detail in FIG. 2, and comprises at least the following elements:
1. At least one bleed volume, 85, inside a pressure vessel container;
2. A first bleed valve, 86, with driver, 87, for opening and closing the bleed valve;
3. A bleed orifice, 88, in the separate bleed flow passage, 89, connecting the bleed volume, 85, to the variable volume chamber, 30, of the gas pressure cycler, 23, via the first bleed valve, 86;
4. A separate return flow passage, 90, connecting the bleed volume, 85, to the variable volume chamber, 30, of the gas pressure cycler, 23, via a unidirectional flow device, 91, such as a check valve. The check valve, 91, permits flow to occur only from the bleed volume, 85, toward the variable volume chamber, 30;
5. An engine intake air mass sensor, 92, for sensing the air mass quantity going into each engine cylinder, 3, during each intake stroke. Various types of air mass sensors can be used of which the simplest is a sensor of the pressure in the engine intake manifold, 9, between the intake throttle, 93, and the engine intake valve, 7;
6. A sensor of when pressure rise is occurring in the variable volume chamber, 30, of the gas pressure cycler, 23. The piston, 32, of the gas pressure cycler, 23, is timed to decrease the volume of the variable volume chamber, 30, and thus increase the pressure, during the first half of the engine intake stroke. Thus the engine intake stroke sensor, 27, 28, is one example of such a sensor of when pressure rise will occur in the variable volume chamber, 30, of the gas pressure cycler, 23. Other types of gas pressure cycler pressure rise sensors can also be used;
7. A controller, 94, controls the opening and closing of the bleed valve, 86, by its driver, 87. The controller, 94, is responsive to the engine intake air mass sensor, 92, and the gas pressure cycler pressure rise sensor, 27, 28, so that the bleed valve, 86, is opened only when pressure rise is occurring in the variable volume chamber, 30, and further so that the product of the number of times the bleed valve, 86, is opened, multiplied by the duration of each opening during each gas pressure cycle pressure rise, increases as the air mass quantity going into each engine cylinder decreases, and decreases as the air quantity increases;
8. Various combinations of sensors, 92, 27, and controllers, 94, and valve drivers, 87, can be used, such as pneumatic or electronic. Where electronic sensors and controller are used, solenoid, or solenoid piloted, valve drivers will be preferred;
The example compensator for manifold fuel injector, shown in FIGS. 1 and 2, and described hereinabove, operates as follows when the engine, 1, is running:
9. When engine torque is decreased, as by restricting the throttle, 93, the consequently decreased engine intake manifold pressure acts via the sensor, 92, and controller, 94, to increase the product of the number of times the bleed valve, 86, is opened times the duration of each opening, during each gas pressure cycler pressure rise. As a result the pressure rise in the variable volume chamber, 30, is reduced, since more air is bled off into the bleed volume, 85, via the bleed valve, 86, and bleed orifice, 88. Hence the pressure in the liquid fuel chamber, 37, is also reduced, and the liquid fuel quantity, injected into the engine intake manifold, 9, via the fuel injector nozzle, 21, is likewise reduced. Thus as engine intake air mass is reduced the liquid fuel quantity injected into this air mass is correspondingly reduced.
10. During the latter half of the engine intake stroke, the pressure in the variable volume chamber, 30, of the gas pressure cycler, 23, is decreasing so that the ratio of instantaneous liquid fuel flow rate to instantaneous intake air flow rate can be kept within desired narrow limits. During this pressure decrease portion of the cycle of pressure rise and decrease of the gas pressure cycler, air can return flow from the bleed volume, 85, into the variable volume chamber, 30, via the check valve, 91, and return flow passage, 90. This return flow will act to maintain an approximate symmetry of the cycle of pressure rise and decrease of the gas pressure cycler, in step with the concurrent roughly symmetrical cycle of air flow rate rise and decrease during the engine intake stroke;
11. At the end of the cycle of pressure rise and decrease of the gas pressure cycler, 23, the piston, 32, uncovers the vent passage, 35, and the pressure in the variable volume chamber, 30, and also in the bleed volume, 85, is restored to engine intake manifold pressure via the passages, 35, and 36. Hence the starting pressure in the variable volume chamber, 30, and the bleed volume, 85, for the next cycle of pressure rise and decrease is always the engine intake manifold pressure;
One of the beneficial objects achievable by use of the manifold fuel injectors described in U.S. Pat. No. 5,456,232 is the creation of an intake air fuel mixture of essentially uniform fuel to air ratio throughout. By thus avoiding both over lean regions and over rich regions, the undesirable exhaust emissions originating in such regions can be minimized. Such manifold fuel injectors, when equipped with a constant mixture ratio cam, 33, create an essentially unstratified engine intake air fuel mixture, as described in U.S. Pat. No. 5,456,232.
Engine torque is varied by varying the density and pressure of the intake air, as by use of a throttle, 93, or an intake supercharger, and the liquid fuel flow must be correspondingly adjusted, in order to maintain an essentially constant overall air fuel ratio over the range of engine torque output used. Various compensator devices, for thusly adjusting the liquid fuel flow of the manifold fuel injector of U.S. Pat. No. 5,456,232, are described therein, and also in U.S. Pat. No. 5,483,937 and U.S. Pat. No. 5,613,475. The alternative compensator device of the invention described herein is mechanically simpler than these earlier compensators, and this is a principal beneficial object of this invention.
The compensator for manifold fuel injectors of this invention reduces liquid fuel flow rate, when engine intake air density, and hence pressure and mass, are reduced, by reducing the pressure generated in the gas pressure cycler, 23, and hence also reducing the pressure acting to force liquid fuel out of the liquid fuel chamber, 37, and into the engine intake manifold, 9, via the fuel injector nozzle, 21. The pressure in the gas pressure cycler is reduced by bleeding off a portion of the air mass therein into the bleed volume, the mass thusly bled off being increased when greater pressure reduction is needed. When engine intake air pressure is increased, the gas pressure cycler pressure and liquid fuel chamber pressure, are correspondingly increased by reduction of the mass bled off from the gas pressure cycler.
B. Sizing Methods
The schedule of gas pressure cycler bleed flow mass, versus engine overall air fuel ratio, over the operating range of engine torque, is preferably determined experimentally for each different engine. The following approximate relations can be used, for preliminary design purposes, for four stroke cycle engines operating at essentially constant speed: ##EQU1## Wherein: (MB)=Bleed mass quantity during each pressure increase portion of the cycle of the gas pressure cycler;
(EF)=Engine factor for engine size and operating conditions;
(PTR)=Pressure transmitter pressure ratio of the manifold fuel injector;
(CRC)=Volumetric compression ratio of the gas pressure cycler;
n=Polytropic exponent for the compression process of the gas pressure cycler; ##EQU2## (A/fo)=Desired constant instantaneous air to fuel mass ratio; Cf=Liquid fuel orifice coefficient of the manifold fuel injector;
Af=Liquid fuel orifice area;
R=Perfect gas constant for intake air;
To=Engine intake air absolute temperature;
g=Gravitational constant;
df=Liquid fuel density;
(VD)=Engine displacement per cylinder;
(Ev)=Engine volumetric efficiency, fractional;
(PTR)=Ratio of gas pressure cycler pressure above intake manifold pressure, divided by liquid fuel chamber pressure above intake manifold pressure; ##EQU3## (VDC)=Displacement volume of the gas pressure cycler; (VCLC)=Clearance volume of the gas pressure cycler;
(MCO)=Air mass inside gas pressure cycler at start of cycle of pressure increase followed by pressure decrease; ##EQU4## (MAP)=Engine intake manifold absolute pressure and pressure inside gas pressure cycler at start of cycle of pressure increase and decrease;
(RPM)--Engine crankshaft rotational speed;
Any consistent system of units can be used in this equation.
The bleed mass quantity (MB) is adjusted by adjusting the number of times the bleed valve is opened, during each gas pressure cycler pressure rise, and by adjusting the duration of each such bleed valve opening. Approximate relations for (MB) in terms of the duration of each bleed valve opening, (TIB), assumed constant, and the number of bleed valve openings per cycle, (BN), can be used for preliminary design purposes as follows, for the case of a single bleed volume as shown in FIG. 1:
(MB)=(Z)(BN)(TIB)(MAP) (FA)(PTR)(EF)+1! Eqn. V
Wherein:
(BN)=Number of bleed valve openings during each gas pressure cycler pressure rise, and also the number of separate bleed flow masses per cycle, assumed essentially uniformly distributed in time during the pressure increase portion of the cycle;
(TIB)=Time duration of each bleed valve opening;
(FA)=Average factor for average absolute pressure in gas pressure cycler assuming critical gas flow through the bleed orifice;
(FA)=Approximately 0.5 for a single bleed volume and orifice; ##EQU5## (KB)=Critical flow constant for air; (AB)=Area of the bleed orifice;
(CB)=Bleed orifice flow coefficient;
(TF)=Absolute temperature of bleed air;
Where two or more bleed volumes are used with separate bleed valves and orifices, the relation of bleed mass, (MB), to the number and duration of bleed valve openings depends upon the number of bleed volumes being used, (N), and the sequence in which these volumes are used. For example, where N bleed volumes are being used, in a cascade sequence of one bleed volume at a time, the following approximate relation for total bleed mass can be used:
(MB)=Z(TIB)(MAP)(BNO)(W) Eqn. VI
Wherein:
(BNO)=Number of bleed masses bled into one bleed volume during each gas pressure cycler pressure increase, assumed equal for all bleed volumes used; ##EQU6## Number of bleed volumes used in the sequence; =N
As another example, N bleed volumes can be used in an increasing cascade, starting with one bleed volume, and adding one additional bleed volume after each cascade time interval, until all N bleed volumes are being used toward the end of each gas pressure cycler pressure increase. For this increasing cascade sequence the following approximate relation for total bleed mass can be used: ##EQU7## Wherein: (BNL)=Number of bleed masses bled into the one last bleed volume during each gas pressure cycler pressure increase; also the number of separate bleed masses bled into one bleed volume during one cascade time interval;
A cascade time interval is defined as the interval when the number of bleed volumes being used remains constant. ##EQU8##
Any consistent system of units can be used in these equations. These equations are approximate and subject to the errors inherent in the several assumptions mentioned above.
These relations for two or more bleed volumes, used in a cascade sequence, are only example cases. There are a great many different ways in which two or more bleed volumes can be used in sequence. Nor is it necessary that the number of bleed valve openings be uniformly distributed throughout each cascade time interval. Neither is it necessary that the duration of each bleed valve opening be constant. Indeed for some applications it may be preferable to adjust the duration of some of the bleed valve openings in response to changes in engine operating conditions.
The product of the number of bleed masses bled into one bleed volume, times the time duration of each bleed valve opening, during a single cascade time interval, cannot exceed the duration of the cascade time interval: ##EQU9## Wherein U is the fraction of the duration of the cascade time interval during which the bleed valve is open:
O≦U≦1
For engines operated at higher speeds, and over a wide range of engine intake manifold pressures, two or more bleed volumes may be needed in order to bleed off the necessary total bleed mass, MB, within the available time of the gas pressure cycler pressure increase.
The function of the return flow passage, 90, and check valve, 91, is to restore the bleed mass into the gas pressure cycler during pressure decrease in order to maintain an approximate symmetry of the cycle of pressure increase and decrease of the gas pressure cycler, 23, corresponding to the approximate symmetry of air flow rate into the engine cylinder during the engine intake stroke. In this way an essentially constant ratio of instantaneous intake air flow rate to instantaneous liquid fuel flow rate can be obtained throughout each engine intake stroke, as may be preferred.
C. Use of Several Bleed Volumes
The bleed mass, MB, increases and decreases oppositely to the engine intake air mass. At low intake air mass a large bleed mass must be stored in the bleed volumes, during pressure increase, and then returned into the gas pressure cycler during pressure decrease. Since bleed volume pressure is necessarily less than gas pressure cycler pressure, a large bleed volume is required for this storage when gas pressure cycler pressures are low at low intake air mass. On the other hand, at high intake air mass, a small bleed mass is to be stored in a small bleed volume at higher pressure so that return flow will commence reasonably symmetrically to bleed flow. Thus for engines operated over a wide range of intake manifold pressure, and hence a wide range of torque and intake air mass, we prefer to adjust the portion of the available bleed volume actually being used. At low engine torque a large bleed volume is used, whereas at high engine torque a small bleed volume is used.
In principle a single bleed volume could be used whose volume was adjusted, as needed, via a moveable piston, to change oppositely to engine intake manifold pressure. But a mechanically powerful adjustment drive is needed for this scheme, which is complex and costly.
The compensators of this invention can use several separate bleed volumes, each with separate bleed valve and return flow passage and check valve, as a means for adjusting the bleed volume being used. Bleed volume is increased by opening more of the separate bleed valves, thus increasing the number, N, of bleed volumes being used. Bleed volume, and N, are decreased by opening fewer of the separate bleed valves. Hence bleed volume is thusly adjusted in steps by the controller, 94, selecting the number, N, of bleed volumes to be used, in response to the engine intake manifold pressure sensor, 92, input, as shown in FIG. 2, where two separate bleed volumes, 85, 95, are available. The second bleed volume, 95, has a bleed valve, 106, with driver, 110, bleed orifice, 107, return flow passage, 108, with check valve, 109, similar in design and operation to these same type elements for the first bleed volume, 85.
Any one bleed volume commences return flow only when pressure in the gas pressure cycler has decreased to the pressure in that one bleed volume. Thus symmetry of the cycle of pressure increase and decrease can be improved by using many more separate bleed volumes, whose final separate pressures are all different. For example, if a very large number of separate bleed volumes are used in a one at a time cascade sequence, with each bleed volume receiving a small bleed mass, the return flow can restore very nearly perfect symmetry to each cycle. But such a large number of bleed volumes and valves increases the complexity and cost of the compensator. Generally adequate symmetry of the cycle of pressure increase and decrease can be achieved by use of fewer bleed volumes in an increasing cascade sequence.
The schedule of the number, N, of bleed volumes to be used, versus the engine intake manifold pressure, MAP, thus depends upon the pressures actually reached in the several bleed volumes, and thus upon the cascade sequence used. This schedule is preferably determined experimentally for the engine and then installed into the controller memory.
For preliminary design and sizing purposes the following approximate relations can be used for compensators having two or more separate bleed volumes, all of equal volume, (VB):
For a one at a time cascade sequence: ##EQU10## For an increasing cascade sequence: ##EQU11## Wherein: (N)=Number of bleed volumes to be used in the sequence, set to the next higher integer;
(VB)=volume of one bleed volume;
(TB)=Temperature of air inside the bleed volume, approximated as constant;
(V)=Ratio of maximum pressure rise to be reached in any bleed volume to the maximum pressure rise reached in the gas pressure cycler;
0<V<1
For critical air flow through the bleed orifices, (V)≦0.5;
Any consistent set of units can be used in these approximate relations.
D. Controller Operation
It is the function of the controller element, 94, to adjust the number of bleed masses, BN, and the duration of each bleed flow, TIB, in order to set the value of total bleed mass, MB, in accord with the engine intake air mass per cycle and the engine speed, so that the overall air to fuel ratio of the intake mixture remains essentially constant over a wide range of engine operating conditions. For this purpose the controller receives at least the following input signals from sensors:
(a) A sensor of engine intake air mass per intake stroke. Commonly this can be a sensor of manifold absolute pressure, MAP, element, 92. Somewhat improved accuracy can be achieved by sensing also the intake air temperature. Alternative intake air mass sensors can also be used as, for example, an intake air mass flow rate sensor plus an engine speed sensor in combination;
(b) A sensor of engine speed, 79, can be any of the several types well known in the art;
(c) An engine intake stroke sensor, 27, 28, senses when the gas pressure cycler, 23, cycle of pressure increase and pressure decrease commences, and the controller, 94, then functions to open bleed valves, 86, only when pressure increase is occurring in the variable volume chamber, 30, of the gas pressure cycler;
The following example illustrates one scheme for controller operation:
(1) Using sensed values of (MAP), (RPM) and known engine size the controller calculates total bleed mass (MB) as by use of approximate equation I:
(2) If more than one bleed volume is available the number to be used (N), is calculated, as by using equation III, or equation IV, as appropriate;
(3) The value of (U) is calculated, as by using equation II, and (N) is increased if (U) approaches a value of 1.0;
(4) The product (BN) (TIB) is calculated, and used to control the bleed valve driver, 87, to open and close the bleed valve, 86, the number of openings, of duration, TIB, needed to remove the required bleed mass, (MB), out of the variable volume chamber, 30, of the gas pressure cycler, 23. For this calculation the following approximate equations can be used:
Equation V for a single bleed volume
Equation VI for a one-at-a-time cascade sequence
Equation VII for an increasing cascade sequence
(5) Instead of using the several approximate equations described above, it will be preferable to use experimentally determined values of (EF), MB), (N) and (U), etc., for each particular engine, these experimental values being retained in a memory circuit;
For engines operated at a constant RPM, as in pumping or electric generating service, the above controller operation is feasible. However, for engines operated over a wide range of speed and torque, as in automotive service, it will be difficult to control the manifold fuel injector over the resulting very wide range of values for the engine factor, (EF). For automotive use, for example, the ratio of maximum to minimum values for (EF) could be as large as 200 or more. It may be preferable, in these latter types of engine usage, to use separate controllers for engine torque compensation and for engine speed compensation. One example of such separate controllers is illustrated in FIG. 1 and FIG. 2 and comprises the following:
(6) A controller, 94, for a bleed mass compensator of this invention operates as described hereinabove;
(7) A separate controller, 76, responsive to the engine speed sensor, 79, operates upon the pivoted lever pressure transmitter shown in FIG. 2, to adjust the pressure transmitter pressure ratio (PTR), so that the product, (PTR) (RPM) 2 remains essentially constant.
With this example scheme, the bleed mass compensator of this invention adjusts the bleed mass (MB), primarily to compensate for changes in engine intake air mass per stroke, or (MAP). The pivoted lever pressure transmitter adjusts the pressure transmitter pressure ratio (PTR), to compensate for changes in engine (RPM). And these separate adjustments are mechanically multiplied together by the gas pressure cycler pressure acting, via the pivoted lever pressure transmitter, to set the pressure in the liquid fuel chamber, 37. With this arrangement, the product (PTR) (EF), in equation I, varies only as (MAP) varies, and thus the needed range of values of (MB) is small enough to lie within reasonable capabilities of the controller, 94. The controller, 94, will nevertheless need an engine speed sensor, 79, input, or an alternate input of pressure transmitter pressure ratio (PTR), in order to calculate the needed bleed mass (MB) via equation I.
The controller, 94, is preferably and probably necessarily, an electronic controller. Electronic sensors can then be used, and the controller can comprise electronic calculators and memory storage elements as needed, such as are well known in the art of electronic devices.
E. Feedback
Actual intake mixture air to fuel ratios will vary over a certain range of values, due, in part to manufacturing tolerances for the various parts of the manifold fuel injector, and also of the compensators. This range of variation may increase with engine use, due to various changes, such as deposit formations in the engine combustion chamber, or on the intake valve, or elsewhere in the fuel system. To keep this range of variation of air to fuel ratio within acceptable limits it will often be preferable to incorporate a feedback system into the controller of the compensator, responsive to a mixture ratio sensor, and operative via the controller, to adjust the duration of bleed valve opening (TIB), to correct excessive variations of mixture ratio.
An example feedback system is shown schematically in FIG. 1 and FIG. 2 and comprises the following:
1. An exhaust gas composition sensor, 96, in the engine exhaust manifold, 10, senses the operating air to fuel ratio of the engine;
2. This mixture ratio signal is an additional input, 96, to the compensator controller, 94;
3. The controller, 94, adjusts the duration , TIB, of opening of the bleed valve, 86, so that, as sensed engine air fuel ratio becomes richer in fuel than a selected range of values, the duration of each bleed valve opening is increased, and further so that, as sensed engine air fuel ratio becomes leaner in fuel than this selected range of values, the duration of each bleed valve opening is decreased.
4. At present, the most common type of exhaust gas composition sensor is the Zirconia based oxygen content sensor, in wide use in automobiles. Improved feedback response time could be obtained if the air to fuel ratio could be sensed in the engine intake manifold, 9, instead of in the engine exhaust manifold, 10. Where fuel evaporation is essentially complete within the intake manifold, the resulting air temperature drop could, in principle, be used as an air to fuel ratio sensor.
5. The adjustments made by the controller in response to the feedback signal are preferably to the duration of bleed valve opening (TIB), rather than to the number of bleed valve openings (BN), since the latter can only be varied in integral steps.
F. Series Bleed Valves
An example of a modified form of compensator of this invention is shown in FIG. 3 and comprises:
1. At least two separate bleed volumes, 85, 95, with return flow passages, 90, 97, and check valves, 91, 98, are used, and these function as described hereinabove for the FIG. 2 form of compensator;
2. Each bleed volume, 85, 95, and connected bleed orifice, 88, 99, has a separate first bleed value, 100, 101, with drives, 102, 103;
3. The first bleed valves, 100, 101, connect to the variable volume chamber, 30, of the gas pressure cycler, 23, via a single second bleed valve, 104, with driver, 105;
4. The controller, 94, operates upon the first bleed valves, 100, 101, drivers 102, 103, to select the number, N, of these first bleed valves to be opened during each pressure increase of the gas pressure cycler, 23, and to hold these first bleed valves open throughout each pressure increase;
5. The controller, 94, operates upon the single second bleed valve, 104, driver 105, so that the second bleed valve is opened only during each gas pressure cycler pressure rise, and so that the product of the number of second bleed valve openings times the duration of each valve opening during each pressure rise, increases as engine intake pressure, MAP, decreases, and decreases as engine intake pressure increases;
6. With this FIG. 3 form of compensator, the several first bleed valves, 100, 101, are thus used only to select the number of bleed volumes, 85, 95, to be used, and these valves and drivers can be of a simpler design. The adjustment of the number of bleed time intervals and the duration thereof is carried out by the single second bleed valve, 104, and thus only one of this more complex valve is needed and this is an advantage of this FIG. 3 form of compensator over the FIG. 2 form;
7. A disadvantage of the FIG. 3 form of compensator is that one more valve is needed over the number needed for the FIG. 2 form;
The several example forms of compensators for manifold fuel injectors are described hereinabove for illustrative purposes, and it is not intended thereby to limit the scope of the invention to these particular examples.
By creating stratified air fuel mixtures within each intake mixture mass for each engine cycle, the occurrence of engine knock can be suppressed, as is described in U.S. Pat. No. 4,425,892, and this material is incorporated herein by reference thereto. Examples of apparatus for creating such stratified air fuel mixtures, using intake manifold fuel injectors, are described in U.S. Pat. No. 5,456,232, and U.S. Pat. No. 5,483,937, and this material is incorporated herein by reference thereto. Such intake stratifier means can also be used in combination with the compensators of this invention.
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A compensator is described for use on those manifold fuel injectors for gasoline engines which utilize a gas pressure cycler to vary the instantaneous rate of liquid fuel injection in proportion to the instantaneous rate of engine intake air flow into each engine cylinder during each intake stroke. The compensator adjusts liquid fuel injection pressure by bleeding adjustable air quantities out of the gas pressure cycler during pressure rise, and then subsequently returning these bleed masses into the gas pressure cycler during pressure decrease. A compensator of this invention is of relatively simple mechanical design, and uses a moderately complex electronic controller.
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BACKGROUND OF THE INVENTION
The present invention relates to an organotin stabilizer mixture, suitable for use in rigid vinyl polymer formulations, which combines several positive and beneficial properties into a single stabilizer composition. The stabilizer formulation provides improved early color, lubricity, and weatherability.
A wide variety of organotin containing stabilizer formulations are known to persons of ordinary skill in the art for use in a variety of polymer compositions including rigid vinyl formulations. Some examples of organotin formulations which are deemed generally relevant to the present invention include the following:
O. S. Kauder U.S. Pat. No. 3,632,538 shows the use of an organotin alpha- or beta-mercapto carboxylic acid ester and an organotin sulfide in PVC resin formulations.
R. D. Dworkin et al U.S. Pat. No. 4,104,292 discloses organotin derivatives of mercaptoalcohol esters.
J. M. Bohen et al. U.S. Pat. No. 4,115,352 illustrates mixtures of alkali and alkaline earth metal salts of mercaptans or mercapto acids with specified sulfur containing organotin or antimony compounds as heat stabilizers for halogenated resins.
L. R. Brecker et al. U.S. Pat. No. 4,255,320 illustrates stabilizer mixtures comprising a monoalkyl 2-acyloxyethylmercaptide and/or a dialkyltin 2-acyloxyethylmercaptide in admixture with an alkyltin sulfide.
In general, two types of organotin stabilizers are in common usage in vinyl chloride polymer formulations: the mixed metal soap type; and tin stabilizers based on mixtures of monoalkyltin and dialkyltin stabilizer compounds. The monoalkyltin compounds generally give good color, whereas the dialkyltin compounds give good long term stability. The present invention relates to a monoalkyltin stabilizer mixture which is preferably adapted to be blended, in various desired ratios, with conventional dialkyltin stabilizer(s), such as the preferred dibutyltin stabilizer compound(s), for use in vinyl chloride polymer formulations.
SUMMARY OF THE INVENTION
The present invention, in one embodiment, is an organotin stabilizer mixture comprising:
(a) a monoalkyltin mercaptoalcohol;
(b) a monoalkyltin mercaptoacid ester; and
(c) a monoalkyltin sulfide.
An optional additional component is a monoalkyltin mercaptoalcohol ester.
DESCRIPTION OF PREFERRED EMBODIMENTS
In the compositions of the present invention the monoalkyltin mercaptoalcohol (a) is of the formula RSn(SR'OH) 3 , where R is lower alkyl and R' is lower alkylene, R preferably being butyl and R' preferably being ethylene, namely, monobutyltin tris(betamercaptoethanol). Free betamercaptoethanol, for example, is frequently added to alkyltin stabilizers for crisp early color and clarity when processing vinyl chloride formulations. A major disadvantage of such a practice is the generation of a foul mercaptan odor. In the present invention this conventional component is replaced with a reaction product of the betamercaptoethanol, namely, the monoalkyltin mercaptoalcohol in order to alleviate the type of odor, corrosivity, and toxicity problems associated with the free betamercaptoalkanol species.
The monoalkyltin mercaptoacid ester component (b) is of the formula RSn(SR'CO 2 R") 3 , where R is lower alkyl, R' is lower alkylene, and R" is C 6 to C 10 alkyl wherein R is preferably butyl, R' is preferably methylene, and R" is preferably isooctyl, namely monobutyltin tris(isooctylthioglycolate). This component imparts good long term stability and color hold to rigid vinyl chloride polymer formulations. It is relatively cheap.
Component (c) the monoalkyltin sulfide comprises monoloweralkyl, such as monobutyl with a preferred compound being monobutyltin sulfide. This component is used in the present formulation to boost the percent tin contained therein.
The above-described components of the stabilizer mixture of the present invention can be present in the following amounts:
(a) 10% to 20%, by weight of monoalkyltin mercaptoalcohol (a);
(b) 35% to 45%, by weight of monoalkyltin mercaptoacid ester (b); and
(c) 15% to 25%, by weight of monoalkyltin sulfide (c).
As an optional fourth component the stabilizer mixture of the present invention further comprises a monoalkyltin mercaptoalcohol ester which is of the formula RSn(SR'O 2 CR") 3 , where R is lower alkyl, R' is lower alkylene, and R" is C 12 to C 20 alkyl, preferably where R is butyl, R' is ethylene, and R" is oleyl, namely monobutyltin tris(betamercaptoethyl-oleate). This component provides good early color, lubrication, and good long-term color hold.
When the stabilizer mixture comprises the optional monoalkyltin mercaptoalcohol ester it will have the following amounts of the four components listed below:
(a) 10% to 20%, by weight of monoalkyltin mercaptoalcohol (a);
(b) 15% to 25%, by weight of monoalkyltin mercaptoacid ester (b);
(c) 25% to 35%, by weight of monoalkyltin sulfide (c); and
(d) 30% to 40%, by weight of a monoalkyltin mercaptoalcohol ester.
The above-described embodiments of the present invention can be conveniently prepared by the reaction of an alkyltin trichloride (e.g., monobutyl tin trichloride) with a betamercaptoalkanol (e.g., betamercaptoethanol), an alkylthioglycolate, such as isooctylthioglycolate, (optionally and preferably) betamercaptoethyloleate, and sodium sulfide.
The present invention is further understood by the Examples which follow.
EXAMPLE 1
This illustrates synthesis of the alyltin stabilizer composition of the present invention which serves as an intermediate suitable for blending with other alkyltin compositions.
a suitable reactor equipped with an agitator, thermometer, and condenser was charged with 500 parts by weight of water, 84 parts by weight of butyltin trichloride, 71.8 parts by weight of 50 wt % aqueous sodium hydroxide, and 70 parts by weight of betamercaptoethanol. Sodium hydroxide (50 wt % in water) was slowly added to adjust the pH to 6.0 to 6.5.
To the resulting mixture was then charged 135 parts by weight of isooctylthioglycolate, 60.3 parts by weight of butyltin trichloride, and 52.8 parts by weight of 50 wt % aqueous sodium hydroxide. The pH of the resulting composition was similarly adjusted to 6.0-6.5 by addition of 50 wt % sodium hydroxide.
Then, 270 parts by weight of betamercaptoethyloleate, 65.5 parts by weight of butyltin trichloride, and 55.8 parts by weight of 50 wt % sodium hydroxide was added to the resulting composition. The pH was adjusted to 6.0 to 6.5 as previously described.
To the resulting composition was added 150 parts by weight butyltin trichloride and 100.3 parts by weight of sodium sulfide was slowly added. The Ph was adjusted to 6.0 to 6.5 by the addition of sodium sulfide. Then, a final charge of the same amounts of butyltin trichloride and sodium sulfide were added along with pH adjustment as just described.
The resulting mixture was heated to 70° C. and held at that temperature for thirty minutes. The product was allowed to phase separate with the lower product layer being returned to the reactor. The reactor contents were stripped at a reduced pressure of 30 mm Hg and a temperature of 90°-95° C. A final addition of 25 parts by weight of tripropylene glycol was made. The remaining liquid product was then filtered through a diatomaceous silica filter aid (SPEEDEX brand) to yield a clear, light amber, mobile liquid having the following composition:
______________________________________Component Weight %______________________________________Monobutyltin tris(betamercaptoethanol) 14.0Monobutyltin tris(isooctylthioglycolate) 20.0Monobutyltin tris(betamercaptoethyloleate) 33.4Monobutyltin sulfide 27.4Mercaptoethyloleate 2.3Tripropylene glycol 2.9 100.0______________________________________
EXAMPLE 2
This illustrates synthesis of another embodiment of an the alkyltin stabilizer intermediate composition of the present invention.
A suitable reactor equipped with an agitator, thermometer, and condenser was charged with 500 parts by weight of water, 84 parts by weight of butyltin trichloride, 71.8 parts by weight of 50 wt % aqueous sodium hydroxide, and 70 parts by weight of betamercaptoethanol. Sodium hydroxide (50 wt % in water) was slowly added to adjust the pH to 6.0 to 6.5.
To the resulting mixture was then charged 135 parts by weight of isooctyl thioglycolate, 60.3 parts by weight of butyltin trichloride, and 52.8 parts by weight of 50 wt % aqueous sodium hydroxide. The pH of the resulting composition was similarly adjusted to 6.0-6.5 by addition of 50 wt % sodium hydroxide.
Then, 270 parts by weight of betamercaptoethyloleate, 65.5 parts by weight of butyltin trichloride, and 55.8 parts by weight of 50 wt % sodium hydroxide was added to the resulting composition. The pH was adjusted to 6.0 to 6.5 as previously described.
To the resulting composition was added 150 parts by weight butyltin trichloride and 100.3 parts by weight of sodium sulfide was slowly added. The pH was adjusted to 6.0 to 6.5 by the addition of sodium sulfide. Then, a final charge of similar amounts of butyltin trichloride and sodium sulfide were added along with pH adjustment as just described.
The resulting mixture was heated to 70° C. and held at that temperature for thirty minutes. The product was allowed to phase separate with the lower product layer being returned to the reactor. The reactor contents were stripped at a reduced pressure of 30 mm Hg and a temperature of 90°-95° C. A final addition of 25 parts by weight of tripropylene glycol was made. The remaining liquid product was then filtered through a diatomaceous silica filter aid (SPEEDEX brand) to yield a clear, light amber, mobile liquid having the following composition:
______________________________________Component Weight %______________________________________Monobutyltin tris(betamercaptoethanol) 13.6Monobutyltin tris(isooctylthioglycolate) 41.1Isooctylthioglycolate 10.8Monobutyltin sulfide 18.7Butylated Hydroxy Toluene 7.9Tripropylene glycol 7.9 100.0______________________________________
EXAMPLE 3
This Example illustrates the performance of the alkyltin stabilizer compositions of Examples 1 and 2 in two polyvinyl chloride-resin containing test compounds.
The following PVC-resin containing compounds were made by processing the materials given below as follows: the resin and process aids were blended at room temperature in a Hobart mixer. The remaining components were added while mixing at room temperature until a homogeneous mixture was achieved.
______________________________________Sample AIngredient Parts by Weight______________________________________PVC resin (Rel. Visc. = 2.0) 100.0Methacrylate-butadiene-styrene 8.0process aid (KANE ACE B22 brand)Methylmethacrylate-ethyl acrylate 2.0process aid (PARALOID K-120N brand)Epoxidized Soyabean Oil 1.5Stabilizer* 1.4Glyceryl monostearate 0.75Montan ester wax 0.3______________________________________ *The stabilizer comprised 78% of dibutyltin bis(isooctylthioglycolate), 15.8% of the composition of Example 1, and 6.2% of styrenated phenol antioxidant.
______________________________________Samples B and CIngredient Parts by Weight______________________________________PVC resin (Rel. Visc. = 2.5) 100.00Calcium Carbonate 12.0Methylmethacrylate-butyl acrylate 5.0impact modifier (PARALOID KM-334brandTitanium dioxide 2.0Paraffin (RHEOLUBE 315S brand) 1.2Calcium stearate 1.1Stabilizer** 0.8Methylmethacrylate-ethyl acrylate 0.5process aid (PARALOID 120N brand)______________________________________ **The stabilizer in Sample B comprised 80% of dibutyltin bis(isooctylthioglycolate), 14.5% of the composition from Example 2, and 5.5% of styrenated phenol. The stabilizer in Sample C comprised 80% of dibutyltin bis(isooctylthioglycolate), 14.5% of the composition from Example 2, 3.2% of styrenated phenol, and 2.0% of epoxidized soyabean oil
Samples A-C were tested, along with a control in which 0.8% of a commercially available alkyltin stabilizer was used with the other ingredients forming Sample A (with the exception of the stabilizer composition), for dynamic heat stability. The testing was done on a BRABENDER PLASTOGRAPH apparatus at 150° C. and 70 rpm. Sixty-five grams of sample was used and triangular sample chips were removed at five minute intervals until a black color was noted and degradation was noticed as evidenced by a significant increase in torque on a Brabender torque rheometer. The results are as follows:
______________________________________ Time to Initial Color Time toSample Color (min) Degrade (min)______________________________________Control 10 34A* 15 34B** 15 34C** 20 34______________________________________ *Contains the stabilizer of Example 1. **Contains the stabilizer of Example 2.
Resin not containing any stabilizer would be expected to turn black in less than five minutes and would be expected to dedgrade after about ten minutes.
The foregoing Examples should not be construed in a limiting sense since they merely represent certain preferred embodiments of the present invention. The scope of protection sought is set forth in the claims which follow.
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An organotin stabilizer mixture comprising: (a) monoalkyltin mercaptoalcohol (b) a monoalkyltin mercaptoacid ester; and (c) a monoalkyltin sulfide provides improved early color, lubricity, and weatherability to rigid vinyl polymer formulations. The formulation may also contain a monoalkyltin mercaptoalcohol ester as an optional component.
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[0001] This application is a continuation International Patent Application No. PCT/US00/12468, with an international filing date of May 8, 2000, published in English under PCT Article 21(2) and now abandoned, which claims the priority of European Patent Application No. 99204504.7, filed Dec. 23, 1999.
BACKGROUND OF THE INVENTION
[0002] Multi-well test plates, also called micro-titer plates or micro-titer test plates, are well-known and frequently used for assays involving biological or biochemical materials. Micro-titer test plates have been described in numerous patents including U.S. Pat. Nos. 4,948,442; 3,540,856; 3,540,857; 3,540,858; 4,304,865; 4,948,564; 5,620,663; 5,464,541; 5,264,184; WO 97/41955; WO 95/22406, EP Patent Nos. 645 187 and 98 534.
[0003] Selected wells in the micro-titer test plate can be used to incubate respective microcultures or to separate biological or biochemical material followed by further processing to harvest the material. Each well has filtration means so that, upon application of a vacuum to one side of the plate, fluid in each well is expressed through the filter leaving solids, such as bacteria and the like, entrapped in the well. The filtration means can also act as a membrane such that certain materials in the test specimen are selectively bonded or otherwise retained in the filter means. The retained material may thereafter be harvested by means of a further solvent. The liquid expressed from the individual wells through the filter means may be collected in a common collecting vessel in case the liquid is not needed for further processing or alternatively, the liquid from the individual wells may be collected in individual collecting containers as disclosed in U.S. Pat. No. 5,464,541 and EP Patent No. 98 534.
[0004] Up until recently, micro-titer plates have been used that conform to a standardized size of about 85.47 by 127.76 mm having 12 rows of 8 wells each. Many expensive automation equipment has been designed to this standard. However, there is now a desire to increase the productivity of such automatic sampling. Such should preferably be accomplished in the most cost effective way and it has been proposed to retain approximately the size of the micro-titer plates yet increasing the number of wells therein. This would require minimal changes in the automation equipment.
[0005] Various methods are known to produce a micro-titer plate. These methods are typically designed to produce the standard micro-titer plates having 96 wells. For example, such plates may be manufactured as multi-layer structures including a single sheet of filter material disposed to cover the bottom apertures of all the wells, the filtration material being bonded to the periphery of one or more of the well apertures. Such a structure may suffer from a problem called “cross-talk” by which fluid from adjacent wells mingles through for example capillary action, gravity or application of pressure.
[0006] As disclosed in U.S. Pat. No. 4,304,865, a micro-titer, multi-layer plate includes a substantially rigid culture tray provided with wells having upstanding edges or rims bounding the wider openings to the wells, and incubation is achieved while the culture tray is held “upside-down”, i.e. the rims are disposed below the sheet. To harvest material from such wells, a sheet of filter paper is placed over the top of a substantially rigid harvester tray having a like plurality of wells, each disposed and dimensioned to provide a tight push-fit with respect to the periphery of the rim of a corresponding well in the culture tray. The latter is then pressed against the harvester tray to push the rims into the wells in the latter, thereby die-cutting filter discs from the filter tray. Such die-cutting may also be carried out by pressing an unused culture tray against the harvester tray. The harvester tray with the filter discs may then be pressed against the culture tray bearing the incubated material. A vacuum applied to the bottom surface of the harvester tray draws fluid from the culture tray wells through the respective filter discs. This technique of cutting the filter sheet while it overlays the wells has the disadvantage that dust formed during the cutting operation gets entrapped between the walls of the well and the filter medium that may cause poor separation performance. Such micro-titer plates are also taught to be prone to “cross talk” according to U.S. Pat. No. 4,948,442.
[0007] Accordingly, the latter U.S. patent proposes a method of manufacturing in which the wells of a culture tray and harvester tray are welded together with there between a filter sheet which extends across the openings of the wells. However, this method still does not completely solve the problem of cross talk. In particular, welding of the wells may not be sufficient to avoid capillary action to cause mingling of fluids from adjacent wells. Moreover, this problem will be even more enhanced with micro-titer plates that have a high number of wells per unit area.
[0008] It could also be contemplated to produce the micro-titer plate by providing an array of integrally connected wells having opposite inlet and outlet openings, separately die cutting filter means conforming to the opening of the wells from a filter sheet and then inserting the filter means into the individual wells of the micro-titer plate. This method however would have the disadvantage of being difficult to automate because the handling of the individual filter means would be complicated and cumbersome, thus requiring sophisticated and expensive equipment. Moreover, the degree of complexity and risk of failure during production would substantially increase when the amount of wells per area increases.
[0009] Accordingly, it is desirable to find a further method for producing micro-titer plates, which method is preferably convenient, cost effective, capable of producing micro-titer plates that have a high number of wells per unit area and which micro-titer plates preferably have a reduced problem of cross-talk and good separation performance.
DISCLOSURE OF THE INVENTION
[0010] The micro-titer plate of the present invention can be obtained by providing an array of a plurality of sample containers connected to each other of which each sample container has one or more side walls enclosing the interior of the sample container, a bottom wall with an outlet opening and an opposite upper end that is open and defines an inlet opening. The sample containers will generally be formed from a thermoplastic material and can be produced by injection molding. Typically thermoplastic materials that can be used include polystyrenes, polyvinyl chloride (including homo and copolymers thereof), polyethylenes and polyvinylidene chloride.
[0011] A plurality of filter means for insertion into the plurality of sample containers are preformed in a filter sheet. By the term “preformed” or “preforming” is meant that the shape and size of the filter means is substantially formed in the filter sheet but wherein the filter means continue to be held within the filter sheet such that they do not accidentally separate from the filter sheet during its handling. By the terms “filter means” and “filter sheet” in connection with this invention are meant any means or sheet that can cause separation of one or more components from a mixture of components. For example, the terms “filter means” and “filter sheet” include sheets that can separate a solid component from the liquid in a dispersion as well as a membrane or sheet which can separate components which may be dissolved by selectively binding them. The filter means of the present invention for example are means that allow selective adsorption, in particular of nucleic acids and proteins from liquids containing complete plant, animal or human cells or parts thereof. The filter sheet and filter means in connection with the present invention may be single layer sheets or means but they are preferably laminates comprising several layers. For example, according to a particular embodiment, the filter sheet and filter means can be a laminate of a pre-filter layer, a solid phase extraction medium preferably in the form of a membrane and a porous support layer. The filter means of the present invention will typically have a rigidity such that they will not substantially deform and substantially stay in place while being used so as to be capable of performing its separation function in the micro titer test plate.
[0012] Preforming the filter means in the filter sheet has the advantage that the filter means can be easily separated from the filter sheet creating a minimum of dust that could interfere with the performance of the filter. According to a first embodiment of preforming the filter means in the filter sheet, the filter means are partially cut out a filter sheet. Such partial cutting may be carried out by any cutting means known to those skilled in the art including, cutting by means of knifes, laser or water jets.
[0013] The filter means are cut out in such a way that the filter means stay connected to the filter sheet at one or more points on their periphery. By the term “stay connected at one or more points on the periphery” is meant that the major part of the periphery of the filter means is cut out and only a small portion on the periphery is not cut. At the minimum, the portion of the periphery that is not cut should be sufficient to retain the filter means on the filter sheet during further handling in the manufacturing of the micro-titer plate. Typically, it will suffice to have the filter means connected at 1, 2, 3 or 4 points on their periphery. Such points of connection will typically have a size of 0.1 mm to 2 mm.
[0014] According to an alternative embodiment, the filter sheet is a laminate of a prefilter layer and a porous support layer with a solid phase extraction medium there between. The filter means can then be preformed in the filter sheet by ultrasonically welding the prefilter layer and the porous support layer together at the periphery of the filter means. Preferably, the prefilter layer and porous support layer are consolidated together at the complete periphery of the filter means and land areas are thereby formed between adjacent preformed filter means. Accordingly, the preformed filter means will then be comprised of the solid phase extraction medium that is enclosed by the prefilter layer and porous support layer that are welded together. Such preformed filter means can be subsequently separated from the filter sheet when overlaying the array of sample containers by punching the preformed filter means out of the filter sheet without substantial dust formation. However, dust formation during the separation of the filter means from the filter sheet may be further reduced by also partially cutting the preformed filter means at their periphery where the prefilter layer and support layer are welded together. The additional partial cutting can be carried out as described above.
[0015] It has further been found that the filter sheet with preformed filter means having the prefilter layer and porous support layer consolidated at their periphery with land areas defined between them, can be used as such as a well-less plate card in separation methods. In particular, it was found that the land areas defined between adjacent preformed filter means effectively prevents lateral liquid transfer between adjacent filter preformed filter means. Thus in another aspect of the present invention independent and separate of the method of producing micro titer plates, the invention also relates to a well-less plate card as described above.
[0016] The internal solid phase extraction medium (SPE) can be in a variety of forms, such as fibers, particulate material, a membrane, other porous material having a high surface area, or combinations thereof. Preferably, the SPE medium is in the form of a membrane that includes a fibril matrix and sorptive particles enmeshed therein. The fibril matrix is typically an open-structured entangled mass of microfibers. The sorptive particles typically form the active material. By “active” it is meant that the material is capable of capturing an analyte of interest and holding it either by adsorption or absorption. The fibril matrix itself may also form the active material, although typically it does not. Furthermore, the fibril matrix may also include inactive particles such as glass beads or other materials for enhanced flow rates. According to a preferred embodiment, the solid phase extraction medium comprises silica based particles derivatized with hydrocarbon chains such as for example C18, C8 or C2 hydrocarbon chains, or styrenedivinylbenzene (e.g., SDB-XC available from Transgenomic Inc., San Jose, Calif.) used separately or in combination with one another; polymeric or resin polymers, including copolymers, terpolymers or polymeric blends of two or more resin types; chelating and ion exchange particles; and other particle types such that derivatization chemistry on the particle yields special ligands that may be used for attachment to proteins or other biomolecules at specific sites. The solid phase extraction media may also comprise particle loaded carrier webs, including thermoplastic nonwoven webs (e.g. melt blown microfiber webs, spunbond webs, etc.), woven fabrics, knitted fabrics, and microporous films. Particle loaded glass fiber fabrics may also be used as SPE media.
[0017] The prefilter layer is a porous material that can be made of a wide variety of materials. Typically, and preferably, it is made of a nonwoven material. More preferably, it is a nonwoven web of melt blown microfibers. Such “melt blown microfibers” or simply “blown microfibers” or “BMF” are discrete, fine, discontinuous fibers prepared by extruding fluid fiber-forming material through fine orifices in a die, directing the extruded material into a high-velocity gaseous stream to attenuate it, and then solidifying and collecting the mass of fibers. In preferred embodiments, the prefilter layer includes a nonwoven web of melt blown polyolefin fibers, particularly polypropylene fibers.
[0018] The prefilter layer preferably has the following characteristics: a solidity of no greater than about 20%; a thickness of at least about 0.5 millimeters (mm); and a basis weight of at least about 70 grams per square meter (g/m 2 ). As used herein, solidity refers to the amount of solid material in a given volume and is calculated by using the relationship between weight and thickness measurements of webs. That is, solidity equals the mass of a web divided by the polymer density divided by the volume of the web and is reported as a percentage of the volume. The thickness refers to the dimension of the prefilter through which the sample of interest flows and is reported in mm. The basis weight refers to mass of the material per unit area and is reported in g/m 2 .
[0019] In accordance with a particular aspect of the present invention, the prefilter can be selected so as to cooperate with the SPE medium to remove the analyte of interest. That is, in certain extraction procedures a prefilter can be chosen such that it helps capture the targeted analyte, thereby increasing the recovery yield. For example in a particular embodiment, the filter medium may be designed to remove hydrocarbon extractables (e.g., nonpolar hydrocarbons such as oil and grease) from a liquid sample (e.g., water). One such filter medium designed to remove hydrocarbon extractables includes a prefilter layer, an SPE medium containing a polytetrafluoroethylene (PTFE such as TEFLON) fibril matrix containing C18 hydrocarbon derivatized silica particles and glass beads, and a support layer. The prefilter of this filter medium is a polyolefin (e.g., polypropylene or polyethylene) blown microfiber web, which acts both as a depth filter and as a medium to help capture the hydrocarbon extractables. This combination of a prefilter with the PTFE fibril matrix and C18 hydrocarbon derivatized silica particles results in high efficiency extractions. Although this prefilter design is not limited to hydrocarbon analysis, a synergistic effect results from the use of the described prefilter in combination with a C18 hydrocarbon derivatized silica particles containing PTFE membrane as the SPE medium. In other applications the action of the prefilter may only reside in its ability to function as a filter for suspended solids, for example, and not as an adjunct to the sorption capabilities of the solid phase extraction medium.
[0020] The support layer can be made of a wide variety of porous materials that do not substantially hinder flow of the liquid of the sample of interest. The porous material is typically a material that is capable of protecting the solid phase extraction medium from abrasion and wear during handling and use. The material is sufficiently porous to allow the liquid sample to flow through it, although it does not allow particles that might be within the solid phase extraction medium from contaminating the sample. Preferably, the support layer is made of a nonwoven material. Typically, and preferably, the material of the prefilter and the support layer are very similar in composition (as opposed to structure), and more preferably, they are the same.
[0021] In a particular embodiment of the present invention, the filter sheet may comprise an SPE medium or loose silica based particles derivatized with hydrocarbon chains such as for example described above or SDB-XC captured between two layers of porous cover sheets. Preferably the porous cover sheets comprise a thermoplastic material, and may be selected from the group consisting of nonwoven webs (e.g. melt blown microfiber webs, spunbond webs, etc.), woven fabrics, and knitted fabrics. Additionally, filter paper having a discontinuous thermoplastic coating, open cell thermoplastic foams, or apertured thermoplastic films can also be used as cover sheet materials.
[0022] Preforming of the filter means through ultrasonically consolidating the prefilter layer and porous layer may be carried out in one single step whereby all of the plurality of filter means are preformed at once. However, if a large number of filter means need to be preformed, the ultrasonic consolidation is preferably carried out in several steps whereby in each step only a number of the total desired number of filter means are preformed. In the latter case, it is desirable that a registration step is included to make sure that the filter means are preformed in the desired arrangement.
[0023] The plurality of preformed filter means when used to produce a microtiter plate conform in arrangement, number and shape to the arrangement, number and shape of the sample containers of the array. Furthermore, the size of the filter means will typically be such that when the filter means are placed into the sample containers and are supported by the bottom wall of the sample containers, the periphery of the filter means will also abut the side walls of the sample container. Accordingly, the filter means will typically correspond to the size of the sample container near the bottom wall where the filter means are placed or they can be slightly larger. Accordingly, a filter sheet is obtained with preformed filter means that correspond in number, arrangement and shape to the sample containers of the array. This filter sheet is registered with the inlet openings of the sample containers such that the filter means can then be separated from the filter sheet and inserted into the sample containers. Separation of the filter means can be caused by pressing the filter means into the sample container thereby tearing off the filter means or alternatively, the filter means may be separated by cutting at the periphery. The remainder of the filter sheet is removed. In accordance with the method of this invention, the filter means are placed such that they are supported by the bottom wall and are in abutment with the side walls of the sample container along their periphery. It should be understood that while the method of the present invention has been described with a certain order of the steps to be taken, it is clear that the steps of the present method of the invention may also be carried out in another order.
[0024] In accordance with a preferred embodiment of the present invention, the sample containers contain a band enclosing an opening. This band abuts along its periphery, the inner surface of the side wall(s) of the sample containers and presses or holds the filter means against the bottom wall of the sample container. The bands generally conform to the shape of the sample container and are preferably rings when the sample containers are tubular. The bands are preferably plastic or rubbery.
[0025] If bands are provided in the sample containers, they can be placed therein individually or they can be placed into the sample containers in a similar fashion as the placement of the filter means. Thus, a plurality of interconnected bands may be provided, for example connected via a thin film sheet. These interconnected bands can then be placed on the upper end of the sample containers in register with the inlet openings of the sample containers and they can then be separated from each other and pressed into the sample containers to abut the filter means.
[0026] Micro-titer plates produced in accordance with the present invention generally are less prone to cross-talk, are fairly convenient to produce, and have a good separation performance. With the micro-titer plates of the present invention, it is possible to perform a physical separation, a chemical separation, or a bio-polymer separation or extraction of liquids containing plant, animal or human cells, and it allows, in particular, to perform the separation of nucleic acids and/or proteins of the cells. To this effect, the liquid in the sample container penetrates a filter means having selective adsorbing material, the liquid leaving the filter means and entering a collecting container. Preferably, the filter means having selectively adsorbing material has chromatographic properties, which can include ion exchange properties or affinity-chromatographic properties, if the filter means comprises suitable affinity ligands. A preferred filter means comprises a fibrillated polytetrafluoroethylene matrix having enmeshed therein sorptive derivatized silica particulates as are disclosed in U.S. Pat. Nos. 4,810,381 and 4,699,717, respectively. Subsequently, the collecting container is replaced by another one, and a liquid containing a solvent is applied onto the filter means, which selectively removes a certain portion of the material adsorbed in the filter means so that it may enter the collecting container.
[0027] The filter means of the device of the present invention may comprise one or several layers. Preferred filter means comprise a fibrillated polytetrafluoroethylene matrix having sorptive particulates enmeshed therein, as is disclosed, for example, in U.S. Pat. No. 4,810,381. In one embodiment, the filter means may be formed by two porous fixation means, in particular frits, with particles therebetween. Preferably, the particles can be in the form of bulk material, have chromatographic properties as described before. The preferred particles are made from a material that is based on silica gel, dextran or agarose. Frits may consist of glass, polyethylene (PE) or polytetrafluoroethylene (PTFE) and have a pore size of about 0.1-250 μm, preferably about 100 μm.
[0028] The thickness of the particle layer is about 1-10 mm, preferably 2.5 mm, with an average particle size of 1-300 μm, preferably 16-23 μm.
[0029] According to a further embodiment, the filter means has a support membrane in which the adsorptive particles are embedded. Since the support membrane can be rather weak and there being a possibility that it can burst when a partial vacuum is applied on it (of comparatively high pressure difference), a back-up fabric or fibrous layer can be arranged below the support membrane, which provides integrity to the support membrane on the bottom wall of the sample container and preferably consists of a non-woven polyalkylene fibrous material such as polypropylene or polyethylene.
[0030] The micro-titer plate of the present invention is not limited to the dimensions of the single parts mentioned herein. Generally, the micro-titer plate of the invention can be produced in any desired size. Nevertheless, the method of the present invention is particularly suitable for producing micro-titer plates that have a large number of sample containers per unit of area.
[0031] Accordingly, the present invention in another aspect also provides a micro-titer plate comprising an array of between 360 and 400 sample containers connected to each other each having one or more side walls enclosing the interior of said sample container, a bottom wall with an outlet opening and an opposite upper end that is open and defines an inlet opening and each of said sample containers having an individual filter means that is in abutment with the side walls along its periphery and that is further in abutment with said bottom wall and wherein said micro-titer test plate has a length between 11 and 13 cm and a width between 8 and 9 cm.
[0032] Typically, the micro-titer plates produced in connection with this invention will have a plurality of sample containers connected to each other each generally of a tubular form although other forms such as sample containers that have at least a section with a rectangular or square cross-section can be used as well. The side walls enclosing the interior of the sample containers may taper towards the outlet opening although preferably the sample containers are tubular without substantially tapering towards the outlet opening. The outlet openings of the sample containers of the micro-titer plates that can be produced in connection with this invention preferably are enclosed by an outlet spout that extends in the axial direction of the sample container. This spout is preferably tapered towards its free end and may be surrounded by a collar.
[0033] In another aspect, the present invention provides a well-less filtration device that includes a pre-filter layer; a support layer; and at least one layer of solid phase extraction medium disposed between the pre-filter layer and the support layer. At least a portion of the pre-filter layer, support layer and solid phase extraction medium are ultrasonically welded together to form a pattern of filter cells and land areas with the land areas being disposed between the filter cells. The filter cells of the device may be arranged to conform to a standardized array format.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The invention is further illustrated by means of reference to the following drawings that represent preferred embodiments of the invention without however the intention to limit the invention thereto:
[0035] [0035]FIGS. 1 a and 1 b show a schematic drawing of a filter sheet showing a plurality of filter means partially cut out.
[0036] [0036]FIG. 2 shows a cross-sectional view of an individual sample container of a micro-titer plate according to the invention.
[0037] [0037]FIG. 3 shows three dimensional representation of a micro-titer plate in connection with the invention.
[0038] [0038]FIGS. 4 a - d schematically shows the insertion of the filter means into the sample containers by tearing them of the filter sheet.
[0039] [0039]FIG. 5 shows the remainder of the filter sheet after the filter means have been separated therefrom.
[0040] [0040]FIG. 6 shows a plurality of rings that are connected of each other by a film.
[0041] [0041]FIG. 7 shows the placement of the rings shown in FIG. 6 into the sample containers of a micro-titer plate according to the invention.
[0042] [0042]FIGS. 8 a - d schematically illustrate a filter sheet having filter means preformed therein via ultrasonic welding.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] Referring now to FIG. 3, there is shown a three dimensional representation of an array of a plurality of sample containers 10 connected to each other. As shown in FIG. 3, the sample containers 10 are connected to each other by a plate 72 . FIG. 2 shows a cross-sectional view of an individual sample container 10 , preferably tubular, of a micro-titer plate produced in connection with the method of the present invention, i.e. with filter means 28 already inserted therein. As can be seen from FIG. 2, each of the plurality of sample containers has a side wall 12 enclosing the interior of the sample container 10 . Sample container 10 further has an upper end 14 which is open and defines an inlet opening 16 . Opposite to the upper end is bottom wall 20 for supporting filter means 28 . Bottom wall 20 has an opening 22 that defines the outlet opening of sample container 10 . The outlet opening 22 is enclosed by a spout 24 which extends in the axial direction of the sample container 10 . Spout 24 preferably tapers towards its free end 26 and can have a length of up to 2 cm, preferably 0.1 to 1 cm, more preferably, 0.2 to 1 cm. The diameter of the spout which optionally decreases towards the free end of spout 24 is typically 0.2 to 2.0 mm. The lower surface of bottom wall 20 of sample container 10 also has an axially projecting annular collar 40 formed thereon and which coaxially encloses the outlet spout 24 . Collar 40 is shorter than outlet spout 24 which projects downwards beyond the end of collar 40 for about half the length thereof.
[0044] [0044]FIG. 2 further shows the filter means 28 within the sample container 10 . Filter means 28 is disposed on bottom wall 20 , covers outlet opening 22 and is in abutment along its periphery with the inner surface of side wall 12 . A rubbery, preferably plastic retaining ring 30 pressing against the inner surface of side wall 12 keeps filter means 28 set against the bottom wall 20 .
[0045] With reference to FIGS. 1 a , 1 b and FIGS. 4 a - d , the method of the present invention for inserting filter means 28 in each of the sample containers 10 will now be illustrated. In accordance with the method of the present invention, there is provided a filter sheet 1 . As shown in FIGS. 1 a and 1 b filter means 28 are partially cut out in the filter sheet 1 . A plurality of filter means 28 are partially cut out from a single filter sheet, which conform in arrangement, shape and number to the plurality of sample containers of the array in which the filter means will be inserted. FIGS. 1 a and 1 b show a few of such filter means 28 partially cut out in the filter sheet 1 . Filter means 28 of FIG. 1 a have a circular periphery to conform to a tubular sample container. As can be seen, filter means 28 in FIG. 1 a have been cut along there periphery except for two oppositely laying points 2 , 3 where the filter means 28 remain connected to the filter sheet 1 . Filter means 28 of FIG. 1 b have a square periphery to conform to a sample container that has a square cross-section in a plane parallel to the bottom wall of the sample container. The filter means 28 in FIG. 1 b have been cut along the periphery leaving only the four comers at the periphery uncut.
[0046] As described above, the filter means may also be preformed using ultrasonic consolidation of a prefilter layer and a porous support layer at the periphery of the filter means. FIG. 8 illustrates an embodiment of an ultrasonically preformed filter means.
[0047] According to the embodiment illustrated, the edges of strip of the filter sheet can be consolidated into a solid film and subsequently notched to allow interaction with a sprocket drive mechanism that precisely advances the filter sheet through the ultrasonic consolidation apparatus, thereby affording precise positioning of the anvil and horn of the ultrasonic welding device. FIG. 8A is a schematic top view and FIG. 8B is a schematic perspective representation of a filter sheet 322 after the indexing sprockets have been removed. FIG. 8C is a schematic representation of cross-section AA of FIG. 8A showing preformed filter means 324 and compressed land areas 326 . FIG. 8D is a schematic representation of an expanded area of FIG. 8C that more clearly shows preformed filter means 324 , land areas 326 and smaller uncompressed areas 328 of filter sheet 322 between adjacent preformed filter means.
[0048] In the ultrasonic welding method to preform the filter means, the shape, size, and spacing of filter cells can be varied over a broad range simply by changing the embossing pattern on the horn and anvil of the ultrasonic consolidation apparatus.
[0049] The following example illustrates a detailed method of preforming the filter means by using the ultrasonic welding technique. A polytetrafluoroethylene (PTFE) having enmeshed therein C18 hydrocarbon derivatised silica particles (mean volume particle size=55 microns, supplied by Varian or United Chemical Technologies) and glass beads was prepared according to the procedure described in U.S. Pat. No. 4,656,663 (Errede et al.). The SPE sheet composition consisted of 6 wt. % C18 hydrocarbon coated beads relative to the weight of the 70 micron glass beads (supplied by 3M Company, St. Paul, Minn. under the trade designation TUNGO) and 2.0 wt. % PTFE (supplied by ICI Americas, Inc. under the trade designation FLURON) relative to the weight of the 70 micron glass beads. The dough was passed through a two-roll mill eight times to produce a SPE membrane 0.064 cm thick and having a durometer of 35.
[0050] The thus formed SPE sheet was placed between two layers of spun bond polypropylene CELESTRA fabric (commercially available from BBA Nonwovens, Simpsonville, S.C.) and the three layer laminate formed into a unitized structure (117 mm×77 mm)using a pinch welding operation in a Branson 901 ae ultrasonic plunge welding machine, (900 watts power, available from Branson Ultrasonics, Danbury, Conn.) equipped with a standard cut-and-seal ultrasonic welding anvil. The anvil had a cutting angle of 25 degrees, the weld time was 1.0 second, and the hold time was 0.17 seconds.
[0051] Ninety-six filter cells, 4 mm in diameter were formed in the filter sheet in a 8×12 array, with a land area approximately 1.5 mm wide separating the adjacent filter cells. Land formation was accomplished using a Branson 901 ae ultrasonic plunge welding machine equipped with an anvil and horn having a matching 48-cell array. The anvil was formed from heat-treated D2 tool steel and had 4 mm diameter circular depressions and 1.5 mm wide welding flats that produced the desired filter cell/land pattern. Filter cells were formed in a two-step operation, with 48 cells being formed in each step. Approximately 1700 watts of power were required for each plunge welding operation with a weld time of 1.0 second, and a hold time was 0.17 second. Filter cell registration for the formation of the second set of 48 filter cells was maintained through frame/anvil fixturing.
[0052] The effectiveness of the land areas' ability to prevent lateral liquid transfer between adjacent preformed filter means was demonstrated by using the above described platecard to isolate a dye from an aqueous solution. A Nile Blue dye (available from Aldrich Chemical, Milwaukee, Wis.) was placed on the filter means and removed and examined for evidence of lateral transfer of the dye. The dye was totally retained within all 96-filter cell areas with no indication of lateral transfer.
[0053] [0053]FIGS. 4 a to 4 d show a cross-sectional view of the plurality of sample containers 10 connected to each other. As shown in FIG. 4 a , the filter sheet 1 with a plurality of filter means 28 partially cut out is placed on inlet openings 16 at the upper end of the plurality of sample containers such that the filter means 28 are in register with the inlet openings 16 . To place the filter means 28 into register with the inlet openings 16 , registering aids well known to those skilled in the art may be employed if desired. For example, the array of sample containers may be provided with register pins (not shown) and the filter sheet 1 can be provided with corresponding register holes (not shown). Further shown in FIG. 4 a is a plurality of pistons 32 that are dimensioned such that they can penetrate the interior of the sample containers 10 up to the bottom of the sample containers 10 . As shown in FIG. 4 b , by moving the plurality of pistons 32 downwards or alternatively by moving the sample containers 10 with the filter sheet thereon over the pistons, the filter means 28 are torn off at the points were they were still connected at the filter sheet 1 and are pressed by the pistons against the bottom wall 20 of the sample container 10 . To avoid that the filter means 28 would be incorrectly positioned at the bottom wall, it may be desirable to apply a vacuum to the pistons to keep the filter means in position while pressing them downwards into the sample containers 10 . However, if movement of the pistons into the sample containers 10 is fast enough, the risk of an incorrect positioning of the filter means will be low and it may not be necessary to apply a vacuum to the pistons in that case. Instead of tearing off the filter means 28 , they may be cut at the points where they are still connected to the filter sheet 1 . For example, the points may be cut by a laser or alternatively, the edges of the pistons may be provided as sharp edges to cut the points while pressing the filter means 28 into the sample containers 10 . When the points are cut to separate the filter means 28 from the filter sheet, cutting of the points is then generally carried out while the filter means 28 are in register with the openings 16 and thereafter the filter means 28 can be pressed by the pistons 32 against the bottom wall 20 . FIG. 4 c shows the result after the pistons are again withdrawn. As can be seen from this figure, the filter means 28 are now supported by the bottom wall of the sample containers 10 and abut the inner surface of the side wall 12 of the containers 10 . The remainder of filter sheet 1 from which the filter means 28 were separated is left on the upper end of the sample containers 10 . This remainder of the filter sheet 1 is then removed. FIG. 5 shows a planar view of filter sheet 1 showing the circular openings 82 created by separation of the filter means 28 from filter sheet 1 .
[0054] According to a preferred embodiment in connection with the present invention, the filter means 28 are pressed against the bottom wall by a band 30 defining an opening and abutting the inner surface of side wall 12 . Preferably band 30 is a ring. These rings may be individually inserted by pistons but are preferably inserted in a similar way in which the filter means 28 are inserted in the sample containers 10 . This is illustrated in FIGS. 6 and 7.
[0055] [0055]FIG. 6 shows a planar view as well as a cross-section along the indicated line of a plurality of rings 30 that are connected to each other by thin film 31 . The film 31 may be thinned at the circumference of the rings 30 to make separation of the rings 30 from the film 31 easier. Alternatively, rings 30 may be connected to each other via thin rods. As shown in FIG. 7, the film 31 with rings 30 is placed on the upper end of the sample containers 10 such that they are in register with openings 16 of the sample containers 10 . Pistons 32 may then press the rings into the sample containers 10 while simultaneously separating the rings 30 from the film 31 . Pistons 32 will push the rings 30 against the filter means 28 to cause a press-tight connection therewith. To further ease the separation of the rings 30 from the film 31 , the pistons may be provided with sharp edges to cut the rings along their circumference. Also, the rings 30 may be partially cut along their circumference in a similar way as the filter means 28 are partially cut from the filter sheet 1 .
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The present invention provides a well-less filtration device that includes a pre-filter layer; a support layer; and at least one layer of solid phase extraction medium disposed between the pre-filter layer and the support layer. At least a portion of the pre-filter layer, support layer and solid phase extraction medium are ultrasonically welded together to form a pattern of filter cells and land areas with the land areas being disposed between the filter cells. The filter cells of the device may be arranged to conform to a standardized array format.
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FIELD
The present application relates to a process for manufacturing a paperboard from a high consistency pulp slurry of cellulosic fibers containing high levels of intrafiber crosslinked celluosic fibers.
SUMMARY
This application is directed to a process for manufacturing a paperboard from a high consistency pulp slurry containing high levels of crosslinked cellulosic fibers by dispersing the fibers in a screen with a rotor in the screen and then passing the fibers through the screen basket with a hole diameter of at least 2 mm and forming the cellulosic fibers on a foraminous support. Another slurry of regular cellulosic fibers is deposited on at least one side of the first slurry during the formation process.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the attendant advantages of this disclosure will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction the accompanying drawings, wherein:
FIG. 1 is a schematic representation of the equipment components utilized in the present application.
FIG. 2 is a lobed rotor.
FIG. 3 is a foil rotor.
FIG. 4 is a bump rotor.
FIG. 5 is a schematic cross-sectional view of a two ply paperboard.
FIG. 6 shows a wall section of a hot cup container.
DETAILED DESCRIPTION
High consistency slurries containing high levels of crosslinked cellulosic fibers cannot be used in paperboard machines due to plugging of the screen by the high levels of crosslinked cellulosic fibers in the slurry. A process for using the high consistency slurry containing high levels of crosslinked cellulosic fibers has been discovered which overcomes this problem.
Referring to FIG. 1 , a high consistency slurry of cellulosic fibers is formed in a dispersion medium, such as water, in a slurry tank, 10 . The resulting slurry is then pumped to a consistency regulator, 12 , where dilution water is added to maintain a fixed consistency. Subsequently the slurry is pumped to the machine chest, 14 , and then into a screen basket, 16 , which may be vertically or horizontally mounted. Various types of rotors may be mounted in the screen basket such as a lobed, foil or bump rotor (see FIGS. 2 , 3 , and 4 ) manufactured by GL&V, Watertown, N.Y. The rotors serve to disperse the fibers in the screen and force acceptable fibers through the screen basket and then to a headbox 18 . Fibers tat are rejected pass to a flat screen, 16 a, where they are further separated into rejects which are discarded and acceptable fibers which are returned to the machine chest, 14 . The headbox may be a single ply headbox, a multiply headbox or two or more single ply headboxes arranged to form two or more layers formed by combining one layer from each single ply headbox. From the headbox, the pulp is formed on the wire, 20 , dewatered and dried.
In one embodiment of the method, at least one high consistency slurry of cellulosic fibers is formed in an aqueous dispersion medium. The cellulosic fibers which are both crosslinked cellulosic fibers and regular cellulosic fibers, are dispersed in a screen by means of a rotor in the screen and then passed through the screen which has a hole diameter of at least 1.5 mm. The cellulosic fibers are formed on a foraminous support. Rotors can be of various types such as lobed, foil, bump, and S; the listing is not meant to limit the types suitable for this application and known by the skilled artisan. In another embodiment the fibers are passed through a screen which has a hole diameter of at least 2 mm. Screen hole sizes up to 6 mm can be used. As used herein, the term “consistency” means the percent solids content of a liquid and solid mixture, for example, a consistency of 2 percent cellulosic fibers means there are two grams of cellulosic fibers in one hundred grams of fiber and liquid. In another embodiment the slurry consistency is at least 2.5 percent and in yet another embodiment the slurry consistency is at least 3 percent. A high consistency slurry means a solid content of 3 to 4 percent, a medium consistency slurry means a solid content of 1 to 2 percent and a low consistency slurry means a solid content of less than 1 percent solids.
Crosslinked cellulosic fibers can be present in the high consistency slurry at levels of at least 35 percent by weight of the total fibers in the high consistency slurry. In one embodiment they are present at a level of at least 40 percent by weight of the total fiber content in the high consistency slurry. In another embodiment they are present at a level of at least 50 percent by weight of the total fiber content in the high consistency slurry and in yet another embodiment they are present at a level of at least 60 percent by weight of the total fiber in the high consistency slurry.
The preferred crosslinked cellulosic fibers for use in the application are crosslinked cellulosic fibers. Any one of a number of crosslinking agents and crosslinking catalysts, if necessary, can be used to provide the crosslinked fibers to be included in the layer. The following is a representative list of useful crosslinking agents and catalysts. Each of the patents noted below is expressly incorporated herein by reference in its entirety.
Suitable urea-based crosslinking agents include substituted ureas, such as methylolated ureas, methylolated cyclic ureas, methylolated lower alkyl cyclic ureas, methylolated dihydroxy cyclic ureas, dihydroxy cyclic ureas, and lower alkyl substituted cyclic ureas. Specific urea-based crosslinking agents include dimethyldihydroxy urea (DMDHU, 1,3-dimethyl-4,5-dihydroxy-2-imidazolidinone), dimethyloldihydroxy-ethylene urea (DMDHEU, 1,3-dihydroxymethyl-4,5-dihydroxy-2-imidazolidinone), dimethylol urea (DMU, bis[N-hydroxymethyl]urea), dihydroxyethylene urea (DHEU, 4,5-dihydroxy-2-imidazolidinone), dimethylolethylene urea (DMEU, 1,3-dihydroxymethyl-2-imidazolidinone), and dimethyldihydroxyethylene urea (DMeDHEU or DDI, 4,5-dihydroxy-1,3-dimethyl-2-imidazolidinone).
Suitable crosslinking agents include dialdehydes such as C 2 -C 8 dialdehydes (e.g., glyoxal), C 2 -C 8 dialdehyde acid analogs having at least one aldehyde group, and oligomers of these aldehyde and dialdehyde acid analogs, as described in U.S. Pat. Nos. 4,822,453; 4,888,093; 4,889,595; 4,889,596; 4,889,597; and 4,898,642. Other suitable dialdehyde crosslinking agents include those described in U.S. Pat. Nos. 4,853,086; 4,900,324; and 5,843,061. Other suitable crosslinking agents include aldehyde and urea-based formaldehyde addition products. See, for example, U.S. Pat. Nos. 3,224,926; 3,241,533; 3,932,209; 4,035,147; 3,756,913; 4,689,118; 4,822,453; 3,440,135; 4,935,022; 3,819,470; and 3,658,613. Suitable crosslinking agents may also include glyoxal adducts of ureas, for example, U.S. Pat. No. 4,968,774, and glyoxal/cyclic urea adducts as described in U.S. Pat. Nos. 4,285,690; 4,332,586; 4,396,391; 4,455,416; and 4,505,712.
Other suitable crosslinking agents include carboxylic acid crosslinking agents such as polycarboxylic acids. Polycarboxylic acid crosslinking agents (e.g., citric acid, propane tricarboxylic acid, and butane tetracarboxylic acid) and catalysts are described in U.S. Pat. Nos. 3,526,048; 4,820,307; 4,936,865; 4,975,209; and 5,221,285. The use of C 2 -C 9 polycarboxylic acids that contain at least three carboxyl groups (e.g., citric acid and oxydisuccinic acid) as crosslinking agents is described in U.S. Pat. Nos. 5,137,537; 5,183,707; 5,190,563; 5,562,740; and 5,873,979.
Polymeric polycarboxylic acids are also suitable crosslinking agents. Suitable polymeric polycarboxylic acid crosslinking agents are described in U.S. Pat. Nos. 4,391,878; 4,420,368; 4,431,481; 5,049,235; 5,160,789; 5,442,899; 5,698,074; 5,496,476; 5,496,477; 5,728,771; 5,705,475; and 5,981,739. Polyacrylic acid and related copolymers as crosslinking agents are described U.S. Pat. Nos. 5,549,791 and 5,998,511. Polymaleic acid crosslinking agents are described in U.S. Pat. No. 5,998,511 and U.S. application Ser. No. 09/886,821.
Specific suitable polycarboxylic acid crosslinking agents include citric acid, tartaric acid, malic acid, succinic acid, glutaric acid, citraconic acid, itaconic acid, tartrate monosuccinic acid, maleic acid, polyacrylic acid, polymethacrylic acid, polymaleic acid, polymethylvinylether-co-maleate copolymer, polymethylvinylether-co-itaconate copolymer, copolymers of acrylic acid, and copolymers of maleic acid. Other suitable crosslinking agents are described in U.S. Pat. Nos. 5,225,047; 5,366,591; 5,556,976; and 5,536,369.
Suitable crosslinking catalysts can include acidic salts, such as ammonium chloride, ammonium sulfate, aluminum chloride, magnesium chloride, magnesium nitrate, and alkali metal salts of phosphorous-containing acids. In one embodiment, the crosslinking catalyst is sodium hypophosphite.
The crosslinking agent is applied to the cellulosic fibers as they are being produced in an amount sufficient to effect intrafiber crosslinking. The amount applied to the cellulosic fibers may be from about 1% to about 25% by weight based on the total weight of fibers. In one embodiment, crosslinking agent in an amount from about 4% to about 6% by weight based on the total weight of fibers. Mixtures or blends of crosslinking agents may be used.
Although available from other sources, noncrosslinked cellulosic fibers usable in the present application are derived primarily from wood pulp. Suitable wood pulp fibers for use with the application can be obtained from well-known chemical processes such as the kraft and sulfite processes, with or without subsequent bleaching. Pulp fibers can also be processed by thermomechanical, chemithermomechanical methods, or combinations thereof. The preferred pulp fiber is produced by chemical methods. Groundwood fibers, recycled or secondary wood pulp fibers, and bleached and unbleached wood pulp fibers can be used. Softwoods and hardwoods can be used. Details of the selection of wood pulp fibers are well known to those skilled in the art. These fibers are commercially available from a number of companies, including Weyerhaeuser Company, the assignee of the present invention. For example, suitable cellulose fibers produced from southern pine that are usable with the present application are available from Weyerhaeuser Company under the designations CF416, CF405, NF405, PL416, FR416, FR516, and NB416. Dissolving pulps from northern softwoods include MAC11 Sulfite, M919, WEYCELL and TR978 all of which have an alpha content of 95% and PH which has an alpha content of 91%. High purity mercerized pulps such as HPZ, HPZ111, HPZ4, and HPZ-XS available from Buckeye and Porosonier-J available from Rayonier are also suitable.
Screen hole diameter can vary. In one embodiment the hole diameter is at least 2 mm, in another embodiment the hole diameter is at least 3 mm. Rotors in the screen used to disperse the fibers and force the fibers through the screen can be lobed, bump or foil rotors. Foil rotors can have from four to ten foils.
Hot foods, particularly hot liquids, are commonly served and consumed in disposable containers. These containers are made from a variety of materials including paperboard and foamed polymeric sheet material. One of the least expensive sources of paperboard material is cellulose fibers. Cellulose fibers are employed to produce excellent paperboards for the production of hot cups, paper plates, and other food and beverage containers. Conventional paperboard produced from cellulosic fibers, however, is relatively dense, and therefore, transmits heat more readily than, for example, foamed polymeric sheet material. Thus, hot liquids are typically served in double cups or in cups containing multiple plies of conventional paperboard.
It is desirable to manufacture a paperboard produced from cellulosic material that has good insulating characteristics, that will allow the user to sense that food in the container is warm or hot and at the same time will allow the consumer of the food beverage in the container to hold the container for a lengthy period of time without the sensation of excessive temperature. It is further desirable to provide a paperboard that can be tailored to provide a variety of insulating characteristics.
Referring to FIG. 5 , the substrate 50 for the insulating paperboard 52 of the present application is produced in a conventional manner from readily available fibers such as cellulosic fibers. At least one ply, 54 , of the paperboard contains crosslinked fibers. The paperboard of the present application can be made in a single-ply, a two-ply construction, or a multi-ply construction, as desired. While the paperboard of the present application may employ synthetic fibers as set forth above, it is most preferred that paperboard comprise all or substantially all of the cellulosic fibers.
The distinguishing characteristic of the present application is that at least one ply of the paperboard, whether a single-ply or a multiple-ply structure, contains crosslinked cellulosic fibers. The crosslinked cellulosic fibers increase the bulk density of the paperboard and thus the insulating characteristics. As used herein, crosslinked cellulosic fibers are kinked, twisted, curly, cellulosic fibers. It is preferred, however, that the fibers be produced by intrafiber crosslinking of the cellulosic fibers as described earlier.
Paperboard of the present application may have a broad set of characteristics. For example, its basis weight can range from 200 gsm to 500 gsm, more preferably, from 250 gsm to 400 gsm. Most preferably, the basis weight of the paperboard is equal to or greater than 250 gsm. To achieve the insulating characteristics of the present invention, it is preferred that the paperboard has a density of less than 0.5 g/cc, more preferably, from 0.3 g/cc to 0.45 g/cc, and most preferably, from 0.35 g/cc to 0.40 g/cc.
When at least one ply of the paperboard contains crosslinked cellulosic fibers in accordance with the present invention, advantageous temperature drop characteristics can be achieved. These temperature drop characteristics can be achieved by altering the amount of crosslinked cellulosic fiber introduced into the paperboard, by adjusting the basis weight of the paperboard, by adjusting the caliper of the paperboard after it has been produced by running it, for example, through nip rolls, and of course, by varying the number and thickness of additional plies incorporated in the paperboard structure. It is preferred that this paperboard have a caliper greater than or equal to 0.5 mm, a basis weight equal to or greater than 250 gsm, and a density less than 0.5 g/cc defined below.
The paperboard of the present application can be a single-ply product. When a single-ply product is employed, the low density characteristics of the paperboard allow the manufacture of a thicker paperboard at a reasonable basis weight. To achieve the same insulating characteristics with a normal paperboard, the normal paperboard thickness would have to be doubled relative to that of the present invention. Using the crosslinked cellulosic fibers of the present invention, an insulating paperboard having the same basis weight as a normal paperboard can be made. This effectively allows the manufacture of insulating paperboard on existing paperboard machines with minor modifications and minor losses in productivity. Moreover, a one-ply paperboard has the advantage that the whole structure is at a low density.
Alternatively, the paperboard of the application can be multi-ply product, and include two, three, or more plies. Paperboard that includes more than a single-ply can be made by combining the plies either before or after drying. It is preferred, however, that a multi-ply paperboard be made by using multiple headboxes arranged sequentially in a wet-forming process, or by a baffled headbox having the capacity of receiving and then laying multiple pulp furnishes. The individual plies of a multi-ply product can be the same or different.
The paperboard of the present application can be formed using conventional papermaking machines including, for example, Rotoformer, Fourdrinier, cylinder, inclined wire Delta former, and twin-wire forming machines.
When a single-ply paperboard is used in accordance with the present invention, it is preferably homogeneous in composition. The single ply, however, may be stratified with respect to composition and have one stratum enriched with crosslinked cellulosic fibers and another stratum enriched with non-crosslinked cellulosic fibers. For example, one surface of the paperboard may be enriched with crosslinked cellulosic fibers to enhance that surface's bulk and the other surface enriched with non-crosslinked fibers to provide a smooth, denser, less porous surface.
The most economical paperboard to produce is homogeneous in composition. The crosslinked cellulosic fibers are uniformly intermixed with the regular cellulosic fibers. For example, in the headbox furnish it is preferred that the crosslinked cellulosic fibers present in high consistency slurry be present in an amount from about 25% to about 100%, and more preferably from about 30% to about 70%. In one embodiment the crosslinked cellulosic fibers are present at a level of at least 35 percent by weight of the total fiber content. In another embodiment the crosslinked fibers are present at a level of alt least 50 percent by weight of total fiber content. In yet another embodiment the crosslinked fibers are present at a level of at least 60 percent by weight of the total fiber content. In a two-ply structure, for example, the first ply may contain 100% non-crosslinked cellulosic fibers while the second ply may contain from 25% to 100% crosslinked cellulosic fibers or from 30% to 70% crosslinked cellulosic fibers. In a three-ply layer, for example, the bottom and top layers may comprise 100% of non-crosslinked cellulosic fibers while the middle layer contains from about 25% to about 100% and preferably from about 30% to about 70% of crosslinked cellulosic fibers.
When crosslinked cellulosic fibers are used in paperboard in accordance with the present invention, it has been found that the paperboard exiting the papermaking machine can be compressed to varying degrees to adjust the temperature drop characteristics across the paperboard. The paperboard once leaving the papermaking machine may be compressed or reduced in caliper by up to 50%, and more preferably, from 15% to 25%. This same result can be achieved by lowering the basis weight of the paperboard.
The paperboard of the present application can be utilized to make a variety of structures, particularly containers, in which it is desired to have insulating characteristics. One of the most common of these containers is the ubiquitous hot cup utilized for hot beverages such as coffee, tea, and the like. Other insulating containers such as the ordinary paper plate can also incorporate the paperboard of the present invention. Also, carry-out containers conventionally produced of paperboard or of foam material can also employ the paperboard of the present invention. FIG. 6 shows a wall section of a hot cup type container produced which may comprise one or more plies 62 and 64 , one of which, in this instance, 64 , contains crosslinked cellulosic fibers. In this embodiment the crosslinked cellulosic fibers are in the interior ply 64 . A liquid impervious backing is preferably extruded or poly coated to the interior ply coated to the. The backing may comprise, for example, a variety of thermoplastic materials, such as polyethylene. It is preferred that the paperboard used in the bottom of the cup contain no bulky fibers.
EXAMPLES 1-9
High consistency slurries were prepared at a 3.2 percent consistency containing 50 to 65 percent by weight citric acid crosslinked cellulosic fibers. The crosslinked fiber was deflaked with a standard Beloit Jones refiner with a zero load. Douglas Fir cellulosic fibers were used as the other component in the high consistency slurry. In some cases the Douglas Fir was refined to 650 CSF. A screen hole size of 2 mm was used in all cases. A rotor with six foils, a bump rotor and a lobed rotor, all well known in the art and manufactured by GL&V, Watertown, N.Y., were used in the screen for different trials. Trials were conducted on a pilot screen machine at GL&V, Watertown, N.Y., that allowed stock to be recirculated through the unit back to the screen tank pump. Flow rates ranged from approximately 3785 l/m (1000 gpm) to 5678 l/m (1500 gpm). Fiber reject rates were run at 10 to 13 percent.
TABLE 1
Screen Trials
Basket
Deflaked
Hole size,
Condition
HBA
Consistency
Doug Fir
mm
Rotor
2
53%
1%
non refined
2
6 foils
1
53%
3.2%
non refined
2
6 foils
3
60%
3.2%
non refined
2
bump
4
60%
3.2%
non refined
2
lobed
5
60%
3.2%
non refined
2
lobed
6
60%
3.2%
non refined
2
lobed
7
60%
3.2%
non refined
2
lobed
8
65%
3.2%
650 CSF
2
lobed
9
65%
3.2%
650 CSF
2
lobed
Condition 2 ran well at 10 percent reject rates and feed rates of 3255 l/m (860 gpm) to 5300 l/m (1400 gpm). Condition 1 ran at a reject rate of 17% but when the reject rate was reduced, the reject line plugged into the center of the screen basket with thick stock.
Condition 3 was run with GL&V's barracuda rotor, a bump rotor, in a random pattern. The run was started with a full reject line but as soon as the accepts line was opened, the flow started to fall off due to stock thickening. The rotor is noted for tendency to fractionate fiber.
All the remaining runs ran well as follows:
Condition 4, the run was made with an 11% reject rate, 0.14 kPa (3 lb) differential pressure to the screen and a rotor speed of 900 RPM. Increasing the rotor speed to 1000 RPM had no impact.
Condition 5, the rotor speed was dropped to 800 RPM, at this point the reject flow started to drop off and the rotor speed was returned to 900.
Condition 6 was the same as condition 4.
Condition 7, the inlet pressure was increased 0.48 kPa (10 lb), feed flow increased from 900 GPM to 4164 l/m (1100 GPM) and the differential pressure increased to 0.17 (3.5 lb). This condition ran well.
Condition 8 was run at a reject rate of 15% with a 3123 I/m (825 GPM) feed flow rate.
Condition 9 was run at a at 13% reject rate with a 3785 l/m (1000 GPM) feed flow rate.
Theses results indicate that screening at 3.2% consistency and 50% to 65% HBA was successful with a lobed style rotor design.
Fiber samples were obtained from the feed stock, the accepts line and the reject line and microscopically analyzed for fiber content. The results, shown in Table 2, indicate that, using various rotor and the 2 mm screen hole size, there was no selective fractionation of the crosslinked fiber.
TABLE 2
Microstructure - Screen Slush Samples
Bleached Softwood
Crosslinked
Rotor Type
Condition
Kraft %
fiber, %
Lobed, F
9
40
60
Lobed, A
9
35
65
Lobed, R
9
38
62
6 Foils, F
1
46
54
6 Foils, A
1
44
56
6 Foils, R
1
45
55
6 Foils, F
2
41
59
6 Foils, A
2
41
59
6 Foils, R
2
46
54
Bump, F
3
39
61
Bump, A
3
39
61
Bump, R
3
38
62
F, feed stock;
A, Accepts;
R, Rejects
EXAMPLE 10
A 3 to 3.2 percent high consistency slurry was prepared containing 40 percent by weight crosslinked cellulosic fibers; Douglas Fir wet lap was used as the regular fiber. A screen with a 4 mm hole diameter and a six foil rotor was used prior to the mid ply headbox. A separate slurry containing only Douglas Fir or Pine fibers was refined to 500 CSF and diluted to 0.5 percent consistency prior to pumping the slurry to the outer headboxes. A paperboard was formed on a 500 cm paperboard machine.
EXAMPLE 11
A 3 to 3.2 percent high consistency slurry is prepared containing 40 percent by weight crosslinked cellulosic fibers; Douglas Fir wet lap is used as the regular fiber. A screen with a 2 mm hole diameter equipped with a lobed rotor is used prior to the mid-ply headbox. A separate slurry containing only Douglas Fir or Pine fibers is refined to 500 CSF and diluted to 0.5 percent consistency prior to pumping the slurry to the outer headboxes. A paperboard is formed on a 500 cm paperboard machine.
EXAMPLE 12
A 3 to 3.2 percent high consistency slurry is prepared containing 50 percent by weight crosslinked cellulosic fibers; Douglas Fir wet lap is used as the regular fiber. A screen with a 2 mm hole diameter equipped with a lobed rotor is used prior to the mid-ply headbox. A separate slurry containing only Douglas Fir or Pine fibers is refined to 500 CSF and diluted to 0.5 percent consistency prior to pumping the slurry to the outer headboxes. A paperboard is formed on a 500 cm paperboard machine.
EXAMPLE 13
A 3 to 3.2 percent high consistency slurry is prepared containing 55 percent by weight crosslinked cellulosic fibers; Douglas Fir wet lap is used as the regular fiber. A screen with a 2 mm hole diameter equipped with a lobed rotor is used prior to the mid-ply headbox. A separate slurry containing only Douglas Fir or Pine fibers is refined to 500 CSF and diluted to 0.5 percent consistency prior to pumping the slurry to the outer headboxes. A paperboard is formed on a 500 cm paperboard machine.
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A process is described for manufacturing a paperboard from a high consistency slurry containing high levels of crosslinked cellulosic fibers by dispersing the fibers in a screen with a rotor in the screen and then passing the fibers through the screen basket with a hole diameter of at least 2 mm and forming the cellulosic fibers on a foraminous support. Another slurry of regular cellulosic fibers is deposited on at least one side of the first slurry during the formation process. The formed web is dewatered and dried.
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FIELD OF THE INVENTION
This invention relates to a carburetor of variable venturi type and associated method of operation.
DESCRIPTION OF PRIOR ART
In conventional carburetors of variable venturi type a slide throttle valve capable of being moved slidingly across a suction passage is operated by a throttle wire. In such carburetor, the throttle slide valve is subjected to a force acting downstream, in the suction direction of air flow, due to the vacuum produced in the engine. Consequently, a relatively large frictional force is developed between the side surface of the slide throttle valve which faces in the downstream direction and the opposed surface of the carburetor body. Therefore, a relatively large tractive force is necessary to operate the throttle wire.
A variable venturi carburetor of so-called constant-vacuum type has also been developed in an effort to eliminate these deficiencies. In this carburetor the vacuum is controlled by means of a butterfly throttle valve provided in the suction passage and the slide throttle valve is opened and closed in accordance with the resulting vacuum. However, if the open degree of the butterfly throttle valve in this carburetor is increased suddenly, the vacuum does not increase accordingly. In consequence, the action of the slide throttle valve does not follow the sudden acceleration operation. Thus, this variable venturi type carburetor has a low acceleration response
The present inventor has already proposed a variable venturi type carburetor which is intended to eliminate these deficiencies. In this carburetor, the butterfly throttle valve and the slide valve are operatively connected for operation in correspondence with one another, and a low-speed fuel discharge port and a main fuel nozzle are respectively provided in the vicinity of the butterfly throttle valve and just under the slide valve. According to this arrangement, the acceleration response of the slide valve can be improved. In addition, the discharge rate of fuel from the low-speed fuel discharge port can be controlled properly in the low-load operational region, and the discharge rate of fuel from the main fuel nozzle can be controlled properly in the high-load operational region.
In the carburetor of the above-described construction, the slide valve and the butterfly throttle valve are moved by operating a throttle wire by application of external force thereto. Accordingly, the vacuum in the suction passage does not increase in accordance with sudden opening operations of these two valves under certain operational conditions. In such case, the discharge rate of fuel from the main fuel nozzle becomes insufficiently low in the region of an intermediate degree of opening of the slide valve.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a construction which avoids the deficiencies of the known carburetor.
It is a particular object of the present invention to provide a variable venturi type carburetor capable of producing an excellent air-fuel ratio in all operational regions, i.e. from the low-load operational region to the high-load operational region.
In order to satisfy the above and further objects of the invention, a carburetor is provided, which comprises a carburetor body having a suction passage therein, a slide valve supported by said body for slidable movement across said suction passage to function as a variable venturi, a butterfly throttle valve pivotably supported by the carburetor body downstream of the slide valve, interlocking means connecting the slide valve and the butterfly throttle valve together for operation in correspondence with one another, operating means connected to one of said valves for operating the same by application of external force thereto, a low-speed fuel nozzle opening into the suction passage in the vicinity of the butterfly throttle valve, an intermediate and high-speed main fuel nozzle opening into the suction passage just under the slide valve, and a low and intermediate-speed primary fuel nozzle opening into the suction passage between the slide valve and the butterfly throttle valve.
According to this arrangement, the discharge rates of fuel from the low-speed fuel nozzle, the main fuel nozzle and the primary fuel nozzle can be controlled properly in a low-load operational region, intermediate-and high-load operational regions and a transitional region, in which low-load operation of the engine is shifted to intermediate and high-load operations respectively. Therefore, an excellent air-fuel ratio can be obtained in all operational regions.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a longitudinal sectional view of one embodiment of the carburetor of the invention.
FIG. 2 is a sectional front elevational view showing the construction of an interlocking mechanism of the carburetor.
FIG. 3 is a side elevational view, in section, of a principal portion of the interior of a housing chamber of the carburetor.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
An embodiment of the present invention will now be described with reference to the drawing wherein a float chamber body 4 forming a float chamber 3 is secured via a seal member 5 to a lower portion of a carburetor body 2 in which a suction passage 1 is formed. In suction passage 1 is a slide valve 6 adapted to be moved slidingly across the suction passage 1, and a butterfly throttle valve 7 pivotably supported by the carburetor body 2 on the downstream side of the slide valve 6 with respect to the direction of air flow 8, i.e., the suction direction. The slide valve 6 and the butterfly throttle valve 7 are operated correlatively from their fully-closed positions to their fully-opened positions.
The carburetor body 2 is provided with an intermediate and high speed main fuel nozzle 10 which opens at the inner surface of the suction passage 1. An air bleeder pipe 11 is connected to a lower portion of the main fuel nozzle 10 integrally and concentrically. A main fuel jet 12 extending under the fuel level in the float chamber 3 is joined to a lower portion of the air bleeder pipe 11. Thus, a main fuel passage Mw extending from the main fuel jet 12 to the main fuel nozzle 10 via the air bleeder pipe 11 is formed. The main fuel passage Mw opens into the suction passage 1 just under the slide valve 6. An annular chamber 17 formed around the air bleeder pipe 11 is in communication with an upstream end of the suction passage 1 via an air bleeder passage (not shown).
The carburetor body 2 is further provided with a low speed fuel passage Sw which opens into the suction passage 1 in the vicinity of the butterfly throttle valve 7. A pilot outlet 18, which opens into the suction passage 1 on the slightly downstream side of the butterfly throttle valve 7, and a low speed fuel nozzle 19, which opens into the suction passage 1 on the slightly upstream side of the butterfly throttle valve 7 in its fully-closed position are also provided in the carburetor body 2. The pilot outlet 18 and the fuel nozzle 19 are in communication with a fuel passage 20. A low speed fuel jet 21, which extends under the fuel level in the float chamber 3, is connected to the fuel passage 20 via an air bleeder pipe 22. In order to regulate the degree of opening of the pilot outlet 18, a pilot screw 23 is engaged with the carburetor body 2 so that the pilot screw 23 can be turned to advance upwardly and downwardly.
The carburetor body 2 is further provided, at its lower portion, with a low and intermediate speed primary fuel nozzle 28 which opens into the suction passage 1 between the slide valve 6 and the butterfly throttle valve 7. An air bleeder pipe 29 is connected to a lower portion of the primary fuel nozzle 28 integrally and concentrically. A primary fuel jet 30 which extends under the fuel level in the float chamber 3 is joined to a lower portion of the air bleeder pipe 29. An annular chamber 31 formed around the air bleeder pipe 29 is in communication with an upstream end of the suction passage 1 via an air bleeder passage (not shown).
A float 13 is housed in the float chamber 3. A float valve 14 is engaged with a pivotably supported portion of the float 13 so as to open and close a valve port 16 in accordance with vertical movement of the float 13. The valve port 16 is in communication with a fuel supply passage 15 formed in the carburetor 2.
A guide cylinder 24 extends upwardly at an upper portion of the carburetor body 2 at a location opposite the main fuel nozzle 10. The guide cylinder is integral with the carburetor body 2. A housing 26 forming an air chamber 25 is integrally joined to an upper portion of the guide cylinder 24. The air chamber 25 is in communication with an upstream end of the suction passage 1 via a passage 27.
The slide valve 6 is formed in the shape of an open top, closed bottom cylinder, and the valve 6 is fitted slidably in the guide cylinder 24. A needle valve 34 is secured to the bottom of the slide valve 6 and is inserted into the main fuel nozzle 10. An upwardly extending recess 32 is provided in the lower end surface of the slide valve 6 and an inverted cutaway 33 is formed in the side surface at the bottom of slide valve 6 on the downstream side with respect to the suction direction 8. The recess 32 thus provided causes turbulence to occur in the air flow therein, so that the vacuum applied to the main fuel nozzle 10 can be made uniform. The cutaway 33 enables the vacuum in the space between the bottom portion of the slide valve 6 and the inner surface of the wall of the suction passage 1, i.e., a venturi portion, to increase. Consequently, the discharge rate of fuel from the main fuel nozzle 10 increases, and the regulation of the air-fuel ratio can be easily effected.
A shaft 43 which extends parallel to a valve shaft 39 of the butterfly throttle valve 7 is pivotably supported in the housing 26, and a driving arm 44 is connected fixedly at one end thereof to the pivotable shaft 43 in the air chamber 25. A bracket 45 is connected fixedly to the slide valve 6. The bracket 45 is also connected at the other end thereof to the other end of the driving arm 44 by a connecting rod 46. Accordingly, reciprocating pivotal movements of the pivotable shaft 43 are converted into linear reciprocating movements of the slide valve 6 along the guide cylinder 24, i.e., the opening and closing movements of the slide valve 6, via the driving arm 44, connecting rod 46 and bracket 45.
Referring to FIGS. 2-3, the valve shaft 39 of the butterfly throttle valve 7 and the pivotable shaft 43 are connected together via an interlocking mechanism 9 so as to correlate the opening and closing actions of the slide valve 6 with those of the butterfly valve 7. The interlocking mechanism 9 is arranged in a housing chamber 60 provided at a side portion of the carburetor body 2. The housing chamber 60 is defined by a wall of a housing recess 61 provided at a side portion of the carburetor body 2, and a cover member 62 fastened to the carburetor body 2 so as to close the housing recess 61.
The interlocking mechanism 9 consists of a throttle lever 47 press-fitted firmly around an end portion of the valve shaft 39, a pivotable arm 48 mounted on an end portion of the pivotable shaft 43, and a connecting arm 49 fixed at one end to the pivotable arm 48 and joined at the other end thereof to the portion of the throttle lever 47 which is remote from the axis thereof. A regulator mechanism 50 is interposed between the pivotable arm 48 and the pivotable shaft 43. A throttle wire 41 is connected to the throttle lever 47. When the throttle wire 41 is drawn in the direction of arrow 42, the butterfly throttle valve 7 is turned in the opening direction. The butterfly throttle valve 7 is urged in the closing direction by a coil spring 40 so that when the tractive force of the throttle wire 41 is decreased, the butterfly throttle valve 7 is turned in the closing direction. The opening and closing actions of the butterfly throttle valve 7 are transmitted to the pivotable shaft 43 via the interlocking mechanism 9 and the regulator mechanism 50 so that the slide valve 6 is opened or closed in accordance with the pivotal movement of the shaft 43.
The regulator mechanism 50 consists of a lever 52 which is mounted on an end portion of the pivotable shaft 43 so that the lever 52 is angularly fixed on the shaft 43 and extends in the same direction as the pivotable arm 48, a projection 53 provided on the lever 52, and a coil spring 55 urging the lever 52 to turn in the direction in which the projection 53 comes into contact with the pivotable arm 48. The coil spring 55 is fitted around the pivotable shaft 43 and is engaged at one end with an integral pin 56 in the housing 26, and at the other end with the lever 52. The pivotable arm 48 is fitted at its base portion around the pivotable shaft 43 so that the arm 48 can be turned relative to the shaft 43. A setting nut 57 is fixedly secured at an end of the pivotable shaft 43 so as to prevent the pivotable arm 48 from coming off from the shaft 43. The pivotable arm 48 is provided with a contact arm 58 which is capable of regulating the circumferential distance between the arm 58 and the portion of the pivotable arm 48 to which the connecting arm 49 is joined. The contact arm 58 is provided with a projection 59 engageable with the projection 53.
In the interlocking mechanism 9 and the regulator mechanism 50, which are formed as described above, the operation of the throttle lever 47 for opening the butterfly throttle valve 7, i.e., clockwise pivotal movement in FIG. 2 of the lever 47, is transmitted to the pivotable arm 48 to cause the arm 48 to turn clockwise. Since the projection 53 in the regulator mechanism 50 is engaged resiliently with the projection 59 of the pivotable arm 48, the lever 52 and the shaft 43 are turned clockwise. The pivotal movement of the shaft 43 is transmitted to the slide valve 6 via the driving arm 44, connecting rod 46 and bracket 45, so that the slide valve 6 is displaced upwardly along the guide cylinder 24, i.e., moved in the opening direction.
Conversely, when the butterfly throttle valve 7 is turned counterclockwise in FIG. 2, the pivotable arm 48 is also turned counterclockwise. In accordance with the counterclockwise movement of the pivotable arm 48, the lever 52, i.e., the pivotable shaft 43 turns counterclockwise by the resilient force of the coil spring 55 as the projection 53 follows the projection 59 in a contacting state. Consequently, the slide valve 6 is forced downwardly via the driving arm 44, connecting rod 46 and bracket 45, i.e., moved in the closing direction. At this time, the pivotable arm 48 can be turned counterclockwise by the regulator mechanism 50. Therefore, the butterfly throttle valve 7 can be closed irrespective of the movement of the slide valve 6.
The regulator mechanism 50 is capable of finely regulating the degree of opening of the slide valve 6 with respect to that of the butterfly throttle valve 7 by regulating the distance between the portion of the pivotable arm 48 to which the connecting arm 49 is joined and the contact arm 58. Since the projection 53 resiliently engages the projection 59, any vibration of the throttle lever 47, pivotable arm 48 and connecting arm 49, due to mounting errors is damped so that the interlocking mechanism is operated smoothly.
The throttle lever 47 is provided with a limit projection 63 extending laterally therefrom. A stop screw 64 is engaged in a threaded bore 71 in a boss 72 formed integrally with the cover member 62, so as to contact the limit projection 63. A loosening-preventing portion 75, opposed to an end surface of the pivotable shaft 43, projects from the cover member 62. The loosening-preventing portion 75 is adapted to engage setting nut 57 and prevent the same from being loosened. A cap 73 is engaged with an upper portion of the wall of the housing recess 61, and an end portion of an outer wire 74 is fixedly secured in the cap 73. The throttle wire 41 which can be moved through the outer wire 74 is connected to the throttle lever 47 within the housing chamber 60.
The operation of this embodiment will now be described.
In accordance with the opening and closing actions of butterfly valve 7 by drawing the throttle valve wire 41, the slide valve 6 is opened and closed via the interlocking mechanism 9. During this time, the suction vacuum does not directly cause the slide valve 6 to be drawn in a downstream direction since the butterfly throttle valve 7 is provided on the downstream side of the slide valve 6. Accordingly, the frictional resistance between the outer surface of the slide valve 6 and the inner surface of the guide cyliner 24 is comparatively low, so that the throttle wire 41 can be operated by a comparatively small tractive force. Moreover, when the opening degree of the butterfly throttle valve 7 is increased suddenly for sudden acceleration of the engine, the slide valve 6 is opened without delay and excellent acceleration can be obtained.
In the case where the opening degree of the butterfly throttle valve 7 is set to a low level to carry out low-load operation of the engine, the discharge rate of fuel from the low-speed fuel nozzle 19 can be controlled in accordance with the opening degree of the valve 7 since the nozzle 19 is provided in the vicinity of the valve 7 and the discharge rate can be controlled with high accuracy.
When the opening degree of the slide valve 6 is set to an intermediate or high level so as to operate the engine with an intermediate or high load, the slide valve 6 carries out its venturi effect to control the vacuum above the main fuel nozzle 10 in accordance with the load. The discharge rate of fuel from the main fuel nozzle 10 is thus regulated to enable the production of a fuel mixture suitable for intermediate and high-load operations of the engine.
When the slide valve 6 is opened suddenly to shift a low-load operation of the engine to an intermediate-load operation thereof, the vacuum in the suction passage 1 does not increase accordingly in some cases. In such cases, there is the possibility that the discharge rate of fuel from the main fuel nozzle 10 becomes insufficiently low. If this occurs, the vacuum in the portion of the suction passage 1 which is between the butterfly throttle valve 7 and the slide valve 6 becomes greater than that below the slide valve 6. Since the low and intermediate-speed primary fuel nozzle 28 opens into the suction passage 1 between the butterfly throttle valve 7 and the slide valve 6, the fuel is discharged from the nozzle 28 so as to compensate for the shortage of fuel discharged from the main fuel nozzle 10.
Thus, an excellent air-fuel ratio can be obtained in all operational regions of the engine, i.e. from the low-load operational region to the high-load operational region.
According to the present invention as described above, a novel carburetor is provided, which comprises carburetor body 1 provided with suction passage 2, slide valve 6 slidingly movable across the suction passage and functioning as a variable venturi, butterfly throttle valve 7 pivotably supported on the carburetor body downstream of the slide valve, interlocking mechanism 9 connecting the slide valve and the butterfly throttle valve for corresponding movement together, operating member 41 connected to one of the valves (valve 7 in the embodiment) to operate the valve by application of external force thereto, low-speed fuel nozzle 19 which opens into the suction passage in the vicinity of the butterfly throttle valve, intermediate and high-speed main fuel nozzle 10 which opens into the suction passage just under the slide valve 6, and low- and intermediate-speed primary fuel nozzle 28 which opens into the suction passage between the slide valve and the butterfly throttle valve.
Therefore, in a low-load operational region, the flow rate of fuel and the air-fuel ratio are controlled properly by the butterfly throttle valve, and, in the intermediate and high operational regions, the discharge rate of fuel from the main fuel nozzle is controlled by the slide valve. When the operating member suddenly opens the valve to which it is connected to go from a low-load operation of the engine to an intermediate or high-load operation thereof, fuel is discharged from the primary fuel nozzle 28 to compensate for the shortage of fuel discharged from the main fuel nozzle 10. Accordingly, the discharge rate of fuel does not become insufficiently low and an excellent air-fuel ratio can be obtained in all operational regions of the engine, i.e. from the low-load operational region to the high-load operational region thereof.
Although the invention has been described in relation to specific preferred embodiments thereof, it will become apparent to those skilled in the art that numerous modifications and variations can be made without departing from the scope and spirit of the invention as defined in the attached claims.
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A variable venturi type carburetor comprising a carburetor body provided with a suction passage for flow of air therethrough, a slide valve supported by the body for slidable movement across the suction passage to serve as a variable venturi and a butterfly throttle valve pivotably supported by the carburetor body downstream of the slide valve. An interlocking mechanism connects the slide valve and butterfly throttle valve together for operating in correspondence with one another and one of the valves is operated by application of an external force thereto. A low-speed fuel nozzle opens into the suction passage in the vicinity of the butterfly throttle valve, an intermediate- and high-speed main fuel nozzle opens into the suction passage opposite the slide valve, and a low- and intermediate-speed primary fuel nozzle opens into the suction passage between the slide valve and the butterfly throttle valve. The lower edge of the slide valve is formed with an inverted cutaway to provide a widened passage facing in the downstream direction of the suction passage.
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This application is a continuation-in-part application of U.S. Pat. application Ser. No. 135,805, filed Dec. 21, 1987, now U.S. Pat. No. 4,863957.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to compounds, pharmaceutical compositions and a method useful for reducing serum cholesterol in humans. More particularly, the invention relates to trans-6-[(2-aryl substituted cycloalkadienyl) alkenyl or alkyl]-3,4,5,6-tetrahydro-4-hydroxy-2H-pyran-2-ones, the corresponding ring opened hydroxy acids derived therefrom and pharmaceutically acceptable salts thereof which are potent inhibitors of the enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase (hereinafter HMG-CoA reductase), pharmaceutical compositions thereof, and a method of inhibiting biosynthesis of cholesterol for the treatment of atherosclerosis, hyperlipidemia and hypercholesterolemia.
2. Related Prior Art
Inhibitors of HMG-CoA are effective in lowering blood plasma cholesterol level as well as inhibiting the biosynthesis of cholesterol in humans. As such, inhibitors of HMG-CoA are useful in the prevention and treatment of coronary heart diseases. The prior art recognizes the importance of such compounds, e.g., Bethridge et al., Brit. Med. J., 4,500 (1975) and Brown et al., Scientific American, 58 Nov. (1984). Illustrative references directed to such compounds follow.
U.S. Pat. No. 4,681,893 to B. D. Roth pertains to trans-6-[2-(3-or 4-carboxamido-substituted pyrrol-1-yl)alkyl]-4-hydroxypyran-2-ones useful as hypochloesterolemic agents.
U.S. Pat. No. 4,668,699 to Hoffman et al. discloses semi-synthetic analogs of compactin and mevinolin and the dihydro and tetrahydro analogs thereof for antihypercholesterolemic application.
U.S. Pat. No. 4,282,155 to Smith et al. is directed to 6(R)-[2-(8'-Etherified-hydroxy-2',6'-dimethylpolyhydronaphtyl-1')ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-ones for inhibition of biosynthesis of cholesterol.
U.S. Pat. No. 4,567,289 relates to methyl, ethyl, n-propyl, 2-(acetylamino)ethyl, or 1-(2,3-dihydroxy)propyl ester of E-(3R,5S)-7-(4'-fluoro-3,3',5-trimethyl[1,1'-biphenyl]-2-yl)-3,5-dihydroxy-6-heptenoic acid that are HMG-CoA reductase inhibitors.
U.S. Pat. No. 4,611,067 discloses a process for the preparation of HMG-CoA reductase inhibitors which contain a 4-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one moiety.
SUMMARY OF THE INVENTION
In accordance with the present invention, certain trans-6-[(2-aryl substituted cycloalkadienyl) alkenyl or alkyl]-3,4,5,6-tetrahydro-4-hydroxy-2H-pyran-2-ones and the corresponding ring-opened hydroxy-acids derived therefrom and pharmaceutically acceptable salts thereof are provided which are potent inhibitors of HMG CoA reductase. Specifically, the invention provides compounds of formula I. ##STR2## and pharmaceutically acceptable salts thereof wherein: Y is: --CHR--, --CHRCHR--, --CHRCHRCHR--, or --RC═CR--, wherein R is H or lower alkyl;
X, X 1 and X 2 are independently: H, F, Cl, Br, OH, CF 3 alkyl, or alkoxy;
R 1 , R 2 and R 3 are independently: H, alkyl, CF 3 , or aryl; and n=0 or 1
DETAILED DESCRIPTION OF THE INVENTION
As employed above and throughout the specification, the following terms, unless otherwise indicated, shall be understood to have the following meaning:
"Lower alkyl" means a saturated or unsaturated aliphatic hydrocarbon which may be either straight--or branched-chained containing from 1 to 4 carbon atoms.
"Alkyl" means a saturated or unsaturated aliphatic hydrocarbon which may be either straight-or branched-chained containing from about one to about six carbon atoms.
"Alkoxy" means an alkyl oxy group in which "alkyl" is as previously defined. Lower alkoxy groups are preferred which include methoxy, ethoxy, n-propoxy, i-propoxy, sec-propoxy, and n-butoxy.
"Aryl" means an aromatic hydrocarbon radical having 6 to 10 carbon atoms. The preferred aryl groups are phenyl, substituted phenyl and naphthyl. The term "substituted" means "alkyl" and halogen substitution.
The pharmaceutically acceptable salts of the present invention include those formed from sodium, potassium, calcium, aluminum, lithium, magnesium, zinc, lysine, arginine, procaine, ethylenediamine and piperazine.
The invention encompasses optical and stereoisomers of the compounds and mixtures thereof defined by the structural formula.
The general procedure for producing the compounds of the present invention is as follows: ##STR3## wherein the symbols used in the reactions denote the following reagents: ##STR4##
The starting materials were obtained from the Aldrich Chemical Co.; however, they may also be synthesized in accordance with methods known in the art.
The following preparative example will further illustrate the invention.
EXAMPLE 1
Step 1
Preparation of 3-chloro-5,5-dimethylcyclohex-2-en-1-one
The title compound was prepared using the method of Clark and Heathcock. J. Org. Chem., 1976, 41, 636. To a suspension of dimedone (15.0 g, 107 mmol) in chloroform (40 ml) was added slowly oxalyl chloride (27.2 g, 214 mmol). The addition was accompanied by vigorous evolution of gas. After stirring at room temperature for 10 minutes, the slurry was refluxed for 20 minutes to give a yellow solution which was evaporated and distilled to give 15.7 g (92%) of chloroenone as a colorless liquid, bp 72° (5 mm). ##STR5##
Step 2
Preparation of 1,3-di(4-fluorophenyl)-5,5-dimethylcyclohexa-1,3-diene
A Grignard reagent, freshly prepared from 1-bromo-4-fluorobenzene (27.47 ml, 250 mmoles) and magnesium powder (7.29 g, 300 mmoles) in 250 ml of THF was added dropwise, under nitrogen, to an ice cold mixture of copper iodide (1.90 g, 10 mmoles), 3-chloro-5,5-dimethylcyclohex-2-en-1-one (15.85 g, 100 mmoles) and 250 ml of THF. The reaction was warmed to room temperature and stirred overnight.
The dark reaction mixture was poured into a mixture of ice and 1 N HCl and extracted with ether. The ether layer was extracted with water and brine and the ether removed in vacuo.
The residue was redissolved in 250 ml toluene and treated with 1.90 g (10 mmoles) of p-toluenesulfonic acid. The toluene was refluxed for 1 hour in a Dean-Stark apparatus. The toluene was evaporated in vacuo and the residue chromatographed on silica gel with hexane as the eluent. Overall yield 19.52 g (66 mmoles). ##STR6##
Step 3
Preparation of 2,4-di(4-fluorophenyl)-6,6-dimethylcyclohexa-1,3-dien-1-vl carboxaldehyde
POCl 3 (4.66 ml, 50 mmoles) was added dropwise to an ice cold solution of 1,3-di(4-fluorophenyl)-5,5-dimethylcyclohexa-1,3-diene (14.8 g, 50 mmoles) and dimethylformamide (15.49 ml, 200 mmoles). The reaction was heated to 90° C. for 15 minutes, then cooled to 0° C.
The ice cold reaction was quenched by the dropwise addition of a solution of sodium acetate (27.22 g, 200 mmoles in 75 ml H 2 O).
After stirring overnight, the reaction was diluted with ether and the layers separated. The ether layer was extracted with water, saturated sodium bicarbonate and brine. The ether was evaporated in vacuo and the residue chromatographed on silica gel. The product from the chromatography was crystallized from cold hexane to yield the aldehyde as yellow crystals. ##STR7##
Step 4
Preparation of (E)-3-[2,4-di-(4-fluorophenyl)-6,6-dimethylcyclohexa-1,3-dien-1-yl]-2-propenaldehyde
To a stirred solution of diisopropylamine (5.04 ml, 36 mmoles), in 72 ml of THF, at -60° C., under nitrogen, was added 13.2 ml, 33 mmoles of a 2.5M hexane solution of n-butyllithium. After 15 minutes, when the temperature had warmed to -40° C., a 1.0M THF solution of ethylidenecyclohexylamine (3.75 g, 30 mmoles) was added dropwise. The reaction was stirred for 30 minutes, while the temperature rose to -10° C. After stirring at -10° C. for an additional 10 minutes, the dark orange solution was cooled to -70° C. A 1.0M THF solution of the unsaturated aldehyde prepared in Step 3 (6.48 g, 20 mmoles) was added dropwise. The reaction was allowed to slowly warm to -10° C. and stirred for an additional hour.
The reaction was poured into H 2 O and extracted with ether. The organic layer was extracted with brine and the solvents evaporated in vacuo.
The crude intermediate was chromatographed on silica gel with hexane and finally hexane/ethyl acetate (20/1) as eluents. The intermediate 3-hydroxypropylidenecyclohexylamine was hydrolized on the silica gel column to the 2,4,6-trienal.
Steps 3 and 4 may be replaced with the alternative method described in Step 5. ##STR8##
Step 5:
Preparation of (E)-3-[2,4-di-(4-fluorophenyl)-6,6-dimethylcyclohexa-1,3-dien-1-yl]2-propenaldehyde
A 2.0M acetonitrile solution of 3-dimethylaminoacrolien (6.00 ml, 60 mmoles) was added dropwise to an ice cold 2.0M acetonitrile solution of POCl 3 (6.06 ml, 65 mmoles). After stirring for 15 minutes at 0° C., a 1.0M acetonitrile solution of the diene prepared in Step 2 (14.8 g, 50 mmoles) was added dropwise. When the addition was complete the reaction was heated to reflux for 4 hours.
After cooling to room temperature the reaction mixture was poured into 150 ml of ice cold IN NaOH.
The aqueous layer was extracted with ether. The ether was removed in vacuo and the residue chromatographed on silica gel using hexane/ethyl acetate (20/1) as the eluent. ##STR9##
Step 6
Preparation of methyl-(E)-7-[2,4-di-(4-fluorophenyl-6,6-dimethylcyclohexa-1,3-dien-1-yl]-5-hydroxy-3-oxo-6-heptenoate
To a stirred solution of diisopropyl amine (12.09 ml, 86.4 mmoles), in 173 ml of THF, at -60° C., under nitrogen, was added 31.68 ml (79.2 mmoles) of a 2.5M hexane solution of n-butyllithium. After 15 minutes, when the temperature had warmed to -40° C., methylacetoacetate (3.89 ml, 36 mmoles) was added dropwise. The solution was stirred for 30 minutes while the temperature was allowed to warm to -10° C.
To the yellow solution of the dianion was added a 0.25M THF solution of 10.50 g (30 mmoles) of the aldehyde prepared in Steps 4 or 5. The addition took 30 minutes. The reaction was stirred an additional 30 minutes at -10° C., then quenched with 9.47 ml (165.6 mmoles) of acetic acid in 40 ml of THF. The reaction was poured into ethyl acetate and extracted with H 2 O, saturated NaHCO 3 and brine.
The residue was purified by flash chromatography on silica gel with hexane/ethyl acetate (5/1) as the eluent. ##STR10##
Step 7
Preparation of methyl-(E)-7-[2,4-di-(4-fluorophenyl)-6,6-dimethylcyclohexa-1,3-dien-1yl]-3,5-dihydroxy-6-heptenoate
The 5-hydroxy-3-keto ester (11.18 g. 24 mmoles) prepared in Step 6 was dissolved in 60 ml of dry THF and treated with triethylborane (1M in THF, 36 ml, 36 mmoles). After aging for 5 minutes, at room temperature, the reaction mixture was cooled to -98° C. (MeOH-liquid N 2 bath). Sodium borohydride (1.04 g, 27.6 mmoles) was added, followed by dropwise addition of methanol (24 ml) over a 30 minute period. The reaction was stirred for 30 minutes at -98° C. and over the next 30 minutes was allowed to warm to -60° C. At -60 20 C. the reaction was quenched by the dropwise addition of 30% H 2 O 2 (50 ML) in H 2 O (125 ml).
The reaction was warmed to room temperature and stirred for 30 minutes. It was poured into 1L of ethyl acetate and extracted with 620 ml of IN HCl. The organic layer was extracted with saturated NaHCO 3 and brine. ##STR11##
Step 8
Preparation of (E)-7-[2,4,-di-(4-fluorophenyl)-6,6-dimethylcyclohexa-1,3-dien-1-yl]-3,5,-dihydroxy-6-heptenoate
Aqueous 1N NaOH (5 ml, 5 mmoles) was added to a 0.2M ethanol solution of the 3,5-dihydroxy ester prepared in Step 7 (1.87 g, 4 mmoles). After stirring for 10 minutes, the ethanol was evaporated in vacuo. The residue was redissolved in H 2 O and the aqueous layer was acidified with 1N HCl.
The aqueous layer was extracted with ether. The ether layer was extracted with brine and dried over Na 2 SO 4 . After filtration, the ether was removed in vacuo. ##STR12##
Step 9
Preparation of trans-(E)-6-[2-[2,4-di-(4-fluorophenyl)-6,6-dimethylcyclohexa-1,3-dien-1-yl ]-ethenyl]-3,4,5,6-tetrahydro-4-hydroxy-2H-pyran-2-one
Dicyclohexyl carbodiimide (0.91 g, 4.4 mmoles) and dimethylaminopyridine (0.049 g, 0.4 mmoles) were added to a 0.25M ether solution of the 3,5-dihydroxycarboxylic acid prepared in Step 8. After stirring for 4 hours at room temperature, the reaction was filtered. The residue was washed with ether and the combined filtrates evaporated in vacuo. The residue was chromatographed on silica gel and the product recrystallized from ether-hexane.
Anal. C 27 H 26 F 2 O 3 C 74.30, H 6.00.
Found C 74.18, H 6.03. ##STR13##
Employing the general method detailed in Example 1, the following compounds can be prepared:
1. trans-(E)-6-[2-[2,4-di-(4-fluorophenyl)-6,6-dimethylcyclohexa-1,3-dien-1-yl]-ethenyl]-3,4,5,6-tetrahydro-4-hydroxy-2H-pyran-2-one;
2. trans-(E)-6-[2-[2,4-di-(3-methyl-4-fluoropheny)-6,6-dimethylcyclohexa-1,3-dien-1-yl]-ethenyl]-3,4,5,6-tetrahydro-4-hydroxy-2H-pyran-2-one;
3. erythro-(E)-7-[2,4-di-(3,4-dichlorophenyl)-6,6-dimethylcyclo hexa-1,3-dien-1-yl]-3,5-dihydroxy-6-heptenoic acid;
4. trans-6-[2-[2,4-di(3-chloro-4-fluorophenyl)-6,6-di-methylcyclohexa-1,3-dien-1-yl]-ethyl-3,4,5,6-tetrahydro-4-hydroxy-2H-pyran-2-one;
5. trans-(E)-6-[2-[2-(4-fluorophenyl)-4-phenyl-5,5-dimethylcyclopenta-1,3-dien-1-yl]-ethenyl]-3,4,5,6-tetrahydro-4-hydroxy-2H-pyran-2-one; and
6. erythro-(E)-7-[2-(4-fluoro-3-methylphenyl)-4-phenyl-5,5-dimethyl-1,3-dien-1-yl]-3,5-dihydroxy-6-heptenoic acid.
The compounds of the present invention are useful as hypocholesterolemic or hypolipidemic agents by virtue of their ability to inhibit the biosynthesis of cholesterol through inhibition of the enzyme HMG-CoA reductase. Having such ability, the compounds are incorporated into pharmaceutically acceptable carriers and administered to a patient in need of such cholesterol biosynthesis inhibition orally or parentally. Such pharmaceutical formulations to contain at least one compound according to the invention.
Suitable carriers include diluents or fillers, sterile aqueous media and various non-toxic organic solvents. The compositions may be formulated in the form of tablets, capsules, lozenges, trochees, hard candies, powders, aqueous suspensions, or solutions, injectable solutions, elixirs, syrups and the like and may contain one or more agents selected from the group including sweetening agents, flavoring agents, coloring agents and preserving agents, in order to provide a pharmaceutically acceptable preparation.
The particular carrier and the ratio of active compound to carrier are determined by the solubility and chemical properties of the compounds, the particular mode of administration and standard pharmaceutical practice. For example, excipients such as lactose, sodium citrate, calcium carbonate and dicalcium phosphate and various disintegrants such as starch, alginic acid and certain complex silicates, together with lubricating agents such as magnesium stearate, sodium lauryl sulphate and talc, can be used in producing tablets. For a capsule form, lactose and high molecular weight polyethylene glycols are among the preferred pharmaceutically acceptable carriers.
Where aqueous suspensions for oral use are formulated, the carrier can be emulsifying or suspending agents. Diluents such as ethanol, propylene glycol, and glycerin and their combinations can be employed as well as other materials.
For parenteral administration, solutions or suspensions of these compounds in aqueous alcoholic media or in sesame or peanut oil or aqueous solutions of the soluble pharmaceutically acceptable salves can be employed.
The dosage regimen in carrying out the methods of this invention is that which insures maximum therapeutic response until improvement is obtained and thereafter the minimum effective level which gives relief. Doses may vary, depending on the age, severity, body weight and other conditions of the patients but are ordinarily in the area of 5 mg/kg to 500 mg/kg of body weight in oral administration; such may, of course be given in two to four divided doses. With other forms of administration equivalent or adjusted doses will be administered depending on the route of administration.
The utility of the claimed compounds is measured by the test methods described hereunder. The methods are based on the articles: "Purification of 3-hydroxy-3-methylglutarylcoenzyme A reductase from rat liver" by Kleinsek et al., Proc. Natl. Acad. Sci. U.S.A., Vol. No. 4, pp. 1431-1435, April 1977 Biochemistry; "Mevinolin: A highly potent competitive inhibitor of hydroxy methyl glutaryl-coenzyme A reductase and a cholesterol-lowering agent" by Alberts et al., Proc. Natl. Acad. Sci. U.S.A., Vol 77, pp. 3951-3961, July 1980, Biochemistry; "Effects of ML-236B on cholesterol metabolism in mice rats: Lack of hypocholesterolemic activity in normal animals" by Endo et al., Biochimica et Biophysica Acta, 575 (1979) 266-276; and "Evidence of Regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and cholesterol synthesis in nonhepatic tissues of rat" by Balasubramaniam et al., Proc. Natl. Acad. Sci. U.S.A., Vol. 73, No. 8, pp. 2564-2568, Aug. 1976, Biochemistry.
The first method used (designated HMGR Screen) was as follows. Male rats were acclimated to an alternate 12 hour light-dark cycle for a period of 2-3 weeks. The animals, weighing 180-230 g, were fed ad libitum a rat chow containing 2% cholestyramine for 5 days prior to sacrifice at the mid-dark period. Liver microsomes were prepared and HMGR enzyme was solubilized from the microsomes by freeze-thaw manipulation in high ionic strength buffer. The enzyme preparation was stored at -80° C. in 300 μl portion samples. Prior to use, the enzyme was activated at 37° C. for 30 minutes in a reaction mixture. The reaction mixture contained in a volume of 240 μl : 0.14 M potassium phosphate buffer (pH 7.0); 0.18 M KCl; 3.5 mM EDTA; 10 mM dithiothreitol; 0.1 mg/ml BSA; 30,000 cpm of [ 14 C]HMG-CoA; 20 μM HMG-CoA, and 200 μg of solubilized enzyme with and without inhibitors (in 10 μl DMSO). After 5 minutes incubation at 37° C. the reaction was initiated with 0.2 mM NADPH. The final assay volume was 300 μl . The reaction then was terminated with 100 μl of 1N HCl. After an additional incubation for 15 minutes at 37° C. to allow for complete lactonization of the product, the mixture was diluted with 3 ml GDW. The diluted mixture was then poured over a 0.7×1.4 cm column containing 100-200 mesh Bio-Rex ion-exchange resin (cloride form of Bio-Rad) which was equilibrated with distilled water. With this resin the unreacted [ 14 C] HMG-CoA was adsorbed and the product .sup. 14C] lactone was eluted (80% recovery) directly into scintillation vials. After the addition of 10 ml of Aquasol®, radioactivities of the samples were measured in a scintillation counter. Result on compound obtained in Example 1, Step 11 and compound obtained in Example 1, Step 12 is shown in Table I.
The second method used, designated Ex-Vivo Fasted, was as follows. Rats of 170-210 g were maintained on a low cholesterol diet for one week prior to use. Drugs (identified in Table I) were given orally in 0.5% methocel to fasted (fasted for 16 hours) rats. After one hour the rats were decapitated and their livers removed and transferred to chilled oxygenated Kreb's-Ringer-bicarbonate buffer (pH 7.4). The livers were then chopped into 0.5 mm slices using a McIlwain tissue chopper, and were suspended in the same buffer. Aliquots of the suspension containing 100 mg tissue were pipetted to culture tubes which contained [ 14 C] sodium acetate (2 μCi, 1 mM). The tubes were gassed with 95% O 2 /5%CO 2 , capped and incubated at 37° C. in a shaking water bath at 150 oscillation/min. for two hours. The final assay volume was 1.0 ml. After incubation the reaction was stopped by the addition of 1.0 ml of 15% KOH in ethanol, and the internal standard 3H-cholesterol was added. The tubes were recapped and the samples were saponified at 75° C. for two hours with periodic mixing. Subsequently an aliquot was removed for protein analysis using Bio-Rad's standard kit, and the remainder of the saponified samples was extracted with 10 ml of petroleum ether for 30 minutes. The lower aqueous phase was frozen in a dry ice/alcohol mixture and the ether layer was poured into labelled tubes. The ether was then evaporated to dryness and the cholesterol was separated by thin layer chromatography on plastic silica gel plates. After visualization with iodine the cholesterol spots were cut and counted with liquid scintillation fluid. Results on the following compounds and lactone form thereof, identified as A and B and A/L and B/L are shown in Table I. ##STR14##
TABLE I__________________________________________________________________________*IC.sub.50 (Micromoles per liter)**% InhibitionAssay Compound A Compound A/L Compound B Compound B/L__________________________________________________________________________*HMGRScreen 5 μM 0.33 μM 50 μM 0.84 μM**Ex VivoFasted 5 ± 19% 55 ± 6%__________________________________________________________________________ *The micromolar concentration of compound required for 50% inhibition of cholesterol synthesis = IC.sub.50 **% Inhibition at 1 mg/kg
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Disclosed are novel 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors useful as antihypercholesterolemic agents represented by the formula ##STR1## and the corresponding ring-opened hydroxy acids derived therefrom and pharmaceutically acceptable salts thereof.
Pharmaceutical compositions containing said compounds and method of inhibiting the biosynthesis of cholesterol therewith are also disclosed.
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BACKGROUND AND SUMMARY OF THE INVENTION
[0001] Despite great strides in cell culture technology and in the medical profession's ability to isolate stem cells and manipulate them to differentiate into various cell types, accomplishments in the field of tissue engineering solid organs remain limited.
[0002] This is because in addition to being a collection of specialized cells, a functional tissue engineered organ is generally thought to necessarily be capable to fulfill the following requirements:
[0003] 1. Contain a scaffold within which the cells reside and organize themselves in the specific three dimensional architectural arrangement required for the organ to function. This scaffold is known in the art as the stromal component of the tissue.
[0004] 2. Ensure that each individual cell in the organ remains within very close proximity to a capillary blood vessel that can supply it with the necessary nutrients. For this to happen, the construct needs to have a dense three-dimensional vascular network of blood vessels and capillaries.
[0005] 3. Be able to connect this capillary network to the systemic circulation.
[0006] These three requirements constitute what is known in the art as the “Holy Grail” of tissue engineering. However, building in the laboratory a stromal scaffold with a functional capillary circulation connected to the arterial and venous circulation of the recipient remains an elusive goal.
[0007] Without a functional internal capillary network, current tissue engineered organs are generally limited to one or two cell layered constructs such as skin, cornea, blood vessels, and most recently urethras. The cells in these tissue engineered organs are generally not more than 1-2 millimeters away from the recipient circulation such that nutrients can reach them by diffusion from the nearby endogenous capillaries of the recipient.
[0008] One known technique used to obtain the expansion of breast tissue without prosthesis implant, is called lipofilling and envisages the graft of adipose tissue (properly treated) into the breast that is to be expanded. The adipose tissue, after a suitable period (some weeks), gives mature fat cells fully integrated into the pre-existing tissue and makes the expansion of the breast essentially complete to result in a breast augmentation or a breast reconstruction in the case of a mastectomy. Even if the basic mechanism is not completely clear, it is supposed that such fat cells come from the transformation of mesenchymal stem cells present in the treated adipose tissue, favoured by the particular environmental conditions in which they are. (see G. Rigotti, A. Marchi, M. Galie, G. Baroni, D. Benati, M. Krampera, A. Pasini and A. Sbarbati (2007) “ Clinical treatment of radiotherapy tissue damages by lipoaspiratres transplant: a healing process mediated by adipose derived adult stem cells ”. Plast Recon Surg. 119(5):1409-22; Rigotti G, Marchi A, Baroni G, Sbarbati A, Delay E, Rietjens M, Coleman SR (2010) “ Fat grafting to the breast: aesthetic and reconstructive applications ” In ed. Jones G E. Bostwick's Plastic and Reconstructive Breast Surgery, Third Edition, Quality Medical Publishing, 2010, pp 251-293; e Rigotti G, Marchi A, Sbarbati A “ Adipose - derived mesenchymal stem cells: past, present and future ” Aesthetic Plast Surg. 2009 May; 33(3):271-3. Epub 2009 Apr. 21. PMID: 19381713 [PubMed—indexed for MEDLINE].
[0009] The treatment of the adipose tissue to be grafted in the involved body region is a known technique: the tissue fat is centrifuged and the fraction containing the vascular-stromal component is actually grafted. Alternatively, the fat harvested by liposuction can be allowed to sediment and the entire supernatant fat suspension used as the grafting material. This approach has several advantages, particularly when the graft is autologous, that is when the fat is taken from another body area of the patient. This technique makes it possible to obtain the elimination of any problem of rejection. In addition, other problems related to the use of prostheses are avoided, such as the risk of failure of the implant (breakage or other). Besides these advantages, the technique of lipofilling (that is the grafting of fat) has, however, some drawbacks, including the fact that the newly grafted fat tissue, before giving mature adipocytes well integrated into the surrounding tissue, may be at least partially absorbed into the body, reducing the effectiveness of the tissue expansion induced by the graft.
[0010] The inventors observed that this phenomenon is facilitated by the natural tendency of the expanded tissues to contract elastically to recover their original condition and therefore, have understood the need to support adequately the expanded body region in order to keep it in shape for the time necessary for the grafted adipose tissue to give rise to mature fat cells, that have stably taken root on the pre-existing tissue.
[0011] The invention as disclosed herein comprises a method of tissue engineering which is a radical departure from the prevailing wisdom in the art of trying to build an organ ex-vivo, in the laboratory (or in what is commonly referred to a tissue reactor), and then transplant it to the needy host. Also disclosed are several devices for achieving this method. The invention finds as one of its main applications in plastic and reconstructive surgery, in particular in the treatments necessary to achieve an increase in the volume of human breast, for example in mammary reconstruction and augmentation mastoplasty, although the invention has broader applications as well and should not be considered as limited thereto. For example, the method and devices disclosed herein also have application in the treatment of body contour defects, whether from scaring or congenital abnormality. Another application is in the expansion of solid organs as the expansion generates the scaffold or stromal component and the grafting provides the necessary cellular complement (whether obtained by liposuction or other harvesting and tissue culturing methods) required to regenerate the organ.
[0012] Previously disclosed in several of a co-inventor's earlier issued patents is a novel method and devices for performing the method of tissue engineering whereby the host organism is induced to generate in-situ this vascular stromal scaffold. As this vascular scaffold grows, it induces new blood vessel formation (neoangiogenesis) and derives its additional circulation from the host. MRI angiograms demonstrate that this method accomplished this tissue engineering crucial effect. This is disclosed and claimed in any one or more of one of the co-inventor's issued U.S. Pat. Nos. 5,536,233; 5,662,583; 5,676,634; 5,695,445; 6,083,912; 6,500,112; 6,514,200; 6,641,527; 6,699,176; 6,730,024; and 6,296,667, the disclosures of which are incorporated herein by reference.
[0013] External expansion as disclosed and claimed in these earlier patents achieved this effect by applying an external or “dynamic” orthogonal outward distractive pull against the surface of the tissues targeted to grow. The preferred methods and devices for achieving this external force application at the time was disclosed and claimed in the co-inventor's previous patents mentioned above, which are presently being successfully commercialized as the Brava Bra® device. At present, to the inventors' knowledge, this device is the only FDA reviewed external three dimensional tissue expander on the market. The Brava® device applies an external distractive pull on the outer surface of the targeted soft tissues by means of a controlled and continuous, relatively low, vacuum pressure. Although modifications of the vacuum pressure and intermittent cycling of the pressure to higher levels that cannot be tolerated for long periods was found to be a more effective method of expanding the organ.
[0014] Vacuum applies an isotropic force on the surface of the tissue, and its outward pull can be controlled through regulating the amount of negative pressure maintained in the dome shell. However, applying constant vacuum over complex and naturally moving surfaces is a challenge and the necessary device, while comfortable enough to achieve commercial success, is necessarily more cumbersome and difficult to wear and, while the inventors are unaware of any serious issues caused directly or indirectly by the use of this device, it must be acknowledged that it may, if not properly administered in accordance with the recommended regimen, exhibit a risk of problems for internal organs and for the surface upon which the device is applied.
[0015] Alternative means of applying a distractive force on an external organ such as the breast is to mechanically pull on the skin surface by pulling on an intermediate layer mechanically secured to the skin by means of an adhesive, or surface tension or sutures, or other mechanical fastening devices. Various examples of these devices may be found in the co-inventor's patents mentioned above.
[0016] In a presently pending U.S. patent application Ser. No. 12/298,011 filed Jul. 24, 2009 with a priority claim to Ser. No. 11/409,294 filed Apr. 21, 2006, the disclosures of both of which are incorporated herein by reference, there is a method disclosed for generating a tissue scaffold with external expansion by applying a vacuum followed by seeding the tissue scaffold with a suspension of fat cells obtained by liposuction and holding the enlarged expanded grafted space open to allow for successful engraftment. Also disclosed is the step of after injecting an expanded scaffold with more liposuctioned fluid volume, maintaining that further enlarged state for a certain period of time so that as the tension dissipates, the tissues stabilize and the graft revascularizes and survives.
[0017] Disclosed also is that to achieve this desired effect a Brava® bra-like external expander device could be used, or alternatively, a splint, bandage or other immobilizing device (hereinafter “splint” or “stent”) could be applied that conformed to the new enlarged shape, adhered to the skin and was rigid enough to prevent any significant recoil, collapse or loss of the surgically engrafted expansion for a period of time.
[0018] As the inventors have continued their inventive activity during the course of their surgical practice, they have discovered that a splint or stent was more comfortable to wear than the Brava® device. Furthermore, compared to the Brava® device where wearing of the larger than ordinary bra was required for hours at a time, which translated to less than desirable patient compliance, a splint which is less cumbersome and more comfortable to the skin resolves the very important patient compliance issue.
[0019] As the patient's expanded scaffold is engrafted with “dilute lipoaspirate”, the injected volume further enlarges the organ (the breast) and holds it in this enlarged state by means of an adhered, at least semi-rigid, splint that prevents recoil, this method not only helps the engraftment process, but can also cause further expansion.
[0020] As the procedure has been refined, more and more dilute lipoaspirate (more fluid, less fat cells) can be injected and more grafting sessions that were smaller in extent (less liposuction required) have been used. In between the grafting sessions, the semi-rigid conforming adherent splint is more comfortable, less discernible to others, and hence more likely to be worn than the Brava Bra® device. With this improved method, the need for using the Brava external expansion device between grafting sessions has been obviated, having been replaced by the less intrusive splint.
[0021] In further refining the procedure, to cause the organ to swell, instead of pulling on the outside for a long sustained period of time as originally performed with the external expander devices, physiologic fluid was injected inside the organ alone, without cells. The injection caused significant swelling and was limited by the internal tension inside the organ. In essence, injecting the breast with fluid produced the same effect as the external expander, i.e. tension in the breast. Left alone, the injected fluid would be expected to be rapidly reabsorbed by the body thereby simply reversing the expansion and reducing the swelling. Thus the tissue would not ordinarily be expected to sense any sustained tension that would induce the formation of a stromal matrix and recipient scaffold and the desired increase in volume obtained with the injection would be lost.
[0022] While working with the external expander and inflating breasts with physiologic solutions, the inventors came to the realization that the immediate application of the splint that retains the swelling maintains the sustained tension required for the tissue engineering matrix to form. Within a period of days to weeks, that sustained tension has been found to induce the formation of the stromal matrix in as effective manner to that of the sustained tension of the Brava external expander.
[0023] Internal tissue fibers under tension sense the same forces whether (under the effect of the Brava® device or other dynamic traction device) the skin surface is pulled from the outside or whether the skin is held up to prevent recoil once the internal tension has already been induced. From a mechanical standpoint the forces required for inflation of the tissue are thought to be approximately the same forces that will be forcing its recoil. The inventors therefore came to the conclusion that preventing the recoil of forced internal inflation by holding up the skin (forced inflation and passive splinting) achieves the same physiologic effect as pulling up on the skin to force its inflation (external dynamic expansion).
[0024] Interestingly, patients subjected to both modalities confirmed experiencing the same sensation.
[0025] While inflation is ideally diffuse if the inflating agent is placed throughout the tissue and within all tissue planes, it is also effective if the inflating agent is placed only in localized areas and we allow for natural diffusion of the injected material through osmotic forces and mechanical gradients of tissue compliance amongst the tissue types and the tissue planes. With respect to cellular agents injected into the tissue, such as fat, stem cells or the like, in order to achieve the best results with minimal necrosis, it has been found that diffuse injection of the inflating agent is preferred. For inflating agents that are acellular, such as saline, suspensions of particulate matters such as tissue matrix agents, or gels and other physiologically compatible fluids such as maybe even air (which has not yet been tried by the inventors but is conceived as eligible for use), it has been found that optimum results are not as dependent on a diffuse inflation.
[0026] The description above discusses inflating the soft tissue through injection of a physiologically compatible agent or fluid. While injection has been used by the inventors with success, the inventors conceive that the soft tissue can also be inflated through other means that can apply a distractive force to the tissues. One such example is to induce acute edema to the tissue and then while the tissue is expanded rapidly apply a passive stent. Using the breast as an example, a high pressure pump may be used to create a temporarily strong distractive force in cups applied to one or both of the breasts at pressures above what can be physiologically tolerated for more than a few minutes and then recycling after a few minutes rest giving time for the tissue to recover to achieve the desirable augmentation, remove the cups, and then apply passive stents to the breasts which are suitable for being comfortably and unobtrusively worn for some extended time period. Depending on the particular construction of the stent, and its ease of application (and expense), the inventors conceive that a patient could herself replace the stent to allow for personal hygiene, or return to the Doctor's office for another round of inflation and then another set of stents larger than the previous ones. In this way, the patient can take a stepwise expansion of her breasts until the desired size has been reached.
[0027] In yet another modality, the inventors are well aware of a low pressure bra-like device made and sold by Brava, LLC as one of the co-inventors is the inventor of that device. One of the issues which interferes with patient success in using the Brava Bra® is that of patient compliance. Although many patients are quite successful and are very happy with the results achieved with the Brava Bra®, some patients are not as diligent in their wearing of it as while it is remarkably slim and unobtrusive, it is yet more so than a thin bra cup. Furthermore, the recommended wear times are less than 24 hours a day, which gives the breast time to recoil and then when the Brava Bra® is reapplied, the starting size is less than when it was removed. The present invention of a passive stent may be coupled for use with the Brava Bra® in order to prevent breast recoil and thereby accelerate the augmentation process. Simply put, use of the passive stent for those times when the Brava Bra® is not worn transforms a sawtooth pattern into a stepwise expansion pattern of augmentation.
[0028] It is also contemplated by the inventors that the repeated inflation or distension of the soft tissue (breast as used for exemplary purposes only) may be achieved through a mixing of these various methods. In other words, the first inflation may be achieved through the creation of an edema or injection in the Doctor's office and subsequent inflations could be achieved through use of a low pressure or higher pressure cycling vacuum pump at home by the patient. It is also conceived by the inventors that a “kit” for home use could be put together comprising the presently commercially available Brava Bra® and vacuum pumps and a set of passive stents which the patient could self-apply during the intervals when not wearing the Brava Bra®.
[0029] In sum, the present invention is expected to be able to be used to maximize expected results through use of the Brava Bra® in soft tissue augmentation without surgical intervention or even injection.
[0030] When the patient returns back to the office, a few days to a few weeks after inflation, the splint is removed and the inventors have found that the organ (breast) has substantially maintained the operative enlargement due in large part to the adherent splint that prevented tissue recoil. However, while immediately after injection the breast was initially tight and firm from the large injection volume, it has been found after the passage of time to be soft and loose as the tissues had internally and externally stretched and expanded to accommodate the tension. In this regard, the physiologic process of tissue expansion has been found to be essentially similar to the dynamic external expanders.
[0031] With the enlarged (organ) breast now soft again, additional physiologic fluid may then be injected, enlarging it more until it becomes tight and firm again. A new splint may then be applied so that it conforms to the newly enlarged expanded state and the patient is then free to return to their normal activities, wearing this rigid splint as an adherent bra cup for the few days to weeks as required for the tension to equilibrate as the tissues expand further.
[0032] The process may then be repeated a few times until the desired recipient scaffold size is reached. At that point, the graft is diffusely dispersed inside the expanded scaffold and a new splint is applied to allow the grafts to revascularize and successfully engraft to regenerate the deficient organ.
[0033] Alternatively, this process of physiologic solution injection to expand the tissues followed by passive splinting to maintain the expanded state can be serially repeated until mechano-transduction, the process through which tissues grow in response to sustained mechanical expansion, generates enough tissue to obviate the need for tissue grafting. In essence, the inventors discovered a new method of tissue expansion which, in effect is an alternative to the devices described in previous patents and patent applications.
[0034] It is thus one aspect of the present invention to create a physical structure to be applied to a body area subject to tissue expansion, which is structurally and functionally designed to overcome the limitations described above with reference to the cited state of the art. In this regard, one function of the invention is to provide a device for maintaining morphology of a soft tissue site or organ, i.e. that is able to maintain the shape and volume of the body area subject to expansion, and to counteract any natural tendency to contract by the involved tissues.
[0035] Another desirable feature of a preferred embodiment of the invention is to provide such a device that is immediately usable in a post-operative phase and which also exhibits a high biocompatibility with the skin, in order to permit it to be safely and comfortably worn for a period of 2-3 weeks. Yet another desirable feature of a preferred embodiment of the invention is to provide such a device that is lightweight and easy to carry, in order to encourage its being worn by the patient during normal daily activities and thus improve patient compliance. Still another desirable feature of a preferred embodiment of the invention is to provide such a device that is readily customizable (malleable) so as to be able to more fully adapt to the shape of the body area of the individual patient. Yet another desirable feature of a preferred embodiment of the invention is to provide such a device that is easy to apply to the involved body area and, if necessary, just as easy to replace.
[0036] The invention also comprises a kit that can contain a device to distend the breast, such as a vacuum pump of the Brava modality or a high pressure pump, one or more breast cups to be applied to the breast to achieve the distention, and one or more passive splints which could potentially be applied over several weeks by the patient herself.
[0037] It will be apparent to any person of ordinary skill in the art of surgical reconstruction that one of the invention's preferred embodiments comprising the splint to be applied over the breast (organ) can be embodied in a multitude of designs using a large variety of materials.
[0038] The common requirement however to these are as follows:
[0039] Important attributes:
a. adheres firmly to the skin or the surface of the organ to prevent recoil and detachment during the patient's regular activities. b. can be conformed to match and cover the exact shape and contour of the swollen breast or organ. c. while malleable when first applied, it should rapidly harden to espouse the desired shape. d. in the hardened state have mechanical properties that can counteract the tissue recoil. e. be bio-compatible and capable of being tolerated for long term application (1-3 weeks of uninterrupted wear). The splint is conveniently adapted to be made out of many bio-compatible “breathable materials” as known in the art.
[0045] Desirable attributes:
a. easy to apply kit b. comfortable (semi-rigid, that is while preventing collapse, rubber like to allow for some bending, as compared to rock hard plastic) c. thin (one Inch or less) d. skin colored e. smooth contours that blend and taper with the chest wall skin f. have the appearance of a stick on, well camouflaged external breast prosthesis. g. items b-f should render the device easy to conceal and to wear 24/7. h. transparent or translucent so the underlying skin can be monitored, both to ensure that the splint is in good adhesive contact at the time of application and that any rash or irritation can be readily detected.
[0054] Another way of mechanically coupling the splint to the skin is surface tension. Surface tension is the naturally occurring means by which the body holds together tissues that need to remain mechanically coupled but yet glide and avoid shear forces. This is how the expanding rib cage transmits the mechanical force of inhalation to the soft sponge like lungs to expand and this is how bowel loops can glide past another while held together too.
[0055] The external splint can be akin to a swim cap or to a toilet plunger pump. Semi-rigid, conforming and with a film layer of surface tension that transmits the mechanical recoil of the plunger rubber to the skin surface and pull it outward.
[0056] The many embodiments of this splint embodiment (or adherent semi-rigid, conforming bra cup) that can be applied over an organ swelled up and tensed up by injection include but are not limited to:
[0057] A. Single layer embodiment:
Here a spray, paint, or putty form of a soft rubber or a rubber sheet is applied over the surface of the organ and that material cures to become rigid enough to prevent recoil. It could be adherent by itself or might require the addition of an adhesive glue such as a biologically tolerated adhesive or use surface tension. It might include imbedded or subsequently applied reinforcing fibers that contribute to the desired mechanical characteristics.
[0059] Specific embodiments would include:
1. The hair spray like device: an aerosol delivered spray of a plastifying material that can coat the surface of the organ and rapidly dry or cure to become an exoskeleton-like shell structure that is hard enough to prevent the forces of recoil. This might be achieved by a modification of the current colloid dressing solutions or the liquid band aids or the cyanoacrylate glues used for wound closure or other biocompatible polymers that can offer the desired characteristics. 2. Materials similar to the above, instead of being sprayed could be painted or smeared over the surface of the organ where they would rapidly cure to become a hard shell that espouses its exact swollen contour and prevents it from recoiling. A solvent can then be used to remove it when needed. 3. A putty-like soft rubber that can be spread over the surface and made to cure and become hard either with a catalyst or on air contact or by varying the temperature or by UV light exposure. The material can be delivered as sheets that are inherently tacky and stick to the surface when applied, or that need a priming sticky layer like a tissue glue to be applied first and then the confirming rubber putty adheres to that glue. Examples of these materials include the cyanoacrylates, epoxy, acrylic, urethane or other polymers such as silicone based medical adhesive glues. 4. A sheet of adhesive tape like material. This can be either a textured or fibrous material or it can be a foamy or porous material that is taped over the surface of the organ. There are many well-tolerated pressure sensitive adhesive compounds that can provide a firm adhesion between that tape or sheet and the skin. The adhered sheet or tape can then become hard either because of its inherent ability to cure on exposure to air or water or with the help of a catalyst, temperature changes or UV exposure. The device would be supplied in an air tight pouch ready to be applied and would cure either by itself on exposure to air or water, or with the help of the necessary catalyst. Alternatively, the device can be made to harden by painting it, spraying it or adding to it a plastic, rubber, fiberglass, epoxy, urethane or other biocompatible polymer, even a plaster of Paris like material.
[0064] B. Two layered embodiment: First apply over the breast or the organ a layer of material that will adhere to the skin or to the surface of the organ to be enlarged. This must be a material known to be well tolerated for prolonged surface contact (this can range from adhesive tape to hydrogels and hydrocolloids, to cyanoacrylates and other liquids or gels that stick to the tissue surface). Then add to this another layer of a material that can be made to adhere to the first layer, be malleable to precisely espouse the contour of the swollen organ, and that can be made to cure and become rigid in this new shape and form (this can range from thermoplastics to fiberglass like tape to plastics that can be cured on air or water contact or with the help of curing agents, catalysts, or temperature or UV light, to rubbers and other biocompatible polymers such as silicone and/or polyurethane and their related products and derivatives.
[0065] Specific embodiments would include:
1. an adhesive hydrogel for the first layer and then glued and stuck to it.
a. a thermoplastic material added for rigidity and made to adhere to the hydrogel. b. fiberglass like material added for rigidity and made to adhere to the hydrogel. c. plaster of Paris-like material added for rigidity and made to adhere to the hydrogel. d. a natural or synthetic polymer or their derivatives capable of adhering to the hydrogel and be malleable enough in the first state to conform to the surface contour and become rigid in the second state to prevent recoil.
2. An adhesive silicone gel for the first layer and a rigidifying silicone putty adhered to it for the second layer. That putty might contain a fibrous mesh as a rigidifying framework. 3. An adhesive foam for the first layer and then glued or stuck to it:
a. a thermoplastic material added for rigidity and made to adhere to the foam b. fiberglass like material added for rigidity and made to adhere to the foam. c. plaster of Paris-like material added for rigidity and made to adhere to the foam. d. a natural or synthetic polymer or their derivatives capable of adhering to the foam and be malleable enough in the first state to conform to the surface contour and become rigid in the second state to prevent recoil.
4. An adhesive biocompatible sheet like Tagaderm® or OpSite® or a woven or knitted material similar to the Second Skin.
a. a thermoplastic material added for rigidity and made to adhere to the breathable material adherent to the skin. b. fiberglass like material added for rigidity and made to adhere to the breathable material adherent to the skin. c. plaster of Paris-like material added for rigidity and made to adhere to the breathable material adherent to the skin. d. a natural or synthetic polymer or their derivatives capable of adhering to the breathable material adherent to the skin and be malleable enough in the first state to conform to the surface contour and become rigid in the second state to prevent recoil.
[0082] Anyone of ordinary skill in the art, given the teaching herein, can also understand that in 1-4 above, the first layer that is conforming, biocompatible and adhesive can be subsequently made rigid by adding to it chemical compounds that can provide it with the desired mechanical rigidity.
5. Biocompatible Materials that can be used:
Natural polymers and their derivatives such as Nitrocellulose, Chitin, etc. Synthetic polymers such as polycarbon, polyvinyl, polyurethane, polyesther, silicone, and their derivatives.
[0086] C. Multiple layer sandwich: First an adherent layer (same range of materials as above) then a rigidifying layer (same range of materials as above), then a final layer that camouflages the entire construct.
[0087] The disclosed invention may also be used for a method of three dimensional tissue expansion.
[0088] In conventional tissue expansion, inflatable silicone shells are surgically inserted and after the surgical wound heals, the expander is serially filled with physiologic fluid to distend it. Multiple filling sessions a few days to a few weeks apart compress the intervening tissues between the skin surface and the expander shell and only expand the surface envelope. When removed these expanders then leave behind a cavity, a dead space that needs to be collapsed if the expansion is used for tissue coverage or in the case of breast reconstruction replaced with an inert foreign material implant.
[0089] With the present invention of tissue expansion, there is no surgical intervention required to insert any device. By simply injecting a physiologic fluid inside the organ to be augmented, by inducing an edema, or otherwise mechanically deforming it, not only is the envelope generated and stretched, but what does occur is that a stromal three dimensional recipient matrix for tissue engineering is also generated. As with conventional expansion, the quantity injected is limited by the level of tissue tension that can be tolerated and repeated injections are preferably needed a few days to weeks apart, or once the tissues expand and become lax again to become eligible for further injections. However, while with the internal expanders tension is maintained by the distended shell that compresses the underlying tissue and only stretches the outer envelope, with the present invention the tension on the tissues is generated by the application of an external shell that prevents collapse and uniformly distributes the tension to all the tissues contacting the splint to induce their uniform expansion. With the present invention using the splint, no surgery is required, no complication can result from foreign material being inserted, no tissue compression at all. Only diffuse generalized internal expansion forces (tension) are created, which have been found to be adequate to achieve the desired effect.
[0090] Other examples of suitable injectable materials range from simple physiologic electrolyte solutions to dilute suspension of specialized cells, to solutions containing growth promoting agents, or to suspensions and solutions of tissue matrix components that might altogether obviate the need for the cell seeding step as the improved injectate stimulates not only stromal matrix formation but also the proliferation of cells required to populate the organ.
[0091] As for the preferred embodiment, the inventors continue to search for new materials which satisfy both the important as well as the desirable attributes. However, at the time of filing, the inventors have successfully used the process of applying a layer of surgical tape, microfoam or hypofix type, and added on top a layer of fiberglass material customarily used to make fracture casts. While it is still malleable, the fiberglass plastic can be made to stick to the tape while it rapidly cures into a hard shell (like a cast) that espouses the contour of the expanded breast. This hard cup bra-like splint then remains adhered to the tape which is itself adhered to the skin. If well applied, the inventors have found that this construction will hold for a week, however the inventors would prefer other materials that would exhibit a longer life. This construction results in a somewhat cumbersome device but does have the advantage of being made out of off the shelf materials routinely available to any surgeon.
[0092] While not to be considered as limiting in any way, or as fully and completely defining the scope of the inventions disclosed herein, the inventors shall further exemplify the invention through the illustrative description and drawings depicting the preferred embodiments.
DEFINITIONS
[0093] It should be noted that in the present description and following claims, an element will be called “deformable” or “malleable” if its shape can be changed even under the effect of negligible forces, such as those expressed by a simple manipulation of an operator, particularly when it can be manually morphed to the shape of a human breast or other organ or other contour defect in need of correction. Malleable would include a moldable or shapeable sheet of material or sheets of material such as fiberglass or plaster of Paris impregnated cloth which is initially shapeless and adopts the morphology of the body tissue to which it may be closely applied. In addition, an element will be called “rigid” or “semi-rigid” when it will not deform significantly due to typical stresses caused by morphological forces such as the natural contraction of a distended breast, which is expanded by for example injecting a physiologically compatible fluid, inducing an edema such as by applying and cycling a high pressure vacuum to the breast, by applying a continuous low pressure vacuum over time (such as under pressures recommended for use with the Brava Bras®), etc. Furthermore, in the description and subsequent claims, the deformation of an element will be called “not appreciable”, when, conformed to the shape of the tissue desired to be enlarged, such as by having the shape of a cup similar to a human breast, and undergoing a load of radial compression, produces a not meaningful volumetric shrinkage which materially detracts from achieving the desired tissue expansion.
[0094] As used herein, the term “physiologically compatible agent” or “physiologically compatible fluid” should be understood as including both “cellular agents” or “cellular fluids” such as stem cells and fat, as well as “acellular agents” or “acellular fluids” such as saline, gels, air, etc. Cellular agents or cellular fluids are understood as an agent or fluid that principally comprises cells, stem cells, harvested cells, genetically manipulated cells, cultured cells or the like. Acellular agents or fluids are understood as comprising gels, suspensions or solutions such as saline, chemicals that might promote growth or stabilization or tissue health, biologic tissue promoters or tissue substitutes, tissue inductive material, tissue matrices, etc.
[0095] As used herein, and elsewhere, the words “splint” and “stent” are used interchangeably but both can be defined as a deformable or moldable device intended to be shaped to be in intimate contact with the skin or other soft tissue surface and which maintains the morphology of the surrounding and underlying tissues. The word “splint” is generally considered as being relatively rigid in orthopedic uses while a “stent” is generally considered as being deformable or moldable to more closely follow the contours of the surface in question. The desirable properties of the stent or splint as described herein characterize the device being referred to so as to enable those of ordinary skill in the art to understand this reference.
[0096] The term “passive splint” or “passive stent” or “splint” or “stent” as used herein shall be understood as meaning a device which does not apply an external force to any underlying tissue to which it might be adhered, other than to resist the natural morphological forces which seek to return soft tissue to its previous relaxed or natural state. It is to be contrasted with what might be referred to as a “dynamic” force application device, such as a vacuum pump, which has the capability to apply an external force to body tissue.
BRIEF DESCRIPTION OF THE DRAWINGS
[0097] FIG. 1 is a cross-sectional view of a first embodiment of the invention comprising a stent or dome applied to a breast previously subjected to tissue expansion;
[0098] FIG. 2 is a perspective view of a sheet shaped adhesive element to be adhered to the breast and conform to its shape;
[0099] FIG. 3 : is a perspective view of a second sheet of material, adhered to the first and adjustable between deformable and rigid in character;
[0100] FIG. 4 is a cross-sectional view of a second embodiment of the invention, applied to a breast subject to tissue expansion;
[0101] FIG. 5 is a cross-sectional view of another embodiment of the invention comprising what can be a single or multiple layer splint, applied to a breast;
[0102] FIG. 6 is a perspective view of another embodiment of the invention comprising a malleable sheet;
[0103] FIG. 7 is a perspective view of yet another embodiment of the invention comprising a malleable sheet which may be woven or reinforced;
[0104] FIG. 8 is a perspective view of yet another embodiment of a splint that may be pre-formed in the approximate shape of a breast;
[0105] FIG. 9 is a perspective view of a vacuum pump connected to a bra cup for inducing an edema to thereby distend the breast;
[0106] FIG. 10 is a perspective view of yet another embodiment of the invention comprising a splint formed in an approximate circular pattern with a slit for being folded over onto itself and creating an approximate cone shape; and
[0107] FIG. 11 is a perspective view of the cone-shaped splint formed with the circular shaped splint shown in FIG. 10 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0108] With reference to FIGS. 1 to 3 , the first embodiment is generally referred to as 1 . The device ( 1 ) is intended to be applied to the soft tissue body area subject to tissue expansion. In this instance, and for illustrative purposes only, the body area consists of a breast ( 2 ) whose volume was increased, preferably by injecting a physiologically compatible fluid such as saline, or less preferably by grafting properly treated autologous adipose tissue, in each instance optionally preceded by a period of treatment of vacuum or mechanical stimulation. Nevertheless it is understood that the present invention can be applied in the same way in any surgery, aimed at changing the congenital or acquired body profile through fluid injection or adipose tissue graft, such as in the treatment of depressions caused by scars, surgical resections or malformations. The device is not only limited to external skin surfaces but can also be applied to internal defects and to solid organs.
[0109] The device ( 1 ) preferably includes a sheet-like layer of an adhesive element ( 3 ), which is preferably made from materials that are easily deformed even at room temperature (about 25° C.) and able to adapt to the widely varying shapes and sizes of the female breast ( 2 ). The adhesive element ( 3 ) is preferably sheet-shaped, and includes, in correspondence of its outer surface ( 3 a ), an adhesive layer ( 4 ) that may be applied directly on the skin surface of the breast ( 2 ), and a backing layer ( 5 ) superimposed to the adhesive layer ( 4 ). Both layers ( 4 ) and ( 5 ) may preferably have a thickness between about 0.5 and 3 mm. The adhesive layer ( 4 ) is preferably an hydrocolloid, with high biocompatibility with the skin, so to ensure that the device ( 1 ) can be safely and comfortably applied to, and worn on, the breast ( 2 ) for reasonably lengthy periods of time, if necessary, without needing replacement. In addition, the biocompatibility of the adhesive layer ( 4 ) allows its application on the skin immediately after the surgical breast expansion, even in the presence of post-operative edema which is typically present after these surgical interventions.
[0110] The backing layer ( 5 ) is preferably made of soft polymer material, e.g. thermoplastic polyurethane based foam or other polymeric material with similar characteristics of softness and deformability. In this way, the adhesive element ( 3 ) can adhere completely to the skin surface of the breast ( 2 ), adapting virtually perfectly to its shape. The adhesive elements described above may be provided for example by the company Convatec under the trade name of DuoDerm®.
[0111] The device ( 1 ) also preferably includes a structural element ( 10 ) coupled to the opposite side of the adhesive layer ( 4 ). Even the structural element ( 10 ), like the adhesive element ( 3 ), is preferably sheet-shaped, with a thickness preferably between 0.5 and 4 mm. The structural element ( 10 ) is preferably basically rigid at room temperature, so that it does not deform significantly when subjected to stresses caused by the natural contraction of the body area involved in the tissue expansion. In particular, the structural element ( 10 ), at room temperature, is preferably able to resist without deforming significantly when loaded by the natural contraction of the expanded soft tissue, such as the breast ( 2 ), following tissue expansion and, among other factors arising from the tissue elasticity and from the post-operative reabsorption of the edema. The material preferably used for the structural element ( 10 ) exhibits a high chemical compatibility with the material used for the backing layer ( 5 ) of the adhesive element ( 3 ), so that it can ensure an effective adhesion to it, even without additional layers of glue. However, it is optionally envisaged that an additional adhesive layer can be applied between the two elements 3 and 10 , for example a cyanoacrylate-based material indicated for medical use. Most preferably, the structural element ( 10 ) is made of thermoplastic polymer having properties such that when heated to a temperature between 50° and 80° C. (at first instance comparable to the melting point of the polymer), it softens in such a way to be easily deformed by a surgeon's manual manipulation. In this way, the structural element ( 10 ) can be stretched over the adhesive element ( 3 ), be adapted perfectly to the shape of the breast ( 2 ) and maintain this conformation.
[0112] Thermoplastic polymer materials softening at temperatures above 80° C. are not presently considered suitable for use in the present invention, because they would be too hot to be manipulated by a surgeon or to be used on a patient, even in overlap with the adhesive layer ( 3 ). On the other hand, thermoplastic polymer materials softening at temperatures below 50° C. are not presently considered suitable for use in the present invention, because they would not have adequate stiffness at room temperature or at temperatures between 35 and 40° C., easily accessible in many countries in summer. Preferably, the structural element ( 10 ) is made of a polymer based on polycaprolactone, covered with a layer of urethane acrylates. Several holes with a diameter ranging between 3 and 5 mm are made preferably on the structural element ( 10 ) and placed regularly on its surface. These holes ( 11 ) allow an easier deformation of the structural element ( 10 ) when brought to temperatures between 50 and 80° C., allowing at the same time a decrease of the mass of the structural element ( 10 ), in order to be lighter and to provide faster and more even temperature changes both in the heating and the cooling phases.
[0113] The use of this preferred embodiment takes place as described below, at the end of the treatment of tissue expansion of the soft tissue, preferably obtained through the injection of physiologically compatible fluid or grafting of properly treated autologous fat tissue. In the first phase, the adhesive element ( 3 ) is carefully laid on the expanded breast ( 2 ) to adhere perfectly to the skin surface. After that, the structural element ( 10 ) is heated at a temperature between 50 and 80° C. so that the surgeon can easily deform it and lay it on the adhesive element ( 3 ) previously applied to the breast ( 2 ), adapting to its morphological conformation. The preferable chemical compatibility between the adhesive element ( 3 ) and the structural element ( 10 ) permits their mutual adhesion. Both the adhesive element ( 3 ) and the structural element ( 10 ) are laid to cover the entire area involved in the tissue expansion, including preferably a considerable margin around it. The structural element ( 10 ) cools rapidly to room temperature, making it stiff enough to hinder effectively the natural tendency to contract of the expanded tissue.
[0114] The sizing and the material of the structural element ( 10 ) are such that the cooling takes place as quickly as possible, but long enough to provide the surgeon with the time necessary to lay the structural element on the adhesive element ( 3 ). After the application of the structural element ( 10 ) and its cooling, the device ( 1 ) can be left on the breast ( 2 ) for a long period, even weeks if considered desirable, to promote the development of mature fat cells and their integration into the pre-existing tissue. If necessary, the device ( 1 ) can be replaced, by detaching the adhesive layer ( 4 ) from the breast ( 2 ) and repeating the steps described above with a new adhesive element and a new structural element. The device of the present invention is very lightweight and easy to wear, without causing discomfort or pain in the body region around the expanded tissue (breast). In fact, the pressures caused by the tissue's natural contraction is very low, in particular if compared with those necessary to stimulate its expansion by vacuum application as in the known devices. In addition the device of the present invention is customizable, as it is adaptable to the morphology of the specific patient. A further advantage of this invention is that its application promotes a biological response, which is thought to lead to the transformation of the stem cells present in the treated and grafted adipose tissue into mature adipocytes. The structural element ( 10 ), before being used, can be provided in the form of a flat sheet or in a convenient alternative, already preformed cup according to different predefined sizes.
[0115] With reference to FIG. 4 , another embodiment of the invention is shown and referred to generally as 100 therein. The device 100 differs from device 1 described above by incorporating an additional element with variable thickness 101 , interposed between the adhesive element ( 3 ) and the structural element ( 10 ). The function of this element with variable thickness ( 101 ) is to improve the adaptability of the structural element ( 10 ) to the morphology of the expanded body region through a controlled reduction of its volume and thickness.
[0116] The element ( 101 ) designed with variable thickness is preferably made of polymer foam, e.g. polyurethane, whose radial thickness is adjusted by aspiration of the air contained in it.
[0117] Yet another embodiment 120 is depicted in FIG. 5 and includes within this single drawing figure a number of alternative constructions. For example, there is depicted a stent 122 which has been adhered to a breast with an adhesive layer 124 . Stent 122 could have the layer 124 of adhesive applied to its inner surface 126 , or the adhesive could be applied separately such as by being sprayed on or as being part of a double-sided, adhesive coated tape 124 . Layer 124 could be a layer of gel or silicone and if necessary an additional layer of adhesive could be applied. Layer 124 could also be a layer of second skin. The single layer stent 122 could be formed from a sheet of material (see FIGS. 6 & 7 ) such as a thermoplastic material, natural or synthetic polymer or from multiple sheets of overlapping material which cures into a rigid construction, like fiberglass or plaster of Paris as might be used for a cast, for example. Stent 122 could also be applied like a putty, such as silicone. There are many other materials, as known to those of skill in the art which could be substituted for these exemplary materials, using the teaching and guidance of the present disclosure.
[0118] As shown in FIG. 6 , the stent 122 may be a single sheet of material before application to the soft tissue site; flexible for being readily conformed to the soft tissue site and then being capable of becoming rigid to maintain the morphology of the site. For example, such a flexible single sheet of material 122 may be sized to adequately cover the breast and as explained above have one of its surfaces covered with adhesive or not. As shown in FIG. 7 , the stent 122 may be woven or reinforced which can make it both easier to pre-mold into shape and also better hold its molded shape after it is cured or otherwise transformed into a rigid structure adhering to the breast. FIG. 8 depicts yet another representative shape for the stent 122 . As shown therein, the stent 122 may be pre-molded into somewhat the shape of different breast cup sizes to minimize the possible introduction of wrinkles as the stent 122 is manipulated around the breast. Also, optionally, a flattened edge surface 126 to help form a seal at the edge of the stent 122 against the patient's chest.
[0119] As shown in FIG. 9 , a Brava Bra® system 128 may include a breast cup 130 adhered around a breast and held in place by a vacuum created between them by a pump 132 . The periphery may also have an adhesive applied to help hold it in place during wearing. Pump 132 could be either a low pressure pump for continuous use in accordance with the recommended protocol, or a higher pressure pump for recycling as explained above to distend the breast.
[0120] As shown in FIG. 10 , the splint or stent 122 may be pre-formed in an approximately circular shape with a slit 134 to facilitate its being folded or collapsed around itself and thereby form the cone shape shown in FIG. 11 .
[0121] The methods of use of the various inventions disclosed herein have been explained above as would be readily understood by those of skill in the art.
[0122] The invention has been illustrated through its preferred embodiments as shown in the drawing figures and as described in the description above. These preferred embodiments are not intended to be limiting in any way. Instead, the invention is intended to be limited solely by the scope of the claims appended hereto and their equivalents.
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A device for maintaining or achieving soft tissue expansion applicable to any body region already temporarily expanded including: an adhesive element deformable and capable of adapting to the shape of this body region, and which can then itself become mechanically rigid enough to resist tendency of the expanded tissue to recoil or to which a second material can be applied to form a stent adapted to the shape of the body area to provide the necessary structural rigidity to prevent recoil of the expansion and thereby induce its retention of its expanded shape after the stent is removed.
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BACKGROUND OF THE INVENTION
The present invention relates generally to seats and stands used by sportsmen while hunting in the outdoors, and more particularly to portable shooting and rifle stands capable of being quickly moved, adjusted, or pivoted to a variety of shooting positions.
The hunting of game using a rifle or other weapon can often require a great deal of patience on the part of the hunter, whether in an open field or in a wooded area. In particular, hunters often have to remain in a fixed location for an extended period of time in order to place themselves where game will enter or move into the shooting range of the hunter. For this reason, many hunters use crude or complex seats and shooting stands to allow them to comfortably maintain a seated position yet still respond quickly when the hunted prey enters the proximity.
When hunting some animals, prairie dogs being one example, it is also important that the hunter visually survey across a wide lateral field of view, looking for the sudden appearance of a target in the field. When the animal is spotted, the hunter then must rapidly change position to place his body and rifle into an adequate shooting position with respect to the visualized target. Unfortunately, prior art shootings seats and stands have not allowed this rapid change of horizontal or lateral position. Rather, prior art shooting stands would require the hunter to either contort his body into an awkward shooting position or to physically move the entire stand, causing both delays and unnecessary noise which might disturb the game.
Those prior art shooting stands which are to some extent adjustable, suffer from the further deficiency of lacking adequate ground engaging support. As a result, a sudden change in position may result in an off-centered tilting or unbalancing of the stand, causing a lack of stability during the shot.
What is needed, then, is a portable shooting stand which allows the hunter to remain in a seated position for an extended period of time, yet facilitate rapid and stable lateral or horizontal adjustment in shooting position when the target is spotted. Such a device is presently lacking in the prior art.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a shooting stand for use by hunters in the field which can be quickly pivoted to different shooting positions.
Another object of the present invention is to provide a pivoting shooting stand that is portable and easy to assemble and disassemble.
A further object of the invention is to adapt a shooting stand having an outer covering for use where rapid change in shooting position is required.
In accordance with these and other objects which will be apparent to those skilled in the art, a shooting stand is described which has a seat and table assembly combined with a separable roller track. A plurality of legs support the seat a comfortable distance above the ground and a table above the seat. The top of each leg is connected to the bottom surface of the table. The lower ends of the legs are joined together and laterally stabilized by front and rear reinforcing members. At the bottom end of each leg is a roller assembly which includes a two piece roller forming a concave roller track engaging surface. The rollers rest on and roll in circular fashion around the roller track, allowing the user to quickly pivot the shooting stand a full three hundred sixty degrees (360°).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an oblique view of the pivoting shooting stand of the present invention.
FIG. 2 is a rear view of the pivoting shooting stand of the present invention.
FIG. 3 is a left side view of the pivoting shooting stand of the present invention.
FIG. 4 is an enlarged view of detail section B of FIG. 3.
FIG. 5 is an enlarged view of detail section A of FIG. 3.
FIG. 6 is a top view of the pivoting shooting stand of the present invention.
FIG. 7 is a rear view of a second embodiment of the shooting stand equipped with an outer camouflage covering and supporting frame.
FIG. 8 is a perspective view of the shooting stand embodiment of FIG. 7 with the outer covering removed to show the supporting frame.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Looking first at FIGS. 1, 2, and 3, the pivoting shooting stand of the present invention is shown generally at 10. Stand 10 generally includes two separable assemblies, a seat and table assembly 12, and a base which, in a preferred embodiment, is a roller track 11. Roller track 11 rests on a ground surface (not shown) to provide stability for seat and table assembly 12. Roller assemblies 26, a plurality of which are attached to seat and table assembly 12, engage the upward facing surface of roller track 11 to provide a means to pivot seat and table assembly 12 with respect to roller track 11 and the ground surface.
In a preferred embodiment of the invention, seat and table assembly 12 includes a table 15 and seat 13 joined together to form an assembly 12 which can pivot together as a single unit. To allow the user to sit comfortably above the ground and rest his rifle and arms on a flat, stable surface, stand 10 must also have means to support seat 13 above the ground and table 15 above seat 13. Accordingly, the top ends of first, second, and third support legs 21, 22, and 23 are attached to the lower surface of table 15 and extend downward a sufficient distance to raise table 15 above the ground surface so that a seated user of stand 10 can be in a comfortable shooting position. Support legs 21, 22, 23 are preferably cylindrical or tubular structures made of aluminum or other lightweight metal. To provide stability and rigidity at the lower ends of legs 21, 22, and 23, they are joined together by a rear reinforcing member 24 and a front reinforcing member 25, as best seen on FIG. 1. Front reinforcing member 25 is preferably a lightweight metal tube bent to form an approximate semi-circular shape, divided at its mid-point by front support leg 21. Rear reinforcement member 24 joins second and third support legs 22 and 23.
As best seen on FIGS. 2 and 3, rear and front reinforcing members 24 and 25 are attached to corresponding first, second, and third support legs 21, 22, and 23 by joint connectors 20. Accordingly, rear and front reinforcing members 24 and 25 preferably have hollow ends so that a laterally protruding stub portion 19 of joint connector 20 can extend within reinforcement members 24 and 25, thereby holding them in place.
To allow the user of stand 10 to remain in a comfortable position over an extended period of time, seat 13 is attached to and between central portions of left and right support legs 22 and 23. As best seen on FIG. 3, the lower surface of seat 13 rests on two seat support rails 14, one of which is bolted in a conventional fashion to the inner surface of left and right support legs 22 and 23 and a second of which is mounted to the outer facing surface of support legs 22 and 23. As seen in FIG. 6, seat 13 is secured to the upward facing surfaces of seat support rails 14 by screw or other conventional fastener inserted through seat attachment holes 38.
Table 15 is preferably oriented horizontally such that it is substantially parallel to the ground and the horizontal plane of roller track 11. An opening 16 is created in the rearward facing portion of table 15 so that the user's torso can extend through opening 16, thus providing close in support for the user's elbows, arms, weapon, and other accessories. As best seen in FIGS. 3 and 4, the lower surface of table 15 is provided with three leg mounting flanges 17. A cylindrical leg engagement member 39 extends downwardly at a slight outward angle with respect to table 15 from each flange 17. Leg engagement members 39 will preferably have an outside diameter corresponding to the inside diameter of each of legs 21, 22, and 23, providing a frictional fit whereby table 15 can be easily removed from legs 21, 22, and 23 for disassembly and traveling. In a preferred embodiment of the invention, to provide additional stability of stand 10, the angle of leg engagement members 39 with respect to table 15 is approximately seven degrees (7°). As shown on FIG. 6, leg mounting flanges 17 are attached to table 15 by screw or other fastener disposed through leg attachment holes 18.
Additional detail describing a preferred embodiment of roller assembly 26 is illustrated in FIG. 5. Each roller assembly 26 will include a roller 27 having left and right roller pieces 28 and 29. Each roller piece 28 and 29 will have an outer segment 30 and a chamfered inner segment 31 such that the aligned combination of left and right roller pieces 28 and 29 will define a roller track engaging surface 32 having an approximate semicircular concave shape. Track engaging surface 32 will preferably conform to the shape of the upper surface of roller track 11 such that each roller 27 can engage track 11 in a rotating fashion while resisting lateral movement of roller 27 off the track to either the inside or outside.
Each roller 27 is rotatably attached through a lower section 37 of roller mount 35 by an axle pin 33. Retainer tings 34 engage a beveled portion (not shown) of axle pin 33 thereby retaining left and right roller pieces 28 and 29 in an aligned position with respect to each other. An upper cylindrical section 36 of roller mount 35 frictionally fits within the inner diameter of the bottom end of each of legs 21, 22, and 23, thereby allowing each roller assembly 26 to be easily removed for disassembly. Lower section 37 makes a transition into upper cylindrical section 36 of roller mount 35 at arcuate portion 40.
Having described the structure of the pivoting shooting stand of the present invention, it will now be apparent to those skilled in the art that the user of stand 10 can position himself or herself in a seated position on seat 13, resting the arms and weapon of the user on table 15. The legs of the user can rest either on front reinforcing member 25 or, preferably, on the ground surface. When an animal of the type being hunted is visualized by the user, the user can simply pivot the entire seat and table assembly 12 of stand 10 rapidly around roller track 11 to stop assembly 12 at the preferred orientation, and then begin shooting.
To maximize the convenience of stand 10, each of legs 21, 22, and 23 can, in fact, be made in two parts with corresponding adjustment holes so that the height of table 15 and seat 13 above the ground is adjustable to the needs of the user. Similarly, second and third support legs 22 and 23 can be provided with multiple mounting holes for attachment of seat support rails 14 thereby allowing for vertical adjustment of seat 13 independent of table 15 to meet the needs of the user as well. Further, the design of stand 10 as shown allows for rapid assembly and disassembly of stand 10 for traveling purposes.
Although the preferred embodiment as described herein suggests a mounting of both table 15 and seat 13 to support legs 21, 22, and 23, to form a unitary seat and table assembly 12, seat 13 can also be mounted such that an additional support leg with attached roller assembly extends downwardly from seat 13 to roller track 11. Alternatively, table 15 can be circular in shape and attached in a fixed position centrally disposed with respect to roller track 11 whereby only seat 13 will pivot, rotating the user around table 15 in a circular fashion.
Also, although FIGS. 4 and 5 illustrate a base defined by a cylindrical roller track 11, with a concave corresponding roller assembly track engaging surface 32, the base could alternatively be provided with an inner rail system whereby the roller assembly will run within a slot in the base.
FIGS. 7 and 8 illustrate a second embodiment of the shooting stand which includes an outer covering 41, the purpose of which is to conceal the shooter. Accordingly, covering 41 will preferably include appropriate tree bark camouflage material 42 surrounding a camouflage colored nylon mesh section 43 for ventilation.
Cover mounting means are additionally provided in this embodiment, including a lower mounting ting 44 (FIG. 8) which is attached to support legs 21, 22, and 23, and an upper ring 45 which is positioned above table 15 by four vertical support members 46 spaced around the periphery of and removable attached to table 15. The top portion 48 of cover 41 assumes a dome shape as it conforms to and rests on curved upper cover frame members 47. Preferably, top portion 48 of cover 41 will be coated with polyurethane 52 or other suitable water resistant material. Also, each of support members 46, lower and upper support rings 44 and 45, and frame members 47 will comprise friction fit interconnecting tubular sections, as described above for roller track 11, support member 25, and support legs 21, 22, and 23 to allow easy disassembly.
Cover 41 is loosely secured to stand 10 by placing it over upper frame members 47. The sections of upper mounting ting 45 are assembled while sliding them within pockets (not shown) sewn into the inside surface of cover 41. The lower margin of cover 41 is draped over lower mounting ring 44 with the sections of lower mounting ting placed within pockets sewn inside cover 41. The rear edges of cover 41 are attached using hook and loop fastener straps 50.
Thus, although there have been described particular embodiments of the present invention of a new and useful pivoting shooting stand, it is not intended that such references be construed as limitations upon the scope of this invention except as set forth in the following claims. Further, although there have been described certain dimensions used in the preferred embodiment, it is not intended that such dimensions be construed as limitations upon the scope of this invention except as set forth in the following claims.
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A portable shooting stand is disclosed in which a modular seat and table assembly rides in a circular fashion on rollers over the top of a ground engaging roller track.
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BACKGROUND OF THE INVENTION
The present invention relates to aircraft engine systems and, more particularly, to an engine controller system for locking in a desired aircraft Mn during cruise.
Commercial aircraft utilize auto throttle systems which interface with the engine control system either electrically or mechanically in order to control engine thrust and thereby control the aircraft to a desired air speed or Mach Number. The existing auto throttle systems require a separate controller with its associated components to perform this function. However, the cost of such a system, in addition to the certification cost, makes a constant airspeed control feature prohibitive for use by small commercial aircraft.
It is therefore highly desirable and an object of the present invention to provide the ability to maintain an aircraft at a constant airspeed, without incurring the cost currently associated with such a feature.
Another object of the present invention is to provide such an engine automatic mach hold feature without implementing a separate controller with associated components.
Another object of the present invention is to provide an engine automatic mach hold feature which utilizes control logic to achieve a constant airspeed.
These objects and other features and advantages will become more readily apparent in the following description when taken in conjunction with the appended drawings.
SUMMARY OF THE INVENTION
The present invention has been developed to fulfill the needs noted above. The present invention is an engine controller full authority digital engine control (FADEC) based system to lock in the desired Aircraft Mn during cruise. The system of the present invention is particularly suited for use on small commercial aircraft.
In accordance with one aspect of the present invention, an engine control system allows engine speed of an aircraft to be varied so the aircraft will maintain a desired mach number, without continuing pilot intervention. The fan speed of a slave engine is synchronized with the fan speed of a master engine. A previous Mach number value is compared with an actual Mach number value to determine a Mach number error. The resulting error corresponds to a fan speed which increases or decreases engine thrust to achieve a Mach number error equal to zero, maintaining the desired aircraft Mach number.
In the drawings as hereinafter described, a preferred embodiment is depicted; however, various other modifications and alternative constructions can be made thereto without departing from the true spirit and scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of a FADEC master and slave engine control system for synchronizing the master and slave engines;
FIG. 2 is a schematic diagram of mach number lock-in enable logic, according to the present invention; and
FIG. 3 is a block diagram of an interface with the pilot when implementing the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the present invention, an engine controller Full Authority Digital Engine Control (FADEC) based system is illustrated. The engine controller system is capable of locking in a desired aircraft mach number (Mn) during cruise. In accordance with the present invention, the entire engine controller function is contained within existing engine FADEC systems, which are well-known industry wide, without the need for additional aircraft controllers. Accordingly, the system of the present invention utilizes the inherent capability found on most existing FADEC based engines without requiring any hardware modifications.
Providing a Mn hold function during cruise is advantageous in that it reduces pilot workload, allows for more precise flight management, and can improve engine life by constantly reducing engine thrust as aircraft weight and drag decreases (due to fuel burn).
Referring now to the drawings, in FIG. 1 there is illustrated a basic operation of an engine FADEC automatic Mach hold design, in accordance with the present invention. The system 10 comprises a master engine portion 12 and a slave engine portion 14, which are synchronized. An enable switch 16 engages a Mn lock-in enable logic of block 18 when activated by the by the pilot. Once the Mn lock in enable logic of block 18 is satisfied, as illustrated in FIG. 2, the master engine FADEC 12 uses the last Mn value from an Aircraft Air Data Computer (ADC) 20, i.e., the existing computer in the aircraft, known in the art, as a Mn reference. The loop is closed by comparing this Mn reference to the actual Mn at comparator 22, with the resulting error corresponding to a fan speed (N1) which increases (or decreases) engine thrust and brings the Mn error back to zero. In addition, a throttle signal from throttle 24 is used to trim the N1 authority limits to allow additional changes to N1 to hold the desired Mn without having to disengage then re-engage the system.
The FADEC of the other engine FADEC, indicated by reference number 14, uses the same switch input to engage a synchronizing function at synchronizing enable logic block 26, to match its N1 to the N1 value of the master engine. Existing cross engine N1 information is used as part of the synchronizing function.
A function G(s) at block 28 is selected based on engine aircraft and flight control dynamics to ensure stable operation and a robust design to external disturbances. A proportional/integral type controller would be typical with the output of the integrator initialized as the actual N1 at the time the system was engaged. The output of the function G(s) at block 28 would be a N1 reference that would then be banded by authority limits. These authority limits would typically be the N1 selected by the throttle ±5% as indicated at 32a and 32b, respectively. The output of the authority limits are then passed on to N1 governor 34 dynamics in lieu of the throttle N1 reference. A fuel flow position (Wfx) loop 36 and the N1 governor loop 38, are identical to those values used during other nonMach hold control modes. Concurrent with the Mach hold function in the master engine FADEC, the slave engine FADEC synchronizes to match the slave engine N1 speed to the master engine N1.
The present invention utilizes the inherent capability found on most existing FADEC based engines without requiring any hardware modifications. Hence, the existing hardware, such as the hydromechanical unit (HMU) 40, the left and right engine fuel flows indicated at blocks 42, aircraft block 44, and N1 rating tables 46 for converting throttle position, all remain in the system of the present invention, operating in their typical manner. Cockpit display 48 can indicate various features and functions, such as explained in reference to FIG. 3.
Continuing with FIG. 1 and referring now to FIG. 2, details of the Mn lock in enable logic 18 are illustrated. The enable logic is easily customized for any aircraft configuration. In the example shown, Mn Hold enable logic is not activated unless all of various conditions are met. Once latched, in addition to the absolute analog authority limits on throttle position (PLA), Mn, N1, and altitude, N1 cannot change by a value greater than ±5% of the throttle N1 at lock in.
By designing the Mach hold logic for cruise conditions only, the logic assures a limited authority for the Mn hold function and thereby does not introduce additional failure modes or certification concerns. The sequence of events to activate the Mach hold function of the present invention is to bring the aircraft to the desired altitude, indicated at block 50, and the desired Mn, indicated at block 52, to achieve a cruise condition. The enable switch 16 is then turned on, activating the latch function 54. As long as the throttle position, altitude, and Mn are all within the required ranges of blocks 56, 50, and 52, respectively, as provided to AND gate 58, the system engages and the Mn value at the time switch 16 was turned on will be maintained.
The engine FADEC logic according to the present invention interfaces with a cockpit display to provide various indications indicating whether the system is enabled, whether the throttle is pushed, and for displaying aircraft Mn, locked in Mn. The typical sequences and displays are illustrated in FIG. 3.
In FIG. 3, once the pilot has established the desired cruise conditions at block 60, the % N1 will be displayed at block 62. The enable switch 16 is then activated. The cockpit display will now show the display of block 64, indicating the locked-in Mn value and the N1 authority limits as a band on the N1 display. If N1 reaches an authority limit during the cruise, such as during fuel burn, N1 will not go lower. Also, the Mn indication will change colors, indicating that the desired Mn is no longer locked in, as indicated at block 66. In order to reacquire the desired Mn, the pilot pulls back the throttle to establish new N1 authority limits and allow the original Mn to be obtained, as indicated at block 68.
The present invention provides a Mach number hold feature using the same engine and aircraft electronics already in place on all modern FADEC based engines. By eliminating the recurring cost and weight of a separate controller, and eliminating non-recurring costs associated with additional auto throttle type systems with their additional components, the present invention provides, at minimal cost, a useful feature which reduces pilot workload.
It will be obvious to those skilled in the art that the invention can be modified to suit the individual needs of a particular airframe and/or customer.
It is seen from the foregoing, that the objectives of the present invention are effectively attained, and, since certain changes may be made in the construction set forth, it is intended that matters of detail be taken as illustrative and not in a limiting sense.
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An engine controller system maintains a desired mach number for an aircraft. The fan speed of a slave engine is synchronized with the fan speed of a master engine. A previous Mach number value is compared with an actual Mach number value to determine a Mach number error. The resulting error corresponds to a fan speed which increases or decreases engine thrust to achieve a Mach number error equal to zero, maintaining the desired aircraft Mach number.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a fire suppression system for enclosed spaces containing equipment, apparatus or materials that require protection from combustion hazards, such as a fire. In particular, the invention concerns an improved retrofitted fire suppression system and method in which the fire suppression agent is HFC 125 as a replacement for Halon 1301. The system and method also has utility for design and installation of new fire suppression equipment based on the use of HFC 125, in lieu of Halon.
Halon 1301 has long been used as a fire suppression agent for areas where utilization of water spray or mist, solid suppressants such as sodium bicarbonate, or liquified compressed carbon dioxide is precluded. Exemplary in this respect are rooms or enclosures containing computer or electronic equipment, which would be damaged by water impingement. Solid suppressant discharge is undesirable in these applications because of the powdered residue that would be left on such equipment. Carbon dioxide suppressant systems have the disadvantage that at levels of CO 2 adequate to suppress a fire, the resultant displacement of air is such that the environment would potentially be unsafe for individuals in the protected area.
2. Description of the Prior Art
It has been the practice for many years to protect sensitive equipment such as computer installations, electronic components, and materials or devices that would be damaged if subjected to fire suppressants such as water, or a solid agent. A common suppressant such as CO 2 is also ruled out because the carbon dioxide displaces air from the enclosed space to an extent that individuals in the protective zone are placed at risk for lack of required oxygen.
In order to meet the need for protecting computer rooms and the like from a fire hazard, it became the practice a number of years ago to use a fluorocarbon, such as Halon 1301 as the suppressant agent. Halon had the advantage of being storable as a liquid under pressure at room temperature and which vaporized to produce a fire suppressant gas when discharged into the enclosure or area to be protected. Halon 1301 was deemed to be a “clean” fire suppressant because upon discharge of the agent it did not damage the equipment being protected from a fire hazard. Furthermore, individuals were still able to breathe adequately in the room or enclosure into which the Halon was discharged because the suppressant agent was found to be effective at a concentration which would put out a fire in the enclosure while still leaving a breathable oxygen level in the protected area.
Because of the clean unique characteristics of Halon 1301 as a fire suppressant agent, which was effective at breathable concentrations, Halon suppressant agent installations became the de facto agent for all applications where discharge of water or solid suppressant, or use of CO 2 as a suppressant was undesirable or impractical. Halon-based suppressant systems have been installed throughout the United States and in many countries abroad.
In recent years, there has been mounting evidence that certain fluorocarbons, including Halon 1301, when discharged into the atmosphere tend to rise and accumulate in the stratosphere, thereby producing a deleterious hole in the ozone level over Antarctica creating undesirable global environmental effects. Because of mounting scientific evidence of the detrimental effect on the environment caused by certain fluorocarbons, such as Halon 1301, countries around the world have banded together and approved treaties either banning the use of Halon 1301, or imposing substantial surcharges on the purchase and use of Halon 1301 in new installations, or in recharging of existing fire suppressant systems. The goal of the largely successful treaties has been to coerce manufacturers and users to abandon use of Halon 1301 as a suppressant agent or at least substantially reduce the population of existing Halon 1301 installations.
Replacement or retrofitting of Halon 1301 fire suppressant systems has been impeded by the difficulty of developing a reasonable substitute for Halon 1301 which is as effective in suppressing fires, that can be made available at a non-prohibitive cost, and that negates the necessity of completely replacing the piping and distribution components of existing fire suppression systems. Noteworthy in this respect is the fact that in a significant proportion of Halon based fire suppression systems installed to protect electronic equipment such as computer components, the piping for the suppression system is located beneath the floor supporting the equipment requiring protection. It therefore is largely impractical to remove the computer equipment, tear up the floor and disconnect all of the wiring to the electronic components, merely for the purpose of replacing the fire suppression system piping.
One substitute fluorocarbon that offered promise as a replacement for Halon 1301 was FM-200®, available from Great Lakes Chemical Company. Principal disadvantages of the use of FM-200® have been the higher product cost, and the need to use a larger quantity of the agent as compared with Halon 1301 for a similar area to be protected. This larger amount of FM-200® required that the receptacles for storing the suppressant agent be larger than those typically used for Halon 1301 to protect the same area, and the FM-200® had different physical properties and flow characteristics which did not necessarily permit use of that agent in an existing fire suppression system without modification of the distribution components and nozzles of the system.
The need to repipe a protected area such as a computer room to replace an existing Halon system with an FM-2000® system presented such a formidable and expensive undertaking that many users elected not to do so and if recharging of the system with Halon was necessary, users decided to pay the necessary excise fees to buy a replacement amount of Halon 1301. The problem presented by Halon 1301 replacement is exacerbated by the fact that it is desirable that a system be tested by discharge of the Halon from time to time to verify the operability of the system and its effectiveness. Each time a test discharge is carried out, replacement Halon 1301 has to be purchased for recharging the system even though the Halon 1301 can be obtained only at what amounts to a largely prohibitive higher cost than the initial cost.
In certain jurisdictions, with Europe being a particular example, recently enacted legislation bars manufacture and sale of Halon 1301 for fire suppression applications in European Union countries. Therefore, replacement of Halon 1301 with a Halon recharge is simply not an option.
Halon 1301 has been stored as a pressurized gas within a pressure vessel in which pressurized nitrogen was contained in the vessel interior above the level of the liquified suppressant agent therein to assure complete delivery of the liquid suppressant agent through the system piping to the nozzles so that the time of discharge of the agent was maintained in the approved time range of 6 to 10 seconds.
Another fire suppressant fluorocarbon proposed as a substitute for Halon 1301 and that does not exhibit the undesirable ecological effects of Halon 1301 is HFC-125. However, use of HFC-125 also has the disadvantage vis a vis Halon 1301 of requiring delivery of a greater amount of the suppressant agent to meet standardized fire suppression tests.
The vapor pressure of Halon 1301 is about 200 psi. However, HFC-125 has a substantially lower vapor pressure, of the order of 125 psi. Accordingly, even if an atmosphere of relatively high pressure nitrogen is provided in overlying relationship to the pressurized liquified suppressant agent in the supply vessel as an aid in delivery of the liquified agent through the piping distribution array, HFC-125 will not flow through such piping at the same rate as is the case with Halon 1301. A HFC-125 system therefore inherently flows slower than a comparable Halon 1301 system.
As a consequence, the specific piping components and arrangement of a particular existing Halon 1301 fire suppression system have a different effect on the overall flow rate of HFC-125 as compared with Halon 1301 suppression agent. Elbows and tees in the piping system are known to have a pronounced effect on flow rates and how the liquid divides one way or the other at a bullhead or a side through tee. Simply adding additional pressure to the liquified HFC-125 in the storage vessel in the form of higher pressurized nitrogen, in an effort to solve the problem of the inherently slower flow rate of HFC-125 as compared with Halon 1301, is not feasible because of the problem of choked flow.
Computer programs have been developed and are available for evaluating the flow characteristics in specific storage vessels, piping and nozzle systems for delivery of liquified gaseous suppressant agents, including pressurized liquefied carbon dioxide, Halon 1301, HFC227ea (FM200) and HFC223 (FE13). The programs take into account factors such as pipeline pressure and agent density in the pipeline, pressure drop along the length of the piping system, turbulence, velocity changes, transients, mechanical effects on density and flow such as occur through an elbow, a bullhead tee or side-through tee, and the internal surface of the pipe sections and connectors. These computer programs have been used by installers of pressurized liquefied gaseous suppressant agents to determine the amount of a particular agent required for a given amount of area to be protected, the piping system necessary for such system, the number, size and location of nozzles and the pressurized nitrogen head required over the stored liquefied suppression agent.
The computer programs contained mathematical correlations and look up tables that gave the installer of a system substantial assurance full discharge of the liquefied suppression agent from the fire protection system would occur in a time range meeting approved regulations or standards, with a built in safety factor, usually in the range of about 20% in the United States to about 30% in Europe.
SUMMARY OF THE INVENTION
This invention relates to retrofitting of existing Halon 1301 charged fire suppression systems with HFC 125 as a fire suppressant agent for protecting a room or other enclosure containing equipment which cannot be subjected to conventional agents such as water from sprinklers, water in mist form, powdered suppressant solids or carbon dioxide.
Existing systems incorporating Halon 1301 as a fire suppressant agent have a pressure vessel or a series of such vessels for storing the suppressant agent in liquid form under a nitrogen head pressure. The storage devices are coupled to a piping system having a plurality of distribution pipes extending from the storage vessels to respective distribution nozzles extending into and strategically located about the enclosure or area to be protected from a fire hazard. Typically, sensors such as infrared or smoke detectors are provided in the room or enclosure for early detection of an event indicative of a conflagration. Upon sensing of an fire condition by one or more of the sensors, selectively actuatable closures normally blocking release of suppressant agent from the storage vessels are actuated, thereby permitting the stored pressurized Halon 1301 to flow as a liquid through the piping system for gaseous discharge through respective nozzles into the protective area.
Every burning material has a specific minimum requirement for fire suppression agent concentration for extinguishment within the specific limits of items allowed in testing. Fire suppression performance is determined by extinguishing specific types of fires within specific limits of time. Test types and time limits are determined by testing agencies such as Underwriters Laboratories (UL) and Factory Mutual (FM). Tests are divided into two main hazards: Class-A and Class-B fires. Class-A fires are based upon wood based products and polymer (plastic) materials. Class-B fires are based upon liquid petroleum derived substances.
Standards established by UL and FM have heretofore mandated that the standard discharge time for a clean agent such as Halon 1301 which is contained in the storage vessels of a particular fire suppression system be completely discharged through the orifices of respective distribution nozzles in a time period of from about 6 to 10 seconds. All testing by UL and FM requires a nominal 10 second discharge time at 70° F. (plus or minus) 5° F. Suppressant agent discharge time in this context and as used herein means the time interval from first arrival of the liquified gaseous agent at a nozzle until such time as 95% of the liquid has been exhausted and delivered from the nozzle as a gaseous product. It is known in this respect that each nozzle opening should not exceed about 80 to 85% of the area of the inside of the liquid delivery pipe connected to that nozzle. Otherwise, the piping is controlling the flow and not the nozzle.
Each manufacturer tests its specific agent delivery system of hardware, nozzles and amount of agent and specifies its own physical limits for each fire type when testing before UL and FM. Extinguishment tests time limits can be anywhere from 30 seconds to 10 minutes after the end of agent discharge. Tests with Class-B materials such as a heptane pan fire must be extinguished within 30 seconds after the end of discharge of the suppressant agent.
The 6 second time interval had its genesis in restricting the outflow of Halon 1301 from the distribution nozzles to a velocity such that the gaseous suppressant discharge from the nozzles did not tend to blow off ceiling tiles conventionally provided in enclosed areas requiring fire protection. If the discharge of Halon from the system had been permitted to be fully exhausted in a time significantly less than 6 seconds, it was believed that the velocity of such gas discharge would have been sufficiently high to deleteriously effect the environs of the protective room or enclosure and especially relatively easily dislodged items such as supported ceiling tile held in place only by gravity.
With a limit of 6 seconds having been determined to be a minimum for reasonably safe discharge time of the suppressant, 10 seconds was established by the testing authorities as the maximum time for suppressant discharge permitted within the standards, on the basis that delivery of the suppressant to the hazard should be accomplished as quickly as feasible in order to obtain necessary fire extinguishment in accordance with test standards.
Authorized fire suppressant testing authorities have promulgated test requirements for fire suppressant agents including Halon 1301 for approved use in specific applications. For example, a suppressant agent to meet the requirements for suppressing a Class B fire must show that a designated amount of the suppressant agent applied in a manner and under conditions established by the test procedure will extinguish a heptane pan fire within 30 seconds when the suppressant agent is discharged within a maximum 10 second period. Class A wood crib fires must be extinguished in accordance with the test protocol in 10 minutes following a maximum 10 second suppressant discharge time. In a polymer material Class A test, the polymeric material must be extinguished within 10 minutes following the maximum 10 second suppressant discharge time.
Based on the standardized tests conducted with Halon 1301 as a suppressant for Class A and Class B fires, computer programs have long been available to installers of Halon 1301 based fire suppression systems for determining the amount of the Halon 1301 suppressant required for a particular installation, the number and location of nozzles necessary for the protected space, and the entire piping system, including size of pipe and distribution of the piping components which will provide an approved system for that location.
It has been found that CF 3 CHF 2 , known generically as “HFC-125” offers fire suppression properties similar to Halon 1301 without the attendant environmental problems that have developed as a result of the use of Halon 1301. Class A and Class B fire extinguishment tests conducted with HFC-125 have shown though that somewhat larger quantities of HFC-125 must be made available than is the case where Halon 1301 was used as the suppressant, especially for Class B pan fires and Class A polymer fires.
Even though the suppressant agent discharge time is increased beyond what has previously been deemed to be the standard discharge period, tests have established that HFC-125 when discharged through an existing Halon 1301 piping system can extinguish both Class A and Class B fires in accordance with approved Class A and Class B fire extinguishment procedures using what amounts to a commercially feasible additional quantity of HFC-125.
Employing the data obtained from testing extinguishment of Class A and/or Class B fires using HFC-125 and causing the HFC-125 suppressant agent to be fully discharged into the area of the test fire in a time period in excess of 10 seconds and up to about 25 seconds, the data generated from the tests has been relied upon to develop a new computer program available from the assignee hereof which calculates the amount of HFC-125 required to extinguish either a Class A and/or Class B fire that may arise in an area requiring protection and using an existing piping system . This computer program allows a fire suppression system installer charged with responsibility for retrofitting an existing Halon 1301 based fire suppression system, where HFC-125 is to be substituted for Halon 1301, to determine how much additional HFC-125 may be required over the approved amount of Halon 1301 to extinguish a fire under the same time period constraints as have been previously applied to Halon 1301 systems.
Insertion of the test data in the HFC-125 dependant software program along with diagram generated information outlining details of the construction and arrangement of an existing piping system, including pipe materials, pipe diameter, number and location of pipe connections allows the operator to establish how much HFC-125 will be required, the size and number of vessels needed to store the full quantity of the suppressant agent for the fire suppression system being retrofitted, and nozzle parameters.
The computer program solves for the amount of HFC-125 necessary to fulfill the requirements of a particular fire suppression installation. When discharge times exceed 10 seconds, the additional amount of HFC-125 required for performance equivalent to a 6 to 10 second discharge may be expressed by the formula C + =((T D −10)/(2×T CRIT )−T D ×100) where C + is the additional percentage on a weight basis of fire suppression agent needed for fire extinguishing performance at least about equivalent to the use of Halon 1301, T CRIT is the critical average time span required for material to be extinguished, and T D is the time of total discharge of HFC-125 from the system.
This invention relates to a retrofitted Halon 1301 system in which HFC-125 is substituted for Halon 1301 using the existing piping distribution, to methods of retrofitting existing Halon 1301 systems substituting HFC-125 for Halon 1301 and to methods of designing and installing new systems based on the use of HFC-125 in lieu of Halon 1301.
The method of this invention permits retrofitting of existing Halon 1301 suppressant agent systems with a minimum extinguishing concentration of the agent taking into account a requisite safety factor as required by a controlling regulatory authority and without change in the piping of the existing system.
BRIEF DESCRIPTION OF THE DRAWINGS
The FIG. 1 drawing is a flow diagram representation of the calculations carried out by a preferred computer program which facilitates retrofitting of an existing Halon 1301 based fire suppression system in which HFC-125 is substituted for Halon 1301.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention concerns extending the agent discharge time from previously mandated 6 to 10 second discharge time to a time interval of in excess of ten seconds to about 25 seconds, thus to accommodate for the decreased flow rate characteristics of HFC-125 and to provide the necessary additional suppressant agent required to meet the approved fire suppressant tests. Because HFC-125 is more costly than Halon 1301, it is necessary to accurately determine the specific amount of HFC-125 which must be released into the area to be protected within a time such that the discharge agent will extinguish a Class-A and/or Class-B fire depending upon whether Class-A and/or Class-B or both test standards must be met.
By conducting actual fire tests, the amount of HFC-125 required to extinguish Class A polymer, Class A crib and Class B pan fires, may be determined using the standard test Class A and Class B fire protocols established by UL and FM. These tests have shown that with pan fires when comparing standard Halon 1301 clean agent concentrations against the same concentration of BFC-125 but with a longer than standard agent discharge time, i.e., of the order of 20 seconds, provision of an additional 6% of HFC-125 resulted in fire extinguishment within 30 seconds, totaling 50 seconds. Similar test results with wood crib fires established that HFC-125 at a concentration equivalent to Halon 1301 standard concentration is sufficient for extinguishment of a crib fire and which prevents re-ignition during the allotted standard 10 minutes fire extinguishment test using the same concentration of HFC-125. Tests of polymers (PMMA) have shown a need for somewhat greater agent concentration than used for Halon 1301 for standard 10 minute fire suppression times with a 20 second discharge period. Clean agent concentrations were adjusted for equivalent 10 second discharge suppressant times.
Both wood cribs and polymers are Class A materials and therefore suppressant agent concentrations require that worst case agent concentration be used for all Class A tests. Thus, the suppressant agent concentration for wood cribs is always excessive because of relatively high concentrations required for polymer fire tests.
The studies were based upon average clean agent room concentration over a 40 second test period. The resultant data showed a good relationship between “average clean agent room concentration” and extinguishment times. This relationship was found to exist when both large and small fires were lit in the same size room. It was determined that each fire type, test setup, and extinguishment time has an impact upon the relationship of the agent discharge time and room concentration time required. In view of the fact that an added amount of HFC-125 is needed as compared with Halon 1301 supplied though the piping of existing Halon based suppressant systems, average clean agent room concentration, extinguishment time and discharge time must be correlated in a manner that allows a reliable prediction of the amount of agent required, for a given hazard, for fire suppression performance equivalent to that of Halon 1301.
Extending the agent suppressant discharge time from 10 seconds to, for example, 20 seconds requires that additional suppressant agent be provided to meet the 30 second Class-B extinguishment test requirement. This is attributable to the average agent concentration in the test cell being lower during the 30 seconds allowed for extinguishment.
It was unexpectedly found that Class-A tests required additional agent to meet the 10-minute extinguishment requirement. The HFC-125 discharged into the test cell during the first 20-seconds of the test allowed at least 9 minutes and 50 seconds for extinguishment to occur. Testing standards specify extinguishment will occur 10 minutes following the end of (a 10 second) discharge and therefore only 10 minutes was allowed past the initial 10 second time period of the standardized testing protocol. The Class A 10 minute tests did not result in extinguishment within allowed time limits, even though the average agent concentration over the 10 minute test exceeded 98% of the same average agent concentration of a Class B standard 10 second discharge, 30 second extinguishment test.
These tests results established that there is a previously unknown and underlying relationship between discharge time and average agent concentration which must be defined to predict agent concentrations required for systems with extended discharge times beyond 10 seconds. This relationship exists for all types of tested materials and even those fire types that are allowed 10 minutes to extinguish.
The average agent concentration in the room during the early portion of the fire suppression event is the prevailing and crucial factor. The critical time period in which this average agent concentration is directly related to extinguishment time is known as T CRIT . The time over which this T CRIT is computed is critical when predicting the amount of agent required. T CRIT is defined as the critical averaging time span for a specific material to be extinguished. This critical time span determines the actual increase in agent concentration when discharged over a time period of from 10 to 25 seconds providing equivalent performance when compared to a 10 second Halon 1301 discharge system.
In order to assess the additional amount of HFC-125 required as a substitute for Halon 1301 in an existing Halon 1301 based system in which the agent discharge time is extended beyond the heretofore standard 10 second maximum discharge time to a discharge time in excess of 10 seconds and up to about 25 seconds, it was found necessary to determine a critical time-averaging period for each fire type. For fire-test-cell purposes the critical time span governing average agent concentration is different for each fire type.
For a specific Class A or Class B test T CRIT must be determined. A fire test cell and various Class A and Class B material were burned and extinguished using extended discharge time of approximately 20 seconds. Agent concentrations were adjusted such that equivalent extinguishment times were achieved. These test results disclosed the actual relationship of T CRIT with respect to extended discharge times. Since extinguishment times and the required agent concentrations are well known for 10 second discharge, T CRIT may be expressed using the 10 second standard agent concentrations as a baseline.
Given any specific fire extinguishment test that results in both the extended discharge and standard discharge extinguishment times being approximately equal, the following preferred formula has been found to predict the critical averaging time span T CRIT :
T CRIT =0.5×((( T D −10)/( C + /100))+ T D ) [I]
Where:
T D is the time of extended agent discharge The constant 10 is based upon a standard 10-second discharge for traditional systems. T CRIT is the critical averaging time span for the specific material to be extinguished. C + is the additional percentage (percent change) of agent concentration needed for equivalent 10-second discharge performance.
Based on tests conducted as described, it has been determined that the critical averaging time span is no more than about 100 seconds in the case of Class A polymers (PMMA) and usually does not exceed about 85 seconds. The average critical time span for Class B fuels (heptane pan) has been found to not exceed about 60 seconds and is usually not more than about 50 seconds.
The additional amount of HFC-125 required for fire suppression times that are equivalent to those obtained from industry standard 10 second agent discharge tests may be calculated using an agent discharge time in the range exceeding 10 seconds and up to about 25 seconds in accordance with the formula:
C + =(( T D −10)/(2 ×T CRIT )− T D ×100) [II]
where C + is the additional percentage on a weight basis of fire suppression agent needed for fire extinguishing performance at least about equivalent to the use of Halon 1301, T CRIT is the critical average time span required for the material to be extinguished, and T D is the time of total discharge of HFC-125 from the system.
Upon rearrangement of formula [II] to solve for T CRIT , the following generalized equation results:
T CRIT =0 .Y ×(( T D −10)/( C + /100))+ T D [III]
wherein Y is a number within the range of from about 0.3 to about 0.7, preferably from about 0.4 to about 0.6 and most preferably about 0.5.
EXAMPLES 1 AND 2
A 10-second discharge test was conducted using a Class-A polymer such as ABS plastic. The required agent concentration in the test cell was 7% by volume. The fire extinguished at the 10-minute time limit.
A 22-second discharge test was conducted using the same Class-A polymer ABS plastic. The agent concentration was increased to 7.4% by volume. The fire also extinguished at the 10minute time limit.
Both tests resulted in extinguishment at the same time and only the agent concentration and agent discharge time changed. Therefore, formula [I] can be applied to determine the critical averaging time span for the ABS plastic.
Since C+ represents the additional percentage (percent change) of agent concentration for equivalent 10-second discharge performance:
C +=((7.4% /7.0%)−1)×100=6% increase.
Thus:
T CRIT =0.5×(((T D −10)/(C + /100))+T D ) T CRIT =0.5×(((20−10)/(6% /100))+20) T CRIT =93.3 seconds
Once T CRIT is known, then C + can be determined for fire suppression performance using HFC-125 as compared with an equivalent Halon 1301 system. Because an HFC-125 system with an extended discharge system from about 10 to about 25 seconds requires more agent be added based on the length of the discharge time, the final determination of the length of discharge time and the amount of agent is an iterative process. That is, the longer the agent discharge time, the more additional HFC-125 agent is needed and the more HFC-125 is needed, the longer the discharge time. This iterative process should be continued until the resulting amount (error) in the calculation becomes a negligible amount.
In accordance with this invention, if retrofitting of an existing Halon 1301 suppressant agent system is to be carried out in a jurisdiction where agent discharge times in the range exceeding about 10 seconds and up to about 25 seconds as opposed to standard 6 to 10 second discharge times have not previously been approved, the first step will be to obtain the required regulatory approval in that jurisdiction by conducting the necessary tests using HFC-125 pursuant to approved fire extinguishment tests for Class A and/or Class B fires. These tests should be carried out as described using iterative suppressant agent discharge times each in the range exceeding 10 seconds and up to about 25 seconds. These tests will then provide the critical averaging time span for each of Class A and Class B fires.
A computer software program identified as the Fike ECARO-25™ program may be obtained from Fike Corporation, Blue Springs, Mo., USA, for use by installers in retrofitting existing Halon 1301 systems in accordance with the method hereof for substitution of HFC-125 for the Halon 1301 without changing the piping system. The Fike ECARO-25 program carries out calculations using incorporated look up tables pursuant to the flow diagram illustrated in Drawing FIG. 1 .
One screen of the Fike ECARO-25 program permits the user of the program to input a schematic representation and data regarding an existing piping system including the piping components, their dimensions and characteristics and the specific arrangement of the piping and connecting elements, and nozzles. The installer may obtain this piping information either from a the user or the original installer of the Halon 1301 system.
Upon entry of the identity of HFC-125 in the computer program as the liquefied suppressant agent to be used in retrofitting of the existing Halon 1301 fire suppression system, the program through an appropriate lookup table uses the thermodynamic properties of the HFC-125 and container fill density to determine the mass of liquid agent that will leave the supply container. The program also performs basic pressure drop and flow rate calculations for each pipe section and connector using the calculated mass of liquid agent leaving the container. The software program further calculates the mass of agent required to vaporize in order to cool each pipe section to a temperature that will support steady state of liquid flow. The program also accumulates a calculated vaporization time for each pipe section. The system discharge time, T D in Equation [I] as determined by and used the computer program is the sum of the liquid discharge time and the accumulated vaporization time. As an output, the computer program tells the installer how much HFC-125 is required to meet the applicable government regulation, plus a safety factor for the system to be retrofitted or built new.
EXAMPLE 3
If it is determined that for a given room volume, 1000 lbs. of HFC-125 must be delivered to that room within the conventional maximum time of 10 seconds in order to obtain a necessary concentration of suppressant agent in the room, a piping arrangement that was installed to deliver a requisite amount of Halon 1301 to the room would in fact restrict the flow of the HFC-125 such that agent discharge time would be of the order of 15 seconds rather than 10 seconds. After input of the parameters of the piping system into the Fike ECARO-25 computer program, the program carries out an iterative process to provide the installer with information regarding the additional amount of HFC-125 that must be furnished at the most efficient agent discharge time.
An iterative calculation process in accordance with equations I and II performed using the inputs described in this example is performed until the residue “error” results in less that 1 lb. agent differential.
The following table is illustrative of this iterative process:
New Calc.
Add'1 time
Agent
Step
Disch. time est.
C+
Add'l Agent
time
Req.
Req.
1
15 seconds
3.31%
3.31%/33.1#
15.495 sec.
.495 sec.
1033.1#
2
15.495 seconds
3.65%
.0341%/3.52#
15.548 sec.
0.053 sec.
1036.62#
3
15.549 seconds
3.68%
0.030%/0.31#
(Stop Iteration - error is less than 1#
agent
In most cases, the amount of HFC-125 required as a substitute for Halon 1301 in a system where the existing piping is to be left in place, will not usually exceed an amount greater than about 1.3 to about 1.6 times the amount of Halon 1301 in the existing system calculated on a weight basis.
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This invention relates to a method of converting Halon-based fire suppression systems by substituting HFC 125 for the Halon without the need for changing the in place existing distribution piping. An amount of HFC 125 greater than the amount of Halon utilized in the fire suppression system is provided, which is under a pressure to effect exhaustion of the HFC 125 of the system within a time range exceeding about 10 seconds and up to about 25 seconds and which meets the standard fire extinguishing requirements for Class A and Class B fires. An existing fire suppression system is analyzed for flow characteristics to find T D of that system. The greater quantity C + of HFC 125 required for the retrofitted system is determined by the formula
C + =(( T D −10)/(2× T CRIT )− T D ×100) wherein T CRIT =0. Y ×( T D −10)/( C + /100))+ T D .
The method may also be utilized to determine the amount of HFC 125 required for the retrofitted fire suppression system.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 11/402,718 filed Apr. 12, 2006 which issued as U.S. Pat. No. 7,408,895 on Aug. 5, 2008, which claims the benefit of U.S. Provisional Application No. 60/673,076 filed Apr. 20, 2005, which is incorporated by reference as if fully set forth.
FIELD OF INVENTION
The present invention relates to wireless communication systems. More particularly, the present invention is related to a method and apparatus for scheduling transmissions via an enhanced dedicated channel (E-DCH).
BACKGROUND
Methods for improving uplink (UL) coverage, throughput, and transmission latency are currently being investigated in the third generation partnership project (3GPP). In order to achieve these goals, enhanced uplink (EU) transmissions have been proposed in 3GPP, in which control, (i.e., scheduling and assigning), of UL resources, (i.e., physical channels), is moved from a radio network controller (RNC) to a Node-B.
FIG. 1A shows a conventional wireless transmit/receive unit (WTRU), (e.g., mobile station), side medium access control (MAC) architecture 100 . The WTRU MAC architecture 100 includes a MAC-es/MAC-e entity 105 , which comprises different independent sub-layer entities within the MAC. The MAC-es/-e functionality split is a result of how the MAC functionality is partitioned within the universal terrestrial radio access network (UTRAN). The WTRU MAC architecture 100 further includes a high speed MAC entity 110 , a MAC-c/sh 115 , a dedicated channel MAC (MAC-d) 120 and a MAC control service access point (SAP) 125 . The MAC-c/sh 115 controls access to all common transport channels, except the HS-DSCH transport channel 145 . The MAC-d 120 controls access to all dedicated transport channels, to the MAC-c/sh 115 and the MAC-hs 110 . The MAC-hs 110 controls access to the HS-DSCH transport channel 145 .
The MAC-es/MAC-e entity 105 controls access to an E-DCH 130 , whereby the MAC-d 120 may access the E-DCH 130 via a connection 135 , and the MAC control SAP 125 may access the E-DCH 130 via a connection 140 .
FIG. 1B shows MAC interworking in the conventional WTRU of FIG. 1A . As shown in FIG. 1B , a radio link control (RLC) protocol data unit (PDU) enters the MAC-d on a logical channel. In the MAC-e header, a data description indicator (DDI) field, (6 bits), identifies the logical channel, MAC-d flow and MAC-d PDU size. A mapping table is signaled over radio resource control (RRC) signaling to allow the WTRU to set the DDI values. The N field, (fixed size of 6 bits), indicates the number of consecutive MAC-d PDUs corresponding to the same DDI value. A special value of the DDI field indicates that no more data is contained in the remaining part of the MAC-e PDU. The transmission sequence number (TSN) field (6 bits) provides the transmission sequence number on the E-DCH 130 shown in FIG. 1A . The MAC-e PDU is forwarded to a hybrid-automatic repeat request (H-ARQ) entity, which then forwards the MAC-e PDU to layer 1 for transmission in one transmission time interval (TTI).
An efficient MAC architecture for scheduling the transmission of E-DCH data is desired.
SUMMARY
The present invention is related to a method and apparatus for scheduling transmissions via an E-DCH. A scheduled power is calculated for scheduled data flows. A remaining transmit power is calculated for the E-DCH transmission. A rate request message is generated, wherein the scheduled power, remaining transmit power and rate request message are used to select transport format combinations (TFCs) and multiplex data scheduled for the E-DCH transmission. The remaining transmit power is calculated by subtracting from a maximum allowed power the power of a dedicated physical data channel (DPDCH), a dedicated physical control channel (DPCCH), a high speed dedicated physical control channel (HS-DPCCH), an enhanced uplink dedicated physical control channel (E-DPCCH) and a power margin.
BRIEF DESCRIPTION OF THE DRAWINGS
A more detailed understanding of the invention may be had from the following description of a preferred example, given by way of example and to be understood in conjunction with the accompanying drawings wherein:
FIG. 1A shows a conventional WTRU side MAC architecture;
FIG. 1B prior art MAC inter-working in the conventional WTRU of FIG. 1A ;
FIG. 2 shows a WTRU MAC-e architecture configured in accordance with the present invention;
FIG. 3 is a flow diagram of a MAC-e scheduling process in accordance with the present invention; and
FIG. 4 shows an example of a pre-processed MAC-e PDU format in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereafter, the terminology “WTRU” includes but is not limited to a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, or any other type of device capable of operating in a wireless environment. When referred to hereafter, the terminology “Node-B” includes but is not limited to a base station, a site controller, an access point or any other type of interfacing device in a wireless environment.
Hereinafter, the terminology “MAC-e” will be used to reference both MAC-e and MAC-es collectively.
The features of the present invention may be incorporated into an integrated circuit (IC) or be configured in a circuit comprising a multitude of interconnecting components.
FIG. 2 shows a WTRU MAC-e architecture 200 configured in accordance with the present invention. The WTRU MAC-e architecture 200 includes a scheduling grant processing unit 210 , a remaining transmit power computing unit 215 and a rate request processing unit 220 .
The scheduling grant processing unit 210 receives at least one scheduling grant from at least one radio link set (RLS) and derives a current scheduling grant. The scheduling grant may be an absolute grant 225 received from a serving E-DCH cell with a primary or secondary identifier, (i.e., an E-DCH radio network temporary identifier (E-RNTI) is used to determine if the absolute grant is primary or secondary), a relative grant 230 received from a serving E-DCH RLS or a relative grant 235 received from a non-serving E-DCH RLS. The scheduling grant processing unit 210 outputs a signal 240 indicating the amount of scheduled power for use by an E-TFC selection and multiplexing function for scheduled data MAC-d flows.
The amount of scheduled power may be identified as a ratio to the DPCCH power. For example, if the DPCCH power is P, the amount of scheduled power has a ratio of 2 to the DPCCH power. Thus, the amount of scheduled power is 2 P. Alternatively, the amount of scheduled power can be identified as the maximum transmit power that can be used for scheduled data to avoid the E-TFC selection and multiplexing function to be aware of DPCCH power measurements. Since DPCCH power changes rapidly, there is processing overhead if it has to be propagated to different entities within the MAC. Furthermore, it is complex to synchronize the timing. Therefore, having only one entity in the MAC-e aware of the DPCCH power is preferred since other scheduling related functions require knowledge of current DPCCH power.
When the MAC-e entity 105 invokes the MAC-e function, the scheduling grant processing unit 210 determines the current serving grant. The physical layer provides absolute grants 225 received from the AGCH, indicating whether the grant was received with a primary or secondary E-RNTI. The physical layer also provides relative grants 230 , 235 received from each RLS, indicating if the RLS is either a serving E-DCH RLS or a non-serving E-DCH RLS. Absolute grants 225 are signaled as the ratio to the current UL DPCCH power. Absolute grants 225 received with a primary E-RNTI always reset the current serving grant. Absolute grants received with a secondary E-RNTI only affect the current serving grant if previously set by a secondary E-RNTI or the grant is set to zero.
Relative grants 230 from the serving E-DCH RLS adjust the serving grant in steps up, or down. Relative grants for the non-serving E-DCH RLS can only lower the serving grant by one step. When a relative grant down from a non-serving E-DCH RLS is received, a hysteresis period is started during which other relative grant downs are ignored.
The remaining transmit power computing unit 215 receives a signal 245 indicating current DPCCH power estimated by the physical layer, a signal 250 indicating an DCH TFC selected by the MAC-d or DPDCH power estimated by the physical layer, a signal 255 for indicating HS-DPCCH active from the physical layer and a signal 260 indicating maximum allowed power (with a power margin) from a lower layer management entity (LLME) configured by the radio resource controller (RRC). If the HS-DPCCH is active, its power (and power from other channels) must be subtracted from the maximum power to determine the remaining power. Based on signals 245 , 250 , 255 and 260 , the remaining transmit power computing unit 215 outputs a signal 265 indicating a remaining transmit power (P remain ) which is computed in accordance with the following equation (1):
P remain =P allowed −P DPDCH −P DPCCH −P HS-DPCCH −P E-DPCCH −Margin; Equation (1)
where P DPCCH , P DPDCH , P HS-DPCCH and D E-DPCCH represent power requirements of the DPCCH, the DPDCH, the HS-DPCCH and the E-DPCCH, respectively. The rate request processing unit 220 monitors triggering events for rate requests, and triggers a scheduling information rate request when a triggering event occurs. The rate request processing unit 220 provides logic for triggering the rate request and logic for constructing a rate request message 270 including rate request bits.
The rate request may be triggered when new data on logical channels mapped to the E-DCH is received when there is no current scheduling grant, new data of a higher priority then last reported is received on a logical channel mapped to the E-DCH, when there is no scheduling grant and rate requests are updated and periodically generated, (which is configured by RRC procedures), and when a serving RLS acknowledgement (ACK) is not received for the previously transmitted rate request, an updated rate request is generated.
The rate request includes the total buffer occupancy for all scheduled MAC-d flows, the highest priority data buffer occupancy for any scheduled MAC-d flow, and a power head-room available for E-DCH transmission.
Referring to FIG. 3 , a MAC-e scheduling process 300 is explained hereinafter. For each E-DCH TTI, the E-DCH is monitored and it is determined whether a scheduling information rate request trigger occurs and/or whether there is E-DCH data with a grant available (step 302 ). If no rate request trigger occurs or there is no E-DCH data available, the process waits until the next TTI. If the determination at step 302 is positive, it is further determined whether there is an H-ARQ process available (step 304 ). Availability of an H-ARQ process is required before E-TFC selection and E-DCH data transmission. If there is no available H-ARQ process, the process 300 waits until the next TTI. If an H-ARQ process is determined to be available at step 304 , a current scheduling grant and remaining transmit power calculation are requested from the scheduling grant processing unit 210 and the remaining transmit power computing unit 215 , respectively (step 306 ). In step 308 , a MAC-e control function invokes scheduling and E-TFC selection functions to generate a MAC-e PDU. In step 310 , the MAC-e PDU is then forwarded to the available H-ARQprocess with a unique power offset and maximum number of retransmissions.
In a separate embodiment to meet the timing requirement of the MAC-e PDU formation, pre-calculation of the possible MAC-e PDUs for speeding up the formation process is employed. When the MAC-e entity is requested with the remaining power budget for the E-DCH transmission, the formation process searches the pre-formatted MAC-e PDU table, (mainly its formatted MAC-e PDU header and appropriated data block PDUs), providing ready information to the H-ARQ/physical layer. There are a number of ways for performing the preprocessing, depending on the timing requirement.
FIG. 4 shows an example of a preprocessed MAC-e PDU format in accordance with the present invention. The preprocessed MAC-e PDU format consists of a power budget for E-DCH or equivalent, a fully formatted MAC-e PDU header optimally fitting the budget or equivalent, a list of transmission sequence numbers (TSNs) and data block pointers, scheduling information and padding bits.
The power budget for E-DCH includes a number of predicted power or equivalent situations based on the last transmission power and the prediction of the current possible power budget. The MAC-e PDU header is formatted based on this budget and the data priority on the same row. The fully formatted MAC-e PDU header describes the MAC-e PDU, with the logical channel priority considered, and the scheduled and non-scheduled data and budget considered. The header includes the DDI, N and the DDI-terminator. A list of the MAC-es PDUs descriptors, including the TSN and data pointers to the MAC-es data blocks, correspond to the same row pre-formatted PDU header. Scheduling information may go with the MAC-e PDU if it exists. Padding bits indicate the number of bits to be padded at the end of the MAC-e PDU for that particular row. The full formation can use the following partial formation: power budget for E-DCH or Equivalent, DDI, scheduled or non-scheduled. This sorted list is based on the data priority. Each row is a MAC-d-flow. (MAC-es PDUs). The power budget is a list of predicted power budget. The DDI represents the MAC-d-flow-ID, logical channel ID and the PDU size. The scheduled or non-scheduled column indicates that the PDUs consume the non-scheduled power budget or scheduled power budget. Non-scheduled data can also be used with scheduled information in the Mac-e PDU.
Although the features and elements of the present invention are described in the preferred embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the preferred embodiments or in various combinations with or without other features and elements of the present invention.
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A method and apparatus for scheduling transmissions via an enhanced dedicated channel (E-DCH) are disclosed. A scheduled power is calculated for scheduled data flows. A remaining transmit power is calculated for the E-DCH transmission. A rate request message is generated, wherein the scheduled power, remaining transmit power and rate request message are used to select transport format combinations (TFCs) and multiplex data scheduled for the E-DCH transmission. The remaining transmit power is calculated by subtracting from a maximum allowed power the power of a dedicated physical data channel (DPDCH), a dedicated physical control channel (DPCCH), a high speed dedicated physical control channel (HS-DPCCH), an enhanced uplink dedicated physical control channel (E-DPCCH) and a power margin.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a portable entry mechanism for use on a device such as a safe. More particularly, the present invention relates to an electronic portable entry mechanism that is removable from a safe or vault when not in use.
[0003] 2. Description of the Related Art
[0004] Electronic locks have become a popular alternative to mechanical locks due to their versatility and security. For example, electronic locks allow a user to set their own combinations. With the increase in passwords, Personal Identification Numbers (PINs) and other codes that people need to remember, a lock combination that is set by the user allows the user to select combinations that are easy to remember.
[0005] Exemplary electronic locks are shown and described in Gartner, U.S. Pat. No. 6,786,519, and Gartner, U.S. Pat. No. 6,760,964, both incorporated by reference herein in their entireties. Electronic locks typically employ an electromagnetic device, such as a solenoid, operably connected to a circuit board. The circuit board, upon receiving a predetermined input representing the access code, sends an electrical signal to the electromagnetic device, thereby energizing the device to an “open” state and allowing the safe to be opened. These electronics are typically powered by a battery, which is either hidden in the safe door or in the keypad housing. The Gartner '519 patent discloses a keypad that includes a battery that can be replaced without opening the safe, and also provides a secure connection to internal circuitry to thwart tampering efforts and accidental breakage during assembly. The Gartner '964 patent discloses a swing bolt lock that is operably connected to a plunger-type solenoid. The plunger engages a locking plate. When the lock is in the locked condition, the locking plate engages the locking bolt to prevent the swing bolt from pivoting. When a user enters the correct combination, the plunger disengages the locking plate so that the locking plate slides out of engagement with the locking bolt. A handle connected by a shaft through the outside of the safe drives the boltworks. Movement of the boltworks acts on the swing bolt and pivots it to the unlocked position. Because the locking plate is out of engagement with the locking bolt, it does not prevent the swing bolt from pivoting thus allowing the user to access the safe.
[0006] Although the Gartner '519 and '964 patents address many of the previous shortcomings of electronic locks, it would be desirable to provide a lock that is operable with a portable entry device that contains the power supply for operating the electromechanical safe lock and that can be stored at a location remote from the lock. Further, a portable entry device that is operable only by authorized users via entry of an authorized user code and that contains a separate lock security code that mates with a code stored in a lock within a safe would also be desirable. If the portable entry device was misplaced or became lost and an unauthorized user found the portable entry device, the unauthorized user would not be able to use the device because the unauthorized user would not have the authorized user code to activate the device.
[0007] For example, automatic teller machines (“ATMs”) are typically located in public places and contain large amounts of cash. Even without an access code, an unauthorized user would have an opportunity to manipulate the keypad on the safe and open the safe. Consequently, such safes are typically hidden behind a locked cabinet, giving an additional degree of security. However, if the lock were constructed and arranged such that the keypad and power supply were removable when not in use, further security would be provided. A portable entry device including external keypad and internal power supply could be further protected in an offsite location, such as in another safe or simply carried by the authorized user. Thus, a security company tasked with emptying money from a vault could securely maintain the necessary entry device in a separate safe and check the entry device out to authorized security personnel for the limited time necessary to access the vault. Not only would the entry device avoid tampering efforts, if it were somehow lost or stolen, it would be useless without the authorized user's security code.
SUMMARY OF THE INVENTION
[0008] The present invention relates to a portable entry device that operates an electromechanical lock inside, for example, a safe. The portable entry device is carried by the user and/or stored at a remote site when the user does not need to operate the lock in order to access the safe. This arrangement provides an added degree of security to the contents of the safe being protected by the lock.
[0009] The portable entry system in accordance with the present invention includes a hand-held, portable entry device, an electromechanical lock positioned within a safe, and a receiving receptacle positioned on the outside of a safe for receiving the portable entry device. An optional docking station is also provided. The electromechanical lock is typically positioned on the backside of a safe door and includes a circuit board and at least one electromagnetic device that is moveable or otherwise influenced by the circuit board. The portable entry device includes a pre-programmed lock security code or codes and an authorized user code or codes, a power supply therewithin, such as a battery, and a user-activated interface such as a keypad, fingerprint identification system, retina scan, voice-recognition device, electronic signature pad, or the like. Alternatively, a global positioning system may be used. If a GPS is installed in the portable entry device, the device cannot be activated unless the coordinates of the portable entry device with installed GPS match the coordinates of safe's location. The portable entry device is constructed and arranged to communicate with a circuit board within the electromechanical lock when placed in operating relationship thereto. Upon input, receipt and verification of the correct authorization code from the user into the user interface, the device is activated and communicates the pre-programmed lock security code to the microprocessor contained within the electromechanical lock positioned within the safe. If the microprocessor recognizes and matches the security code, it sends a signal to the circuit board, which in turns sends a command to the electromagnetic device. When the electromagnetic device receives the command, a plunger on the solenoid disengages the locking bolt, which locks the safe boltworks. A handle connected by a shaft through the outside of the safe is operably connected to the safe's boltworks. A user operating the safe's handle turns the handle. Movement of the handle causes the boltworks to act on the locking bolt which retracts or otherwise moves to the unlocked position thereby allowing the authorized user to open the safe. The power supply contained within the portable entry device provides the necessary electricity to not only the circuit board and user interface, but also to the electromagnetic device, which may be a solenoid or a motor. If a motor is used, the motor actuates the locking bolt to withdraw or otherwise retract from an engaged position, which locks the boltworks to an unengaged position, which allows the boltworks to move and open the safe. The present invention may be used with a variety of locking bolts such as a slide bolt, a dead bolt, a swing bolt and other locking bolts known to those skilled in the art.
[0010] One aspect of the present invention provides a lock system including a portable entry device that activates an electromechanical lock inside a safe. The electromechanical lock includes a locking bolt moveable between an open position and a closed position. The locking bolt blocks the safe's boltworks. The electromagnetic device includes an engaged state and a disengaged state, and prevents the locking bolt from being moveable to the open position when the electromagnetic device is in the engaged state. In the disengaged state, the electromagnetic device allows the locking bolt to move to the open position. A solenoid-operated plunger, such as disclosed in U.S. Pat. No. 6,786,519, is one example of such an electromagnetic device.
[0011] The electromechanical lock further includes a circuit board electronically connected to the electromagnetic device. The circuit board has computer memory attached thereto that is capable of storing one or more pre-programmed codes. A processor is also attached to the circuit board and in communication with the computer memory. The processor is capable of comparing a received code to at least one of the plurality of codes stored in the computer memory and sending a signal that causes the electromagnetic device to change between the engaged and disengaged states.
[0012] The electromechanical lock also includes at least one communication channel that allows communication between the portable entry device and the circuit board. Upon verifying that a code is received from an authorized user using the portable entry device, the circuit board sends a signal that causes the electromagnetic device to change between the engaged and disengaged states. An example of a communication channel is a conductor connecting the circuit board to an electrical contact on an external surface of the electromechanical lock. Another example of a communication channel is a radio frequency receiver or transceiver operably connected to the circuit board that controls the electromagnetic device.
[0013] Additionally, the electromechanical lock includes at least one power channel capable of transferring power from the portable entry device to the electromagnetic device.
[0014] The portable entry device has a housing with a user interface operably attached to the housing. The user interface may be a variety of devices, including but not limited to a keypad, a fingerprint, voice or retina recognition device, a global positioning system, or an electronic signature recognition pad. Each of these user interfaces has unique attributes that make it advantageous in different applications.
[0015] The portable entry device further includes a power supply contained within the housing and capable of supplying enough power to the electromechanical lock to power the circuit board and the electromagnetic device. The power is delivered to the circuit board through the power channel.
[0016] The physical relationship between the electromechanical lock and the portable entry device can be embodied in various configurations. A durable configuration includes a handheld device that is relatively rectangular in shape, an entire end of which constitutes a male coupling. A receiving receptacle positioned on the outside portion of the safe door defines a female coupling sized to receive the handheld device. When the male coupling end of the portable entry device is placed in the female coupling, electrical contacts on both components abut, establishing electrical communication therebetween.
[0017] Alternatively, the handheld device could comprise a male USB or serial connector or the like. A corresponding female port would then be found on the receiving receptacle. The receptacle then communicates via cable with the electromechanical lock. Another alternative provides a portable entry device that establishes data flow communication and power transfer with the electromechanical lock without physical contact between the two components and without the need for a receptacle. Isolation transformers are usable to transfer power without physical contact, while there are many forms of wireless data communication useable to relay code data between the portable entry device and the electromechanical lock. Another alternative provides a portable entry device that is in power and data flow communication directly with the electromechanical lock without the need for a receptacle.
[0018] Another aspect of the invention provides an optional docking station that is connectable to a computer. The docking station is constructed and arranged to receive the portable entry device and includes a charger operably connected to the power supply of the portable entry device when the portable entry device is received by the docking station. The charger is capable of charging or recharging the power supply in the handheld device.
[0019] The docking station also includes a data link capable of operably connecting the processor of the portable entry device to a computer when the portable entry device is in the docking station and the docking station is connected to a computer. The data link allows data flow communication between the computer and the processor of the portable entry device.
[0020] In an alternative embodiment, the portable entry device may be designed to operate without the need for a docking station. The portable entry device may be directly connectable to a computer capable of charging or recharging the power supply in the device.
[0021] Another aspect of the present invention provides a method of opening a safe. The method includes providing a safe having a door containing a receptacle for a portable entry device, boltworks that lock the safe's door, and an electromagnetic device contained within a safe, the electromagnetic device in communication with a lock that prevents the boltworks from being moved into a retracted position.
[0022] A portable entry device containing a pre-programmed user security code and a pre-programmed lock security code is provided. A user places the portable entry device in mating relationship with a receiving receptacle located on a safe door and enters a PIN, fingerprint identification, retinal scan, etc. If the user security code is correct, the portable entry device activates and sends a signal to a microprocessor located within the electromechanical lock. The microprocessor then determines whether the lock security code matches the code stored within the microprocessor. If the codes match, a signal is transmitted from the microprocessor to the electromagnetic device activating it and causing it to disengage the locking bolt allowing the authorized user to turn the safe handle and access the safe.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a perspective view of an embodiment of a portable entry device of the present invention;
[0024] FIG. 2 is a perspective view of an embodiment of a docking station of the present invention;
[0025] FIG. 3 is a perspective view of the portable entry device of the present invention placed in the docking station;
[0026] FIG. 4 is a perspective view of an embodiment of an electromechanical lock of the present invention;
[0027] FIG. 5 is a perspective view of an embodiment of a safe door with a handle in an open position, the safe door including the portable entry device and electromechanical lock of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Referring now to FIGS. 1-4 , it can be seen that the present invention includes a portable entry device 20 ; a docking station 80 ; an electromechanical lock 50 located within, for example, a safe; and a portable entry device receiving receptacle 64 located on, for example, the door of a safe 70 . The portable entry device 20 , shown in FIG. 1 , includes a housing 22 that houses a microprocessor or microchip 24 , computer memory 26 operably connected to the microchip 24 , and a power supply 28 operably connected to the microchip 24 . The internal components 24 , 26 and 28 are shown schematically in phantom lines. The power supply 28 is preferably a rechargeable battery. One skilled in the art will realize that the computer memory 26 could be integrated with the microchip 24 . Optimally, microchip 24 and computer memory 26 are components of a circuit board 30 .
[0029] The portable entry device 20 also includes, on an outer surface, a user interface 32 . The user interface 32 is operably connected to the circuit board 30 such that data flow inputted into the user interface 32 can flow to the microchip 24 . The user interface 32 is embodied in FIG. 1 as a keypad. In alternative embodiments of the present invention, user interface 32 may be a fingerprint recognition or retinal scan device or other biometric devices. Also on an external surface 35 of portable entry device 20 is a plurality of contacts 33 , 34 . The contacts 33 , 34 allow the portable entry device 20 to communicate in mating relationship with contacts 56 , 57 of receptacle 64 (which in turn communicate with electromechanical lock 50 ) and contacts 85 , 86 of docking station 80 (which in turn communicate with an external power source and a computer storing data).
[0030] Contacts 33 are in data flow communication with the microchip 24 . Contacts 34 are electrically connected to the power supply 28 and usable to supply power to the electro-magnetic device 54 of lock 50 when connected thereto. Contacts 34 also receive power from the docking station 80 when connected thereto during a recharging operation. As those skilled in the art will appreciate, the number of contacts for power and data communication can vary and may include one contact each or a plurality of contacts. The contacts 33 , 34 shown for data flow communication and power supply are exemplary only and as those skilled in the art will appreciate may be reversed, may be on the front, back, sides or on opposites sides of the portable entry device in any usable configuration.
[0031] Referring now to FIG. 2 , there is shown optional docking station 80 of the present invention. Docking station 80 includes a body 82 defining a receiving dock 84 sized to receive at least a portion of the portable entry device 20 . The dock 84 includes data communication and power contacts 85 , 86 , respectively. The docking station 80 further includes a data link 88 capable of connecting the docking station 80 to a computer. The data link 88 may terminate with a universal serial bus (USB) connector, fire wire connector, or any connector usable to connect an external device to a computer. The computer may store useful information that is uploaded to the portable entry device when the portable entry device is docked in the docking station 80 . For example, useful data such as the authorized users for the portable entry device, the events that transpired during, for instance, a cash-carrier route such as time of lock openings and the personnel associated with the openings may be uploaded.
[0032] The docking station 80 has a charging function and a data communications function. The charging function is used to recharge the power supply 28 of the portable entry device 20 when the portable entry device 20 is placed in the dock 84 . When placed in the receiving dock 84 , the contacts 34 of the portable entry device 20 are electrically connected to the contacts 86 of the docking station 80 . At least one of contacts 86 supplies charging power to the power supply 28 of the portable entry device 20 . Again, those skilled in the art will appreciate that the number of contacts can be varied without sacrificing functionality. Power cable 89 connects to an external power supply to maintain docking station 80 fully charged.
[0033] Those skilled in the art will also appreciate that the charging function can be accomplished by a charger 92 within the docking station 80 , or may be supplied by a charger contained within the computer leaving the docking station to serve only as a connector between the power supplied by the computer and the power supply 28 . If the charger 92 is contained within the docking station 80 it may receive electricity from the computer or an external source.
[0034] The data communications function establishes data flow between a external computer and microchip 24 of portable entry device 20 via data link 88 . The data flow is preferably two-way flow allowing the computer to input new codes into the portable entry device 20 as well as receive data from the microchip 24 for purposes of record keeping.
[0035] FIG. 3 depicts the portable entry device of the present invention docked in docking station 80 with power contacts 34 in communication with contact 86 and data communication contacts 33 in data flow communication with communication contacts 85 .
[0036] Referring now to FIG. 4 , there is shown the second and third components of the present invention, an electromechanical lock 50 and a portable entry device receiving receptacle 64 . The electromechanical lock 50 includes a locking bolt 52 , which retracts or otherwise moves between an open position and a closed position by operation of an electromagnetic element 54 , discussed in detail below. The electromechanical lock 50 could be any mechanical lock mechanism such as the swing bolt lock disclosed in U.S. Pat. No. 6,786,519 to Gartner. Alternatively, the lock mechanism may be a slide bolt, a dead bolt and other locking bolts known to those skilled in the art.
[0037] Electromechanical lock 50 includes an electromagnetic device 54 , shown diagrammatically in phantom lines as an exemplary solenoid-operated plunger, which has an engaged state and a disengaged state. The electromagnetic element 54 may be a solenoid, which is a linear electromagnetic device. A motor or other rotary electromagnetic device may also be employed. A plunger 53 on the solenoid engages locking bolt 52 . When the locking bolt 52 is in its locked position, it engages boltworks 55 and prevents boltworks from moving. The electromagnetic lock 50 is operably attached to the safe's boltworks 55 , such that the boltworks 51 are prevented from being movable between an open position and a closed position when the electromagnetic lock 50 is in an engaged state. In the disengaged state, the electromagnetic lock 50 allows a user to rotate handle 72 on safe 70 into an open position, as shown in FIG. 5 .
[0038] Receiving receptacle 64 includes a plurality of contacts 56 , 57 that are positioned to electrically interact with the contacts 34 , 35 of the portable entry device 20 , respectively. It can be seen in FIG. 4 , that the receiving receptacle 64 is configured to mate with the portable entry device 20 of FIG. 1 . Receptacle 64 that is sized to receive housing 22 of the portable entry device 20 . Thus, receptacle 64 constitutes a female coupling and the end 36 proximate the contacts 33 , 34 of the portable entry device 20 constitutes a male coupling.
[0039] Contacts 56 , 57 are electrically connected to a microchip 58 . The microchip or processor 58 is a component of a circuit board 59 that is either contained within the electromechanical lock 50 or contained within the safe that the lock 50 is securing. Also on the circuit board is computer memory 61 , accessible by the microchip 58 . The circuit board 59 is electrically connected to at least one of the contacts 57 to form a communications channel 60 therebetween. Furthermore, the circuit board 59 is electrically connected to at least one of the contacts 56 to form a power channel therebetween. The power channel 62 further connects the circuit board 59 to the electromagnetic device 54 .
[0040] In operation, the portable entry device 20 is stored in docking station 80 where data is uploaded into computer memory 26 of microprocessor 24 . The stored data may include information such as any number of authorized user codes, any number of security codes that correspond to safes located along a carrier's route, the events that transpired during a cash-carrier route such as time of safe openings and the personnel associated with the openings. Upon arriving at a safe's location, the user would typically first place the portable entry device 20 in the receiving receptacle 64 located on safe door 70 . Contacts 33 and 34 are placed in communication with contacts 57 and 56 , respectively and power communication and data communication is established. The user then enters his authorized user security code (or scans his retina or applies his fingerprint) into the user interface 32 of the portable entry device 20 . If the user security code, retina or fingerprint matches the pre-programmed information stored within the portable entry device 20 , the portable entry device is activated. Data communications channel 60 in operating communication with contact 33 relays the pre-programmed lock security code that is stored within the portable entry device 20 to microprocessor 58 . Upon receiving the code, microprocessor 58 compares the received lock security code to the lock security code stored in memory 61 . If the codes match, microprocessor 58 sends a signal to the electromagnetic device 54 . Use of the power channel 62 may be obviated or combined with the communications channel 60 in the event that the voltage required to operate the electromagnetic device 54 is sufficiently small to be drawn from the communications channel. Upon receiving a signal from the microprocessor 58 , solenoid 54 causes plunger 53 to retract thereby disengaging locking bolt 52 . In an alternative embodiment, a motor (not shown) causes a locking bolt to slide, retract or otherwise move thereby disengaging the locking bolt. The user receives an audible signal indicating that the safe may be opened. The user operates handle 72 , turning it to the unlocked position. Because the locking bolt 52 is disengaged, handle 72 causes the boltworks to act on the locking bolt and locking bolt retracts, pivots, slides or otherwise moves permitting boltworks 51 to freely move into the open position as shown in FIG. 5 .
[0041] It is contemplated that features disclosed in this application can be mixed and matched to suit particular circumstances. Various other modifications and changes will be apparent to those of ordinary skill in the art without departing from the spirit and scope of the present invention. Accordingly, reference should be made to the claims to determine the scope of the present invention.
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A portable entry system and method is provided. The portable entry system includes an electromechanical lock used for securing a safe door to a safe housing. The system also includes a portable entry device that allows the electromechanical lock to be operated between open and closed positions. The portable entry device is removable from the electromechanical lock such that it may be programmed and recharged at a location remote from the electromechanical lock. An authorized user enters an authorized user security code that activates the portable entry device. Without an activated device, the electromechanical lock cannot be operated.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/028,433 entitled AQUEOUS CLEANING COMPOSITION, filed on 13 Feb. 2008, which is hereby incorporated herein by reference.
BACKGROUND OF INVENTION
[0002] The present invention generally relates to commercial cleaning compositions. More particularly, the present invention relates to non-emulsified, aqueous cleaning compositions which aid in the removal of contaminants such as grease, oil, paint, paint sludge, tar, asphalt, underbody rust protection coatings and adhesives from surfaces, including for example paint overspray deposited on walls, floors, windows, equipment, hoses and the like during the process of painting or coating an object.
[0003] During the process of spray painting an object, at least some of the paint being sprayed does not contact the intended object and eventually drifts onto an unintended object, such as the floor, walls, equipment or windows surrounding the area in which the spray painting occurs. This is referred to as overspray. The surfaces upon which overspray can deposit may include any range of surfaces including hard or flexible surfaces, and smooth or porous surfaces, with said surfaces being made of metal, wood, glass, rubber or plastic materials. In certain circumstance the painting may occur in a controlled environment in which the surfaces affected by overspray can be selected to be more durable and achieve easier removal of the overspray. However, over time the accumulation of overspray needs to be removed to ensure safe working conditions and ensure the integrity of the overall manufacturing process.
[0004] For example, in the automobile industry, many parts are conveyed through special chambers in assembly line fashion to be spray painted or coated. According to some estimates, as much as 40% of the paint being sprayed misses the intended object and eventually ends up on unintended surfaces. Such surfaces include the floor, walls and windows of the chamber. Further, it is quite common to have robotic arms with spray nozzles contained within the chamber to apply the spray paint. These too can become covered in paint. In addition, the paint or coating material tends to migrate outside the chamber through air drafts, foot traffic, equipment traffic and the like. Eventually, the accumulation of the overspray on unintended surfaces must be removed. For example, the accumulation of clear coat onto viewing windows must eventually be removed, otherwise the window will not be able to be seen through.
[0005] The overspray and paint sludge can be removed from the unintended surfaces by either mechanical or chemical means. Mechanical means may include the use of abrasives, wire brushes, meshes and sharpened instruments, such as razor blades, to physically remove the overspray from the unintended surface. These means of removing overspray and paint sludge, however, have their disadvantages in that they are time and labor intensive, and can be dangerous to workers. Moreover, such mechanical means are either an inefficient or ineffective way of removing overspray from porous materials, or surfaces which are not hard and smooth. In fact, it may be impossible to fully remove all of the overspray by mechanical means alone. Further, mechanical means of removing overspray may damage the unintended surface, either abruptly or gradually, resulting in having to replace or refurbish the surface, which may include a piece of equipment or viewing glass.
[0006] A variety of chemical means for removing overspray have been employed in the prior art to remove overspray, amongst other contaminants as well. In order to be effective, though, it is desirable that the chemical processes should be quick and provide complete removal of the overspray without damaging the unintended surface. Such chemical means have traditionally included chemical compositions containing undesirable quantities of volatile organic compounds such as aliphatic and aromatic solvents, non-ethoxylated alcohols, amines, ketones and chlorinated solvents. For example, compositions containing xylene, or ethyl benzene, are widely employed in the automobile industry to remove paint and paint sludge. Examples of such products include Cyclosol #52/GP-100 as made commercially available by Gage Products Company of Ferndale, Mich., and Shellsol A100 as made commercially available by Shell Chemicals Company. However, due to recent government regulations based upon increased consumer safety and environmental concerns, it is desirable to reduce the use of volatile organic compounds. Unfortunately, with a vapor pressure of approximately 7 mm of Hg at 20° C., xylene is a highly volatile organic compound. Moreover, these solvents are typically sprayed at a rate of approximately one gallon per minute onto a surface or object to remove overspray and paint sludge. To clean one side of a one square meter window with these products typically takes about five minutes of spraying to remove about 80% of the overspray, leaving the window surface hazy or tacky. Additionally, to clean an entire painting chamber as used in the automobile manufacturing industry, nearly 500 gallons of solvent and four and one-half hours of labor are needed. When the above solvents are used, they are one time use products because the paint solids dissolve into the solvent, thereby rendering the used solutions not reusable.
[0007] Other chemical compositions, such as acetone, are exempt as being classified as volatile organic compounds by the United States Environmental Protection Agency even though they exhibit extremely high vapor pressures. Acetone, though, while being able to satisfactorily remove some paints and residues, is difficult to contain because of its high evaporation rate and relatively low flash point (i.e., <−9° C.). This makes such compositions unsatisfactory for many commercial purposes.
[0008] For both environmental and economic reasons, it is also desirable to provide a non-corrosive cleaner. Water based cleaning formulations having a neutral pH are therefore preferred. It is, however, difficult to provide an effective aqueous cleaning composition that reduces volatile organic compound levels while providing acceptable evaporation rates, has a non-corrosive pH, and cleans as effectively as aliphatic solvents, aromatic solvents, alcohols, amines, ketones, chlorinated solvents, other solvents, caustics, and acids.
[0009] There exist several examples in the prior of cleaning compositions employing water based emulsions and micro-emulsions for removing paint and contaminants. Such compositions, however, have inherent deleterious traits in that separation of the miscible components may occur during transport, or during storage thereof. Further, emulsions and micro-emulsions tend to be corrosive (acidic or caustic), have unsatisfactory evaporation rates, and also tend to leave oily residues on the surfaces in which they are applied. Such emulsions and micro-emulsions may also contain components deemed not to be environmentally friendly.
[0010] Accordingly, there is a need for an environmentally friendly, non-corrosive, aqueous-based, low volatile organic compound chemical composition, substantially free if not entirely free of aromatic solvents, chlorinated solvents, ketones, amines and strong acids, which is applicable to a variety of surfaces to thoroughly and easily remove overspray, paint sludge, grease, tar, asphalt, underbody protective coatings and adhesives from said surfaces.
BRIEF SUMMARY OF INVENTION
[0011] The present invention includes an aqueous cleaning composition that effectively reduces volatile organic compound levels, performs in a non-corrosive pH range, and effectively dissolves and removes paint, overspray, paint sludge, grease, oil, tar, asphalt, underbody coatings and adhesives from floors, walls, mats, equipment and windows. The aqueous cleaning composition of the present invention generally comprises a first solute and a second solute mixed with water, wherein the water is in sufficient amount to act as a solvent. The first solute includes a water soluble aliphatic glycol ether (excluding glycol diethers) component. The second solute includes a water soluble glycol diether component. The resulting aqueous cleaning composition exhibits a vapor pressure equal to or less than 0.8 mm Hg at 20° C., a pH range of between about 6.0 and 8.0 and a flash-point of 149° F. (Setaflash closed cup). The aqueous cleaning composition may optionally include a surface active agent or a corrosion inhibitor. The composition constituents of the present invention do not include, and effectively replace, aromatic solvents, oil soluble aliphatic solvents, non-ethoxylated alcohols, amines, ketones, chlorinated solvents, caustics and acids. The aqueous cleaning composition of the present invention can also be reused until it eventually loses its efficacy.
DETAILED DESCRIPTION
[0012] The present invention provides a cleaning composition completely soluble in water for removing contaminants such as paint, overspray and paint sludge from floors, walls, grates and windows within an area or enclosure in which a spray painting process is used, and also for removing the same from any equipment or tools contained therein as well. For purposes of this specification, the term overspray will generally refer to the application of any form of paint, resins, sprayable coatings, varnish, stain or other airborne particulate material deposited onto an unintended surface. Also for purposes of this specification, the term paint sludge will generally refer to an accumulation of overspray, or any other accumulation of paint, resins, sprayable coatings, varnish or stain. The cleaning composition of the present invention can be referred to as an aqueous cleaning composition with the addition of water in instances where a concentrated form of the cleaning composition is utilized. The cleaning composition can also be employed in environments other than where paint is being applied. In accordance therewith, the present invention further provides a cleaning composition for removing glue, wood coatings, grease, grime, oil, tar, asphalt, underbody protective coatings, tire marks, decals and adhesives from a variety of substrate surfaces, including but not limited to metal surfaces including stainless steel surfaces, painted surfaces, glass surfaces, cement surfaces, wood surfaces, porcelain surfaces, vitreous tile surfaces, ceramic tile surfaces, plastic surfaces and the like.
[0013] The present invention further includes a process for cleaning a substrate by providing the aqueous cleaning solution in accordance with the present invention and effectively contacting the substrate to be cleaned to substantially remove the aforementioned contaminants therefrom. The aqueous cleaning composition of the present invention can be directly applied to the surface to be cleaned, or can be applied thereto by means of a mop, moistened cloth, sponge or the like.
[0014] The present invention was developed in response to eliminating the use of xylene, ethyl benzene and other volatile organic compounds, including those exempt by the EPA from being classified as such, for dissolving and removing overspray, paint and paint sludge from floors, walls, equipment and windows. Considerations involved in the development process of the present invention were to match the cleaning performance of xylene based cleaning compositions while reducing volatile organic compound levels, obtaining acceptable evaporation rates and achieving a non-corrosive pH level. For purposes of this specification, acceptable cleaning performance includes the substantial removal of overspray and residues from a surface in a one-step process, without a post-rinse step, while leaving the surface streak free. For purposes of this specification, acceptable evaporations rates include drying times of 30 seconds or less, wherein the time is measured from the point after removing the cleaning composition with a mop, rag or squeegee from the substrate surface until the surface is substantially free of a liquid presence and not slippery. Further, for purposes of this specification, non-corrosive pH ranges preferably include a pH range of between about 2.0 and 12.5, and more preferably between about 6.0 and 8.0.
[0015] The aqueous cleaning composition of the present invention generally includes a first solute component mixed with a second solute component. The cleaning composition further includes water acting as a solvent. A surface active agent (“surfactant”) or a corrosion inhibitor may be optionally added dependent upon the specific application. The cleaning composition of the present invention does not include, and effectively replaces, oil soluble aliphatic solvents, aromatic solvents, non-ethoxylated alcohols, amines, ketones, chlorinated solvents, caustics and acids. It should be noted that it is well within the scope of the present invention to provide the cleaning composition in concentrated form, either having less water or substantially free of water, to reduce volume and mass of the product for purposes of lowering transportation costs or reduce the amount of space needed to store the composition. Water can later be added to the concentrate by the end user to make a working solution in accordance with the present invention. The working solution of the present invention is prepared by mixing together the aforementioned components in any order at room temperature.
[0016] The first solute component includes an aliphatic glycol ether component, excluding glycol diethers. The aliphatic glycol ether component used as a solute in the present invention can include either an ethylene oxide based material, a propylene oxide based material and any combination thereof. Examples of suitable ethylene oxide based materials, excluding glycol diethers, for use in the present invention include, but are not limited to, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol phenyl ether, diethylene glycol methyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and any mixture thereof. Examples of suitable propylene oxide based materials, excluding glycol diethers, include, but are not limited to propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol t-butyl ether, propylene glycol phenyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol methyl ether, tripropylene glycol n-butyl ether, and any mixture thereof. Ethylene glycol monobutyl ether (2-butoxyethanol) is the preferred aliphatic glycol ether for use in the present invention.
[0017] The second solute component of the present invention includes a glycol diether, or glyme. The glycol diethers suitable for use in the present invention include monoethylene glycol dimethyl ether (monoglyme), diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme), tetraethylene glycol dimethyl ether (tetraglyme), dipropylene glycol dimethyl ether (proglyme) or diethylene glycol dibutyl ether (butyl glyme), and any mixture thereof. The preferred glycol diether for use in the present invention includes dipropylene glycol dimethyl ether, which is commercially available from Clariant Corporation of Charlotte, North Carolina, or under the trade name PROGLYDE® DMM by the Dow Chemical Company of Midland, Mich.
[0018] The aqueous cleaning composition of the present invention provides numerous advantages and benefits. For example, it has been suprisingly discovered that by employing the glycol diether component with the alkyl glycol monoether component in an aqueous solvent, there is a synergistic effect on cleaning performance not seen in other aqueous based detergent compositions or compositions containing volatile organic compounds having an equal or lesser vapor pressure than that as exhibited by the aqueous cleaning composition of the present invention. Furthermore, it has been discovered that the aqueous cleaning composition of the present invention breaks the paint sludge bonds by separating the solvent from paint solids, allowing the paint solids to fall to the bottom of the cleaning solution. This allows cleaning composition of the present invention to work better on more surfaces than originally intended and allows the solution to retain its efficacy through multiple reuses.
[0019] The surfactant, which is optional and not necessarily essential to practice the present invention, may be included up to about 20 weight percent of the cleaning composition. The surfactant is meant to reduce surface tension and can include any number of nonionics, anionics, cationics, or amphoterics including, but not limited to, nonylphenoxypolyethoxyethanols, octylphenoxypolyethoxyethanols, block copolymers based on ethylene oxide and propylene oxide, amphoterics, betaines and amine oxides. The surfactant for use in the present invention preferably includes a detergent range alcohol ethoxylate, including ethoxylated alcohols having between nine and eleven carbon atoms. Such preferred ethoxylated alcohols include, for example, TOMADOL® 91-6 and NEODOL® 91-6. TOMADOL® 91-6 is made commercially available through Air Products and Chemicals, Inc. of Allentown, Pennsylvania. NEODOL® 91-6 is made commercially available in the United States through Shell Chemical LP of Houston, Tex.
[0020] The corrosion inhibitor, which is optional and not necessarily essential to practice the present invention, can be added up to 50 weight percent of the cleaning composition of the present invention. The corrosion inhibitor (or inhibitors) is added to prevent metal corrosion on metal surfaces that have been cleaned with the aqueous cleaning composition of the present invention. Exemplary corrosion inhibitor additives and combinations for use in the aqueous cleaning composition of the present invention include, but are not limited to: amines including triethanolamine, monoethanolamine, and diethanolamines; borates including sodium borate, and calcium borate; borate esters such as amine borate esters; silicates including potassium silicate, sodium silicate, and metasilicates; alkanolamides; carboxylates such as amine salts of dibasic acids; nitrates; nitrites; azelaic and sebacic acid salts and esters; phosphate esters; and castor oil.
[0021] In a first embodiment of the cleaning composition of the present invention, the aliphatic glycol ether component comprises up to about 90 weight percent of the total cleaning composition, the glycol diether component comprises up to about 90 weight percent of the total cleaning composition, and the surfactant component comprises up to about 20 weight percent of the cleaning composition, with the remainder including water at about 0-90 weight percent. Preferably, the first embodiment of the present invention includes the alkyl glycol monoether component comprising about 10-40 weight percent of the total cleaning composition, the glycol diether component comprising about 5-25 weight percent of the total cleaning composition, and the surfactant component comprising about 0-5 weight percent of the total cleaning composition, with the remainder being water at about 50-85 weight percent. More preferably, the first embodiment of the present invention includes the alkyl glycol monoether component comprising approximately 25.000 weight percent of the total cleaning composition, the glycol diether component comprising approximately 15.000 weight percent of the total cleaning composition, and the surfactant component comprising approximately 0.036 weight percent of the cleaning composition, with the remainder including water at approximately 59.964 weight percent. The following Table 1 lists the most preferred composition of the aqueous cleaning composition, as a working solution, in accordance with the first embodiment of the present invention.
[0000]
TABLE 1
Most Preferred Composition of First
Embodiment (percent total weight)
Water
59.964%
2-Butoxyethanol
25.000%
Dipropylene Glycol Dimethyl Ether
15.000%
Alcohols, C9-11, ethoxylated
0.036%
[0022] The following Table 2 summarizes the physical data associated with the working solution of the most preferred embodiment of the aqueous cleaning composition as contained in Table 1.
[0000]
TABLE 2
Physical Data of Aqueous Cleaning Composition of Table 1
Form:
Liquid
Color:
Clear
Odor:
Slight solvent
Specific Gravity (Water = 1):
0.975-0.980 @ 24° C
Boiling Point:
100° C.
Evaporation Rate (Water = 1)
<1.0
pH of working solution:
6.5-7.5
pH (1% volume):
7.0-8.0
Solubility in Water:
Complete
Vapor Density (Air = 1):
>4
% Volatile Organic Compounds:
<40% (3.25 lbs per gallon)
Vapor Pressure:
<0.8 mm Hg @ 20° C.
Flash Point:
149° F. (Setaflash closed cup)
[0023] Alternatively, if a concentrated form is desired, it will be understood by those skilled in the art that the proportion of water in the working solution can be lessened, even to the point of containing no water, to form the concentrate. The preferred concentrated cleaning composition, being substantially free of water, includes the alkyl glycol monoether component comprising about 62.44 weight percent of the total concentrated cleaning composition, the glycol diether component comprising about 37.47 weight percent of the concentrated cleaning composition, and the surfactant component comprising about 0.09 weight percent of the concentrated cleaning composition. Similar to the working solution, the concentrate can be prepared by mixing together the aforementioned components in any order at room temperature. The working solution can be derived from the concentrate simply by adding the appropriate amount of water to the concentrate.
[0024] In a second embodiment of the cleaning composition of the present invention, the alkyl glycol monoether component comprises up to about 90 weight percent of the total cleaning composition, the glycol diether component comprises up to about 90 weight percent of the total cleaning composition, the surfactant component comprises up to about 20 weight percent of the cleaning composition, and the corrosion inhibitor comprises up to about 50 weight percent of the cleaning composition, with the remainder including water at about 0-90 weight percent. Preferably, the second embodiment of the present invention includes the alkyl glycol monoether component comprising about 10-40 weight percent of the total cleaning composition, the glycol diether component comprising about 5-25 weight percent of the total cleaning composition, the surfactant component comprising about 0-5 weight percent of the total cleaning composition, and the corrosion inhibitor component comprising about 0-10 with the remainder being water at about 50-85 weight percent. Most preferably, the second embodiment of the present invention includes the alkyl glycol monoether component comprising approximately 25.000 weight percent of the total cleaning composition, the glycol diether component comprising approximately 15.000 weight percent of the total cleaning composition, and the surfactant component comprising approximately 0.036 weight percent of the cleaning composition, the corrosion inhibitor component comprising approximately 0.600 weight percent of the cleaning composition, with the remainder including water at approximately 59.364 weight percent. The following Table 3 lists the most preferred composition of the aqueous cleaning composition, as a working solution, in accordance with the second embodiment of the present invention.
[0000]
TABLE 3
Most Preferred Composition of Second
Embodiment (percent total weight)
Water
59.364%
2-Butoxyethanol
25.000%
Dipropylene Glycol Dimethyl Ether
15.000%
Alcohols, C9-11, ethoxylated
0.036%
CORFREE ® M1
0.200%
Triethanolamine
0.200%
Monoethanolamine
0.200%
[0025] CORFREE® M1 is a nitrite-free dibasic acid mixture made commercially available through INVISTA S.ar.l. of Wilmington, Del.
COMPARATIVE EXAMPLES
[0026] The cleaning composition of the present invention provides an environmentally preferred aqueous solution, low in volatile organic compounds, and effective at removing paint, resins, varnish, stain, glue, wood coatings, grease, grime, oil, tar, asphalt, tire marks, decals and adhesives from a variety of substrate surfaces including, but not limited to, metal surfaces including stainless steel surfaces, glass surfaces, cement surfaces, wood surfaces, porcelain surfaces, vitreous tile surfaces, ceramic tile surfaces, plastic surfaces and the like.
Comparative Example 1
[0027] In support thereof, a working solution of the aqueous cleaning composition of the present invention was prepared in accordance with the components as contained in Table 1. Approximately 0.1 gallons of the working solution was applied, by means of a mop, to a glass surface of approximately one square meter containing paint overspray. A squeegee was applied to the glass surface to remove excess solution and the dissolved overspray, whereby 99-100% of the overspray was removed from the glass surface in approximately one minute. No rinse was required and the glass was streak-free and substantially dry in approximately 30 seconds.
Comparative Example 2
[0028] Similar to Comparative Example 1, a like amount of the working solution of the present invention in accordance with Table 1 was applied by means of a mop to a similar area of concrete containing tacky overspray. The overspray contained on the floor was entirely removed after one and one-half minutes with assistance with a floor squeegee. No rinse was required and the floor was streak-free and substantially dry in approximately 30 seconds.
Comparative Example 3
[0029] A coco coir mat containing paint solids and paint sludge was allowed to soak in an appropriate amount of the working solution of the present invention in accordance with Table 1 for ten minutes. The mat was then rinsed off with water. The cleaning composition of the present invention in accordance with Table 1 broke down and dissolved the paint solids and paint sludge, leaving the mat substantially free of any paint residue. Additionally, to test the coco coir mat for compatibility, the mat was soaked in the same cleaning composition for two months after which no deleterious effects to the mat were observed.
Comparative Example 4
[0030] A working solution of the aqueous cleaning composition of the present invention was prepared in accordance with the components as contained in Table 3. This sample was made with an amine salt of dibasic acids to prevent flash corrosion of cast iron chips. The cast iron chips were submerged in solution for 1 minute, then removed and left to air dry. The chips remained corrosion free for more than 48 hours.
[0031] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A water soluble, non-emulsified cleaning composition for removing contaminants, especially paint and overspray, from a surface comprises from about 1 to about 90 weight percent of an aliphatic glycol diether and from about 1 to about 90 weight percent of an aliphatic glycol monoether. Water can be added to form a working solution from about 0.001 to about 90 weight percent of the entire composition. The resulting aqueous cleaning composition exhibits a pH between about 6.0 and 8.0 and a vapor pressure of less than about 0.8 millimeters of mercury at 20° C.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is in the field of organic chemistry. The invention relates to a process for the synthesis of (3R,3′R,6′R)-lutein and its stereoisomers from commercially available (rac)-α-ionone by a C 15 +C 10 +C 15 coupling strategy. Employing this methodology, (3R,3′R,6′R)-lutein (dietary), (3R,3′S,6′S)-lutein, (3R,3′S,6′R)-lutein (3′-epilutein), and (3R,3′R,6′S)-lutein have been prepared. Based on this strategy, the other 4 stereoisomers of lutein that are enantiomeric to the above lutein isomers can also be prepared. These are: (3S,3′S,6′S)-lutein, (3S,3′R,6′R)-lutein, (3S,3′R,6′S)-lutein, and (3S,3′S,6′R)-lutein.
2. Background Art
(3R,3′R,6′R)-Lutein and (3R,3′R)-zeaxanthin are two dietary carotenoids that are present in most fruits and vegetables commonly consumed in the US. These carotenoids accumulate in the human plasma, major organs, and ocular tissues (macula, retinal pigment epithelium (RPE), ciliary body, iris, lens). In the past decade, numerous epidemiological and experimental studies have shown that lutein and zeaxanthin play an important role in the prevention of age-related macular degeneration (AMD) that is the leading cause of blindness in the U.S. and Western World. While (3R,3′R)-zeaxanthin has been commercially available by total synthesis for more than two decades, the industrial production of (3R,3′R,6′R)-lutein by chemical synthesis has not yet materialized. Consequently, this carotenoid is commercially produced from saponified extracts of marigold flowers. The major difficulty with the total synthesis of (3R,3′R,6′R)-lutein is due to the presence of 3 stereogenic centers at C3, C3′, and C6′ positions in this carotenoid that can result in 8 possible stereoisomers. The chemical structures of 4 of these stereoisomers are shown in Scheme 1. Among these, dietary (3R,3′R,6′R)-lutein (1) and one of its metabolites, (3R,3′S,6′R)-lutein (3′-epilutein) (3), have been detected in human plasma and tissues. The other 4 stereoisomers of lutein (structures not shown), are those in which the configuration at C3 position is S while the stereochemistry at C3′ and C6′ remains the same as those lutein isomers shown in Scheme 1.
To date, the only total synthesis of dietary (3R,3′R,6′R)-lutein (1) has been reported by Mayer and Rüttimann ( Helv. Chim. Acta, 1980, 63:1451-55) and is based on the C 15 +C 10 +C 15 strategy as shown in FIG. 1 . According to this methodology, the C 15 -Wittig salt, (3R)-3-hydroxy-(β-ionylideneethyl)triphenylphosphonium chloride (5), is reacted with one equiv. of 2,7-dimthylocta-2,4,6-triene-1,8-dial (C 10 -dialdehyde) to give a C 25 -aldehyde, (3R)-3-hydroxy-12′-apo-β-caroten-12′-al. Both starting materials for this reaction are commercially available and have been employed in the total synthesis of (3R,3′R)-zeaxanthin by the same group. To complete the synthesis of (3R,3′R,6′R)-lutein, Mayer and Rüttimann prepared (3R,6R)-3-acetoxy-α-ionylideneethyl)triphenylphosphonium chloride in 8 steps from (S)-4-hydroxy-2,6,6-trimethyl-2-cyclohexene-1-one in an overall yield of 6.3%. In the final step of this synthesis, these investigators reacted the C 25 -aldehyde with (3R,6R)-3-acetoxy-α-ionylideneethyl)triphenylphosphonium chloride or bromide to obtain (3R,3′R,6′R)-lutein in 25% yield. Therefore the overall yield for the reported total synthesis of lutein according to this methodology was about 1.6%.
The total synthesis of lutein described in FIG. 1 , involves numerous steps and results in a poor overall yield. Consequently, this synthetic approach does not provide an efficient and economically viable route for industrial production of (3R,3′R,6′R)-lutein (1). Therefore, the present invention was developed to provide a more practical route to 1 by employing a divergent synthetic strategy that could be simultaneously applied to the synthesis of other stereoisomers of this carotenoid such as (3R,3′S,6′S)-lutein (2), (3R,3′S,6′R)-lutein (3), and (3R,3′R,6′S)-lutein (4). In addition, this synthetic strategy also provides access to the precursors of optically active carotenoids with 3-hydroxy-ε-end group that are otherwise difficult to prepare.
SUMMARY OF THE INVENTION
Despite the difficulties encountered with the synthesis of (3R,3′R,6′R)-lutein, the C 15 +C 10 +C 15 building block strategy for the synthesis of carotenoids is, in most cases, the method of choice. This is because the formation of the double bonds at 11 and 11′ positions yields predominantly the all-E (trans)-isomer (Soukup, M; Spurr, P; Widmer, E. In: Carotenoids, Volume 2 : Synthesis , Britton, G; Liaaen-Jensen, S; Pfander, H. Eds.; Birkhäuser: Basel, 1995, pp 7-14). Therefore, this strategy has also been employed in the present invention. However, because of the poor overall yield in the reported synthetic strategy by Mayer and Rüttimann, we employed entirely different C 15 - and C 10 -building blocks. This was because (3R,6R)-3-acetoxy-(α-ionylideneethyl)triphenylphosphonium halide that was used in the final step of the reported synthesis of lutein appeared to be difficult to synthesize due to the presence of an acid-sensitive allylic hydroxyl group in the precursor to this Wittig salt ( FIG. 1 ). In addition, the olefination of (3R)-3-hydroxy-12′-apo-β-caroten-12′-al (C 25 -aldehyde) with this Wittig salt according to Mayer and Rüttimann only gave 25% yield of lutein.
The retrosynthetic pathways employed in the present invention is shown in FIG. 2 . In contrast to the reported synthesis of lutein, the final step of our synthesis involved the elongation of the optically pure C 25 -hydroxyaldehydes 6-9 with the Wittig salt 5 that could be readily prepared according to the known processes (Widmer et al., Helv. Chim. Acta, 1990, 73: 861-867; Soukup et al., Helv. Chim. Acta, 1990, 73: 868-873). We rationalized that the optically pure C 25 -hydroxyaldehydes 6-9 could be prepared from deprotection of their corresponding dimethylacetals 10-13 under mild acidic conditions without epimerization of their allylic hydroxyl groups at C3. These acetals could in turn be prepared from the reaction of protected Wittig salt 14 with the optically pure C 15 -hydroxyaldehydes 15-18 with the required stereochemistry at C3 and C6. The protected Wittig salt 14 was readily accessible according to published methods (Bernhard et al., Helv. Chim. Acta, 1980, 63:1473-1490; Haugen, Acta Chimica Scand. 1994, 48: 657-664). The application of this Wittig salt in the synthesis of unsymmetrical carotenoids with sensitive end-groups has been well documented in the literature (Bernhard et al., Helv. Chim. Acta, 1980, 63:1473-1490; Haag and Eugster, Helv. Chim. Acta, 1985, 68:1897-1906; Yamano et al. Heterocycles, 2000, 52: 141-146). However, this building block has not been employed in the synthesis of lutein or its precursors. The C 15 -hydroxynitriles 19-22 as a racemic mixture or with the appropriate stereochemistry at C3 and C6 could serve as the precursors to C 15 -hydroxyaldehydes 15-18. (7E,9E)-3-Keto-α-ionylideneacetonitrile (23a) and its (7E,9Z)-isomer (23b), prepared from nitriles 24a and 24b, could be transformed into C 15 -hydroxynitriles 19-22. However the (7E,9E)-isomer (23a) would be preferable since this would avoid the difficulties associated with the separation of optically active E/Z-isomers throughout our entire synthetic strategy.
The commercially available and inexpensive (rac)-α-ionone was selected as the starting material for the synthesis of nitriles 24a/24b that have been previously synthesized according to known methods. However, we had to develop a methodology that could provide 24a as a single isomer and transform this nitrile into 23a without stereisomerization. Other challenges with our synthetic approach involved separation of C 15 -hydroxyaldehydes 15-18 and their precursors in high optical purity and maintaining their integrity throughout the total synthesis of luteins 1-4. It should be noted that all of the precursors to luteins 1-4 that are shown in our retrosynthetic pathways in FIG. 2 , are reported here for the first time and have not been synthesized previously. This is with the exception of nitriles 24a/24b and ketonitriles 23a/23b that have been prepared as a mixture of E/Z isomers by entirely different processes than those developed in the present invention.
One of the key starting materials in the retrosynthetic pathways shown in FIG. 2 is (rac)-3-keto-α-ionylideneacetonitrile which had to be preferentially synthesized as the (7E,9E)-isomer (23a) at the expense of its (7E,9Z)-isomer (23b). This is because when (rac)-ketonitrile 23a is reduced in the following step, a new stereogenic center at C3 is generated that results in the formation of four stereoisomers, namely, (rac)-hydroxynitriles 19-22. Consequently, the reduction of a mixture of ketonitriles 23a and 23b, could afford as many as 8 stereoisomeric hydroxynitriles which would be difficult to separate in high optically purity. Therefore, the initial goal of this invention was to explore the possible routes by which (rac)-α-ionone could be transformed into ketonitrile 23a. Three synthetic routes were employed for transformation of (rac)-α-ionone to ketonitrile 23a that served as a precursor to C 15 -hydroxynitriles 19-22 ( FIG. 3 ). According to the first route, Horner-Wadsworth-Emmons (HWE) reaction of (rac)-α-ionone with diethyl cyanomethylphosphonate or diisopropyl cyanomethylphosphonate gave (rac)-α-ionylideneacetonitriles 24a (75%) and 24b (25%) as a mixture of isomers that were converted to a mixture of 23a (75%) and 23b (25%) by allylic oxidation.
However, a more effective strategy (Route 2, FIG. 3 ) was developed that involved Knoevenagel condensation of (rac)-α-ionone with cyanoacetic acid to afford 24a (92%) as the major isomer and 24b (8%) as the minor isomer. When a mixture of 24a (92%) and 24b (8%) was subjected to allylic oxidation, 23a (92%) and 23b (8%) were obtained without E/Z-isomerization and the (7E,9E)-isomer (23a) could be crystallized from the mixture.
In an alternative approach (Route 3, FIG. 3 ), (rac)-α-ionone was first converted to (rac)-3-keto-α-ionone by allylic oxidation followed by HWE olefination with diethyl cyanomethylphosphonate to yield a mixture of 23a (75%) and 23b (25%). Consequently, among these three strategies, Route 2 that involved Knoevenagel reaction of (rac)-α-ionone with cyanoacetic acid and provided 23a in high stereoselectivity was the preferred route. Reduction of the ketonitrile 23a with a number of reducing agents provided a mixture of four stereoisomeric C 15 -hydroxynitriles 19-22. Among the reducing agents employed, potassium tri-sec-butylborohydride (K-SELECTRIDE™) at −30° C. in TBME or THF produced the greatest amount of the hydroxynitriles 19 and 20 (86%) relative to the hydroxynitriles 21 and 22 (14%). However, when BH 3 /(R)-2-methyl-CBS-oxazaborolidine was used as the reducing agent, this stereoselectivity was reversed and hydroxynitriles 21 and 22 (86%) were the major products and hydroxynitriles 19 and 20 (14%) were the minor products. The separation of hydroxynitriles 19 and 20 from hydroxynitriles 21 and 22 by column chromatography proved to be challenging. However, this was accomplished by subjecting these nitriles to two successive column chromatography separations. In the next step, enzyme-mediated acylation with lipase AK ( Pseudomonas fluorescens ) or lipase PS ( Pseudomonas cepacia ) was employed to separate the enantiomeric hydroxyaldehydes 21 from 22. However, these enzymatic separations resulted in poor enantiomeric excess (ee) and the partially resolved enantiomers had to be subjected to a second enzymatic acylation to provide the optically pure hydroxynitriles 19-22. Consequently, this approach was not appealing due to the need for repeated column chromatography and enzyme-mediated acylation of racemic nitriles. Therefore, a more robust strategy was developed that eliminated these difficulties and afforded the hydroxyaldehydes 15-18 in excellent optical purities ( FIG. 4 ). As shown in FIG. 4 , the hydroxynitriles 19-22 were first transformed into a racemic mixture of hydroxyaldehydes 15-18 by DIBAL-H and the mixture was then subjected to column chromatography. Unlike hydroxynitriles, hydroxyaldehydes 15+16 were readily separated from hydroxyaldehydes 17+18 by column chromatography. In an alternative one-pot reaction, ketonitrile 23a was reduced to hydroxynitriles 19-22 with K-SELECTRIDE™ followed by the reduction with DIBAL-H to afford hydroxyaldehydes 15-18 in one convenient step.
In the following step, enzyme-mediated acylation was employed to resolve the racemic mixture of hydroxyaldehydes 15 and 16. Therefore, when a mixture of hydroxyaldehydes 15 and 16 was subjected to enzymatic acylation with lipase AK ( Pseudomonas fluorescens ) in the presence of vinyl acetate in refluxing pentane (35-36° C.), hydroxyaldehyde 16 was acylated to acetoxyaldehyde 25 within 48 h, while hydroxyaldehyde 15 remained unchanged ( FIG. 4 ). Acetoxyaldehydes 25 was then readily separated from hydroxyaldehyde 15 by column chromatography. Acetoxyaldehyde 25 was saponified with KOH/MeOH at 0° C. to yield hydroxyaldehyde 16. According to this strategy, hydroxyaldehydes 15 and 16 were obtained in enantiomeric excess (ee) of 94% and 93%, respectively.
Similarly, the resolution of a racemic mixture of hydroxyaldehydes 17 and 18 was accomplished with enzyme-mediated acylation with lipase AK ( Pseudomonas fluorescens ) in the presence of vinyl acetate in refluxing pentane. While hydroxyaldehyde 17 underwent acylation to acetoxyaldehyde 26, hydroxyaldehyde 18 remained unchanged; these were then separated by column chromatography. Saponification of acetoxyaldehyde 26 with KOH/MeOH at 0° C. afforded hydroxyaldehyde 17. Employing this methodology, hydroxyaldehydes 17 and 18 were obtained in enantiomeric excess (ee) of 91% and 92%, respectively. Therefore, all four C 15 -hydroxyaldehydes 15-18 became accessible in excellent optical purity and were utilized in the synthesis of luteins 1-4 according to the synthetic pathways shown in FIG. 5 .
The Wittig reaction of optically pure C 15 -hydroxyaldehydes 15-18 with the required stereochemistry at C3 and C6 with the protected Wittig salt 14 afforded 3-hydroxy-12′-apo-ε-caroten-12′-al dimethylacetals 10-13 (protected C 25 -aldehydes) in yields ranging from 75-85%. As part of the work-up of the same reaction, the protecting group in acetals 10-13 was removed under mild acidic conditions without epimerization at C3 to afford C 25 -hydroxyaldehydes 6-9, respectively. In the final step of the synthesis of luteins, aldehydes 6-9 were allowed to react with the Wittig salt 5 to yield luteins 1-4 in yields ranging from 65-74%. Therefore, according to the present invention, luteins 1 and 2 were each prepared in an overall yield of 21% based on the optically active C 15 -hydroxyaldehydes 15+16. Similarly, luteins 3 and 4 were prepared in overall yields of 16% and 18%, respectively. These C 15 -hydroxyaldehydes served as the key starting material in our synthetic strategy.
In one embodiment of the present invention, a compound having the Formula (I):
is synthesized by reacting a compound having the Formula (II):
with a compound having the Formula (III):
via Wittig coupling, wherein A ⊖ is an anionic counterion such as Cl − , Br − or I − . In some embodiments, the compound of Formula (I) is (3R,3′R,6′R)-lutein, (3R,3′S,6′S)-lutein, (3R,3′S,6′R)-lutein, (3R,3′R,6′S)-lutein, (3S,3′S,6′S)-lutein, (3S,3′R,6′R)-lutein, (3S,3′R,6′S)-lutein or (3S,3′S,6′R)-lutein, or a combination thereof. In some embodiments, the compound of Formula (III) is (3R)-3-hydroxy-(β-ionylideneethyl)triphenylphosphonium salt or (3S)-3-hydroxy-(β-ionylideneethyl)triphenylphosphonium salt. In some embodiments, the triphenylphosphonium salt is a fluoride, chloride, bromide or iodide salt.
In one embodiment, the compound having the Formula II is prepared by deprotecting a compound having the Formula (IV):
to obtain the compound having the Formula II, wherein R 1 and R 2 are independently a branched C 1 -C 7 alkyl, a straight chain C 1 -C 7 alkyl, or taken together form a 5-7 membered ring. In some embodiments, R 1 and R 2 are independently C 1 -C 7 alkyl. In some embodiments, R 1 and R 2 are methyl. In some embodiments, the compound having the Formula (IV) is deprotected under mild acidic conditions without loss of optical purity. In some embodiments, the compound having the Formula (II) is (3R,6R)-3-hydroxy-12′-apo-ε-caroten-12′-al (6), (3S,6S)-3-hydroxy-12′-apo-ε-caroten-12′-al (7), (3S,6R)-3-hydroxy-12′-apo-ε-caroten-12′-al (8) or (3R,6S)-3-hydroxy-12′-apo-ε-caroten-12′-al (9), or a combination thereof. In some embodiments:
(i) (3R,6R)-3-hydroxy-12′-apo-ε-caroten-12′-al dimethylacetal (10) is deprotected to form (3R,6R)-3-hydroxy-12′-apo-ε-caroten-12′-al (6), (ii) (3S,6S)-3-hydroxy-12′-apo-ε-caroten-12′-al dimethylacetal (11) is deprotected to form 3S,6S)-3-hydroxy-12′-apo-ε-caroten-12′-al (7); (iii) (3S,6R)-3-hydroxy-12′-apo-ε-caroten-12′-al dimethyl acetal (12) is deprotected to form (3S,6R)-3-hydroxy-12′-apo-ε-caroten-12′-al (8) or (iv) (3R,6S)-3-hydroxy-12′-apo-ε-caroten-12′-al dimethylacetal (13) is deprotected to form (3R,6S)-3-hydroxy-12′-apo-ε-caroten-12′-al (9).
In one embodiment, a compound having the Formula (IV) is prepared by elongating a compound having the Formula V:
with a compound having the Formula VI:
via Wittig coupling to obtain the compound having the Formula IV, where X ⊖ is an anionic counterion such as Cl − , Br − or I − , wherein R 3 and R 4 are independently a branched C 1 -C 7 alkyl, a straight chain C 1 -C 7 alkyl, or taken together form a 5-7 membered ring. In some embodiments, R 1 and R 2 are independently C 1 -C 7 alkyl. In some embodiments, R 1 and R 2 are methyl. In some embodiments, the compound having the Formula (IV) is protected C 25 -hydroxyaldehyde 10, 11, 12, or 13, or a combination thereof. In some embodiments, the compound having the Formula (VI) is (all-E)-(7-formyl-2-methyl-2,4,6-octatrienyl)triphenylphosphonium salt. In some embodiments, the triphenylphosphonium salt is a chloride, bromide or iodide salt. In another embodiment:
(i) (all-E)-(7-formyl-2-methyl-2,4,6-octatrienyl)triphenylphosphonium salt is reacted with (7E,9E,3R,6R)-3-hydroxy-α-ionylideneacetaldehyde (15) to obtain protected C 25 -hydroxyaldehyde 10; (ii) (all-E)-(7-formyl-2-methyl-2,4,6-octatrienyl)triphenylphosphonium salt is reacted with (7E,9E,3S,6S)-3-hydroxy-α-ionylideneacetaldehyde (16) to obtain protected C 25 -hydroxyaldehyde 11; (iii) (all-E)-(7-formyl-2-methyl-2,4,6-octatrienyl)triphenylphosphonium salt is reacted with (7E,9E,3S,6R)-3-hydroxy-α-ionylideneacetaldehyde (17) to obtain protected C 25 -hydroxyaldehyde 12; or (iv) (all-E)-(7-formyl-2-methyl-2,4,6-octatrienyl)triphenylphosphonium salt is reacted with (7E,9E,3R,6S)-3-hydroxy-α-ionylideneacetaldehyde (18) to obtain protected C 25 -hydroxyaldehyde 13.
In one embodiment, the compound having the Formula V:
is prepared by reacting the cyano group of a compound having the Formula VII:
with a reducing agent to obtain the compound having the Formula V. In some embodiments, the compound having the Formula (V) is C 15 -hydroxyaldehyde 15, 16, 17 and 18, or a combination thereof. In some embodiments, the compound having the Formula (VII) is (3R,6R)-3-hydroxy-α-ionylideneacetonitrile (19), (3S,6S)-3-hydroxy-α-ionylideneacetonitrile (20), (3S,6R)-3-hydroxy-α-ionylideneacetonitrile (21) or (3R,6S)-3-hydroxy-α-ionylideneacetonitrile (22), or a combination thereof.
In one embodiment, a mixture of C 15 -hydroxynitriles (3R,6R)-3-hydroxy-α-ionylideneacetonitrile (19), (3S,6S)-3-hydroxy-α-ionylideneacetonitrile (20), (3S,6R)-3-hydroxy-α-ionylideneacetonitrile (21) and (3R,6S)-3-hydroxy-α-ionylideneacetonitrile (22) is reduced with diisobutylaluminum hydride (DIBAL-H), to obtain a mixture of C 15 -hydroxyaldehydes 15, 16, 17 and 18.
In some embodiments, a mixture of C 15 -hydroxyaldehydes 15, 16, 17 and 18 is separated by using a combination of column chromatography and enzyme-mediated acylation. In some embodiments, a mixture of C 15 -hydroxyaldehydes 15 and 16 is separated from the mixture of C 15 -hydroxyaldehyde 15, 16, 17 and 18 by column chromatography using a combination of a hydrocarbon solvent selected from the group consisting of pentane, hexane, heptane and cyclohexane, and ethyl acetate or acetone, to obtain a mixture of C 15 -hydroxyaldehydes 15 and 16. In some embodiments, the column chromatography is carried out on n-silica.
In some embodiments, the mixture of C 15 -hydroxyaldehydes 15 and 16 is acylated with lipase AK ( Pseudomonas fluorescens ) or lipase PS ( Pseudomonas cepacia ) in the presence of an acyl donor such as vinyl acetate, wherein C 15 -hydroxyaldehyde 16 is converted to (3S,6S)-3-acetoxy-α-ionylideneacetaldehyde (25) while C 15 -hydroxyaldehyde 15 remains unesterified. In some embodiments, C 15 -acetoxyaldehyde 25 is saponified with alcoholic potassium hydroxide (KOH) or sodium hydroxide (NaOH) to obtain C 15 -hydroxyaldehyde 16.
In some embodiments, a mixture of C 15 -hydroxyaldehydes 17 and 18 is separated from the mixture of C 15 -hydroxyaldehyde 15, 16, 17 and 18 by column chromatography using a combination of a hydrocarbon solvent selected from the group consisting of pentane, hexane, heptane and cyclohexane, and ethyl acetate or acetone, to obtain a mixture of C 15 -hydroxyaldehydes 17 and 18. In some embodiments, the column chromatography is carried out on n-silica. In some embodiments, the mixture of C 15 -hydroxyaldehydes 17 and 18 is acylated with lipase AK ( Pseudomonas fluorescens ) or lipase PS ( Pseudomonas cepacia ) in the presence of an acyl donor such as vinyl acetate, wherein C 15 -hydroxyaldehyde 17 is converted to (3S,6R)-3-acetoxy-α-ionylideneacetaldehyde (26) while C 15 -hydroxyaldehyde 18 remains unesterified. In some embodiments, C 15 -acetoxyaldehyde 26 is saponified with alcoholic potassium hydroxide (KOH) or sodium hydroxide (NaOH) to obtain C 15 -hydroxyaldehyde 17.
In one embodiment, the ketone group of a compound having the Formula (VIII):
is reacted with a reducing agent, to obtain the compound having the Formula (VII):
In some embodiments, the reducing agent is stereoselective. In some embodiments, a compound having the Formula (VIII) is (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) or (7E,9Z)-3-keto-α-ionylideneacetonitrile (23b), or a combination thereof. In some embodiments, the compound having the Formula (VII) is (3R,6R)-3-hydroxy-α-ionylideneacetonitrile (19), (3S,6S)-3-hydroxy-α-ionylideneacetonitrile (20), (3S,6R)-3-hydroxy-α-ionylideneacetonitrile (21) or (3R,6S)-3-hydroxy-α-ionylideneacetonitrile (22), or a combination thereof.
In some embodiments, (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) is stereoselectively reduced with a reducing agent to obtain (3,6-trans)-C 15 -hydroxynitriles 19+20 and (3,6-cis)-C 15 -hydroxynitriles 21+22 in a ratio ranging from 6:1 to 1:6. In some embodiments, the reducing agent is NaBH 4 , NaBH 4 /dl-tartaric acid, NaBH 4 /d-tartaric acid, NaBH 4 /l-tartaric acid, NaBH 4 /dibenzoyl-d-tartaric acid, NaAlH 2 (OCH 2 CH 2 OMe) 2 (RED-AL™), LiB[CHMeCH 2 CH 3 ] 3 H (L-SELECTRIDE™), NaB[CHMeCH 2 CH 3 ] 3 H(N-SELECTRIDE™), KB[CHMeCH 2 CH 3 ] 3 H (K-SELECTRIDE™), KB[CHMeCHMe 2 ] 3 H (KS-SELECTRIDE™), BH 3 /(R)-2-methyl-CBS-oxazaborolidine, or BH 3 /(S)-2-methyl-CBS-oxazaborolidine.
In some embodiments, ketonitrile 23a is selectively reduced with KB[CHMeCH 2 CH 3 ] 3 H (K-SELECTRIDE™) to obtain (3,6-trans)-C 15 -hydroxynitriles 19+20 as the major products and (3,6-cis)-C 15 -hydroxynitriles 21+22 as the minor products.
In some embodiments, ketonitrile 23a is selectively reduced with BH 3 /(R)-2-methyl-CBS-oxazaborolidine to obtain (3,6-cis)-C 15 -hydroxynitriles 21+22 as the major products and (3,6-trans)-C 15 -hydroxynitriles 19+20 as the minor products. In some embodiments, ketonitrile 23a is reduced to obtain a mixture of C 15 -hydroxyaldehydes 15, 16, 17 and 18 by (i) reducing (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) with a metal hydride reagent to form a mixture of C 15 -hydroxynitriles 19, 20, 21 and 22 and (ii) reducing the mixture of C 15 -hydroxynitriles 19, 20, 21 and 22 with DIBAL-H to obtain a mixture of C 15 -hydroxyaldehydes 15, 16, 17 and 18 in a one-pot reaction. In some embodiments, the metal hydride reagent is NaAlH 2 (OCH 2 CH 2 OMe) 2 (RED-AL™) LiB[CHMeCH 2 CH 3 ] 3 H (L-SELECTRIDE™), NaB[CHMeCH 2 CH 3 ] 3 H(N-SELECTRIDE™), KB[CHMeCH 2 CH 3 ] 3 H (K-SELECTRIDE™) or KB[CHMeCHMe 2 ] 3 H (KS-SELECTRIDE™).
In one embodiment, a compound having the Formula (VIII):
is prepared by reacting a compound having the Formula (IX):
with an oxidizing agent, to obtain the compound having the Formula (VIII) via allylic oxidation. In some embodiments, the compound having the Formula (IX) is (7E,9E)-α-ionylideneacetonitrile (24a) or (7E,9Z)-α-ionylideneacetonitrile (24b), or a mixture thereof. In some embodiments, the compound having the Formula (VIII) is (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) or (7E,9Z)-3-keto-α-ionylideneacetonitrile (23b), or a combination thereof.
In some embodiments, a mixture of (7E,9E)-α-ionylideneacetonitrile (24a) and (7E,9Z)-α-ionylideneacetonitrile (24b) in an isomeric ratio ranging from 3:1 to 12:1 is reacted with an oxidizing reagent, to obtain a mixture of (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) and (7E,9Z)-3-keto-α-ionylideneacetonitrile (23b) in an isomeric ratio ranging from 3:1 to 12:1.
In some embodiments, a mixture of (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) and (7E,9Z)-3-keto-α-ionylideneacetonitrile (23b) is purified by separating a mixture of ketonitrile 23a and ketonitrile 23b via crystallization with an alcohol such as ethanol, at a temperature ranging from −15 to 0° C.
In some embodiments, the compound having the Formula (IX) is a mixture of (7E,9E)-α-ionylideneacetonitrile (24a) and (7E,9Z)-α-ionylideneacetonitrile (24b) in an isomeric ratio ranging from 3:1 to 12:1 is oxidized with a combination of tert-BuOOH (TBHP) and bleach (5.25% NaOCl), at a temperature ranging from −5 to 0° C., in a solvent selected from the group consisting of acetonitrile (CH 3 CN), methylene chloride (CH 2 Cl 2 ), ethyl acetate, hexane, tetrahydrofuran (THF), tert-butyl methyl ether (TBME), dimethylformamide (DMF), dimethylsulfoxide (DMSO), ethylene glycol, a straight chain C 1 -C 5 alcohol and a branched C 1 -C 5 alcohol, to obtain the compound having the Formula (VIII) as a mixture of (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) and (7E,9Z)-3-keto-α-ionylideneacetonitrile (23b).
In some embodiments, the compound having the Formula (IX) is a mixture of (7E,9E)-α-ionylideneacetonitrile (24a) and (7E,9Z)-α-ionylideneacetonitrile (24b) in an isomeric ratio ranging from 3:1 to 12:1 and is oxidized with a combination of tert-BuOOH (TBHP) and Pd/C at a temperature ranging from 0° C. to room temperature (R.T.), in a solvent selected from the group consisting of acetonitrile (CH 3 CN), methylene chloride (CH 2 Cl 2 ), ethyl acetate, hexane, tetrahydrofuran (THF), tert-butyl methyl ether (TBME), dimethylformamide (DMF), dimethylsulfoxide (DMSO), ethylene glycol, a straight chain C 1 -C 5 alcohol and a branched C 1 -C 5 alcohol, to obtain the compound having the Formula (VIII) as a mixture of (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) and (7E,9Z)-3-keto-α-ionylideneacetonitrile (23b).
In some embodiments, a compound having the Formula (IX):
by condensing a compound having the Formula (X):
with cyanoacetic acid to obtain the compound having the Formula (IX). In some embodiments, the compound having the Formula (IX) is (7E,9E)-α-ionylideneacetonitrile (24a) or (7E,9Z)-α-ionylideneacetonitrile (24b), or a combination thereof. In some embodiments, the compound having the Formula (X) is (rac)-α-ionone.
In one embodiment, (rac)-α-ionone is condensed with cyanoacetic acid in the presence of an amine such as cyclohexylamine, at a temperature ranging from 80° C. to 100° C., to obtain (7E,9E)-α-ionylidene-acetonitrile (24a) and (7E,9Z)-α-ionylideneacetonitrile (24b) in a ratio of 12:1 or greater. In some embodiments, the mixture of nitriles 24a and 24b in an isomeric ratio of 12:1 or greater is purified by vacuum distillation, wherein the isomeric ratio of 24a and 24b is unaltered.
In one embodiment, (rac)-3-keto-α-ionone is prepared by reacting (rac)-α-ionone with an oxidizing agent to obtain (rac)-3-keto-α-ionone.
In some embodiments, (rac)-α-ionone is reacted with a combination of tert-BuOOH (TBHP) and bleach, at a temperature ranging from −5 to 0° C., in a solvent selected from the group consisting of acetonitrile (CH 3 CN), methylene chloride (CH 2 Cl 2 ), ethyl acetate, hexane, tetrahydrofuran (THF), tert-butyl methyl ether (TBME), dimethylformamide (DMF), dimethylsulfoxide (DMSO), ethylene glycol, a straight chain C 1 -C 5 alcohol and a branched C 1 -C 5 alcohol, to obtain to (rac)-3-keto-α-ionone.
In some embodiments, (rac)-α-ionone is reacted with a combination of tert-BuOOH (TBHP) and Pd/C, at a temperature ranging from 0° C. to room temperature (R.T.), in a solvent selected from the group consisting of acetonitrile (CH 3 CN), methylene chloride (CH 2 Cl 2 ), ethyl acetate, hexane, tetrahydrofuran (THF), tert-butyl methyl ether (TBME), dimethylformamide (DMF), dimethylsulfoxide (DMSO), ethylene glycol, a straight chain C 1 -C 5 alcohol and a branched C 1 -C 5 alcohol, to obtain to (rac)-3-keto-α-ionone. In some embodiments, ketonitriles 23a and 23b are prepared by condensing (rac)-3-keto-α-ionone with (EtO) 2 P(O)CH 2 CN or (iso-PrO) 2 P(O)CH 2 CN in the presence of a base to obtain ketonitriles 23a and 23b.
In one embodiment, a compound of the Formula XII is prepared by oxidatively degrading a compound having the Formula XI:
with an oxidizing agent, to obtain a compound of the Formula XII:
and a compound of the Formula XIII:
In some embodiments, the compound having the Formula (XI) is (3R,3′R,6′R)-lutein diacetate, (3R,3′S,6′S)-lutein diacetate, (3R,3′S, 6′R)-lutein diacetate, (3R,3′R,6′S)-lutein diacetate, (3S,3′S,6′S)-lutein diacetate, (3S,3′R,6′R)-lutein diacetate, (3S,3′R,6′S)-lutein diacetate or (3S,3′S,6′R)-lutein diacetate or a combination thereof.
In some embodiments, (3R,6R)-3-hydroxy-13-apo-ε-caroten-13-one (27) and (3R)-3-hydroxy-13-apo-β-caroten-13-one (28) are prepared by oxidatively degrading (3R,3′R,6′R)-lutein diacetate with tert-BuOOH (TBHP) and bleach, at a temperature ranging from −5° C. to room temperature (R.T.), in a solvent selected from the group consisting of acetonitrile (CH 3 CN), methylene chloride (CH 2 Cl 2 ), ethyl acetate, hexane, tetrahydrofuran (THF), tent-butyl methyl ether (TBME), dimethylformamide (DMF), dimethylsulfoxide (DMSO), a straight chain C 1 -C 5 alcohol and a branched C 1 -C 5 alcohol to obtain (3R,6R)-3-hydroxy-13-apo-ε-caroten-13-one (27) and (3R)-3-hydroxy-13-apo-β-caroten-13-one (28).
BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES
FIG. 1 is a schematic representation of the total synthesis of dietary (3R,3′R,6′R)-lutein according to the published procedure by Mayer and Ruttimann ( Helv. Chim Acta, 1980, vol. 63, pp. 1451-1455).
FIG. 2 is a schematic representation of the retrosynthesis of four stereoisomers of lutein from (rac)-α-ionone (the cartenoid numbering system has been used for all end-group precursors of luteins).
FIG. 3 is a schematic representation of the synthesis of (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 19-22 from (rac)-α-ionone (the cartenoid numbering system has been used for all end-group precursors of luteins).
FIG. 4 is a schematic representation of the synthesis and separation of optically pure C 15 -hydroxyaldehydes 15-18 employed as precursors for the total synthesis of stereoisomer luteins (the cartenoid numbering system has been used for all end-group precursors of lutein).
FIG. 5 is a schematic representation of the synthesis of lutein 1-4 from hydroxyaldehydes 15-18.
FIG. 6 is the schematic representation of the oxidative degradation of (3R,3′R,6′R)-lutein diacetate to C 18 -ketones 27 and 28.
DETAILED DESCRIPTION OF THE INVENTION
All chemicals and reagents were commercially available and obtained from Aldrich Chemical Co. (St. Louis, Mo.). Lipase AK ( pseudomonas fluorescens ) and Lipase PS ( Pseudomonas cepacia ) were from Amano Enzyme USA (Lombard, Ill.). All carotenoids and their precursors were fully characterized by 1 H and 13 C-NMR, MS, and UV-Vis, and circular dichroism (CD). Combination of NMR and CD was employed to assign the relative and absolute stereochemistry of all synthetic carotenoids and their precursors. The purity of all compounds was determined by HPLC on a silica-based nitrile bonded column (hexane, 75%; CH 2 Cl 2 25%; MeOH, 0.5%; 0.7 mL/min) and a chiral HPLC [amylose tris-(3,5-dimethylphenylcarbamate)] column was employed to assess the optical purity of stereoisomers. The absolute configurations of C 15 -hydroxynitriles 19-22 and C 1s -hydroxyaldehydes 15-18 were unequivocally established by comparison of their NMR and CD spectra with those of (3R,6R)-3-hydroxy-13-apo-ε-caroten-13-one which was prepared from oxidative degradation of naturally occurring (3R,3′R,6′R)-lutein.
Synthesis of (7E,9E)-3-Keto-α-ionylideneacetonitrile (23a) from (rac)-α-Ionone. In one embodiment of the present invention, HWE reaction of commercially available (rac)-α-ionone with diethyl cyanomethylphosphonate in dry tert-butyl methyl ether (TBME) or tetrahydrofuran (THF) using NaH or NaOMe/MeOH as base gave (7E,9E)-nitrile 24a (75%) and (7E,9Z)-nitrile 24b (25%) in 74% isolated yield after distillation (Route 1, FIG. 3 ). Alternatively, diisopropyl cyanomethylphosphonate could also be used with similar results. A mixture of nitriles 24a and 24b was then oxidized with tert-BuOOH (TBHP, 70% in water), household bleach, and catalytic amounts of K 2 CO 3 in acetonitrile at −5 to 0° C. to yield ketonitriles 23a (75%) and 23b (25%). After purification by chromatography, a mixture of these nitriles was obtained in 57% yield. This mixture was crystallized from ethanol at −15° C. to give the (7E,9E)-ketonitrile 23a as a white crystal free from 23b in 37% isolated yield. While this reaction can be carried out in other solvents such as ethyl acetate, ethylene glycol, and hexane, the highest isolated yield of 57% was obtained with acetonitrile and ethanol. This water-based oxidation system, using household laundry bleach and aqueous TBHP, has been shown to convert steroidal olefins to α,β-enones by an economical and environmentally friendly methodology (Marwah, Green Chem., 2004, 6, 570-577). Ketonitriles 23a and 23b were also prepared in 53% yield by palladium(II)-mediated oxidation of nitriles 24a and 24b with TBHP in dichloromethane (CH 2 Cl 2 ) at 0° C. similar to a methodology that has been employed for allylic oxidation of olefins (Yu and Corey, Org. Lett. 2002, 4: 2727-2730). However to date, there are no literature reports on the direct oxidation of nitriles 24a and 24b to ketonitriles 23a and 23b. These oxidation reactions clearly revealed that conversion of a mixture of 24a/24b to 23a/23b is not accompanied by E/Z-isomerization and the isomeric ratio of these nitriles remains unchanged. As mentioned earlier, the reduction of a mixture of ketonitriles 23a and 23b can yield a complicated mixture of (7E,9E)- and (7E,9Z)-hydroxynitriles 19-22 that would be difficult to separate in high optical purity ( FIG. 3 ). Therefore, an alternative process was needed that could preferably provide 23a or its precursor 24a as a single isomer. It has been previously shown that Knoevenagel condensation of 13-ionone with cyanoacetic acid in boiling pyridine (115° C.) in the presence of catalytic amounts of piperidinium acetate affords 13-ionylideneacetonitrile in 75% yield, predominantly as the (7E,9E)-isomer (Andriamialisoa et al. Tetrahedron Lett., 1993, 34: 8091-8092). However, in this literature report, the isomeric ratio of (7E,9E)/(7E,9Z) was not specified. When we applied the reported reaction conditions employed with β-ionone to condensation of (rac)-α-ionone with cyanoacetic acid, no reaction was observed. After examining this reaction with a number of organic amines, we discovered that cyclohexylamine could promote this reaction under mild conditions to give a high yield of (7E,9E)-α-ionylideneacetonitrile (24a) (Route 2, FIG. 3 ).
Therefore, in a preferred embodiment, Knoevenagel condensation of (rac)-α-ionone (1 eq) with cyanoacetic acid (1.3 eq) in cyclohexylamine (3 eq), also used as solvent, at 80-85° C. after 3.5 h affords 24a (92%) and 24b (8%) as a colorless oil in 75% isolated yield after distillation. Another reported method for the synthesis of α-ionylideneacetonitrile and β-ionylideneacetonitrile, involves condensation of α-ionone or β-ionone with methyl cyanoacetate in the presence of glacial acetic acid, acetamide, and ammonium acetate to yield the corresponding methyl α-ionylidenecyanoacetate or methyl β-ionylidenecyanoacetate (Young et al. J. Am. Chem. Soc., 1944, 66: 520-524). These esters were then saponified to their corresponding α- or β-ionylidenecyanoacetic acid and subsequently decarboxylated to α- or β-ionylideneacetonitrile. Due to the old nature of this publication and lack of sophisticated analytical methods in 1944, the ratio of (7E,9E)/(7E,9Z) isomers in these nitriles were not reported.
In the following step, the mixture of 24a:24b=92%:8% (1 eq) and K 2 CO 3 (0.1 eq) in acetonitrile (16 eq) was oxidized with tert-BuOOH (TBHP, 70% in water, 7 eq) and household bleach containing 5.25% NaOCl (2 eq of NaOCl) at −5 to 0° C. under nitrogen to yield ketonitriles 23a (92%) and 23b (8%). After extraction with ethyl acetate (EtOAc), the product was then purified by column chromatography (n-Silica) employing hexane:EtOAc (90%:10 to 70%:30%) to give a mixture of 23a (92%) and 23b (8%) in 53% yield. When this mixture was dissolved in ethanol and cooled down to −15° C., (7E,9E)-ketonitrile 23a was obtained as white crystals in 37% isolated yield and contained no measurable amounts of 23b. Therefore the present invention relates to two novel routes that converts (rac)-α-ionone to a single isomer of (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) in crystalline form via allylic oxidation of α-ionylideneacetonitriles 24a and 24b. Depending on the selected route, the isomeric (7E,9E):(7E,9Z) ratio of nitriles 24a:24b may vary from 75%:25% to 92%:8% (Routes 1 and 2, FIG. 3 ).
In an alternative embodiment (Route 3, FIG. 3 ), (rac)-α-ionone was oxidized to crystalline (rac)-3-keto-α-ionone with TBHP (70% in water), bleach, and catalytic amounts of K 2 CO 3 in ethyl acetate at −5 to 0° C. in 64% isolated yield. The palladium(II)-mediated oxidation of (rac)-α-ionone with TBHP in CH 2 Cl 2 also afforded this ketone as a white crystalline solid in 53% isolated yield. There are three reported procedures for preparation of (rac)-3-keto-α-ionone in the literature. The first procedure employs tert-butyl chromate to oxidize (rac)-α-ionone to (rac)-3-keto-α-ionone in only 14% isolated yield (Prelog and Osgan, Helv. Chim. Acta, 1952, 35: 986-992) and the second uses Ac 2 Co.4H 2 O/NH 4 Br/O 2 to improve the yield to 31% (Widmer et al., Helv. Chim. Acta 1982, 65: 944-57). More recently, another procedure for allylic oxidation of ionone-like dienes with TBHP catalyzed by CaCl 2 and MgCl 2 .6H 2 O at 60° C. has also been reported that can afford (rac)-3-keto-α-ionone in yields comparable to ours (Yang et al. Synlett 2006, 16: 2617-2620).
The HWE reaction of (rac)-3-keto-α-ionone with diethyl cyanomethylphosphonate in TBME or THF gave (rac)-ketonitrile 23a (75%) and 23b (25%) in 81% yield. After purification by flash chromatography and crystallization from ethanol at −15° C., (7E,9E)-ketonitrile 23a was obtained as white crystals in 40% isolated yield. This reaction has been previously reported by Imai et al. to yield a mixture of 23a and 23b as an oil that was not crystallized and the isomeric ratio of these ketonitriles were not reported (Imai, Photochem. Photobiol. 1999, 70: 111-115). Our methodology for the synthesis of ketonitriles 23a and 23b according to the routes 1 and 2, as shown in FIG. 4 , is novel and has not been reported previously. Further, the present invention, for the first time, describes the isolation of (7E,9E)-ketonitrile 23a as a single isomer by crystallization in greater than 98% purity with virtually no contamination from its (7E,9Z)-isomer (23b).
Reduction of (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) to (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 19-22. As shown in FIG. 3 , (7E,9E)-ketonitrile 23a was reduced to four stereoisomeric hydroxynitriles 19-22 with a number of reagents in 92-97% yield and the results are shown in Table 1. Because (3R,6R)-hydroxynitrile 19 with a trans relationship between the OH at C3 and C6-dienenitrile side chain is the precursor of the naturally occurring (3R,3′R,6′R)-lutein (1), it was desirable to increase the composition of the trans-hydroxynitriles 19 and 20 relative to the cis-hydroxynitriles 21 and 22 in the reduction products. The reduction of ketonitrile 23a with NaBH 4 was very sluggish and showed no selectivity with respect to the relative stereochemistry at C3 and C6. This was determined by HPLC analysis of the products employing a silica-based nitrile bonded column that allowed the separation of trans-hydroxynitriles (19+20) from cis-hydroxynitriles (21+22). The reduction products were also monitored by chiral HPLC that allowed the separation of all four stereoisomers of hydroxynitriles 19-22. While the reduction with TIBA was quite efficient even at low temperature (−40° C.), the relative composition of trans-hydroxynitriles (19+20) to cis-hydroxynitriles (21+22) could not be dramatically affected. However, the reduction of ketonitrile 23a with a combination of NaBH 4 and dl-tartaric acid provided trans-hydroxynitriles (19+20) as the major products (75%) and the cis-hydroxynitriles (21+22) as the minor products (25%). The use of enantiomerically pure d- or l-tartaric acid or their 2,3-dibenzoyl derivatives did not improve the stereoselectivity of this reduction. There are only several reported examples of the use of the combination of NaBH 4 and tartaric acid and its derivatives in the reduction of ketones but none of these examples involve the reduction of cyclic α,β-enones (Hirao et al., Agric. Biol. Chem. 1981, 45: 693-697; Adams, Synth. Commun. 1984, 14: 955-959; Yatagai and Ohnuki, J. Chem. Soc. Perkin Trans. 11990, 1826-1828; Cordes et al., Eur. J. Org. Chem. 2005, 24: 5289-5295).
TABLE 1
Reduction of ketonitrile 23a to hydroxynitriles 19-22 with various reagents.
Temperature
(19 + 20):((21 + 22)
Reducing agent
Solvent
(Time, h)
(trans:cis)*
NaBH 4
EtOH:H 2 O
0° C. to R.T.
1:1
1.4:1
(24 h)
Triisobutylaluminum (TIBA)
Toluene
−40° C. to R.T.
2:3
(1 h)
NaBH 4 /dl-Tartaric acid (3/1)
EtOH
−10 to −15° C.
3:1
(2 h)
NaBH 4 /d-Tartaric acid (3/1)
EtOH
−10 to −15° C.
3:1
(2 h)
NaBH 4 /l-Tartaric acid (3/1)
EtOH
−10 to −15° C.
3:1
(2 h)
NaBH 4 /Dibenzoyl-d-
EtOH
−10 to −15° C.
3:1
tartaric acid (3/1)
(2 h)
Sodium bis(2-methoxyethoxy)-
TBME
−5 to 0° C.
1.3:1
aluminum hydride,
(1 h)
NaAlH 2 (OCH 2 CH 2 OMe) 2
(RED-AL ™)
Lithium tri-sec-butylborohydride,
TBME
−30° C.
1.2:1
LiB[CHMeCH 2 CH 3 ] 3 H
(0.5 h)
(L-SELECTRIDE ™)
Sodium tri-sec-butylborohydride,
TBME
−30° C.
2.5:1
NaB[CHMeCH 2 CH 3 ] 3 H
(0.5 h)
(N-SELECTRIDE ™)
Potassium tri-sec-butylborohydride
TBME
−30° C.
6:1
KB[CHMeCH 2 CH 3 ] 3 H
(0.5 h)
(K-SELECTRIDE ™)
Potassium trisiamylborohydride,
TBME
−30 to 0° C.
2.2:1
KB[CHMeCHMe 2 ] 3 H
(2 h)
(KS-SELECTRIDE ™)
BH 3 /(R)-2-methyl-CBS-
TBME
0° C.,
1:6
oxazaborolidine
(1.5 h)
BH 3 /(S)-2-methyl-CBS-
TBME
0° C.,
1:3
oxazaborolidine
(1.5 h)
*Indicates the stereochemical relationship between the hydroxyl group at C3 and the dienenitrile side chain at C6.
The reduction of 23a with sodium bis(2-methoxyethoxy)aluminum hydride (RED-AL™) or lithium tri-sec-butylborohydride (L-SELECTRIDE™) produced essentially the same results and did not show a significant preference for the formation of trans-hydroxynitriles (19+20). However, when sodium tri-sec-butylborohydride (N-SELECTRIDE™) or potassium tri-sec-butylborohydride (K-SELECTRIDE™) were employed as the reducing agents, the relative composition of trans-hydroxynitriles (19+20) to cis-hydroxynitriles (21+22) was 71%:29% and 84%:16%, respectively.
The reduction of 23a with potassium trisiamylborohydride (KS-SELECTRIDE™) did not improve the results obtained with K-SELECTRIDE™ and afforded the trans-hydroxynitriles (19+20, 69%) as the major products and cis-hydroxynitriles (21+22, 31%) as the minor products.
Contrary to the results obtained with K-SELECTRIDE™, the reduction of ketonitrile 23a with BH 3 /(R)-2-methyl-CBS-oxazaborolidine gave cis-hydroxynitriles (21+22) as the major products (86%) and the trans-hydroxynitriles (19+20) as the minor products (14%). When BH 3 /(S)-2-methyl-CBS-oxazaborolidine was used as the reducing agent, the cis-hydroxynitriles (21+22) were still obtained as the major products but the stereoselectivity was not as high as that obtained with the R-isomer of CBS-oxazaborolidine.
Therefore, the present invention relates to a stereoselective method for reducing ketonitrile 23a to hydroxynitriles 19-22 in which the ratio of trans-hydroxynitriles (19+20) to that of cis-hydroxynitriles (21+22) can be controlled by the use of appropriate reducing agents and can vary from 6:1 to 1:6.
Synthesis of optically pure hydroxyaldehydes 15-18 from hydroxynitriles 19-22. In one embodiment of the present invention, a mixture of the four hydroxynitriles 19-22 was reduced with DIBAL-H in dichloromethane to a racemic mixture of hydroxyaldehydes 15-18 in 95% yield. In the following step, a mixture of hydroxyaldehydes 15 and 16 was readily separated from a mixture of hydroxyaldehydes 17 and 18 by column chromatography ( FIG. 4 ). The direct reduction of ketonitrile 23a to hydroxyaldehydes 15-18 could also be accomplished in a one-pot reaction using K-SELECTRIDE™ followed by reduction with DIBAL-H to yield 15+16 (86%) as the major products and 17+18 (14%) as the minor products.
The racemic mixture of hydroxyaldehydes 15 and 16 were separated by enzyme-mediated acylation with lipase AK ( Pseudomonas fluorescens ) in refluxing pentane in the presence of vinyl acetate within 48 h. While hydroxyaldehyde 16 was acylated to acetoxyaldehyde 25, hydroxyaldehyde 15 remained unreacted. Due to their large difference in their solubility properties, 25 and 15 were readily separated by column chromatography. Acetoxyaldehyde 25 was nearly quantitatively hydrolyzed to hydroxyaldehyde 16 with KOH/MeOH at 0° C. to prevent the degradation of this sensitive end-group. According to chiral HPLC, (3R,6R)-3-hydroxy-α-ionylideneacetaldehyde (15) and (3S,6S)-3-hydroxy-α-ionylideneacetaldehyde (16) were obtained in enantiomeric excess (ee) of 94% and 93%, respectively.
Employing this overall strategy, the racemic mixture of hydroxyaldehydes 17 and 18 were similarly resolved by enzyme-mediated acylation with immobilized lipase AK ( Pseudomonas fluorescens ) in refluxing pentane in the presence of vinyl acetate in 50 h. Hydroxyaldehyde 17 underwent acylation to acetoxyaldehyde 26 while hydroxyaldehyde 18 remained unreacted ( FIG. 4 ). Separation of 18 and 26 was readily accomplished by column chromatography. This afforded (3R,6S)-3-hydroxy-α-ionylideneacetaldehyde (18) as a single enantiomer in an ee of 92%. Alkaline hydrolysis of 26 with KOH/MeOH at 0° C., provided (3S,6R)-3-hydroxy-α-ionylideneacetaldehyde (17) in an ee of 91%.
Therefore, all four hydroxyaldehydes 15-18 became accessible in optical purities ranging from 91-94%. These hydroxyaldehydes were subsequently used in the synthesis of the stereoisomeric luteins 1-4 via C 25 -hydroxy-apocarotenals 6-9 as shown in FIG. 5 .
Determination of the absolute configuration of C 15 -hydroxyaldehydes 15-18. In an attempt to determine the absolute configuration of the four C 15 -hydroxyaldehydes 15-18, a model compound in which the stereochemistry at C3 and C6 is known was needed. Such a model compound could be prepared from oxidative cleavage of the polyene chain of naturally occurring (3R,3′R,6′R)-lutein in which the stereochemistry in the ε-end group of this carotenoid at C3′ and C6′ is known to be R. It has been well established that the oxidative cleavage (degradation) of carotenoids results in the formation of numerous ketones, aldehydes, and acids that are known as apocarotenones, apocarotenals, and apocarotenoic acids, respectively. Our overall strategy for the preparation of a model compound by oxidative degradation of (3R,3′R,6′R)-lutein is shown in FIG. 6 . However, prior to oxidative cleavage of (3R,3′R,6′R)-lutein, the two hydroxyl groups in this carotenoid had to be protected. Therefore, (3R,3′R,6′R)-lutein was first acylated with acetic anhydride/Et 3 N/TBME at 50° C. and the resulting (3R,3′R,6′R)-lutein diacetate was then subjected to oxidative degradation with TBHP/bleach. The reaction conditions for this oxidative degradation was similar to those used in oxidation of α-ionylideneacetonitrile (24a/24b) to 3-keto-α-ionylideneacetonitrile (23a/23b) described earlier. The only exception was that after the addition of bleach at 0° C., the reaction mixture was allowed to warm up to ambient temperature and stirred for 3 h to complete the oxidative cleavage of lutein diacetate ( FIG. 6 ).
After alkaline hydrolysis (KOH/MeOH) followed by column chromatography, HPLC analysis of the partially purified product showed the presence of numerous oxidation products of lutein. Among these, (3R,6R)-3-hydroxy-13-apo-ε-caroten-13-one (27) with an ε-end group and (3R)-3-hydroxy-13-apo-β-caroten-13-one (28) with a β-end group were the major stable products. These were isolated by semipreparative HPLC and fully characterized from their NMR, MS, UV-Vis, and CD spectra. Comparison of the CD and NMR spectra of C 18 -ketone 27 with those of the individually purified C 15 -hydroxyaldehydes 15-18 established the absolute configuration of these compounds.
Synthesis of Luteins 1-4 via C 25 -Hydroxy-Apocarotenals 6-9. The transformation of hydroxyaldehydes 15-18 to luteins 1-4 is shown in FIG. 5 . In one embodiment of the present invention, the optically pure C 15 -hydroxyaldehydes 15-18 were first elongated to their corresponding protected C 25 -aldehydes 10-13 by olefination with the protected Wittig salt 14 in the presence of NaOMe/MeOH at ambient temperature. After solvent evaporation and without isolation of the products, the C 25 -acetals 10-13 that were obtained as a mixture of all-E and 11Z were deprotected in dilute aqueous HCl (0.3 N) in acetone to give C 25 -aldehydes 6-9 as a mixture of all-E and 11Z in isolated yields ranging from 75-85%. Under the conditions employed for the deprotection of acetals 10-13, the hydroxyl group at C3 did not undergo epimerization and the optical purities of the resulting C 25 -aldehydes 6-9 were not compromised. This was confirmed by chiral HPLC of the individually synthesized C 25 -aldehydes. The 11Z-isomers of C 25 -aldehydes 6-9 could be catalytically isomerized to their corresponding all-E-isomers in the presence of palladium (II) acetate in refluxing ethyl acetate within 2 h. However, in a simplified process, this step was shown to be unnecessary and the isomerization of the 11Z and 11′Z-bonds that are formed by Wittig coupling reactions could be postponed until after luteins 1-4 were prepared.
As mentioned earlier, the preparation and application of the Wittig salt 14 in the total synthesis of carotenoids has been well documented in the literature but this building block has never been employed for the synthesis of lutein nor it has been applied to the synthesis of its precursors, the C 25 -acetals 10-13 or C 25 -hydroxyaldehydes 6-9.
In the final step of the synthesis of luteins, each of the C 25 -hydroxyaldehydes 6-9 that were prepared as a mixture of all-E and 11Z-isomers were allowed to react with the Wittig salt 5 to yield their corresponding luteins 1-4 as a mixture of all-E and 11Z,11′Z-isomers. Each of the individually prepared E/Z-lutein was then thermally isomerized to its corresponding all-E isomer in a refluxing solution of ethyl acetate within 4 h. The isolated yields of all-E-luteins 1-4 in the final step of this synthesis ranged from 65-74%. The Wittig salt 5 was prepared according to published procedures (Widmer et al., Helv. Chim. Acta, 1990, 73: 861-867; Soukup et al., Helv. Chim. Acta, 1990, 73: 868-873). Similarly, the same strategy described above can also be used to elongate C 25 -hydroxyaldehydes 6-9 with the S-enantiomer of Wittig salt 5 to synthesize the other four stereoisomers of luteins 1-4; these are: (3S,3′S,6′S)-lutein, (3S,3′R,6′R)-lutein, (3S,3′R,6′S)-lutein, and (3S,3′S,6′R)-lutein.
It will be readily apparent to one of ordinary skill in the relevant arts that other suitable modifications and adaptations to the methods and applications described herein are obvious and may be made without departing from the scope of the invention or any embodiment thereof. Having now described the present invention in detail, the same will be more clearly understood by reference to the following examples, which are included herewith for purposes of illustration only and are not intended to be limiting of the invention.
Example 1
Synthesis of (rac)-α-Ionylideneacetonitrile (24a/24b) (Route 1, FIG. 3 )
Methanol (70 mL) was transferred into a 500 mL three-necked flask equipped with a nitrogen inlet, a thermometer, and an addition funnel. The flask was cooled down in an ice bath under N 2 and sodium (5.47 g, 0.238 mol) washed with hexane, was added in small portions by maintaining the temperature below 10° C. After the sodium was completely dissolved, the solution was stirred at R.T. for 15 minutes and then cooled down to 0° C. A solution of diisopropyl cyanomethylphosphonate (47 g of 95% pure, 44.65 g, 0.218 mol) in TBME (20 mL) was added dropwise at 0-5° C. in 20 min. The ice bath was removed and the mixture was allowed to stir at R.T. for 1 h. The reaction mixture was cooled down in an ice bath and freshly distilled rac-α-ionone (38.10 g, 0.198 mol) in TBME (20 mL) was added dropwise in 45 min at 0-5° C. The mixture was allowed to warm up to room temperature and stirred for 4 h under N 2 . The product was quenched with water (100 mL) and the organic layer was removed. The aqueous layer was extracted with TBME (2×50 mL) and the combined organic layer was sequentially washed with brine and water, dried over Na 2 SO 4 , and evaporated to dryness to give 45.4 g of a pale yellow oil. The crude product was purified by fractional distillation to yield a mixture of 24a and 24b (b.p.=107-110° C. at 10 mm) as a colorless oil (31.6 g, 0.147 mol, 74%) which was shown by 1 H- and 13 C-NMR to consist of an isomeric mixture of 7E,9E:7E,9Z=3:1.
Example 2
Oxidation of (rac)-α-Ionylideneacetonitrile (24a/24b) to (rac)-3-Keto-α-Ionylideneacetonitrile (23a/23b) by Bleach and Aqueous TBHP
(rac)-α-Ionylideneacetonitrile (13.15 g, 61.06 mmol) was transferred into a 500 mL three-necked flask using acetonitrile (30 mL, 23.58 g, 0.574 mol). K 2 CO 3 (0.844 g, 6.11 mmol) was added and the mixture was cooled down in an ice-salt bath to 0° C. under N 2 . A 70% solution of TBHP in water (52 mL, 46.8 g 70%≈32.76 g, 0.364 mol) was diluted with acetonitrile (21 mL, 16.51 g, 0.40 mol) and added dropwise to the mixture under N 2 at 0° C. in 30 min. Household bleach containing 5.25% NaOCl (260 g, 13.65 g NaOCl, 0.183 mol) was then added over a period of 5 h at −5 to 0° C. After the addition was completed, the reaction mixture was stirred at 0° C. for an additional hour. The product was extracted with hexane (150 mL) and the organic layer was separated. The water layer was washed with hexane (2×100 mL) and the combined organic layer was washed with water (3×150 mL), dried over Na 2 SO 4 , and evaporated to give 20 g of a yellow oil. The crude product was purified by column chromatography (hexane:ethyl acetate, from 98:2 to 92:8) to yield a mixture of (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) and (7E,9Z)-3-keto-α-ionylideneacetonitrile (23b) (7.92 g, 34.54 mmol, 57%) as a yellow oil. The product was shown by HPLC (silica-based nitrile bonded column) and 1 H- and 13 C-NMR to consist of an isomeric mixture of 7E,9E:7E,9Z=3:1. Crystallization from ethanol at −20° C. gave 23a as a white crystal (5.15 g, 22.46 mmol, 37% isolated yield, m.p.=93-95° C.).
Example 3
Palladium(II)-Mediated Oxidation of (rac)-α-Ionylideneacetonitrile (24a/24b) to (rac)-3-Keto-α-Ionylideneacetonitrile (23a/23b) with Anhydrous TBHP
A solution of (rac)-α-Ionylideneacetonitrile (19.60 g, 91.02 mmol) in dichloromethane (150 mL) in a 500 mL three-necked flask was cooled down in an ice-salt bath to 0° C. under N 2 and was treated with K 2 CO 3 (8.4 g, 60.78 mmol) and Pd/C (10 wt. % on C, 7.5 g˜0.75 g Pd, 7.05 mmol). A 5.5 M anhydrous solution of TBHP in decane (100 mL, 0.55 mol) was added to the mixture dropwise while maintaining the temperature at 0° C. The mixture was stirred for 36 h at 0° C. and 50 h at R.T. under N 2 . The solids were removed by filtration through celite and the filtrate was washed with water (3×150 mL), brine, and dried over Na 2 SO 4 . The solvent was removed under reduced pressure to give 24 g of a yellow oil. The crude product was purified by column chromatography (hexane:ethyl acetate, from 98:2 to 92:8) to yield a mixture of 23a and 23b (11.05 g, 48.18 mmol, 53%) as a yellow oil. The product was shown by HPLC and 1 H- and 13 C-NMR to consist of an isomeric mixture of 7E,9E:7E,9Z=3:1. Crystallization from ethanol at −20° C. gave the (7E,9E)-isomer (23a) as a white crystal (6.00 g, 26.20 mmol, 29% isolated yield).
Example 4
Synthesis of (rac)-α-Ionylideneacetonitrile (24a/24b) by Condensation of α-Ionone with Cyanoacetic Acid (Route 2, FIG. 3 )
Freshly distilled rac-α-ionone (32.0 g, 0.166 mol) was transferred into a 250 mL three necked flask using cyclohexylamine (55 mL, 47.63 g, 480 mmol). Cyanoacetic acid (17.85 g, 210 mmol) was added and the mixture was heated at 80-85° C. under N 2 . After 3.5 h, the mixture was allowed to cool down to room temperature and the product was partitioned between hexane (150 mL) and water (150 mL). The organic layer was removed and the aqueous layer was extracted with hexane (50 mL). The combined organic layer was washed with water (3×200 mL), dried over Na 2 SO 4 , and evaporated to dryness to give 33.9 g of a pale yellow oil. The crude product was purified by fractional distillation to yield a mixture of 24a and 24b (b.p.=105-110° C. at 10 mm) as a colorless oil (26.66 g, 0.124 mol, 75%) that was shown by 1 H- and 13 C-NMR as well as HPLC to consist of 24a (92%) and 24b (8%) [ratio of isomeric mixture: 7E,9E:7E,9Z=11.5:1].
Example 5
Oxidation of (rac)-α-Ionylideneacetonitrile (24a:24b=11.5:1) to (7E,9E)-3-Keto-α-Ionylideneacetonitrile (23a) by Bleach and Aqueous TBHP
(rac)-α-Ionylideneacetonitrile (26.66 g, 123.8 mmol; 24a:24b=11.5:1) was transferred into a 1 L three-necked flask using acetonitrile (103 mL, 80.96 g, 1.97 mol). K 2 CO 3 (1.71 g, 12.37 mmol) was added and the mixture was cooled down in an ice-salt bath to 0° C. under N 2 . A 70% solution of TBHP in water (124 mL, 111.6 g 70%≈78.12 g, 867 mmol) was added dropwise to the mixture under N 2 at 0° C. in 30 min. Household bleach containing 5.25% NaOCl (386 g, 20.27 g NaOCl, 272.3 mmol) was then added over a period of 8 h at −5 to 0° C. After the addition was completed, the reaction mixture was stirred at 0° C. for an additional hour. The product was extracted with hexane (200 mL) and the organic layer was separated. The water layer was washed with hexane (2×100 mL) and the combined organic layer was washed with water (3×200 mL), dried over Na 2 SO 4 , and evaporated to give 36.7 g of a yellow oil. The crude product was purified by column chromatography (hexane:ethyl acetate, from 98:2 to 92:8) to yield a mixture of (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) and (7E,9Z)-3-keto-α-ionylideneacetonitrile (23b) (15.05 g, 65.63 mmol, 53%) as a yellow oil. The product was shown by HPLC (silica-based nitrile bonded column) and 1 H NMR to consist of 23a (92%) and 23b (8%) [ratio of isomeric mixture: 7E,9E:7E,9Z=11.5:1]. Crystallization from ethanol at −20° C. gave 23a as a white crystal (10.5 g, 45.79 mmol, 37% isolated yield, m.p.=93-95° C.).
Example 6
Oxidation of (rac)-α-Ionone to (rac)-3-Keto-α-Ionone by Bleach and Aqueous TBHP (Route 3, FIG. 3 )
Freshly distilled (rac)-α-ionone (20.00 g, 104.0 mmol) was transferred into a 500 mL three-necked flask using EtOAc (103 mL, 92.08 g, 1.05 mol). K 2 CO 3 (1.44 g, 10.42 mmol) was added and the mixture was cooled down in an ice-salt bath to 0° C. under N 2 . A 70% solution of TBHP in water (89 mL, 80.1 g 70%≈56.07 g, 0.622 mol) was added dropwise to the mixture under N 2 at 0° C. in 30 min. Household bleach containing 5.25% NaOCl (295 g, 15.49 g NaOCl, 0.208 mol) was then added over a period of 5 h at −5 to 0° C. After the addition was completed, the reaction mixture was stirred at 0° C. for an additional hour. The organic layer was removed and the water layer was washed with EtOAc (2×100 mL). The combined organic layer was washed with water (2×150 mL), dried over Na 2 SO 4 , and evaporated to give 26.8 g of a yellow oil. The crude product was purified by column chromatography (hexane:acetone, from 98:2 to 92:8) to yield (rac)-3-keto-α-ionone (13.70 g, 66.41 mmol, 64%).
Example 7
Palladium(II)-Mediated Oxidation of (rac)-α-Ionone to (rac)-3-Keto-α-Ionone with Anhydrous TBHP (Route 3, FIG. 3 )
Freshly distilled (rac)-α-ionone (1.00 g, 5.20 mmol) in dichloromethane (10 mL) was cooled down in an ice-salt bath to 0° C. under N 2 and was treated with K 2 CO 3 (0.180 g, 1.30 mmol) and Pd/C (10 wt. % on C, 0.150 g˜15 mg Pd, 0.14 mmol). A 5.5 M anhydrous solution of TBHP in decane (5 mL, 27.5 mmol) was added to the mixture at 0° C. The mixture was stirred for 24 h at 0° C. and 12 h at R.T. under N 2 . The solids were removed by filtration through celite and the filtrate was washed with water (3×20 mL), brine, and dried over Na 2 SO 4 . The solvent was removed under reduced pressure to give 1.3 g of a yellow oil. The crude product was purified by column chromatography (hexane:ethyl acetone, from 98:2 to 92:8) to yield (rac)-3-keto-α-ionone (0.57 g, 2.76 mmol, 53%).
Example 8
Synthesis of (rac)-3-Keto-α-Ionylideneacetonitrile (23a/23b) from (rac)-3-Keto-α-Ionone
Sodium hydride (0.427 g of 60% suspension in oil ≈0.256 g, 10.67 mmol) was placed in a three-necked flask equipped with a nitrogen inlet and a thermometer and washed with hexane (2×10 mL). TBME (30 ml) was added and the mixture was cooled to 0° C. Diethyl cyanomethylphosphonate (0.964 g of 98% pure, 0.945 g, 5.33 mmol) in 10 mL TBME was added to the suspension at 5-10° C. under N 2 and the mixture was allowed to stir at R.T. for 1 h. The reaction mixture was cooled down in an ice bath and (rac)-3-keto-ionone (1 g, 4.85 mmol) in 10 mL TBME was added dropwise in 30 min at 0-5° C. After stirring for 6 hours at R.T., the reaction was quenched with water and the organic layer was removed. The aqueous layer was extracted with TBME (2×20 mL). The combined organic layer was washed with water, dried over Na 2 SO 4 , and evaporated to dryness. The crude product (1.1 g) was purified by column chromatography (hexane:acetone, from 98:2 to 95:5) to yield a mixture of 23a and 23b (0.9 g, 3.92 mmol, 81%) as a pale yellow oil. The product was shown by HPLC as well as 1 H- and 13 C-NMR to consist of 23a (75%) and 23b (25%) [ratio of isomeric mixture: 7E,9E:7E,9Z=3:1].
Example 9
Reduction of (7E,9E)-3-Keto-α-Ionylideneacetonitrile (23a) to (7E,9E)-3-Hydroxy-α-Ionylideneacetonitrile (19-22) with NaBH 4
To a solution of (7E,9E)-3-keto-α-ionylideneacetonitrile (2 g, 8.72 mmol) in 20 mL ethanol and 15 mL water was added NaBH 4 (0.66 g, 17.45 mmol) at 0° C. The mixture was allowed to warm up to room temperature, stirred for 24 h, and the product was partitioned between water (30 mL) and ethyl acetate (50 mL). The organic layer was removed and the aqueous layer was extracted with 30 mL of ethyl acetate. The combined organic layer was washed with brine and water, dried over Na 2 SO 4 , and evaporated to dryness. The crude product was purified by column chromatography (hexane:acetone=97:3) to afford 3-hydroxy-α-ionylideneacetonitriles 19-22 (1.95 g, 8.43 mmol, 97%) as a colorless oil. A mixture of 19+20 was separated from 21+22 by semipreparative HPLC and was fully characterized by 1 H and 13 C NMR as well as mass spectrometry and UV-visible spectrophotometry. The isomeric ratio of (19+20):(21+22)=1:1 was established by normal phase HPLC (silica-based nitrile bonded column) of the mixture. Hydroxynitriles 19+20 and 21+22 were each shown by chiral HPLC (hexane, 95%; 2-propanol, 5%; CH 3 CN, 0.75%) to consist of an approximately 1:1 mixture of enantiomers.
Example 10
Reduction of (7E,9E)-3-Keto-α-Ionylideneacetonitrile (23a) to (7E,9E)-3-Hydroxy-α-Ionylideneacetonitrile (19-22) with Triisobutylaluminum (TIBA)
A solution of (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) (148 mg, 0.65 mmol) in toluene (10 mL) was cooled down to −40° C. under N 2 and a solution of triisobutylaluminum (3 mL of 1M in toluene, 3 mmol) was added. The course of the reaction was monitored by HPLC. The mixture was allowed to warm up to R.T. and stirred for 1 h. The reaction was quenched by adding a dilute aqueous solution of HCl (0.5 mL, 5% v/v) followed by water (10 mL). The product was diluted with TBME (10 mL) and washed sequentially with brine and water. The organic layer was dried over Na 2 SO 4 and evaporated to dryness. The product (143 mg, 0.62 mmol, 95%) was shown by HPLC to consist of two fractions which were separated by semipreparative HPLC and identified in the order of chromatographic elution (silica-based nitrile bonded column) as (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 19+20 (40%) and (7E,9E)-3-hydroxy-α-ionylidene-acetonitriles 21+22 (60%). The identification was accomplished by comparison of the 1 H- and 13 C-NMR spectra as well as HPLC retention times of the hydroxynitriles with those of authentic samples characterized earlier. Hydroxynitriles 19+20 and 21+22 were each shown by chiral HPLC to consist of an approximately 1:1 mixture of enantiomers.
Example 11
Reduction of (7E,9E)-3-Keto-α-Ionylideneacetonitrile (23a) to (7E,9E)-3-Hydroxy-α-Ionylideneacetonitrile (19-22) with Sodium Borohydride/dl-Tartaric acid
A solution of dl-tartaric acid (46 mg, 0.31 mmol) in EtOH (4 mL) was cooled down to 0° C. and was treated with NaBH 4 (12 mg, 0.32 mmol). After the evolution of H 2 subsided, the mixture was stirred at R.T. for 1 h and was then cooled down to −15° C. and treated with a solution of (7E,9E)-rac-3-keto-α-ionylideneacetonitrile (23a) (72 mg, 0.31 mmol) in EtOH (3 mL). NaBH 4 (24 mg, 0.63 mmol) in EtOH (3 mL) was added to the suspension at −15° C. and the course of the reaction was followed by HPLC (silica-based nitrile bonded column). After 2 h, the product was partitioned between water (10 mL) and ethyl acetate (15 mL). The organic layer was removed and the aqueous layer was extracted with ethyl acetate (10 mL). The combined organic layer was washed with water (2×10 mL), dried over Na 2 SO 4 , and evaporated to dryness. The crude product (68.0 mg, 0.29 mmol, 94%) was shown by HPLC to consist of two major fractions which were separated by semipreparative HPLC and identified in the order of chromatographic elution as (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 19+20 (70%) and (7E,9E)-3-hydroxy-α-ionylidene-acetonitriles 21+22 (30%). The 1 H- and 13 C-NMR as well as HPLC retention times of the hydroxynitriles were identical with those of authentic samples of these compounds characterized earlier. Hydroxynitriles 19+20 and 21+22 were each shown by chiral HPLC to consist of an approximately 1:1 mixture of enantiomers.
Example 12
Reduction of (7E,9E)-3-Keto-α-Ionylideneacetonitrile (23a) to (7E,9E)-3-Hydroxy-α-Ionylideneacetonitrile (19-22) with Sodium Borohydride/2,3-Dibenzoyl-d-Tartaric acid
A solution of 2,3-dibenzoyl-d-tartaric acid (94 mg, 0.26 mmol) in EtOH (4 mL) was cooled down to 0° C. and was treated with NaBH 4 (10 mg, 0.26 mmol). After the evolution of H 2 subsided, the mixture was stirred at R.T. for 1 h and was then cooled down to −15° C. and treated with a solution of (7E,9E)-rac-3-keto-α-ionylideneacetonitrile (23a) (60 mg, 0.26 mmol) in EtOH (3 mL). NaBH 4 (20 mg, 0.53 mmol) in EtOH (3 mL) was added to the suspension at −15° C. and the course of the reaction was followed by HPLC (silica-based nitrile bonded column). After 2 h, the product was partitioned between water (10 mL) and ethyl acetate (15 mL). The organic layer was removed and the aqueous layer was extracted with ethyl acetate (10 mL). The combined organic layer was washed with water (2×10 mL), dried over Na 2 SO 4 , and evaporated to dryness. The crude product (57.8 mg, 0.25 mmol, 96%) was shown by HPLC to consist of a mixture of (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 19+20 (74%) and (7E,9E)-3-hydroxy-α-ionylidene-acetonitriles 21+22 (26%). The 1 H- and 13 C-NMR spectra as well as HPLC retention times of the hydroxynitriles were identical with those of authentic samples of these compounds characterized earlier. Hydroxynitriles 19+20 and 21+22 were each shown by chiral HPLC to consist of an approximately 1:1 mixture of enantiomers.
Example 13
Reduction of (7E,9E)-3-Keto-α-Ionylideneacetonitrile (23a) to Hydroxynitrile 19-22 with Sodium bis(2-methoxyethoxy)aluminum hydride (RED-AL™)
A solution of (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) (120 mg, 0.524 mmol) in TBME (5 mL) was cooled down to −5° C. under N 2 , a solution of Red-Al™ (0.18 mL of 0.65 wt. % in toluene, 0.119 g, 0.59 mmol) in TBME (1 mL) was added, and the mixture stirred for 1 h at this temperature. The reaction was quenched by adding water (10 mL) and the product was extracted with TBME (10 mL) and washed sequentially with brine and water. The organic layer was dried over Na 2 SO 4 and evaporated to dryness. The product (115 mg, 0.497 mmol, 95%) was shown by HPLC (silica-based nitrile bonded column) to consist of (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 19+20 (57%) and (7E,9E)-3-hydroxy-α-ionylidene-acetonitriles 21+22 (43%). The identification was accomplished by comparison of the HPLC retention times and UV spectra of the hydroxynitriles obtained by a photodiode array detector with those of authentic samples characterized earlier. Hydroxynitriles 19+20 and 21+22 were each shown by chiral HPLC to consist of an approximately 1:1 mixture of enantiomers.
Example 14
Reduction of (7E,9E)-3-Keto-α-Ionylideneacetonitrile (23a) to Hydroxynitrile 19-22 with Lithium tri-sec-butylborohydride (L-SELECTRIDE™)
A solution of (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) (100 mg, 0.436 mmol) in TBME (5 mL) was cooled down to −30° C. under N 2 , A solution of L-SELECTRIDE™ (0.52 mL of 1 M in THF, 0.52 mmol) in TBME (1 mL) was added by a gas-tight syringe, and the mixture was stirred at this temperature for 0.5 h. The reaction mixture was treated with 0.5 mL of 3 N NaOH followed by 0.5 mL of 30% H 2 O 2 and stirred at R.T. for 30 min. The product was extracted with TBME (10 mL) and washed sequentially with brine and water, dried over Na 2 SO 4 , and evaporated to dryness to give a colorless oil. The product (94 mg, 0.406 mmol, 93%) was shown by HPLC (silica-based nitrile bonded column) to consist of (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 19+20 (55%) and (7E,9E)-3-hydroxy-α-ionylidene-acetonitriles 21+22 (45%). These were identified by comparison of their HPLC retention times and UV spectra obtained by a photodiode array detector with those of authentic samples of these hydroxynitriles characterized earlier. Hydroxynitriles 19+20 and 21+22 were each shown by chiral HPLC to consist of an approximately 1:1 mixture of enantiomers.
Example 15
Reduction of (7E,9E)-3-Keto-α-Ionylideneacetonitrile (23a) to Hydroxynitrile 19-22 with Sodium tri-sec-butylborohydride (N-SELECTRIDE™)
A solution of (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) (100 mg, 0.436 mmol) in TBME (5 mL) was cooled down to −30° C. under N 2 , A solution of N-SELECTRIDE™ (0.52 mL of 1 M in THF, 0.52 mmol) in TBME (1 mL) was added by a gas-tight syringe, and the mixture was stirred at this temperature for 0.5 h. The product was worked up as in Example 14 to give a mixture of (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 19+20 (71%) and (7E,9E)-3-hydroxy-α-ionylidene-acetonitriles 21+22 (29%) [(94 mg, 0.406 mmol, 92%)]. Hydroxynitriles 19+20 and 21+22 were each shown by chiral HPLC to consist of an approximately 1:1 mixture of enantiomers.
Example 16
Reduction of (7E,9E)-3-Keto-α-Ionylideneacetonitrile (23a) to Hydroxynitrile 19-22 with Potassium tri-sec-butylborohydride (K-SELECTRIDE™)
A solution of (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) (3 g, 13.08 mmol) in TBME (25 mL) was cooled down to −30° C. under N 2 , A solution of K-SELECTRIDE™ (20 mL of 1 M in THF, 20 mmol) in TBME (10 mL) was added dropwise in 40 min and the mixture was stirred at this temperature for 4 h. The reaction mixture was treated with 15 mL of 3 N NaOH followed by 15 mL of 30% H 2 O 2 and stirred at R.T. for 30 min. The product was extracted with TBME (10 mL) and washed sequentially with brine and water, dried over Na 2 SO 4 , and evaporated to dryness to give a colorless oil. The product (2.85 g, 12.32 mmol, 94%) was shown by HPLC (silica-based nitrile bonded column) to consist of a mixture of (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 19+20 (86%) and (7E,9E)-3-hydroxy-α-ionylidene-acetonitriles 21+22 (14%). Hydroxynitriles 19+20 and 21+22 were each shown by chiral HPLC to consist of an approximately 1:1 mixture of enantiomers.
Example 17
Reduction of (7E,9E)-3-Keto-α-Ionylideneacetonitrile (23a) to (7E,9E)-3-Hydroxy-α-Ionylideneacetonitrile (19-22) with (R)-2-Methyl-CBS-oxazaborolidine
To a solution of (R)-2-methyl-CBS-oxazaborolidine (0.3 mL 1M in toluene, 0.30 mmol) in TBME (4 mL) was added BH 3 .THF (0.3 mL 1M in THF, 0.30 mmol) at R.T. under N 2 . The mixture was stirred at R.T. for 20 min and was then cooled down to 0° C. and treated with a solution of (7E,9E)-rac-3-keto-α-ionylideneacetonitrile (23a) (69 mg, 0.30 mmol) in TBME (3 mL). After stiffing the reaction mixture for 1.5 h at 0° C., HPLC (silica-based nitrile bonded column) showed the complete reduction of 23a. The reaction was quenched by slow addition of methanol (1 mL) and the product was diluted with TBME, washed with a saturated solution of NH 4 Cl, followed by 5% NaHCO 3 , and then brine. The organic layer was washed with water (10 mL), dried over Na 2 SO 4 , and evaporated to dryness. The crude product (66.6 mg, 0.29 mmol, 97%) was shown by HPLC to consist of a mixture of (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 19+20 (14%) and (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 21+22 (86%). The hydroxynitriles 19+20 and 21+22 were each shown by chiral HPLC to consist of an approximately 1:1 mixture of enantiomers.
Example 18
Reduction of (7E,9E)-3-Keto-α-Ionylideneacetonitrile (23a) to (7E,9E)-3-Hydroxy-α-Ionylideneacetonitrile (19-22) with (S)-2-Methyl-CBS-oxazaborolidine
To a solution of (R)-2-methyl-CBS-oxazaborolidine (0.3 mL 1M in toluene, 0.30 mmol) in TBME (4 mL) was added BH 3 .THF (0.3 mL 1M in THF, 0.30 mmol) at R.T. under N 2 . The mixture was stirred at R.T. for 20 min and was then cooled down to 0° C. and treated with a solution of (7E,9E)-rac-3-keto-α-ionylideneacetonitrile (23a) (69 mg, 0.30 mmol) in TBME (3 mL). The product was worked up as described above to give a colorless oil (65 mg, 0.28 mmol, 93%) was shown by HPLC to consist of a mixture of (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 19+20 (25%) and (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 21+22 (75%). The hydroxynitriles 19+20 and 21+22 were each shown by chiral HPLC to consist of an approximately 1:1 mixture of enantiomers.
Example 19
Reduction of Hydroxynitriles 19-22 to Hydroxyaldehydes 15-18 with DIBAL-H
A solution of hydroxynitriles 19+20 (86%) and 21+22 (14%) [2.31 g, 10 mmol] in CH 2 Cl 2 (10 mL) was cooled down to −40° C. under N 2 and a 1M solution of DIBAL-H in CH 2 Cl 2 (33 mL, 33 mmol) was added dropwise in one hour. After the addition was completed, the reaction mixture was allowed to stir at −30° C. for 1 h. The mixture was then treated with a very slow addition of a homogeneous mixture of 26 g of water absorbed on n-silica (0.3 g of water/g of silica) at a rate that the temperature remained below −10° C. [caution: the addition of silica/water results in rapid elevation of the temperature]. After the addition was completed, the reaction mixture was allowed to stir at 0° C. for 2 h. Na 2 SO 4 (3 g) was added and the solids were filtered off and washed with CH 2 Cl 2 (20 mL). The organic layer was washed with water, dried over Na 2 SO 4 , and evaporated to dryness to give a pale yellow oil (2.7 g). Column chromatography (hexane:ethyl acetate, 95:5 to 80:20) of the product gave two fractions as 15+16 (1.155 g, 4.93 mmol, 49%) and 17+18 (0.493 g, 2.1 mmol, 21%).
Example 20
One-Pot Reduction of (7E,9E)-3-Keto-α-Ionylideneacetonitrile (23a) to Hydroxyaldehydes 15-18 with Potassium tri-sec-butylborohydride (K-SELECTRIDE™) Followed by DIBAL-H
A solution of (7E,9E)-3-keto-α-ionylideneacetonitrile (23a) (1.2 g, 5.23 mmol) in TBME (10 mL) was cooled down to −30° C. under N 2 , A solution of K-SELECTRIDE™ (7.6 mL of 1 M in THF, 7.6 mmol) in TBME (5 mL) was added dropwise in 30 min and the mixture was stirred at this temperature and the course of the reaction was monitored by HPLC (silica-based nitrile bonded column). After 2 h, 23a was shown by HPLC to have converted to a mixture of (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 19+20 (86%) and (7E,9E)-3-hydroxy-α-ionylideneacetonitriles 21+22 (14%). The reaction mixture was then treated with a 1M solution of DIBAL-H in CH 2 Cl 2 (13 mL, 13 mmol) dropwise in 30 minutes. After the addition was completed, the reaction mixture was allowed to stir at −20° C. for 3 h. The product was then treated with a very slow addition of a homogeneous mixture of 20 g of water absorbed on n-silica (0.5 g of water/g of silica) at a rate that the temperature remained below −10° C. [caution: the addition of silica/water results in rapid elevation of the temperature]. The reaction mixture was allowed to stir at 0° C. for 2 h. Na 2 SO 4 (3 g) was added and the solids were filtered off and washed with CH 2 Cl 2 (20 mL). The organic layer was washed with water, dried over Na 2 SO 4 , and evaporated to dryness to give a pale yellow oil (1.9 g). Column chromatography (hexane:ethyl acetate, 95:5 to 80:20) of the product gave two fractions as 15+16 (0.942 g, 4.0 mmol, 77%) and 17+18 (0.077 g, 0.33 mmol, 6%).
Example 21
Oxidative Degradation of (3R,3′R,6′R)-Lutein Diacetate to (3R,6R)-3-hydroxy-13-apo-ε-caroten-13-one (27) and (3R)-3-hydroxy-13-apo-β-caroten-13-one (28)
Preparation of (3R,3′R,6′R)-Lutein Diacetate. Naturally occurring (3R,3′R,6′R)-lutein was obtained from Kemin Health (Des Moines, Iowa) and converted to (3R,3′R,6′R)-lutein diacetate as follows. A solution of (3R,3′R,6′R)-lutein (3 g, 75% pure ≈2.25 g, 3.96 mmol) in 20 mL of THF was treated with pyridine (2.5 mL, 2.45 g, 30.97 mmol) and acetic anhydride (2.5 mL, 2.71 g, 26.55 mmol) and the mixture was heated at 45° C. under N 2 overnight. The product was partitioned between water (50 mL) and hexane (50 mL). The organic layer was removed and washed sequentially with 50 mL of aqueous HCl (5%, v/v), 50 mL of saturated sodium bicarbonate solution, and water (50 mL). The organic layer was dried over Na 2 SO 4 and evaporated to dryness to give a red solid which was purified by column chromatography on n-silica (hexane:acetone, from 90:10 to 70:30) to give lutein diacetate (2.30 g, 3.52 mmol; 89%).
Oxidative Degradation of (3R,3′R,6′R)-Lutein Diacetate. A solution of (3R,3′R,6′R)-lutein diacetate (1 g, 1.53 mmol) in ethyl acetate (30 mL) was cooled down in an ice-salt bath to 0° C. under N 2 and was treated with a 70% solution of TBHP in water (2.70 mL, 2.43 g 70%≈1.70 g, 18.86 mmol). Household bleach containing 5.25% NaOCl (8.84 g, 0.464 g NaOCl, 6.23 mmol) was then added over a period of 20 min at 0° C. After the addition was completed, the reaction mixture was allowed to warm up to R.T. and stirred for 3 h. The organic layer was removed and the water layer was washed with EtOAc (2×100 mL). The combined organic layer was washed with water (2×150 mL), dried over Na 2 SO 4 , and evaporated to dryness. The residue was dissolved in dichloromethane (30 mL) and saponified with KOH/MeOH (30 mL, 10%, wt/v) at R.T. under N 2 . After 2 h, the product was washed with water (3×100 mL), dried over Na 2 SO 4 , and evaporated to dryness. Purification by column chromatography on n-silica (hexane:acetone, from 95:5 to 70:30) followed by semipreparative HPLC (nitrile bonded column) afforded two major products which were fully characterized from their UV-Vis, CD, 1 H- and 13 C-NMR, and mass spectra as (3R,6R)-3-hydroxy-13-apo-ε-caroten-13-one (27) and (3R)-3-hydroxy-13-apo-β-caroten-13-one (28).
Example 22
Enzyme-Mediated Acylation of (7E,9E)-3-Hydroxy-α-Ionylideneacetaldehydes 15+16 with Lipase AK ( pseudomonas fluorescens )
To a solution of (7E,9E)-3-hydroxy-α-ionylideneacetaldehydes 15+16 (2.4 g, 10.32 mmol) in 20 mL of pentane was added 1.5 g of lipase AK ( pseudomonas fluorescens ) and vinyl acetate (2.84 mL, 2.65 g, 30.78 mmol). The mixture was refluxed (35-36° C.) under N 2 and the course of the enzymatic acylation was monitored by chiral HPLC (2-propanol, 2%; CH 3 CN, 98%). After 48 h, the product was filtered through celite and the filtrate was evaporated to dryness to give a yellow oil (2.7 g). Column chromatography (hexane:ethyl acetate, 98:2 to 85:15) of the product gave two major fractions.
The first fraction was tentatively identified from its 1 H NMR and UV spectrum as (3S,6S)-3-acetoxy-α-ionylideneacetaldehyde (25) [1.22 g, 4.41 mmol, 43%]. This fraction was dissolved in CH 2 Cl 2 (25 mL) and treated with KOH/MeOH (2.3 mL, 10% wt/v) for 2 h at 0° C. The product was washed with water (3×50 mL), dried over Na 2 SO 4 , and evaporated to dryness. The product was fully characterized from its UV, CD, 1 H- and 13 C-NMR, and mass spectra as (3S,6S)-3-hydroxy-α-ionylideneacetaldehyde (16) (1.00 g, 4.27 mmol; 97%). The optical purity of 16 (93% ee) was established by chiral HPLC.
The second fraction was fully characterized from its UV, CD, 1 H- and 13 C-NMR, and mass spectra as (3R,6R)-3-hydroxy-α-ionylideneacetaldehyde (15) (1.03 g, 4.40 mmol, 43%). The optical purity of 15 (94% ee) was established by chiral HPLC.
The absolute configuration of hydroxyaldehydes 15 and 16 was assigned from comparison of their 1 H NMR and CD spectra with those of C 18 -ketone 27.
Example 23
Enzyme-Mediated Acylation of (7E,9E)-3-Hydroxy-α-Ionylideneacetaldehydes 17+18 with Lipase AK ( pseudomonas fluorescens )
To a solution of (7E,9E)-3-hydroxy-α-ionylideneacetaldehydes 17+18 (0.843 g, 3.60 mmol) in 20 mL of pentane was added 0.58 g of lipase AK ( pseudomonas fluorescens ) and vinyl acetate (1.4 mL, 1.31 g, 15.22 mmol). The mixture was refluxed (35-36° C.) under N 2 and the course of the enzymatic acylation was monitored by chiral HPLC (2-propanol, 2%; CH 3 CN, 98%). After 50 h, the product was filtered through celite and the filtrate was evaporated to dryness to give a yellow oil (1.0 g). Column chromatography (hexane:ethyl acetate, 98:2 to 85:15) of the product gave two major fractions.
The first fraction was tentatively identified from its 1 H NMR and UV spectrum as (3S,6R)-3-acetoxy-α-ionylideneacetaldehyde (26) [0.319 g, 1.15 mmol, 32%]. This fraction was dissolved in CH 2 Cl 2 (25 mL) and hydrolyzed with KOH/MeOH (0.8 mL, 10% wt/v) for 2 h at 0° C. The product was worked up as in Example 21 and was fully characterized from its UV, CD, 1 H- and 13 C-NMR, and mass spectra as (3S,6R)-3-hydroxy-α-ionylidene-acetaldehyde (17) (0.267 g, 1.14 mmol; 99%). The optical purity of 17 (91% ee) was established by chiral HPLC.
The second fraction was fully characterized from its UV, CD, 1 H and 13 C-NMR, and mass spectra as (3R,6S)-3-hydroxy-α-ionylideneacetaldehyde (18) (0.31 g, 1.32 mmol, 37%). The optical purity of 18 (92% ee) was established by chiral HPLC.
The absolute configuration of hydroxyaldehydes 17 and 18 was assigned from comparison of their 1 H NMR and CD spectra with those of C 18 -ketone 27.
Example 24
Preparation of (all-E)-(7-Fomyl-2-methyl-2,4,6-octatrienyl)-triphenyl phosphonium chloride dimethyl acetal (14)
(all-E)-(7-Fomyl-2-methyl-2,4,6-octatrienyl)triphenyl phosphonium chloride was prepared according to the method developed by Bernhard et al. ( Helv. Chim. Acta 1980, 63: 1473-1490) and was freshly converted to its dimethyl acetal (14) prior to Wittig condensation reactions. A mixture of (all-E)-(7-fomyl-2-methyl-2,4,6-octatrienyl)triphenyl phosphonium chloride (1.36 g, 3.04 mmol), trimethylorthoformate (0.38 g, 3.58 mmol), p-TsOH (6 mg) in methanol (20 mL) was stirred for 3 h at 30° C. The mixture was treated with a few drops of N,N-diisopropylethylamine (DIPEA) and concentrated on a rotary evaporator below 40° C. The concentrated solution of the protected Wittig salt 14 (1.42 g, 2.88 mmol, 95%) in methanol was directly used in the coupling reactions without purification.
Example 25
General Procedure for the Synthesis of C 25 -hydroxyaldehydes 6-9 Synthesis of (3R,6R)-3-Hydroxy-12′-apo-ε-caroten-12′-al (6)
A solution of (3R,6R)-3-hydroxy-α-ionylideneacetaldehyde (15) (250.4 mg, 1.07 mmol) in MeOH (3 mL) was treated with a solution of the protected Wittig salt 14 (817.7 mg, 1.66 mmol) in methanol (2 mL) at R.T. under N 2 . 1 mL of a 0.42 M solution of NaOMe (0.42 mmol) in MeOH (freshly prepared from Na in MeOH) was added and the mixture was stirred at R.T. for 4 h. The product was partitioned between water (50 mL) and CH 2 Cl 2 (30 mL), the organic layer was removed, and the water layer was extracted with CH 2 Cl 2 (20 mL). The combined organic layer was washed with water (2×30 mL), dried over Na 2 SO 4 , and evaporated to dryness to give a red solid (1.3 g). A small quantity of the solid was purified by semipreparative HPLC and identified from its UV-visible, 1 H- and 13 C-NMR, and mass spectra as (3R,6R)-3-hydroxy-12′-apo-ε-caroten-12′-al dimethyl acetal (10). The red solids were dissolved in acetone (4 mL) and water (1 mL) and stirred with 0.075 mL of 0.3 N HCl for 1 h at R.T. under N 2 . The product was extracted with CH 2 Cl 2 , and sequentially washed with saturated solution of NaHCO 3 and water, dried over Na 2 SO 4 , and evaporated to dryness to give a red oil. Column chromatography (hexane:ethyl acetate, 95:5 to 80:20) gave a red solid that was identified from its UV-visible, CD, 1 H- and 13 C-NMR, and mass spectra as (3R,6R)-3-hydroxy-12′-apo-ε-caroten-12′-al (6) (334 mg, 0.91 mmol; 85%).
Following the above procedure, (3S,6S)-3-hydroxy-12′-apo-ε-caroten-12′-al (7), (3S,6R)-3-hydroxy-12′-apo-ε-caroten-12′-al (8), and (3R,6S)-3-hydroxy-12′-apo-ε-caroten-12′-al (9) were prepared in yields ranging from 75-85%.
Example 26
General Procedure for the Synthesis of Luteins 1-4 Synthesis of (3R,3′R,6′R)-Lutein (1)
A solution of (3R,6R)-3-hydroxy-12′-apo-ε-caroten-12′-al (6) (257 mg, 0.70 mmol) and (3R)-3-hydroxy-(β-ionylideneethyl)triphenylphosphonium chloride (Wittig salt 5) (410 mg, 0.79 mmol) in CH 2 Cl 2 (5 mL) was cooled down to −5° C. under N 2 . A solution of KOH (130 mg, 2.32 mmol) in H 2 O (0.5 mL) was added and the mixture was stirred for 0.5 h at −5° C. and 3 h at R.T. Dichloromethane (20 mL) was added, and the product was washed with water (3×10 mL). The organic layer was removed, dried over Na 2 SO 4 , and evaporated to dryness to give 1 g of a red oil. The crude product was then refluxed in ethyl acetate for 4 h under N 2 to affect the cis (Z) to trans (E) thermal isomerization of lutein. After solvent evaporation, the product was purified by column chromatography (hexane:ethylacetate, from 90:10 to 50:50) to give a red solid that was crystallized from hexane:acetone=4:1 and identified from its UV-visible, CD, 1 H- and 13 C-NMR, and mass spectra as (3R,3′R,6′R)-Lutein (1) (0.294 g, 0.517 mmol; 74%).
Following the above procedure, (3R,3′S,6′S)-lutein (2), (3R,3′S,6′R)-lutein or 3′-epilutein (3), and (3R,3′R,6′S)-lutein (4) were prepared in yields ranging from 65-74%.
Having now fully described this invention, it will be understood by those of ordinary skill in the art that the same can be performed within a wide and equivalent range of conditions, formulations and other parameters without affecting the scope of the invention or any embodiment thereof. All patents, patent applications and publications cited herein are fully incorporated by reference herein in their entirety.
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(3R,3′R,6′R)-Lutein and (3R,3′R)-zeaxanthin are two dietary carotenoids that are present in most fruits and vegetables commonly consumed in the US. These carotenoids accumulate in the human plasma, major organs, and ocular tissues. In the past decade, numerous epidemiological and experimental studies have shown that lutein and zeaxanthin play an important role in the prevention of age-related macular degeneration (AMD) that is the leading cause of blindness in the U.S. and Western World. The invention provides a process for the synthesis of (3R,3′R,6′R)-lutein and its stereoisomers from commercially available (rac)-α-ionone by a C 15 +C 10 +C 15 coupling strategy. In addition, the present invention also provides access to the precursors of optically active carotenoids with 3-hydroxy-ε-end group that are otherwise difficult to synthesize. The process developed for the synthesis of lutein and its stereoisomers is straightforward and has potential for commercialization.
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This invention relates generally to welding systems and more particularly to a full function in-place weld head permitting automatic welding of in-place pipes wherein surrounding structure prohibits the use of conventional automatic welding equipment.
BACKGROUND OF THE INVENTION
Automatic welding systems for effecting a 360° weld about either the exterior or interior of pipes are well known. Generally these systems will include a welding mechanism having a travelling carriage which will support a torch head and cause it to actually orbit around the exterior of the pipe where an exterior weld is to be made or in those instances where an interior weld is to be made, the travelling carriage will move about the inside of a pipe.
These known machines also include mechanism for causing the carriage to oscillate back and forth as it progresses over 360° so that an oscillating path for the torch is effected and thereby provides for proper heating of the material and proper welding with only one 360° sweep. Also, controls are provided for varying the arc gap of the torch head relative to the weld to provide for automatic voltage control. In addition, automatic wire feed rate controls are provided in TIG systems, the various relative motions all being programmed to provide for a high quality controlled weld.
While the above-described automatic welding systems are highly successful, they cannot readily be used for relatively small pipe welding operations; that is, small pipes that may vary in diameter from 1/2 inch to 3 inches and particularly they cannot be used for pipes that are already in place, where the surrounding pipe connections can block the entry of the welding mechanism.
As a consequence of the foregoing, it has been necessary to hand weld some of the smaller pipe sections and thus the advantage of consistency and proper weld quality realizable with automatic welding equipment is lost.
While it might be possible to automate some of the welding movements such as an orbiting of the weld torch head about the pipe without requiring too much space, there has never been available a full function automatic welding system for the small diameter pipes in in-place applications which provides for appropriate oscillation of the torch head across the weld path as it progresses about the pipe, nor has there been available any automatic system for providing other weld functions.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
With the foregoing in mind, the present invention contemplates the provision for the first time of a full function in-place welding system capable of effecting automatic welds for in-place pipes in environments which prohibit the use of conventional automatic welding equipment.
More particularly, the present invention comprises a pipe clamping structure having spaced clamping shoes for engaging and clamping an in-place pipe to hold the structure stationary relative to the pipe. A welding mechanism surrounds a portion of the pipe adjacent to the pipe clamping structure and is supported by parallel movement control means to the clamping structure for guided axial movement back and forth along the axial direction of a pipe clamped in the clamping structure relative to the clamping structure. A horseshoe-shaped weld head support rotor in turn is mounted in the welding mechanism for rotational movement in its own plane over 360° about a pipe received in the mechanism. Additionally, a link plate is pivoted to one side of the horseshoe shaped rotor and serves to carry a welding torch head such that swinging movement of the link plate about its pivot moves the torch head in a generally normal direction further from and closer to the axis of a pipe clamped in the clamping structure. First, second and third motors are programmed to provide for oscillating the torch head back and forth on either side of the weld path as the torch head follows a 360° weld path about the pipe held in the clamping structure. Also, the torch head can be moved towards and away from the weld to control the arc gap and thus provide for a voltage control as the other movements are taking place thereby resulting in a controlled high quality weld carried out in a fully automatic manner.
The overall length of the welding system as measured between the clamping shoes and the torch head in the direction of the pipe axis is less than twice the diameter of the largest sized pipe which can be accommodated in the system, so that access to awkward areas to be welded can be had as compared to accessibility of conventional automatic welding equipment.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of this invention as well as many further features and advantages thereof will be had by now referring to the accompanying drawings in which:
FIG. 1 is an overall perspective view of the full function in-place weld head of this invention showing a typical in-place pipe exploded above the mechanism on which a welding path has been defined;
FIG. 2 is a fragmentary exploded perspective view of upper portions of the welding apparatus illustrated in FIG. 1 useful in explaining features of the invention;
FIG. 3 is a front elevational view of the welding apparatus of FIG. 1;
FIG. 4 is a side elevational view taken in the direction of the arrows 4--4 of FIG. 3;
FIG. 5 is a fragmentary view taken in the direction of the arrows 5--5 of FIG. 4;
FIG. 6 is a fragmentary cross section taken in the direction of the arrows 6--6 of FIG. 3;
FIG. 7 is a cross section taken in the direction of the arrows 7--7 of FIG. 4;
FIG. 8 is a fragmentary cross section taken in the direction of the arrows 8--8 of FIG. 4; and,
FIG. 9 is a cross section taken in the direction of the arrows 9--9 of FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the righthand portion of FIG. 1, there is shown at 10 a pipe clamping structure having spaced clamping shoes as will be subsequently described for engaging and clamping an in-place pipe to hold the structure 10 stationary relative to the pipe. A welding mechanism designated generally by the numeral 11 surrounds a portion of the pipe adjacent to the pipe clamping structure and is supported to the pipe clamping structure by appropriate parallel movement control means components of which are indicated at 12. As will also become clearer as the description proceeds, the control means 12 provides for guided axial movement in planes parallel to itself of the welding mechanism 11 relative to the clamping structure 10, back and forth in an axial direction along a pipe held in the clamping structure.
Still referring to FIG. 1, there is shown in the upper portion a horseshoe-shaped weld head support rotor 13 mounted in the welding mechansim for rotation by movement in its own plane over 360° about a pipe received in the horseshoe opening. Details of this mounting for the rotor will also be subsequently described.
Finally, there is provided a link plate 14 pivoted at 15 to one side of the horseshoe-shaped rotor 13 and serving to mount a torch head 16. The arrangement is such that swinging movement of the link plate about the pivot 15 will move the torch head in a generally normal direction relative to the axis of a pipe held in the clamping structure and passing through the horseshoe-shaped rotor.
A first motor 17 shown in the broken away portion of the clamping structure 10 is provided for operating the parallel movement control means 12. A second motor 18 shown on the welding mechanism 11 serves to rotate the weld head supporting rotor 13 to cause the torch head 16 to orbit about a pipe to be welded when positioned in the clamping structure and passing through the horseshoe rotor 13. A third motor 19 in turn is carried on the weld head support rotor and coupled to the link plate 14 to swing this plate about its pivot point and thereby move the torch head 16 closer to and further from the weld to provide control of the arc gap and thus voltage control.
With the foregoing arrangement as described thus far, the three motors can be programmed so that the torch head 16 is oscillated to either side of the weld path by the first motor 17 as the rotor 13 is rotated by the second motor 18 over 360°. Also, simultaneously the arc gap can be controlled by the third motor 19 cooperating with the link plate 14 supporting the torch head 16. It will thus be seen that three major functions in providing for a high quality weld which can be consistently repeated in an automatic manner can be carried out.
In FIG. 1 there is shown exploded above the welding apparatus a pipe P on which a weld path 20 to be welded is defined. It will be noted that this pipe extends from curved portions on either side of the weld path 20. However, because of the compact design of the welding system of the present invention, the pipe P can readily be clamped by the clamping structure 10 and a 360° weld carried out without interference from the end curved portions of the pipe P.
Appropriate wire feed for the system of FIG. 1 in the embodiment disclosed is provided by a flexible feed wire guide 21 connected to a feed drive motor 22 which can be located remote to the welding head so as to minimize the bulk and overall dimensions of the weld head. Welding power for the arc itself as well as the various motors is supplied through a cable 23 from a remote power source.
As depicted in FIG. 1, the entire welding apparatus can be held by appropriate handles on the clamping structure with one hand. Of course once the clamping structure has thoroughly engaged the pipe, the entire structure is self-supporting and can be controlled from a remote control box having appropriate electrical connections through the cable 23 to the various motors and other components. In this latter operation of clamping the structure, there is shown at 24 a manually operable screw which serves to operate an appropriate camming mechanism within the clamping structure 10 and thereby cause appropriate clamping arms terminating in clamping shoes, two of which are shown at 25 and 26 engaging the pipe P.
All of the foregoing as well as further features will be more readily understood by now referring to FIGS. 2, 3 and 4.
Considering first the exploded view of FIG. 2, the third clamping shoe for the clamping structure 10 is illustrated at 27 and is simultaneously operated with the clamping shoes 25 and 26 by an appropriate camming means indicated in phantom lines at 28. The exact manner in which clamping takes place will be described subsequently. Suffice it to say at the moment that operation of the screw 24 described in FIG. 1 will raise the camming means 28 to cause the camming shoes 25, 26 and 27 to move radially inwardly simultaneously equal distances so that different diameter pipes can be clamped without changing their axes relative to the welding mechanism. In FIG. 2, the pipe axis for the exploded elements is indicated at A.
Still referring to FIG. 2, the welding mechanism 11 is shown by itself wherein essentially a bearing plate of similar horseshoe shape to that of the rotor 13 described in FIG. 1 includes a plurality of guide rollers 29 having V grooves in their peripheries mounted at points lying on the circumference of a circle whose center corresponds with the axis A of a pipe held in the clamping structure. Also shown as part of the clamping mechanism 11 are two drive rollers 30 spaced below and on either side of the axis A.
The horseshoe-shaped weld head support rotor 13 described in FIG. 1 is shown exploded away from the welding mechanism 11 in FIG. 2 and has an undercut portion defining a lip 31 following a circular path up to the opposite sides of the horseshoe opening. This lip is receivable in the V grooves of the guide rollers 29 so that the rotor 13 is supported for rotary movement in the welding mechanism and is held by the guide rollers to follow axial movements of the welding mechanism 11 relative to the clamping structure 10.
Rotor 13 as shown in FIG. 2 has an outer smooth periphery 32 following a circular path up to the side openings of the horseshoe shape. This periphery 32 seats on the drive rollers 30 described in the welding mechanism 11, the spacing between the drive rollers being greater than the horseshoe opening spacing so that the rotor is engaged at all times by at least one of the drive rollers 30 throughout a 360° rotation.
Finally, to the extreme left of FIG. 2 there is illustrated exploded away from the rotor 13 the link plate 14 and pivot 15 for the torch head 16. A further coupling member 33 is illustrated which connects to the motor 19 described in FIG. 1 to provide for the swinging movement of the link plate 14 about the pivot 15 to move the torch head 16 towards and away from the axis A.
Most of the foregoing described features are illustrated in the front and side views of FIGS. 3 and 4 wherein the same reference numerals designate corresponding parts. In the upper portion of FIG. 3, there is indicated by the phantom lines a pipe held within the clamping shoes 25, 26 and 27. Further, there is shown the torch head 16 and wire feed manipulator both held on the link plate 14. Also illustrated are the rollers 30 engaging the outer smooth periphery of the horseshoe shaped rotor 13 to drive the same.
In FIG. 4, there is shown the pipe P in phantom lines being held by the clamping structure 10 within the shoes 25 and 27. Also indicated in FIG. 4 by the phantom lines is the movement of the welding mechanism 11 relative to the clamping structure 10 as by means of the parallel movement control means 12. Essentially, and as will be described in further detail subsequently, the components 12 for this parallel movement control means constitute threaded nuts fixed to the welding mechanism 11 and arranged to receive three lead screws one of which is shown at 34 in the broken away portion. These lead screws, as will be described subsequently, extend from points defining the vertices of a equilateral triangle in the clamping structure 10 and all three lead screws are caused to be rotated simultaneously in the same direction to effect the desired aligned axial movement with the welding mechanism assuming successive positions parallel to itself.
Referring now to FIG. 5, which is a cross section in the direction of the arrows 5--5 of FIG. 4 of the welding mechanism 11 the various guide rollers are shown on a circular path indicated by the dashed line. Also shown are the drive rollers 30 the same being coupled together by a chain 35 passing over appropriate guide pulleys such as 36 so that the chain can be driven by the motor 18.
Referring to the cross section of FIG. 6, this driving of the chain 35 is effected through appropriate bevel gears 37.
In FIG. 6 the manner in which the horseshoe shaped rotor 13 has its undercut lip 31 supported in the V grooves of the guide rollers 29, as heretofore described with respect to FIG. 2, is shown.
Referring now to FIG. 7, further details of the operation of the camming member 28 as briefly described in FIG. 2 will become evident. As shown, the clamping structure includes a vertical guide channel 38 within which the camming member 28 is received for vertical movement. The top surface of the camming member 28 terminates in a support 39 for the central shoe 27 and in sloping camming shoulders 40 and 41 on either side of the central shoe support 39. Spaced arm members 42 and 43 are centrally pivoted at 44 and 45 at points above the camming shoulders 40 and 41. The arrangement is such that the lower ends of the arms 42 and 43 engage the camming shoulders 40 and 41, the upper ends of these arms terminating in the remaining two clamping shoes 25 and 26.
With the foregoing description in mind, it will now be evident that when the manual screw means 24 is threaded upwardly into the clamping structure 10, the camming member 28 will be urged upwardly in the guide channel 38 to thereby raise the central shoe 27 and simultaneously spread the lower ends of the arms 42 and 43 apart to cause the remaining clamping shoes 25 and 26 at the other ends of the arms to close together and thereby effect the referred-to equal inner radial movement of all of the shoes 25, 26 and 27. In FIG. 7, the axis A of a pipe held in the clamp is indicated and it will be understood that because of the equal inward radial movement of the clamping shoes 25, 26 and 27, this axis A will remain in the same position for different diameter pipes, all as described heretofore.
FIGS. 8 and 9 shows details of the parallel movement control means for effecting the desired oscillatory movement of the welding mechanism relative to the clamping structure.
As described heretofore, there are provided three screws one of which has already been indicated at 34 in FIG. 4. The other screws are shown at 46 and 47 in FIG. 8, the three screws all being rotatably mounted in the clamping structure with their axes extending from points defining the vertices of an equilateral triangle in directions parallel to and below the axis of a pipe held in the clamping structure. The welding mechanism as is clear from FIGS. 3 and 4 includes three fixed nuts 12 in positions to receive the screws 34, 46 and 47.
As shown in FIG. 8, a central gear 48 is positioned in the clamping structure for cooperation with three outer gears 49, 50 and 51 secured to the screws 34, 46 and 47 respectively, and also in threaded engagement with peripheral points of the central gear 48.
With the foregoing described gear arrangement, rotation of any one of the gears will rotate all of the other gears. Further, it will be evident that the three outer gears will always be rotated in a like direction which is opposite in sense to the rotation of the central gear 48.
FIG. 9 shows how the first motor 17 within the clamping structure connects to drive one of the gears shown in FIG. 8. The particular gear selected is gear 51 and coupling to this gear is by way of bevel gears 52. When motor 17 which is a reversible motor is energized in one direction, it will cause gear 51 to rotate which in turn will rotate the central gear 48 and thereby effect rotations of the outer gears 49 and 50. The outer gears are all of the same diameter and the screws 34, 46 and 47 to which they connect are all of the same pitch. Thus, all three screws are rotated simultaneously in like directions and will thus effect the desired parallel movement of the welding mechanism to itself. Even though there may be unequal loading or torques acting on the welding mechanism, a smooth movement of the welding mechanism parallel to itself is assured as a consequence of the triangular configuration and the fact that three screws are all driven.
Summarizing from all of the foregoing, it will become evident that the present invention has provided an extremely useful full function in-place weld head. Important automatic control functions, specifically, oscillation control of the torch head across the weld path, simultaneous moving of the torch head over the pipe throughout 360° at a controlled rate, and arc gap distance control are all realizable in the present invention. In addition, wire feed rate can be controlled as the welding process is carried out.
Finally, because of the compact configuration providing for an overall axial length of the welding structure of less than twice the largest diameter pipe contemplated to be clamped and welded by the present invention, in-place pipe welding can be effected where the environmental conditions are such as would block conventional welding equipment, all as set forth.
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A pipe clamping structure is arranged to clamp an in-place pipe to be welded. A welding mechanism in turn is coupled to the pipe clamping structure for rigid guided movement in directions parallel to itself towards and away from the clamping structure in an axial direction along the pipe. The welding mechanism in turn supports a horseshoe-shaped weld head support rotor which receives the pipe in the horseshoe opening and is arranged to rotate about the pipe axis. A torch head is carried on the horseshoe rotor so that a 360° weld can be achieved and simultaneously, the welding mechanism can be oscillated back and forth by the rigid guidance and alignment coupling with the clamp structure. In addition, the torch head is held on a link plate to the rotor, the link plate being swingable to vary the arc gap and thus provide appropriate voltage control. The overall dimensions of the welding apparatus as measured in an axial direction are not greater than twice the diameter of the largest size pipe which can be accommodated so that in-place welding can take place in relatively awkward situations in a completely automatic manner.
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CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM TO PRIORITY
This application relates to International Application No. PCT/FR2010/050939 filed Mar. 8, 2010 and French Patent Application No. 09/52804 filed Apr. 29, 2009, of which the disclosures are incorporated herein by reference and to which priority is claimed.
FIELD OF THE INVENTION
The present invention relates to a rotary electrical machine such as an alternator, a starter, or an alternator-starter for a motor vehicle. More particularly, the invention relates to a rotary electrical machine which is equipped with means for compensation for the armature magnetic reaction.
BACKGROUND OF THE INVENTION
The phenomenon of the armature magnetic reaction is known to persons skilled in the art. The armature magnetic reaction occurs when a current is circulating in the armature of the rotary electrical machine.
Taking as an example an alternator for a motor vehicle in which the armature is the stator of the machine, and the inductor is its rotor, the armature magnetic reaction occurs when the alternator is live and is discharging a current. The stator coils in which a current is circulating then produce a so-called armature reaction magnetic field, which can give rise to saturation and downgrade the magnetic field of the inductor. Subsequently, the electromagnetic force emf) is distorted (with possible saturation), and the performance of the alternator, in particular in terms of output, is adversely affected. This distortion of the emf produces harmonics which give rise to an increase in the Joule losses and iron losses of the machine. In addition, the performance relating to the acoustic vibrations and electromagnetic compatibility can also be affected by the inductor reaction.
In the field of rotary electrical machines with a high power level, it is known in the prior art to provide so-called armature reaction compensation auxiliary coils. These coils, which are included in the stator of the machine, produce a compensation magnetic field which opposes the armature reaction magnetic field, such as to reduce the effects.
The above-described solution can provide satisfactory compensation for the armature magnetic reaction in a rotary electrical machine, but it is unsuitable for the motor vehicle field, in which the constraints of weight, compactness and cost are extremely strict.
It is therefore desirable to propose a solution for compensation for armature magnetic reaction which is designed for the rotary electrical machines which are used in motor vehicles.
SUMMARY OF THE INVENTION
According to a first aspect, the present invention provides a rotary electrical machine comprising an inductor in the form of a rotor, an armature in the form of a stator, and means for compensation for the armature magnetic reaction. According to the invention, the means for compensation for the armature magnetic reaction comprise at least one permanent compensation magnet which is implanted in a pole of the inductor.
According to a particular characteristic, the means for compensation for the armature magnetic reaction comprise a permanent compensation magnet which is implanted in each of the poles of the inductor.
According to another particular characteristic, the means for compensation for the armature magnetic reaction comprise two permanent compensation magnets which are implanted in each of the poles of the inductor. Preferably, each of the two permanent compensation magnets is implanted in one half of the corresponding pole.
According to particular embodiments, a length of the permanent compensation magnet occupies approximately 30 to 45% of a half-width of the corresponding pole. In addition, the permanent compensation magnet has a residual magnetic field of between 0.8 and 1.4 Tesla, it is positioned at a distance of between approximately 2 to 6 mm relative to an end of the corresponding pole, it has a length of between approximately 1 and 6 mm, and a thickness of between approximately 1 and 4 mm.
According to a preferred embodiment, the permanent compensation magnet is positioned at a distance equal to 5.3 mm relative to an end of the corresponding pole, it has a length equal to 4.4 mm, and a thickness equal to 2 mm.
According to another characteristic, the rotary electrical machine according to the invention which has been described briefly above also comprises a progressive air gap. According to a particular embodiment, this progressive air gap varies between approximately 0.4 and 0.7 mm.
According to another characteristic, the permanent compensation magnet of the rotary electrical machine according to the invention is of the surface or buried type.
BRIEF DESCRIPTION OF THE DRAWINGS
Other characteristics and advantages of the invention will become apparent from reading the following description of one of its particular embodiments, with reference to the following figures, in which:
FIG. 1 shows a simplified general structure of a rotary electrical machine of the type with projecting poles;
FIGS. 2A to 2C are skeleton diagrams used to explain the phenomenon of armature magnetic reaction;
FIG. 3 is a real measurement curve of the magnetic field present in an air gap of the machine;
FIG. 4 is a partial view in cross-section of a rotary electrical machine according to the invention, equipped with permanent magnets for compensation for the armature magnetic reaction;
FIG. 5 is a curve for measurement of the magnetic field present in an air gap of the machine, which shows the effect of compensation for the armature magnetic reaction provided by the permanent compensation magnets;
FIG. 6 is a partial view in cross-section showing the position of a permanent compensation magnet in a corresponding pole of the machine;
FIG. 7 is a partial view in cross-section of a rotary electrical machine according to the invention equipped with two permanent magnets for compensation for the armature magnetic reaction;
FIG. 8 shows the torque curves obtained with and without compensation magnets when the rotary electrical machine is functioning in engine mode;
FIG. 9 is a partial view in cross-section of a rotary electrical machine according to the invention comprising a progressive air gap; and
FIG. 10 is a curve for measurement of a magnetic field present in an air gap of the machine, showing the effect of compensation for the armature magnetic reaction provided by the progressive air gap of the machine in FIG. 9 , and
FIG. 11 is a partial cross-sectional view of the rotary electrical machine according to the invention with the permanent compensation magnet of the buried type.
DETAILED DESCRIPTION
FIG. 1 shows in simplified form the structure of a rotary electrical machine 1 of the type with projecting poles. The machine 1 comprises a stator 10 and a rotor 11 , and is without current compensation means.
The stator 10 is provided with a plurality of notches 101 which are designed to receive stator coils (not shown). The rotor 11 comprises 4 pairs of poles with North (N) and South (S) polarities, consisting of poles S 110 , N 110 , S 111 , N 111 , S 112 , N 112 , S 113 and N 113 .
An excitation coil 114 , which defines a field coil generating a magnetic field, is provided in the rotor 11 of the machine 1 , and comprises eight windings in series, E 0 to E 7 , which are localized respectively at the level of the eight projecting poles of the machine 1 . Each of the windings E 0 -E 7 is wound about one of the projecting poles S 110 , N 110 , S 111 , N 111 , S 112 , N 112 , S 113 and N 113 . An excitation current Iex supplies the excitation coil 114 , such as to produce magnetic fields with the required polarities at the level of the poles S 110 , N 110 , S 111 , N 111 , S 112 , N 112 , S 113 and N 113 .
When the machine 1 is functioning in an alternator mode and is discharging current, an armature magnetic reaction occurs which is now described with reference to FIGS. 2A, 2B and 2C . The armature magnetic reaction is a change in a magnetic field of the field coil of the rotor 11 caused by a magnetic field induced by current flowing through the stator coil of the stator 10 in the alternator mode.
FIGS. 2A, 2B and 2C show schematically the magnetic fields in an air gap e of the machine 1 , at the level of a pole N of the latter, FIGS. 2A, 2B and 2C show the pole N with an excitation winding E, as well as conductors CS of the stator coil which are accommodated in notches 101 ( FIG. 1 ) in the stator.
FIG. 2A shows a magnetic field FI, Which is a magnetic field produced by the pole N in the air gap e when the machine 1 is functioning without charge, i.e. when no current is circulating in the stator coil. The wave form of the field FI is then substantially regular in the air gap assembly in relation to the pole N.
FIG. 2B shows the effect of the armature magnetic reaction in the form of a field FRI, Which is an armature reaction magnetic field produced by the conductors CS of the stator coil, when a charge current is circulating in the conductors. As shown in FIG. 2B , the field FRI comprises positive alternation and negative alternation.
FIG. 2C shows a field FC which is a resultant magnetic field present in the air gap e when the machine is discharging a charge current. The field FC is the sum of the fields FI and FRI. As shown in FIG. 2C , the field FC is significantly deformed and dephased in comparison with the field FI produced when the machine 1 is functioning without charge. In addition, saturation of the magnetic current (cf. reference SA in FIG. 2C ) may occur as a result of this armature magnetic reaction. Saturation of this type may give rise to a loss of performance.
The wave forms of the magnetic fields FI, FRI and FC shown in FIGS. 2A, 2B and 2C are theoretical curves, which are simplified for the needs of the explanation.
FIG. 3 shows a real measurement curve of the magnetic curve FC which is present in the air gap of a rotary electrical machine with projecting poles. The x-axis shows the angular position of the rotor of the machine, and the y-axis shows the Tesla value corresponding to the magnetic field FC. The wave form of the field FC comprises peaks which are essentially caused by the presence of the notches in the stator. A wave form of this type comprises many harmonics which downgrade the performance of the rotary electrical machine.
According to the present invention, means are incorporated in the poles of the rotor of the rotary electrical machine, for compensation for magnetic reaction in the form of permanent magnets. The magnetic flow which is produced by the permanent magnet then opposes that of the armature magnetic reaction, thus decreasing the effect of the latter.
FIG. 4 shows permanent magnets AC N1 and AC S1 included in two successive poles of type N and S of a rotary electrical machine with projecting poles, such as the machine 1 in FIG. 1 .
The permanent magnets AC N1 and AC S1 form part of the means for compensation for the armature magnetic reaction according to the present invention. In this embodiment, a permanent magnet AC is included in each of the poles of the rotary electrical machine, which is not necessarily the case in other applications of the invention.
The effect of the permanent magnets AC on the magnetic field FC in the air gap of the machine is shown in FIG. 5 . The addition of the permanent magnets AC to the magnetic field FC is shown by the portions P AC in bold on the curve in FIG. 5 . The permanent magnets AC provide compensation for the armature magnetic reaction by correcting the intensity of the magnetic field FC, as shown in FIG. 5 . This correction improves the frequential spectrum of the magnetic field FC in the sense of reduction of the harmonics which affect adversely the performance of the machine.
In order to obtain the required compensation for the armature magnetic reaction, it is desirable to optimise different parameters, in particular the position of the permanent magnet AC in the pole, as well as the dimensional and residual magnetic field characteristics of the magnet.
Tests and simulations have been carried out by the inventive organisation, in particular on a rotary electrical machine for a motor vehicle with a nominal power of 40 kW, an outer diameter of 200 mm, and a length of 240 mm.
Permanent magnets AC which have a residual magnetic field of between 0.8 and 1.4 T give good results for motor vehicle applications. However, other residual magnetic field intensities could also be appropriate, depending on the applications.
With reference to FIG. 6 , the characteristics of dimensions and position of the magnets AC are defined by the following parameters:
La=Length of the magnet AC in the direction perpendicular to the radius of the rotor 11 ;
Ha=thickness of the magnet AC in the radial direction of the rotor 11 ;
Da=distance between the magnet AC and an end of the pole in the direction perpendicular to the radius of the rotor 11 ;
Lp=width of the pole in the direction perpendicular to the radius of the rotor 11 .
In this embodiment with a single magnet AC per pole, the magnet AC is situated in the first half of the width ½ LP of the pole. The first half of the pole is considered in this case to be the one which corresponds to the front part of the pole, determined by the direction of rotation of the rotor of the machine. In other words, the magnet AC is offset from a center line Lc of the pole, as best shown in FIG. 6 .
For the above-described rotary electrical machine for a motor vehicle, the following optimum values have been determined: La=4.4 mm and Da=5.3 mm for a thickness of magnet of Ha=2 mm.
It will be appreciated that the aforementioned optimum values are non-limiting, since, depending on the applications, different values can be determined by persons skilled in the art.
Thus, depending on the applications, the length La of the magnet AC can represent approximately 30 to 45% of the half-width ½ LP of the pole. In addition, the magnet AC can advantageously be positioned at a distance Da Which will be between approximately 2 and 6 mm. The length La of the magnet AC can be between approximately 1 and 6 mm, and the thickness Ha can be between approximately 1 and 4 mm.
FIG. 7 shows an embodiment in which two armature magnetic reaction compensation magnets AC 1 and AC 2 are provided for each pole.
In this machine in FIG. 7 , the magnets AC 1 and AC 2 have opposite polarities, and are situated in the first and second halves of the pole. With alternation of the magnetic field FC, as shown in FIG. 3 , one of the magnets, for example AC 1 , will have the effect of increasing the intensity of the magnetic field FC in the first part of the alternation, and the other magnet, for example AC 2 , will have the effect of reducing the intensity in the second part of the alternation. Correction of the distortion, caused by the armature reaction, of the wave form of the magnetic field, is thus carried out such as to obtain a more regular wave form, comprising fewer harmonics. As illustrated in FIG. 7 , a direction of magnetization of the magnets AC 1 and AC 2 extends in the radial direction of the rotor 11 .
The present invention also provides the advantage of a clear improvement in the mechanical torque which is provided when the rotary electrical machine is functioning in engine mode.
FIG. 8 shows, according to the density of current in the stator, the torque provided by the aforementioned 40 kW machine functioning in engine mode at a speed of 3,000 rpm, depending on whether or not the machine is equipped with permanent magnets AC for compensation for the armature magnetic reaction.
A first curve with square points is that of the machine without the magnets AC. A second curve with round points is that of the machine with the magnets AC, and has torque values which are higher than those of the first curve.
The above-described embodiments comprise permanent magnets AC of the surface type, i.e. which abut the surface of the pole situated opposite the air gap, as shown in FIGS. 4 and 9 . However, it will be noted that permanent magnets AC of the buried type (shown in FIG. 11 ) can also be used in certain applications of the invention.
According to the present invention, a progressive air gap ep, as shown in FIG. 9 , can be associated with the permanent magnets AC for compensation for the armature reaction. Each of the permanent compensation magnets AC produces a magnetic flow in the direction D MF , which is opposite to the direction D MR of the armature magnetic reaction of said stator.
In the embodiment in FIG. 9 , the air gap ep varies in the angular direction of the rotor 11 progressive from approximately 0.4 mm to approximately 0.7 mm, from one end to the other of the pole. The surface of the pole which is opposite the air gap ep and the notches in the stator is machined so as to obtain this progressive air gap ep.
FIG. 10 shows an example of the compensation which is provided by the progressive air gap ep. The effect of the progressive air gap ep on the wave form of the magnetic field is indicated, by the portions in bold P EP . The curve in FIG. 10 shows only the compensation effect provided by the progressive air gap ep, i.e. without the compensation magnets AC.
It will also be noted that a compensation magnet AC can be provided in a divided manner, i.e. in the form of at least two magnets which are disposed side by side, and are separated by a thin wall of magnetic material (the rotor iron). An embodiment of this type makes it possible to reduce the losses in the magnet AC.
The invention has been described here within the context of a particular rotary electrical machine. It should be clear that the invention will have applications in a broader field, in other words that of synchronous machines. More particularly, the invention has a significant application in rotary electrical machines with a toothed rotor, i.e. machines of the Lundell type which are very widely used in motor vehicles. It will also be noted that the invention can be used in rotors which comprise interpolar permanent magnets.
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A rotary electrical machine comprises a rotor including a plurality of poles and a plurality of windings (E 0 -E 7 ) wound about the poles, a stator, and a compensation device configured to compensate the armature magnetic reaction of the stator. The compensation device comprises at least one permanent compensation magnet which is implanted in a pole(s) of the rotor. The magnet(s) is/are sized and placed in accord with the desired compensation effect desired.
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This application is a divisional application of U.S. patent application Ser. No. 10/793,877, filed Mar. 8, 2004, and claims priority thereof and is hereby incorporated by reference for all purposes as if fully set forth herein.
BACKGROUND OF THE INVENTION
The present invention relates to a micro-electro-mechanical component, and more particularly to actuator.
Micro-electro-mechanical mirrors have great potential in wide variety of optical applications including optical communication, confocal microscope, laser radar, bar code scanning, laser printing and projection display. For some optical scanning applications such as laser printing and scanning projection display, the mirror needs to achieve large optical scanning angle at specific frequency. Large optical angle is also a key to optical resolution and smaller product footprint. For scanning mirror, this requirement poses a challenge in the design of actuator to generate large actuation force. A variety of micro-electro-mechanical actuator designs have been proposed to steer or scan light beam for various applications. In order to achieve deflection or movement of the micro-component out of the chip plane, it is known to design a movable element containing electrodes and a stationary element containing counter-electrodes such that the movable element can be driven by the electrical force.
In U.S. Pat. No. 6,595,055, Harald Schenk, et al described a micromechanical component with both the oscillating body and the frame or stationary layer located on the same chip plane. Capacitance is formed between the lateral surfaces of the oscillating body and the frame layer and will vary as the movable body oscillates about a pivot axis out of the chip plane. The structure is suspended and supported by an insulating layer and a substrate to allow out-of-plane motion of the oscillating body. They described in “Large Deflection Micromechanical Scanning Mirrors for Linear Scan and Pattern Generation” in Journal of Selected Topics in Quantum Electronics, Vol 6, No 5, 2000 that the scanning mirror can scan at large angle with low driving voltage at low frequency. However, movable comb electrodes located on the mirror perimeter will increase dynamic deformation of the mirror or movable body. Excessive dynamic deformation of scanning mirror will increase divergence of reflected light beam and significantly deteriorate optical resolution of the device for high speed scanning applications such as printing and scanned display. Additional electrode insulated from the structure may be required to perturb the symmetry of the setup in order to quickly initiate oscillation of the mirror. Furthermore, the setup only allows analog operation (scanning) but not digital operation (static angle positioning) of the movable body.
R. Conant describes in “Staggered Torsional Electrostatic Combdrive and Method of Forming SAME” (U.S. patent application No. 2003/0019832), a comb-drive actuator with a stationary comb teeth assembly and a moving comb teeth assembly with a mirror and a torsional hinge, and the method of fabricating such devices. The moving assembly is positioned entirely above the stationary assembly by a predetermined vertical displacement during resting state. The actuator is able to scan at relative high frequency with mirror dynamic deformation lower than the Rayleigh limit. However, the optical scan angle which dominates the optical resolution is notably smaller than what Schenk has reported despite a relative high voltage is applied. An alternate design was proposed with additional stationary comb teeth assemblies stacked on top of the stationary comb teeth assembly. This stacked comb teeth assemblies were claimed to be used for the purpose of capacitive sensing and frequency tuning of the movable assembly despite that the method of frequency tuning was not described. In the fabrication process steps, a process step is required to open alignment windows by etching through the top wafer to reach the insulating oxide layer then removing the oxide layer in order to use features located on the bottom wafer for alignment of subsequent steps. If the top wafer is thick for the purpose of minimizing dynamic deformation, this process could be time-consuming and hence, expensive.
S. Olav describes in “Self-Aligned Vertical Combdrive Actuator and Method of Fabrication” (US Patent Application US2003/0073261), a vertical comb-drive actuator with small gaps between comb teeth for increased torsional deflection, a double-sided vertical comb-drive actuator for dual-mode actuation, vertical piston and scan, and the method of making them. Despite the proposed fabrication process steps allow self-alignment of the embedded comb teeth, the process of vertical comb-drive actuator requires highly skilled techniques to etch the bottom comb teeth and twice deep silicon trench etching of the bottom substrate. For dual-mode vertical comb-drive actuator, the fabrication process steps start with deep silicon trench etching of the device layer of a Silicon-On-Insulator (SOI) wafer then fusion bonding to another silicon wafer that resulting in a complex five-layer structure, two insulation oxide layers and three silicon layers. To form the bottom comb teeth highly skilled self-alignment etching techniques and twice deep silicon trench etching are still required.
SUMMARY OF THE INVENTION
It is the objective of the present invention to provide a-micro-electro-mechanical actuator with in-plane comb electrodes and a supporting substrate with a cavity of specific depth.
It is the objective of the present invention to provide a micro-electro-mechanical actuator with both in-plane and vertical comb electrodes that increase the actuation force on the movable element, and the methods of fabricating such device.
It is a further objective of this invention to provide a micro-electro-mechanical actuator with both in-plane and dual-side vertical comb electrodes that increase the actuation force on the movable element, and the methods of fabricating such devices.
It is another objective of this invention to provide a method to support and fan out the bottom electrodes of the vertical comb electrodes.
It is another objective of this invention to provide a torsional hinge design with built-in electrodes that can be used to increase the effective torsional stiffness of the hinges such that the resonance frequency of the movable element in an actuator can be adjusted.
It is another objective of this invention to provide a method to decrease the effective torsional stiffness of the torsional hinges such that the resonance frequency of the movable element in an actuator can be adjusted.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A , 1 B, and 1 C show the top views of the top, middle and bottom layers of one embodiment of the present invention.
FIGS. 1D , 1 E and 1 F illustrate the fabrication process flow steps of the embodiment described in FIGS. 1A , 1 B and 1 C.
FIGS. 1G and 1H illustrate another fabrication process flow steps of the embodiment described in FIGS. 1A , 1 B and 1 C.
FIG. 2A˜2D illustrate another side view of the embodiment described in FIG. 1 and show the relationship of actuation force of in-plane and vertical comb electrodes when the mobile element of top layer is in oscillation motion. The vertical comb electrodes on the bottom layer are located only on one side of the torsional hinges.
FIG. 3 illustrates one example of the relationship between the phase of mirror deflection angle and the phase of applied voltage sources for MEMS actuator depicted in FIG. 2 .
FIG. 4 illustrates the three dimensional view of the present invention where the mobile element is supported by a pair of torsional hinges and actuated by both in-plane and vertical comb structure.
FIGS. 5A , 5 B, and 5 C show the top views of the top, middle and bottom layers of another embodiment of present invention where vertical comb electrodes on the bottom layer are electrically isolated into two halves of the different sides of the torsional hinges. Three voltage sources can be applied to achieve large actuation force on the mobile element.
FIG. 5D illustrates another design of the bottom layer of the embodiment as depicted in FIG. 5C . The two sets of electrically isolated vertical comb electrodes are reinforced through thin film deposition processes.
FIG. 6A˜6D illustrate one fabrication process flow steps of the embodiment as described in FIGS. 5A , 5 B and 5 C.
FIG. 7A˜7F illustrate the fabrication process flow steps of the embodiment as described in FIGS. 5A , 5 B and 5 D.
FIGS. 8A˜8D illustrate the side view of the embodiment as described in FIG. 5 and show the relationship of actuation force of in-plane and vertical comb electrodes when the mobile structure of top layer is in oscillation motion. The vertical comb electrodes on the bottom layer are electrically isolated on each side of the torsional hinges.
FIG. 9 illustrates one example of the relationship between the phase of mirror deflection angle and the phase of applied voltage sources for MEMS actuator depicted in FIG. 8 .
FIGS. 10A , 10 B, and 10 C illustrate the methods to connect the two set of electrically isolated vertical comb electrodes located on the bottom layer of the actuator as described in FIG. 1 and FIG. 5 .
FIG. 11 illustrates another embodiment of the invention that additional in-plane comb electrodes are added to the torsional hinges and to the stationary structure on the top layer of the actuator. A voltage difference between the additional comb electrodes sets may be applied to increase the effective stiffness of the hinges.
FIG. 12 illustrates the torsional hinge with protrusion areas that may be removed by laser or other means to reduce the torsional stiffness of the hinge.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1A , 1 B and 1 C show the exploded top views of the three layers of a MEMS actuator in accordance with one embodiment of the present invention. Top layer, FIG. 1A , is consisted of a stationary and a movable elements both made of electrically conductive material, typically doped single crystal silicon. Movable element including comb electrodes is supported by multiple torsional hinges and is electrically isolated from stationary structure. The stationary element has comb electrodes that are interdigitated in the same horizontal plane with the comb electrodes of the movable element such that the top layer is an in-plane comb-drive actuator. Middle layer, FIG. 1B , is made of electrically non-conductive material, typically silicon dioxide. Bottom layer, FIG. 1C , consisting of a cavity and stationary comb electrodes located on one side of the torsional hinge, is made of electrically conductive material, typically doped single crystal silicon. Stationary comb electrodes on bottom layer are interdigitated with comb electrodes of the movable element on top layer such that the movable element and the bottom layer form a vertical comb-drive actuator. Middle and bottom layers support the top layer while middle layer electrically isolates top and bottom layers. As a result, the MEMS actuator is consisted of both in-plane and vertical comb-drive actuators.
The movable element is typically connected to electrical ground while the stationary element on the top layer is connected to a voltage source and the bottom layer is connected to another voltage source. FIG. 3 illustrates the phase and amplitude relationships between deflection angle of movable element and applied voltage sources. The waveform of the voltage source can be square, triangular, sinusoidal, half-sinusoidal or other shapes to meet specific angular velocity needs.
FIG. 1D–1F illustrate one method of fabricating the comb-drive actuator in accordance with one embodiment of the present invention as described in FIG 1 A– 1 C. The first step, FIG 1 D, starts by etching the backside of a semiconductor wafer, preferably single crystal silicon then etches the front-side using deep reactive ion etching (DRIE) with the etched features on backside for alignment. The next step is to fusion bond the double-side etched wafer to another wafer coated with silicon dioxide then annealed to increase bonding strength. The bonded wafer becomes a three layer structure and the top layer may be ground and polished to desired thickness and to the required surface quality, FIG. 1E . The top layer is then DRIE etched down to the middle layer using the backside features for alignment and the movable element of the three-layer structure is released by removing the silicon dioxide connecting to the stationary elements, FIG 1 F.
FIGS. 1G and 1H illustrate another fabrication method of the comb-drive actuator. The process starts with back-side DRIE etching to the middle oxide layer of a silicon-on-insulator (SOI) wafer, FIG. 1G . The wafer is then etched from the front-side of the wafer to the middle oxide layer, FIG. 1H . The movable element of the three-layer structure is then released by removing the silicon dioxide connecting to the stationary elements.
FIG. 2A–2D and FIG. 3 show the operation of the MEMS actuator as described in FIG. 1 . The movable element is connected to electrical ground, the top stationary comb electrodes and the bottom stationary comb electrodes are connected to the first and the second AC voltage sources, respectively as shown in FIG. 2A . Top stationary and movable elements form an in-plane comb actuator whereas bottom stationary element and top movable element form a vertical comb actuator. The movable element starts oscillation with respect to the torsional hinges through either the unbalance of electrostatic force in the in-plane comb actuator or the electrostatic attraction from the vertical actuator, FIG. 2A . The unbalance force in the in-plane comb may be introduced from manufacturing tolerances or intentional design features. Electrostatic attraction force from the vertical comb actuator will rotate the movable element with respect to the torsional hinges to the maximum deflection angle, FIG. 2A˜2B . After the movable element reaches the largest deflection angle, electrostatic attraction force from the in-plane comb actuator will be applied to the movable element until horizontal position is restored, FIG. 2B˜2C . The movable element continues to rotate without actuation force to another maximum deflection angle, FIG. 2C˜2D . After the movable element reaches another maximum deflection angle, electrostatic attraction force from the in-plane comb actuator will again be applied to the movable element until horizontal position is restored to complete one oscillation cycle, FIG. 2D˜2A .
FIG. 3 illustrates the relationship of the applied voltage sources and the operation of the MEMS actuator corresponding to FIG. 2 . The movable element is typically designed to oscillate at or near its resonance frequency of primary oscillation mode. The movable element including top movable comb electrodes is connected electrical ground. The first voltage source AC 1 is applied to the top stationary structure with in-plane comb electrodes. The second voltage source AC 2 is applied to the bottom stationary comb electrodes. The frequency of voltage source AC 1 is typically twice the oscillation frequency of the movable element. The frequency of voltage source AC 2 is the same as the oscillation frequency of the movable element. The waveform of AC 1 and AC 2 can be various shapes to achieve desired angular velocity of the movable element. Typically, waveform of square shape gives the highest efficiency in driving the movable element to the largest rotation angle under given amplitude of AC 1 and AC 2 . FIG. 4 shows a three-dimensional view of the MEMS actuator with movable element rotating to its largest angle.
The present invention combines both in-plane and vertical comb actuators to drive the movable element to oscillate at large angle and at high frequency. Furthermore, the cavity depth in the bottom layer of the actuator, described in fabrication flow of FIGS. 1D , 1 E and 1 F, can be designed to be a mechanical stop to prevent excess deflection of the movable structure that could induce mechanical failure of the actuator.
FIGS. 5A , 5 B and 5 C show the exploded top views of the three layers of a MEMS actuator in accordance with another embodiment of the present invention. Top layer, FIG. 5A , is consisted of a stationary and a movable elements, both made of electrically conductive material, typically doped single crystal silicon. Movable element including comb electrodes is supported by multiple torsional hinges and is electrically isolated from stationary structure. The stationary element has comb electrodes that are interdigitated in the same horizontal plane with the comb electrodes of the movable element such that the top layer is an in-plane comb-drive actuator. Middle layer, FIG. 5B , is made of electrically non-conductive material, typically silicon dioxide. Bottom layer, FIG. 5C , consisting of a cavity and stationary comb electrodes, is made of electrically conductive material, typically doped single crystal silicon. Comb electrodes on the bottom layer are electrically isolated into two halves located on different sides of the torsional hinges. Stationary comb electrodes on bottom layer are interdigitated with comb electrodes of the movable element on top layer such that the movable element and the bottom layer form a vertical comb-drive actuator with dual-side driving capability. Middle and bottom layers support the top layer while middle layer electrically isolates top and bottom layers. As a result, the MEMS actuator is consisted of both in-plane and vertical comb-drive actuators.
FIG. 6A–6D illustrate one method of fabricating the comb-drive actuator in accordance with the embodiment as described in FIG. 5A–5C . The first step, FIG. 6A , starts by etching the backside of a semiconductor wafer, preferably single crystal silicon then etches the front-side using deep reactive ion etching (DRIE) with the etched features on backside for alignment. Cavity size and depth, and the stationary vertical comb electrodes are defined. The next step is to fusion bond the double-side etched wafer to another wafer coated with silicon dioxide then annealed to increase bonding strength, FIG. 6B . The bonded wafer becomes a three layer structure and the top layer may be ground and polished to desired thickness and to the required surface quality. Backside of the bonded wafer is separated into two halves using DRIE, FIG. 6C . Since the bottom layer is bonded to the top layer so the three layer structure remains intact. The top layer is then DRIE etched down to the middle layer using the backside features for alignment and the movable element of the three-layer structure is released by removing the silicon dioxide connecting to the stationary elements, FIG. 6D .
The comb-drive actuator, described in FIGS. 5A , 5 B and 5 C, can also be fabricated using process flow steps of FIGS. 1G and 1H . The process starts with back-side DRIE etching of the bottom layer to the middle oxide layer of a SOI wafer and also separates the bottom layer into two halves, FIG. 1G . Since the bottom layer is bonded to the top layer so the three layer structure remains intact. The wafer is then etched from the front-side of the wafer to the middle oxide layer, FIG 1 H. The movable element of the three-layer structure is then released by removing the silicon dioxide connecting to the stationary elements.
FIG. 5D shows a variation of the bottom layer as described in FIG. 5C . The bottom layer are electrically isolated into two halves and reinforced with thin film deposited materials. The reinforcement materials must have electrically non-conductive materials such as silicon dioxide. The comb-drive actuator, defined by FIGS. 5A , 5 B and 5 D, can be fabricated with process steps of FIG. 7A˜7F . Process steps of FIG. 7A˜7C is the same as process steps of FIG. 6A˜6C . After the backside of wafer is etched and separated into two halves, FIG. 7C , electrically isolated material such as silicon dioxide is deposited on the backside and the opened channels using thin film processes, FIG. 7D . Another layer of material, such as polysilicon, is further deposited on the backside and the opened channels to complete the reinforcement, FIG. 7E . The thin film materials on the backside may be removed by grinding and polishing. Top layer is then DRIE etched down to the middle layer using the backside features for alignment and the movable element of the three-layer structure is released by removing the silicon dioxide connecting to the stationary elements, FIG 7 F.
FIG. 8 and FIG. 9 illustrate the operation of the MEMS actuator as described in FIG. 5 . Movable element on top layer is connected to electrical ground while stationary comb electrodes is connected the first AC voltage source. The two sets of bottom stationary comb electrodes are connected to the second and the third AC voltage sources, respectively as shown in FIG. 8A . Movable element starts oscillation with respect to the torsional hinges through either the unbalance of electrostatic force in the in-plane comb electrodes or the electrostatic attraction from the vertical comb electrodes, FIG. 8A . The unbalance force in the in-plane comb may be introduced from manufacturing tolerances or intentional design features. Electrostatic attraction force from one side of the vertical comb actuator will rotate the movable element with respect to the torsional hinges to the maximum deflection angle, FIG. 8A˜8B . After the movable element reaches the largest deflection angle, electrostatic attraction force from the in-plane comb actuator will be applied to the movable element until horizontal position is restored, FIG. 8B˜8C . Electrostatic attraction force from another side of the vertical comb electrodes will rotate the movable element to another maximum deflection angle, FIG. 8C˜8D . After the movable element reaches another maximum deflection angle, electrostatic attraction force from the in-plane comb actuator will again be applied to the movable element until horizontal position is restored to complete one oscillation cycle, FIG. 8D˜8A .
FIG. 9 illustrates the relationship of the applied voltage sources and the operation of the MEMS actuator corresponding to FIG. 5 . The movable element is typically designed to oscillate at or near its resonance frequency of primary oscillation mode. The movable element including top movable comb electrodes is connected electrical ground. First voltage source AC 1 is applied to the top stationary structure with in-plane comb electrodes. Second voltage source AC 2 is applied to one set of the bottom stationary comb electrodes. Third voltage source AC 3 is applied to another set of the bottom stationary comb electrodes. The frequency of voltage source AC 1 is typically twice the oscillation frequency of the movable element. The frequency of voltage sources AC 2 and AC 3 are the same as the oscillation frequency of the movable element but at different phases. The waveform of AC 1 , AC 2 and AC 3 can be various shapes to achieve desired angular velocity of the movable element. Typically, waveform of square shape gives the highest efficiency in driving the movable element to the largest rotation angle under given amplitude of AC 1 , AC 2 and AC 3 .
FIG. 10A illustrates a method to form electrical connections to the bottom layer of the actuator with SOI structure. Additional openings on the top layer are etched in DRIE etching process step as described in FIG. 1F , 1 H, 6 D or 7 F to expose access to the middle layer. Electrical insulation material of the middle layer in the exposed area is then removed during structure release process. Connections can be made to the bottom layer through conventional methods, such as wire-bonding after deposition of metallic contact pad.
FIGS. 10B and 10C illustrate another method to form electrical connections to the bottom layer of the actuator with SOI structure. The SOI structure is connected to a substrate through a layer of electrically conductive material which is separated into two halves to avoiding electrical bridging. The conductive material may be conductive paste, conductive film, solder paste, etc. The substrate is configured for fan-out of the bottom comb electrodes. Dielectric material is disposed on the substrate which insulates the metal conductor pads on she substrate. Fan-out can be done on the from the top side conductor pads of the substrate, FIG. 11B or from bottom side conductor pads connecting to top side conductor pads through via holes, FIG. 11C .
FIG. 11 illustrates one invention embodiment to adjust the structural resonance frequency of the movable element by increasing the effective torsional stiffness of the torsional hinges. Torsional hinges are designed with comb electrodes and are interdigitated with a set of comb electrodes on the stationary structure of the top layer. This set of comb electrodes on the top stationary structure are connected to a DC voltage source and are electrically isolated from the rest of the comb electrodes on the top layer. During oscillation motion of the movable element, the voltage difference between the DC voltage and the ground will generate electrostatic attraction force between the additional comb electrodes which will suppress the torsional rotation of the portion of hinge with additional electrodes. By adjusting the voltage difference between DC and ground, the effective torsional stiffness of the hinges can be increased such that resonance frequency of the movable element can be tuned.
FIG. 12 illustrates another invention embodiment to adjust the structural resonance frequency of the movable element by thinning portions or trimming portions of protrusions on the torsional hinges. The protrusions may be removed selectively utilizing techniques such as laser trimming, E-beam lithography, etc without damaging structural integrity. The effective torsional stiffness of the torsional hinges are reduced such that the resonance frequency of the movable element can be tuned.
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A micro-electro-mechanical component comprising a movable element with comb electrodes, and two stationary elements with comb electrodes aligned and stacked on each other but electrically insulated by a layer of insulation material. The movable element is supported by multiple torsional hinges and suspended over a cavity such that the element can oscillate about an axis defined by the hinges. The comb electrodes of the movable element are interdigitated with the comb electrodes of one stationary element in the same plane to form an in-plane comb actuator. The comb electrodes of the movable element are also interdigitated in an elevated plane with the comb electrodes of another stationary element to form a vertical comb actuator. As a result, the micro-electro-mechanical component is both an in-plane actuator and a vertical comb actuator, or a multiple-plane actuator. Methods of fabricating such actuator are also described.
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BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to a device for releasably connecting two axially aligned tubes. The invention is specifically directed to a generally linear device having opposing end portions which are to be inserted into the open ends of tubes and then radially expanded by a hand-actuated mechanism.
[0002] There are various types of connector apparatuses of the prior art which are adapted to facilitate the quick releasable coupling of tubes. Many such connectors employ bolts, screws or pins which must be inserted through compatible holes in the tubes in order to secure a connection. Unfortunately, shear stress often makes these fastening objects susceptible to yield or even catastrophic failure that eventually necessitates their replacement, if not rendering more serious consequences. Furthermore, since pins, bolts, etc. are generally removable from the connector devices, they can be easily misplaced.
[0003] Therefore, it can be appreciated that there exists a need for a truss connector apparatus that is adapted to facilitate a secure coupling of tubes without employing any loose parts that can be misplaced or damaged. The truss connector of the present invention substantially fulfills this existing need.
SUMMARY
[0004] The present invention is a mechanical device for rigidly joining open-ended pipes and tubular objects generally. The constituent major components of a preferred embodiment of the invention include: a pair of arbors, a pair of collets, a pair of traveling collet nuts, a key member and a rotable handwheel for turning the key member, all mounted on a differential screw. One arbor, collet and traveling nut sit side-by-side along a proximal segment of the screw while the other arbor, collet and traveling nut sit side-by-side along its distal segment. The key member is stationed generally within a middle segment of the screw. The rotable handwheel is axially movable within the middle segment, and the handwheel features a taper for receiving the key member.
[0005] Both combinations of arbor, collet and nut act as inserting members for being plugged into tubes that the connector device is joining. The handwheel, when engaged with the key member, functions as a means for driving the collet nuts to and fro along the screw and ultimately causing radial expansion of the collets and their consequential binding to the tubes' interior walls. In fact, the present connector facilitates a rigid joining of two tubes by a user following the three successive steps of: (1) slipping the ends of both tubes over the proximal and distal segments of the connector, thereby disposing the connector's arbors, collets and collet nuts within the tubes; (2) sliding the handwheel toward the key and eventually fitting the key into a matching slot along the handwheel; and (3) turning the handwheel (and therefore the screw itself) to propel the collet nuts against the collets, eventually causing radial expansion of the collets and friction binding the expanded collets to the interior walls of the tubes.
[0006] It is, therefore, an object of the present invention to provide a tube connector device that rigidly binds tubes together while effectively eliminating the possibility of connection failure due, specifically, to yielding or shearing of the connector's fastening components.
[0007] It is another object of the present invention to provide a tube connector device does not employ any loose or unattached parts that can be easily lost. All of the instant connector's components can remain integrated within a single physical apparatus before, during and after the connector is applied in use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view of the tube connector of in a disassembled state;
[0009] FIG. 2 is a perspective view of the connector when fully assembled;
[0010] FIG. 3 is a perspective view of two tubes being coupled by the connector; and
[0011] FIG. 4 is an exploded view of the key member and the arbor to which the key member attaches.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] A preferred embodiment of the tube connector 1 of the present invention is illustrated in the accompanying FIG. 1 as fully assembled and FIG. 2 in an unassembled state. The connector 1 is comprised of metal components which are mounted on an elongate differential screw 2 . As shown in FIG. 2 , the screw 2 comprises three distinct linear segments: a threaded proximal segment 4 , a reversely threaded distal segment 8 and an unthreaded middle segment 6 .
[0013] Referring back to FIG. 1 , arranged consecutively along the proximal segment, from near the proximal end of the screw 2 toward its middle segment, are a traveling collet nut 26 , a collet 24 and an arbor 22 . Similarly, arranged along the distal segment, from near the distal end inward, are another collet nut 26 , collet 24 and arbor 22 . At both ends of the differential screw 2 are welded-on retaining rings 30 or some other retaining parts for preventing the adjacent collet nuts 26 from traveling off the screw 2 .
[0014] The arbors 22 each comprise a tubular section 22 a and a generally conical tapered section 22 b , and they are oriented such that their tapered ends abut the collets 24 . The collets 24 are each shaped such that one end wedges over the adjacent arbor's tapered section 22 b while the opposite end wedges over the adjacent traveling nut 26 . O-rings 32 circumscribe and compress the middles of the collets 24 to further facilitate wedging action.
[0015] The screw's middle segment 6 is defined, essentially, as the linear portion of the screw 2 that sits between the arbors 22 . At one edge of the middle segment 6 , abutting the tubular end of an arbor 22 , is a washer 28 . Another washer 28 is stationed at the opposite end of the middle segment 6 . Immediately next to one washer 28 is a key member 14 . In a preferred embodiment of the connector 1 , the key 14 is simply a short stud that screws into and protrudes from the tubular end of an arbor 22 , as shown in exploded view in FIG. 4 . This embodiment of a key 14 pierces a matching bore in the adjacent washer 28 and projects into the middle segment 6 of the screw 2 . However, the key device 14 can conceivably take on a number of alternative embodiments of articles stationed within, or immediately adjacent to, the screw's middle segment 6 . In any event, the key is fixedly attached to the screw 2 such that the screw 2 will rotate when force acting upon the key 14 revolves the key 14 around the screw axis.
[0016] A knurled handwheel 18 is loosely mounted along the screw's middle segment 6 such that a user may slide the handwheel 18 back and forth between the two washers 28 . The handwheel 18 features a notch or slot 20 for fitting the key 14 within. Therefore, as illustrated in FIG. 3 , the handwheel 18 may be engaged with the key 14 by simply aligning the key slot 20 with the key 14 and then sliding the handwheel 18 over the key 14 so that the key 14 lodges into the slot 20 .
[0017] The connector 1 joins separate tubes 100 , 200 at their ends by friction binding itself to their respective interior walls in spigot fashion. A first tube 100 is slid over the proximal segment 4 of the screw 2 such that the end of the tube 100 meets the proximal side washer 28 , and the second tube 200 is fitted over the distal segment 8 in like fashion. Thus, in addition to fitting over much of the length of the screw 2 , the tubes 100 , 200 engulf the pairs of arbors 22 , collets 24 and collet nuts 26 . In fact, the arbors' tubular sections 22 a are a push fit within the tubes 100 , 200 .
[0018] Once the connector 1 is properly disposed within the tubes 100 , 200 and the handwheel 18 is engaged with the key device 14 as illustrated in FIG. 3 , a user secures the connector 1 to the tubes 100 , 200 by actuating the collet nuts 26 . Specifically, the user turns the rotatable handwheel 18 clockwise. This handwheel 18 rotation revolves the key 14 around the screw axis and thereby rotates the screw 2 . However, due to friction between the abutting collet nuts 26 and collets 24 , the collet nuts 26 are inhibited from rotating with the screw 2 . Instead, both nuts 26 are drawn inward, pressing the collet nuts 26 against the collets 24 and, in turn, the collets 24 against the arbors 22 . As the differential screw 2 continues to be rotated, the collet nuts 26 wedge under the collets 24 while the collets 24 wedge over the arbors' tapered sections 22 b . The collets' ends radially expand and friction-bind themselves to the interior walls of the tubes 100 , 200 .
[0019] When the collets 24 are sufficiently bound to the tubes 100 , 200 , the user discontinues turning the handwheel 18 and slides it off of the key 14 . Disengaging the handwheel 18 from the key 14 prevents the handwheel 18 from causing any reverse rotation of the screw 2 and resulting contraction of the collets 24 . Of course, to detach the connector 1 from the tubes 100 , 200 , the user simply re-engages the handwheel 18 to the key 14 and then turns the handwheel 18 counterclockwise. This causes the collet nuts 26 to travel outward and relieves sandwiching pressure exerted on the collets 24 , allowing the collets 24 to radially contract.
[0020] Although the present invention has been described in considerable detail and with reference to and illustration of a preferred version, it should be understood that other versions are contemplated as being a part of the present invention.
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A tube connector for quickly and releasably coupling tubes. The connector is a fully integrated device which connects tubes, end-to-end, by binding to them in spigot fashion with an arbor, traveling nut and expandable collet assembly.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a wear resistant, flame-retardant material composition and to an electric cable or wire covered with a material containing such a composition. This type of protected electric cable or wire is used, for example, in automotive vehicles.
[0003] 2. Description of Background Information
[0004] Polyvinyl chloride has been widely used as a coating material for electrical cables or wires used in vehicles, owing to its excellent mechanical strength, facility with which it can be extruded around an electric cable, its excellent flexibility and paintability, as well as its low cost.
[0005] However, because of recent environmental measures, manufacturing of parts for vehicles, including coatings of electrical wires used in vehicles, has started to use halogen free (polymer) materials instead of polyvinyl chloride.
[0006] A halogen free resin composition containing a polyolefin as a base polymer and metal hydroxides as flame retardants is well known (see JP-A-7-176219 and JP-A-7-78518). This composition is a wear resistant resin composition and has the advantage of not producing toxic gas such as halogen gas when burning.
[0007] However, it is necessary to add large amounts of metal hydroxides to make this composition sufficiently flame retardant to yield a self extinguishing property. When adding such large amounts of metal hydroxides, the mechanical strength of the composition, such as its wear resistance and tensile strength falls dramatically. To prevent such lowering of mechanical strength, it has been suggested to raise the amount of propylene having a relatively high hardness and the amount of polypropylene having a high density. However, in this case, the flexibility of the protected electric cable or wire is then lowered and the manufacturability thereof is also lowered.
[0008] JP-A-6-290638 discloses a resin composition containing metal hydroxides used for insulating electrical wires. This composition contains polypropylene as the main component (more than 80%). The other components of this composition are copolymers of styrene and polyethylene modified by acid anhydrides.
[0009] U.S. Pat. No. 5,561,185 discloses as a resin composition containing metal hydroxides, used for protecting electrical wires, a resin composition containing:
[0010] (a) 40 to 88.5% by mass (or by weight) of a polypropylene type resin containing at least 50% by mass of ethylene-propylene random copolymers;
[0011] (b) 1.5 to 30% by mass of polyethylene modified by an unsaturated carboxylic acid or derivatives thereof (e.g. maleic anhydride); and
[0012] (c) 10 to 48% by mass of ethylene type copolymer, typically ethylene/vinyl acetate copolymer.
[0013] U.S. Pat. No. 5,180,889 discloses a resin composition containing metal hydroxides as a coating for the conductor of a crush resistant cable. This composition contains:
[0014] a) ethylene/α olefin copolymer having a low density;
[0015] b) a system of styrene-ethylene-butylenes-styrene tri-block copolymer-elastomer, preferably modified by maleic anhydride; and
[0016] c) optionally, a shock-resistant propylene copolymer or polypropylene.
[0017] It has been proposed to improve the heat resistance of the resin composition used for electrical wire insulation by cross-linking the resin composition.
[0018] JP-A-8-161942 proposes to coat electrical wires with a resin composition containing an ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate (EEA) and metal hydrates, and to cross-link this composition using electron beam irradiation.
[0019] JP-A-2000-294039 proposes to cross-link a composition containing ethylene type polymer(s) and maleic anhydride modified polyolefins.
[0020] The compositions obtained by cross-linking a resin composition containing as a base an ethylene type polymer have excellent heat resistance but insufficient wear resistance.
[0021] JP-A-2000-86830 discloses a composition obtained by cross-linking a resin composition containing polyolefin type elastomers, metal hydroxides and a coupling-agent surface treated potassium titanate.
[0022] JP-A-2000-336215 discloses a resin composition containing a polyolefin type resin prepared with magnesium hydroxide or aluminum hydroxide whose surface is treated, silicone powder and a cross-linking accelerator. This composition is also cross-linked.
[0023] Such compositions have an improved tensile and mechanical strength, but a poor flexibility and formability.
SUMMARY OF THE INVENTION
[0024] One purpose of the present invention is to provide a flame retardant resin composition containing metal hydroxides which is suitable for coating electrical wires or cables, and which has an improved flame retardant quality, as well as improved wear resistance, flexibility and formability.
[0025] To solve the above-mentioned problem, there is provided a resin composition comprising:
[0026] (a) about 30 to 90 parts by mass of polyethylene having a melt flow rate (MFR) of about 5 g/10 min at the most and a density of at least about 0.930;
[0027] (b1) about 5 to 65 parts by mass of olefin type polymer containing intra molecular oxygen atoms;
[0028] (c) about 5 to 40 parts by mass of at least one type of polymer selected from the group consisting of:
[0029] (c1) acid modified olefin polymers containing intra-molecular oxygen atoms;
[0030] (c2) acid modified styrene type thermoplastic elastomers;
[0031] (c3) acid-modified polyethylenes having a density of about 0.920 at the most; and
[0032] (c4) acid modified rubbers,
[0033] with the proviso that the total of components (a), (b1) and (c) represents 100 parts by mass; and
[0034] (d) about 30 to 250 parts by mass of metal hydroxide.
[0035] Preferably, the resin composition is cross-linked by electron beam irradiation.
[0036] Alternatively, the invention relates to a resin composition comprising:
[0037] (a) about 30 to 90 parts by mass of polyethylene having a melt flow rate (MFR) of about 5 g/10 min at the most and a density of at least about 0.930;
[0038] (b2) about 5 to 65 parts by mass of styrene type thermoplastic elastomer; and
[0039] (c) about 5 to 40 parts by mass of at least one type of polymer selected from the group consisting of:
[0040] (c1) acid modified olefin type polymers containing intra-molecular oxygen atoms, and
[0041] (c2) acid modified styrene type thermoplastic elastomers;
[0042] with the proviso that the total of components (a), (b2) and (c) represents 100 parts by mass; and
[0043] (d) about 30 to 250 parts by mass of metal hydroxide.
[0044] Preferably, the resin composition is cross-linked by electron beam irradiation.
[0045] The invention further relates to a process for applying, to a conductor element, a resin composition comprising:
[0046] (a) about 30 to 90 parts by mass of polyethylene having a melt flow rate (MFR) of about 5 g/10 min at the most and a density of at least about 0.930;
[0047] (b1) about 5 to 65 parts by mass of olefin type polymer containing intra molecular oxygen atoms;
[0048] (c) about 5 to 40 parts by mass of at least one type of polymer selected from the group consisting of:
[0049] (c1) acid modified olefin polymers containing intra-molecular oxygen atoms;
[0050] (c2) acid modified styrene type thermoplastic elastomers;
[0051] (c3) acid-modified polyethylenes having a density of about 0.920 at the most; and
[0052] (c4) acid modified rubbers,
[0053] with the proviso that the total of components (a), (b1) and (c) represents 100 parts by mass; and
[0054] (d) about 30 to 250 parts by mass of metal hydroxide;
[0055] so as to prepare an electrical cable.
[0056] Preferably, the above process further comprises the step of irradiating the resin composition with electron beams.
[0057] Alternatively, the invention concerns a process for applying, to a conductor element, a resin composition comprising:
[0058] (a) about 30 to 90 parts by mass of polyethylene having a melt flow rate (MFR) of about 5 g/10 min at the most and a density of at least about 0.930;
[0059] (b2) about 5 to 65 parts by mass of styrene type thermoplastic elastomer; and
[0060] (c) about 5 to 40 parts by mass of at least one type of polymer selected from the group consisting of:
[0061] (c1) acid modified olefin type polymers containing intra-molecular oxygen atoms, and
[0062] (c2) acid modified styrene type thermoplastic elastomers;
[0063] with the proviso that the total of components (a), (b2) and (c) represents 100 parts by mass; and
[0064] (d) about 30 to 250 parts by mass of metal hydroxide;
[0065] so as to prepare an electrical cable.
[0066] Preferably, the above process further comprises the step of irradiating the resin composition with electron beams.
[0067] There is further provided an electrical cable coated with a resin composition comprising:
[0068] (a) about 30 to 90 parts by mass of polyethylene having a melt flow rate (MFR) of about 5 g/10 min at the most and a density of at least about 0.930;
[0069] (b1) about 5 to 65 parts by mass of olefin type polymer containing intra molecular oxygen atoms;
[0070] (c) about 5 to 40 parts by mass of at least one type of polymer selected from the group consisting of:
[0071] (c1) acid modified olefin polymers containing intra-molecular oxygen atoms;
[0072] (c2) acid modified styrene type thermoplastic elastomers;
[0073] (c3) acid-modified polyethylenes having a density of about 0.920 at the most; and
[0074] (c4) acid modified rubbers,
[0075] with the proviso that the total of components (a), (b1) and (c) represents 100 parts by mass; and
[0076] (d) about 30 to 250 parts by mass of metal hydroxide.
[0077] Suitably, the resin composition is further cross-linked by electron beam irradiation.
[0078] There is further provided an electrical cable coated with a resin composition comprising:
[0079] (a) about 30 to 90 parts by mass of polyethylene having a melt flow rate (MFR) of about 5 g/10 min at the most and a density of at least about 0.930;
[0080] (b2) about 5 to 65 parts by mass of styrene type thermoplastic elastomer; and
[0081] (c) about 5 to 40 parts by mass of at least one type of polymer selected from the group consisting of:
[0082] (c1) acid modified olefin type polymers containing intra-molecular oxygen atoms and
[0083] (c2) acid modified styrene type thermoplastic elastomers;
[0084] with the proviso that the total of components (a), (b2) and (c) represents 100 parts by mass; and
[0085] (d) about 30 to 250 parts by mass of metal hydroxide.
[0086] Suitably, the resin composition is further cross-linked by electron beam irradiation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0087] Each component of the composition of the invention is chosen in order to confer, when mixed with the others, a desired property to the resulting material. Explanations regarding each of the components are given hereinafter.
[0088] Component (a) is a polyethylene having a melt flow rate (MFR) of 5 g/10 min or less and a density of at least 0.930.
[0089] The polyethylene used can be any polyethylene having the above-mentioned density and melt flow rate. However, high density polyethylene or straight-chain low density polyethylene are preferably used.
[0090] When the MFR of polyethylene exceeds 5 g/10 min, the formability of the composition is deteriorated.
[0091] The MFR value is measured according to JIS K 6921-2.
[0092] Moreover, when the density of the polyethylene is less than 0.930, the hardness of the composition is lowered, and its wear resistance is also lowered.
[0093] The amount of component (a) represents 30 to 90 parts by mass, preferably 30 to 80 parts by mass, in the total of 100 parts by mass consisting of component (a), component (b1) or (b2) and component (c).
[0094] When the amount of component (a) is higher than the upper limit, the flexibility and formability of the composition are lowered. When this amount is lower than the lower limit, the composition has a poor wear resistance.
[0095] Examples of olefin polymers (b1) containing intramolecular oxygen atoms include a copolymer of olefins (e.g. ethylene) and unsaturated monomers containing oxygen atoms (e.g. vinyl acetate, ethyl acrylate and ethyl methacrylate). In practice, ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers and ethylene-methyl methacrylate copolymers can be given as examples.
[0096] The styrene type thermoplastic elastomers (b2) may be, for example, thermoplastic copolymers of styrene and olefins (e.g. ethylene or propylene). Practically, styrene-ethylene block copolymers, styrene-ethylene-propylene block copolymers and their hydrogenated derivatives obtained by adding hydrogen atoms in their unsaturated bonds can be given as examples.
[0097] The amount of component (b1) or (b2) ranges from 5 to 65 parts by mass, preferably from 10 to 60 parts by mass, in the total of 100 parts by mass consisting of component (a), component (b1) or (b2) and component (c).
[0098] When the amount of component (b1) or (b2) is higher than the above-mentioned upper limit, the wear resistance of the composition is lowered. When this amount is lower than the above-mentioned lower limit, the flexibility and formability of the composition are lowered.
[0099] Examples of acid-modified olefin polymers (c1) containing intramolecular oxygen atoms include polymers which may be obtained by introducing, as acid components, unsaturated carboxylic acids or their derivatives (e.g. anhydrides or esters) into olefin polymers (b1) containing intramolecular oxygen atoms. Typical examples of such unsaturated carboxylic acids or their derivatives include maleic acid, fumaric acid, maleic anhydride, maleic acid monoesters and maleic acid diesters.
[0100] The acids can be introduced into the olefin type polymer by grafting or by any direct method (copolymerization). The amount of acid used for modification or denaturation preferably range from 0.1 to 20 by mass with respect to the mass amount of olefin type polymer.
[0101] The acid-modified styrene type thermoplastic elastomers (c2) may be the polymers obtained by introducing, as acid components, unsaturated carboxylic acids or their derivatives (e.g. acid anhydrides or esters) into styrene type thermoplastic elastomers (b2). The types of unsaturated carboxylic acids or their derivatives, the method of their introduction and the amount used are the same as described above for the case of component (c1).
[0102] The acid-modified polyethylene (c3) having a density of 0.920 or less may be the polymers obtained by introducing, as acid components, unsaturated carboxylic acids or their derivatives (e.g. acid anhydrides or esters) into relatively low density polyethylene (e.g. so-called ultra-low density polyethylene such as ethylene-octene copolymers). The types of unsaturated carboxylic acids or their derivatives, the method of their introduction and the amount used are the same as described above for the case of component (c1).
[0103] When the density of acid modified polyethylene is more than 0.920, the hardness of the composition is increased and its flexibility is lowered.
[0104] The acid modified rubber (c4) may be obtained, for example, by introducing the above-mentioned unsaturated carboxylic acids or their derivatives into a rubber. Examples of such rubber include ethylene-propylene rubber, ethylene-propylene-diene rubber or the like. The types of unsaturated carboxylic acids or their derivatives, the method of their introduction and the amount used are the same as described above for the case of component (c1).
[0105] The amount of component (c) represents from 5 to 40 parts by mass, preferably 10 to 40 parts by mass, in the total of 100 parts by mass consisting of component (a), component (b1) or (b2) and component (c).
[0106] When the amount of component (c) is greater than the above-mentioned upper limit, the wear resistance of the composition is lowered. Conversely, when its amount is less than the above-mentioned lower limit, the flexibility and formability of the composition tends to decrease.
[0107] Examples of metal hydroxides (d) include magnesium hydroxide, aluminum hydroxide, and the like. Metal hydroxide particles need not be specifically treated. However, the surface may also be treated with a surface treatment agent such as coupling agents, in particular, silane coupling agents (e.g. amino silane coupling agent, vinyl silane coupling agent, epoxy silane coupling agent, methacryloxysilane coupling agent) or optionally higher fatty acids (e.g. stearic acid, oleic acid or the like).
[0108] A silane coupling agent typically contains a Si—O bond which can form a bond with hydroxides. Among metal hydroxides, a preferred compound is magnesium hydroxide or aluminium hydroxide whose surface is treated with a coupling agent, preferably a silane coupling agent, in particular an aminosilane coupling agent.
[0109] The particles of metal hydroxides need not be pre-treated with a coupling agent. Instead, they may be mixed directly with a resin, then supplemented with a coupling agent, according to a method called “integral blending”.
[0110] The amount of metal hydroxide usually represents from 30 to 250 parts by mass, preferably from 50 to 200 parts by mass, of the total of component (a), component (b1) or (b2) and component (c) representing 100 parts by mass.
[0111] Any known additive may be added into the composition in such an amount that does not damage preferable characteristics of the composition. Examples of the above additives include those usually added into olefin type resins such as heat stabilizers (e.g. oxidation-preventing agents), metal-inactivating agents (copper-pollution preventing agents), lubricants (fatty acids, fatty acid amides, metallic soaps, hydrocarbons e.g. wax, esters, silicone type lubricants), light stabilizers, core-forming agents, electrification-preventing agents, colorants, flame retardant adjuvants, (e.g. zinc borate, silicone type flame retardant, nitrogen type retardant), coupling agents (e.g. silane type coupler, titanate type coupler), softening agents (e.g. process oils), cross-linking adjuvants (poly functional monomers and the like).
[0112] The resin composition of the invention may be prepared by mixing and/or kneading the components cited above according to any known method.
[0113] The resin composition of the invention may be cross-linked according to any known method e.g. electron beam irradiation.
[0114] The resin composition of the present invention may be used for coating electrical cables, in particular electrical cables for vehicles according to any known method.
[0115] The above, and the other features and advantages of the present invention will be made apparent from the following description of the preferred examples, given as non-limiting examples, with references to the following Examples and Comparative Examples.
EXAMPLES 1 TO 10 AND COMPARATIVE EXAMPLES 1 TO 9
[0116] The components shown in Tables 1 to 4 were mixed together in the amounts (parts by mass) indicated therein, kneaded in a temperature range of 180° C. to 260° C., and extruded into pellets by a two-axis extruder. The pellets were dried and extruded and shaped around a conductor element (7/0.30) having a cross section of 0.5 mm 2 , so as to yield a coating of 0.28 mm thick. The coated resin composition was then cross-linked by electron beam irradiation.
[0117] The extrusion-shaping was performed using a nipple and die respectively having a diameter of about 0.93 mm and about 1.45 mm. The extrusion temperatures for the die and cylinder were respectively about 180° C. to about 250° C. and about 160° C. to about 240° C. The extrusion line speed was 100 m/min.
[0118] The electron beam irradiation conditions were as follows.
[0119] Device: EPS-750 KV
[0120] Irradiation intensity: 120 KGy
[0121] The following properties of the coated electrical cables obtained in Examples 1 to 10 and Comparative Examples 1 to 9 were evaluated.
[0122] Flexibility:
[0123] The flexibility was evaluated on the basis of resistance feeling, when the electrical cable was bent manually.
[0124] Wear Resistance and Flame Retardant Quality
[0125] Wear resistance and flame retardant quality were measured according to Standards JASO D 611. As to wear resistance, the results were considered good when the minimum value among 3 samples tested was more than 150 times.
[0126] Formability
[0127] The formability was evaluated by observing whether or not whiskers were formed when coatings were peeled at the end portion of electrical cables. The results are shown in Tables 1 to 4
TABLE 1 Example Example Example Example Example 1 2 3 4 5 HDPE 1) 65 50 65 30 40 LLDPE 2) EVA 3) 30 10 65 30 EEA 4) 5 MAH- 5 40 30 30 EVA 5) MAH- 5 EEA 6) magnesium 100 120 100 250 30 hy- droxide 7) anti-aging 1 1 1 1 1 agent 8) cross- 4 4 2 4 linking ad- juvant 9) Total 205 225 203 355 131 flexibility passed passed passed passed passed wear passed passed passed passed passed resistance flame passed passed passed passed passed retardant quality formability passed passed passed passed passed
[0128] [0128] TABLE 2 Example Example Example Example Example 6 7 8 9 10 HDPE 1) 50 50 70 40 LLDPE 2) 90 EVA 3) 5 30 10 40 EEA 4) 30 MAH- 5 20 20 20 EVA 5) MAH- 20 EEA 6) magnesium 40 90 100 120 30 hy- droxide 7) anti-aging 1 1 1 1 1 agent 8) cross- 2 4 4 2 2 linking agent 9) Total 143 195 205 223 133 flexibility passed passed passed passed passed wear passed passed passed passed passed resistance flame passed passed passed passed passed retardant quality formability passed passed passed passed passed
[0129] [0129] TABLE 3 Comparative Comparative Comparative Comparative Comparative Example 1 Example 2 Example 3 Example 4 Example 5 HDPE 1) 100 20 LLDPE 2) 30 EVA 3) 100 70 50 PP 10) MAH-EVA 5) 80 50 MAH-PP 11) magnesium 100 80 50 100 30 hydroxide 7) anti-aging agent 8) 1 1 1 1 1 cross-linking 4 2 2 2 2 agent 9) Total 205 183 153 203 133 Flexibility failed passed passed passed passed wear resistance passed failed failed failed failed flame retardant passed passed passed passed passed quality Formability failed passed passed passed passed
[0130] [0130] TABLE 4 Compar- Compar- Compar- Compar- ative ative ative ative Example 6 Example 7 Example 8 Example 9 HDPE 1) 65 60 85 70 LLDPE 2) EVA 3) 10 10 25 PP 10) 30 MAH-EVA 5) 5 5 5 MAH-PP 11) 30 magnesium 30 200 10 300 hydroxide 7) anti-aging 1 1 1 1 agent 8) cross-linking 2 4 2 2 agent 9) Total 133 305 112 403 flexibility failed failed passed failed wear resistance passed passed passed passed flame retardant passed passed failed passed quality formability failed failed passed failed
[0131] From the results of Comparative Examples 1 to 5, it can be understood that, when the amount of any one component chosen among components (a), (b1) and (c1) is outside the range defined in the present invention, at least one of the tested physical properties is not satisfied.
[0132] The results of Comparative Examples 6 and 7 show that, when any one of component (b1) and component (c1) is not used, the flexibility and formability of the composition deteriorate.
[0133] The results of Comparative Examples 8 and 9 indicate that, when the amount of magnesium hydroxide, a flame retardant (d) is too small, the flame retardant quality of the composition deteriorates. Conversely, when this amount is too large, the flexibility and formability of the composition deteriorate.
EXAMPLES 11 TO 20 AND COMPARATIVE EXAMPLES 10 TO 18
[0134] The components shown in Tables 5 to 8 were used in the amounts indicated therein (parts by mass). Coated electrical cables were produced through the methods described for Examples 1 to 10, and the properties of the obtained coating were evaluated. The results thus obtained are given in Tables 5 to 8.
TABLE 5 Example Example Example Example Example 11 12 13 14 15 HDPE 1) 60 50 65 30 50 LLDPE 2) EVA 3) 35 10 65 30 EEA 4) 5 MAH- 5 40 30 5 20 SEBS 12) MAH-PP 11) magnesium 120 100 100 250 30 hydroxide 7) anti-aging 1 1 1 1 1 agent 8) cross-linking 4 4 2 4 2 agent 9) Total 225 205 203 355 133 flexibility passed passed passed passed passed wear passed passed passed passed passed resistance flame passed passed passed passed passed retardant quality formability passed passed passed passed passed
[0135] [0135] TABLE 6 Example Example Example Example Example 16 17 18 19 20 HDPE 1) 50 50 70 60 LLDPE 2) 90 EVA 3) 5 30 10 20 EEA 4) 30 MAH- 5 20 20 20 20 SEBS 12) MAH-PP 11) magnesium 50 90 100 120 30 hydroxide 7) anti-aging 1 1 1 1 1 agent 8) cross-linking 4 4 4 4 4 agent 9) total 155 195 205 225 135 flexibility passed passed passed passed passed wear passed passed passed passed passed resistance flame passed passed passed passed passed retardant quality formability passed passed passed passed passed
[0136] [0136] TABLE 7 Comparative Comparative Comparative Comparative Comparative Example 10 Example 11 Example 12 Example 13 Example 14 HDPE 1) 100 20 LLDPE 2) 20 EVA 3) 100 80 50 PP 10) MAH-SEBS 12) 80 50 MAH-PP 11) magnesium 90 100 80 100 30 hydroxide 7) anti-aging agent 8) 1 1 1 1 1 cross-linking agent 9) 4 2 4 4 4 Total 195 203 185 205 135 flexibility failed passed passed passed passed wear resistance passed failed failed failed failed flame retardant quality passed passed passed passed passed formability passed passed passed passed passed
[0137] [0137] TABLE 8 Compar- Compar- Compar- Compar- ative ative ative ative Example 15 Example 16 Example 17 Example 18 HDPE 1) 55 60 75 80 LLDPE 2) EVA 3) 10 5 10 PP 10) 40 MAH-SEBS 12) 5 20 20 MAH-PP 11) 30 magnesium 30 180 10 300 hydroxide 7) anti-aging 1 1 1 1 agent 8) cross-linking 2 2 4 4 agent 9) total 133 283 115 405 flexibility failed failed passed failed wear resistance passed passed passed passed flame retardant passed passed failed passed quality formability failed failed passed failed
[0138] From the results of Comparative Examples 10 to 14, it can be understood that, when the amount of any one component chosen among component (a), (b1) and (c2) is outside the range defined in the present invention, at least one of the physical properties tested is not satisfied.
[0139] The results of Comparative Example 15 show that, when an olefin polymer (b1) containing intra molecular oxygen atoms is not used, the flexibility and formability of the composition deteriorate.
[0140] The results of Comparative Example 16 indicate that, when an acid modified styrene type thermoplastic elastomer (c2) is not used, the flexibility and formability of the composition are lowered.
[0141] The results of Comparative Examples 17 and 18 show that, when the amount of magnesium hydroxide, a flame retardant (d), is too small, the flame retardant quality of the composition is poor. Conversely, when this amount is too large, the flexibility and formability of the composition deteriorate.
EXAMPLES 21 TO 30 AND COMPARATIVE EXAMPLES 19 TO 27
[0142] The components shown in Tables 9 to 12 were used in the amounts (parts by mass) indicated therein, and coated electrical cables were produced according to the methods mentioned for Examples 1 to 10. The properties of the coatings obtained were then evaluated. The results are shown in Tables 9 to 12.
TABLE 9 Example Example Example Example Example 21 22 23 24 25 HDPE 1) 65 50 65 30 50 LLDPE 2) EVA 3) 30 10 5 30 EEA 4) 65 MAH- 5 40 30 5 20 VLDPE 13) MAH-PP 11) magnesium 110 100 120 250 30 hydroxide 7) Anti-aging 1 1 1 1 1 agent 8) cross-linking 2 4 4 4 agent 9) total 213 205 225 355 131 flexibility passed passed passed passed passed wear passed passed passed passed passed resistance flame passed passed passed passed passed retardant quality formability passed passed passed passed passed
[0143] [0143] TABLE 10 Example Example Example Example Example 26 27 28 29 30 HDPE 1) 50 50 70 40 LLDPE 2) 90 EVA 3) 5 30 10 40 EEA 4) 30 MAH- 5 20 20 20 20 VLDPE 13) MAH-PP 11) magnesium 40 90 120 100 30 hydroxide 7) Anti-aging 1 1 1 1 1 agent 8) cross-linking 4 4 4 4 2 agent 9) total 145 195 225 205 133 flexibility passed passed passed passed passed wear passed passed passed passed passed resistance flame passed passed passed passed passed retardant quality formability passed passed passed passed passed
[0144] [0144] TABLE 11 Comparative Comparative Comparative Comparative Comparative Example 19 Example 20 Example 21 Example 22 Example 23 HDPE 1) 100 10 LLDPE 2) 30 EVA 3) 100 70 50 PP 10) MAH-VLDPE 13) 90 50 MAH-PP 11) magnesium 100 80 40 100 30 hydroxide 7) anti-aging agent 8) 1 1 1 1 1 cross-linking agent 9) 4 2 4 2 2 Total 205 183 145 203 133 flexibility failed passed passed passed passed wear resistance passed failed failed failed failed flame retardant passed passed passed passed passed quality formability failed passed passed passed passed
[0145] [0145] TABLE 12 Compar- Compar- Compar- Compar- ative ative ative ative Example 24 Example 25 Example 26 Example 27 HDPE 1) 55 60 85 70 LLDPE 2) EVA 3) 10 10 25 PP 10) 40 MAH- 5 5 5 VLDPE 13) MAH-PP 11) 30 magnesium 50 200 10 300 hydroxide 7) Anti-aging 1 1 1 1 agent 8) cross-linking 4 4 2 2 agent 8) total 135 305 112 403 flexibility failed failed passed failed wear passed passed passed passed resistance flame passed passed failed passed retardant quality formability failed failed passed failed
[0146] The results of Comparative Examples 19 to 23 show that, when the amount of any one component chosen among components (a), (b1) and (c3) is outside the range defined in the present invention, at least one of the properties tested is not satisfied.
[0147] The results of Comparative Example 24 indicate that, when an olefin polymer (b1) containing intra-molecular oxygen atoms is not used, the flexibility and formability of the composition are poor.
[0148] The results of Comparative Example 25 show that, when an acid modified styrene type thermoplastic elastomer (c3) is not used, the flexibility and formability of the composition are poor.
[0149] From the results of Comparative Examples 26 and 27, it can be understood that, when the amount of magnesium hydroxide, flame retardant as component (d), is too small, the flame retardant quality of the composition is poor. Conversely, when this amount is too large, the flexibility and formability of the composition deteriorate.
EXAMPLES 31 TO 40 AND COMPARATIVE EXAMPLES 28 TO 36
[0150] The components shown in Tables 13 to 16 were used in the amounts (parts by mass), to produce coated electrical cables according to the methods described for Examples 1 to 10. The properties of the coatings were then evaluated. The results are shown in Tables 13 to 16.
TABLE 13 Example Example Example Example Example 31 32 33 34 35 HDPE 1) 65 50 65 30 50 LLDPE 2) EVA 3) 30 10 5 30 EEA 4) 65 MAH- 5 40 30 5 EPM 14) MAH- 20 EPDM 15) magnesium 100 120 120 250 30 hy- droxide 7) Anti-aging 1 1 2 1 1 agent 8) cross- 4 4 2 4 4 linking agent 9) total 205 225 224 355 135 flexibility passed passed passed passed passed wear passed passed passed passed passed resistance flame passed passed passed passed passed retardant quality formability passed passed passed passed passed
[0151] [0151] TABLE 14 Example Example Example Example Example 36 37 38 39 40 HDPE 1) 50 50 70 40 LLDPE 2) 90 EVA 3) 5 30 10 40 EEA 4) 30 MAH- 5 20 20 20 EPM 14) MAH- 20 EPDM 15) magnesium 40 90 120 100 90 hy- droxide 7) anti-aging 1 1 1 1 1 agent 8) cross- 4 4 4 4 2 linking agent 9) total 145 195 225 205 193 flexibility passed passed passed passed passed wear passed passed passed passed passed resistance flame passed passed passed passed passed retardant quality formability passed passed passed passed passed
[0152] [0152] TABLE 15 Comparative Comparative Comparative Comparative Comparative Example 28 Example 29 Example 30 Example 31 Example 32 HDPE 1) 100 10 LLDPE 2) 30 EVA 3) 100 70 50 PP 10) MAH-EPM 14) 90 50 MAH-PP 11) magnesium hydroxide 7) 100 80 60 100 30 anti-aging agent 8) 1 1 1 1 1 cross-linking agent 9) 4 2 4 2 2 Total 205 183 165 203 133 Flexibility failed passed passed passed passed wear resistance passed failed failed failed failed flame retardant quality passed passed passed passed passed formability failed passed passed passed passed
[0153] [0153] TABLE 16 Compar- Compar- Compar- Compar- ative ative ative ative Example 33 Example 34 Example 35 Example 36 HDPE 1) 55 60 85 70 LLDPE 2) EVA 3) 10 10 25 PP 10) 40 MAH- 5 5 5 VLDPE 13) MAH-PP 11) 30 magnesium 50 180 10 300 hydroxide 7) Anti-aging 1 1 1 1 agent 8) cross-linking 2 4 2 2 agent 9) total 133 285 112 403 flexibility failed failed passed failed wear passed passed passed passed resistance flame passed passed failed passed retardant quality formability failed failed passed failed
[0154] The results of Comparative Examples 28 to 32 suggest that, when the amount of any one component chosen among components (a), (b1) and (c4) is outside the range defined in the present invention, at least one of the properties evaluated is not satisfied.
[0155] The results of Comparative Example 33 show that, when an olefin polymer (b1) containing intra-molecular oxygen atoms is not used, the flexibility and formability of the composition are poor.
[0156] The results of Comparative Example 34 indicate that, when an acid modified rubber (c4) is not used, the flexibility and formability of the composition are poor.
[0157] The results of Comparative Examples 35 and 36 show that, when the amount of magnesium hydroxide, which is a flame retardant (component (d)), is too small, the flame retardant quality of the composition is poor. However, when this amount is too large, the flexibility and formability of the composition are deteriorated.
EXAMPLES 41 TO 50 AND COMPARATIVE EXAMPLES 37 TO 45
[0158] The components shown in Tables 17 to 20 were used in the amounts (parts by mass), to produce coated electrical cables according to the methods described for Examples 1 to 10. The properties of the coatings were then evaluated. The results are shown in Tables 17 to 20.
TABLE 17 Example Example Example Example Example 41 42 43 44 45 HDPE 1) 65 50 65 30 50 LLDPE 2) SEBS 16) 30 10 65 30 SEPS 17) 5 MAH- 5 40 30 5 20 SEBS 12) MAH-PP 11) magnesium 90 100 90 250 30 hy- droxide 7) anti-aging 1 1 1 1 1 agent 8) cross- 4 4 4 2 2 linking agent 9) Total 195 205 195 353 133 flexibility passed passed passed passed passed Wear passed passed passed passed passed resistance flame passed passed passed passed passed retardant quality formability passed passed passed passed passed
[0159] [0159] TABLE 18 Example Example Example Example Example 46 47 48 49 50 HDPE 1) 50 50 70 60 LLDPE 2) 90 SEBS 16) 5 30 10 20 SEPS 17) 30 MAH- 5 20 20 20 20 SEBS 12) MAH-PP 11) magnesium 40 120 90 100 30 hydroxide 7) anti-aging 1 1 1 1 1 agent 8) cross- 2 2 4 4 4 linking agent 9) total 153 223 195 205 135 flexibility passed passed passed passed passed wear passed passed passed passed passed resistance flame passed passed passed passed passed retardant quality formability passed passed passed passed passed
[0160] [0160] TABLE 19 Comparative Comparative Comparative Comparative Comparative Example 37 Example 38 Example 39 Example 40 Example 41 HDPE 1) 100 20 LLDPE 2) 20 SEBS 16) 100 80 70 PP 10) MAH-SEBS 12) 80 30 MAH-PP 11) magnesium hydroxide 7) 90 120 80 100 30 anti-aging agent 8) 1 1 1 1 1 cross-linking agent 9) 4 2 4 4 4 Total 195 223 185 205 135 Flexibility failed passed passed passed passed wear resistance passed failed failed failed failed flame retardant quality passed passed passed passed passed formability failed passed passed passed passed
[0161] [0161] TABLE 20 Compar- Compar- Compar- Compar- ative ative ative ative Example 42 Example 43 Example 44 Example 45 HDPE 1) 55 60 85 80 LLDPE 2) SEBS 16) 10 5 10 PP 10) 40 MAH- 5 10 10 SEBS 12) MAH-PP 11) 30 magnesium 30 200 10 300 hydroxide 7) Anti-aging 1 1 1 1 agent 8) cross-linking 2 4 4 4 agent 9) total 133 305 115 405 flexibility failed failed passed failed wear passed passed passed passed resistance flame passed passed failed passed retardant quality formability failed failed passed failed
[0162] From the results of Comparative Examples 37 to 41, it can be understood that, when the amount of any one component chosen among components (a), (b2) and (c2) is outside the range defined in the present invention, at least one of the physical properties evaluated is not sufficient.
[0163] The results of Comparative Example 42 indicate that, when an olefin polymer (b2) containing intra-molecular oxygen atoms is not used, the flexibility and formability of the composition are not sufficient.
[0164] The results of Comparative Example 43 show that, when an acid modified styrene type thermoplastic elastomer (c2) is not used, the flexibility and formability of the composition are poor.
[0165] The results of Comparative Examples 44 and 45 suggest that, when the amount of magnesium hydroxide, which is a flame retardant (component (d)), is too small, the flame retardant quality of the composition is poor. However, when this amount is too large, the flexibility and formability of the composition are poor.
EXAMPLES 51 TO 60 AND COMPARATIVE EXAMPLES 46 TO 54
[0166] The components shown in Tables 21 to 24 were used in the amounts (parts by mass), to produce coated electrical cables according to the methods described for Examples 1 to 10. The properties of the coatings were then evaluated. The results are shown in Tables 21 to 24.
TABLE 21 Example Example Example Example Example 51 52 53 54 55 HDPE 1) 65 50 60 30 50 LLDPE 2) SEBS 16) 30 10 65 30 SEPS 17) 5 MAH- EVA 5) MAH- 5 40 35 5 30 EEA 6) magnesium 90 100 100 250 30 hy- droxide 7) anti-aging 1 1 1 1 1 agent 8) cross- 4 4 2 4 4 linking agent 9) Total 195 205 203 355 135 flexibility passed passed passed passed passed Wear passed passed passed passed passed resistance flame passed passed passed passed passed retardant quality formability passed passed passed passed passed
[0167] [0167] TABLE 22 Example Example Example Example Example 56 57 58 59 60 HDPE 1) 50 50 70 60 LLDPE 2) 90 SEBS 16) 30 20 SEPS 17) 5 10 20 MAH- 5 20 20 EVA 5) MAH- 30 20 EEA 6) magnesium 70 120 100 120 30 hy- droxide 7) anti-aging 1 1 1 1 1 agent 8) cross- 4 4 4 4 4 linking agent 9) Total 175 225 205 225 135 flexibility passed passed passed passed passed Wear passed passed passed passed passed resistance flame passed passed passed passed passed retardant quality formability passed passed passed passed passed
[0168] [0168] TABLE 23 Comparative Comparative Comparative Comparative Comparative Example 46 Example 47 Example 48 Example 49 Example 50 HDPE 1) 100 20 LLDPE 2) 20 SEBS 16) 100 80 50 PP 10) MAH-EVA 5) 80 50 MAH-PP 11) magnesium hydroxide 7) 90 120 50 100 40 anti-aging agent 8) 1 1 1 1 1 cross-linking agent 9) 4 2 2 4 4 Total 195 223 153 205 145 Flexibility failed passed passed passed passed wear resistance passed failed failed failed failed flame retardant quality passed passed passed passed passed Formability failed passed passed passed passed
[0169] [0169] TABLE 24 Compar- Compar- Compar- Compar- ative ative ative ative Example 51 Example 52 Example 53 Example 54 HDPE 1) 55 60 90 85 LLDPE 2) SEBS 16) 5 5 5 PP 10) 40 MAH-EVA 5) 5 5 10 MAH-PP 11) 35 magnesium 200 180 10 300 hydroxide 7) Anti-aging 1 1 1 1 agent 8) cross-linking 2 2 4 4 agent 9) total 303 283 115 405 flexibility failed failed passed failed wear passed passed passed passed resistance flame passed passed failed passed retardant quality formability failed failed passed failed
[0170] The results of Comparative Examples 46 to 50 indicate that, when the amount of any one component chosen among components (a), (b2) and (c1) is outside the range defined in the present invention, at least one of the properties evaluated is not satisfactory.
[0171] The results of Comparative Example 51 suggest that, when an olefin polymer (b2) containing intra-molecular oxygen atoms is not used, the flexibility and formability of the composition are poor.
[0172] The results of Comparative Example 52 show that, when an acid modified styrene type thermoplastic elastomer (c1) is not used, the flexibility and formability of the composition are poor.
[0173] The results of Comparative Examples 53 and 54 indicate that, when the amount of magnesium hydroxide, flame retardant component (d), is too small, the flame retardant quality of the composition is poor, whereas, when this amount is too large, the flexibility and formability of the composition are poor.
[0174] Although the invention has been described with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to the particulars disclosed and extends to all equivalents within the scope of the claims.
[0175] The present disclosure relates to subject matter contained in priority Japanese Application No. 2001-382711, filed on Dec. 17, 2001, which is herein expressly incorporated by reference in its entirety.
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The present invention relates to a resin composition comprising: (a) 30 to 90 parts by mass of polyethylene having a melt flow rate (MFR) of about 5 g/10 min at the most and a density of at least 0.930; (b1) 5 to 65 parts by mass of olefin type polymer containing intra molecular oxygen atoms; (c) 5 to 40 parts by mass of at least one type of polymer selected from the group consisting of (c1) acid modified olefin polymers containing intra-molecular oxygen atoms, (c2) acid modified styrene type thermoplastic elastomers, (c3) acid-modified polyethylenes having a density of about 0.920 at the most, and (c4) acid modified rubbers, with the proviso that the total of components (a), (b1) and (c) represents 100 parts by mass; and (d) 30 to 250 parts by mass of metal hydroxide. This abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.
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FIELD OF THE INVENTION
This invention relates to gas turbine components for reduced corrosion when in contact with off gas from paraxylene oxidation. Specifically, the invention relates to gas turbine components constructed of nickel and cobalt based super alloys with aluminide and MCrAIY coatings.
BACKGROUND OF THE TECHNOLOGY
The production of terephthalic acid (TA) typically involves the liquid phase oxidation of para-xylene (PX) feedstock using molecular oxygen in acetic acid as a process solvent, in the presence of a dissolved heavy metal catalyst system usually incorporating a promoter, such as bromine as disclosed in U.S. Pat. No. 2,833,816. In general, acetic acid, molecular oxygen in the form of air, para-xylene and catalyst are fed continuously into the oxidation reactor at elevated temperature and pressure, typically a temperature from about 150° C. to about 250° C. and a pressure from about 100 kPa to about 5000 kPa.
Para-xylene oxidation produces a high-pressure gaseous stream (or “off-gas”) which comprises nitrogen, unreacted oxygen, carbon dioxide, carbon monoxide and, where bromine is used as a promoter, methyl bromide. In addition, because the reaction is exothermic, the acetic acid solvent is frequently allowed to vaporize to control the reaction temperature and is removed in the gaseous stream. This vapour is typically condensed and most of the condensate is refluxed to the reactor, with some condensate being withdrawn to control reactor water concentration. The portion of the gaseous stream which is not condensed is either vented or passed through a catalytic combustion unit (CCU) to form an environmentally acceptable effluent, as disclosed in publication WO 96/39595. Catalytic combustors have been deployed on TA plants typically upstream of an energy recovery step. Their function is to catalytically combust volatile organic compounds (VOC's) and carbon monoxide and effect complete conversion of any methyl bromide content to HBr and/or Br2. The resulting gas stream can be passed to an energy conversion device, such as an expander, under controlled conditions of pressure and temperature whereby condensation of HBr and/or Br2 is substantially prevented thereby allowing the energy conversion device to be fabricated from relatively inexpensive materials.
In TA production plants power recovery, for example as disclosed in publication 96/39595, is conventionally carried out using an expander at temperatures from about 150-750 ° C., typically 450° C. However, there is scope to improve power recovery using an expander by changes to the configuration of the manufacturing process and the means for recovering power from the process. An improved power recovery system with methods for recovering more power from the gaseous streams of oxidation reactions have been disclosed in publication WO 09/136146. This publication describes an Internal Combustion Open Cycle Gas Turbine (ICOCGT), as disclosed in API 616 Gas Turbines for the Petroleum, Chemical and Gas Industry Services, utilising a standard gas turbine.
The materials of construction for such machines have been developed to avoid corrosion at high temperatures in an oxidative environment and without chemical contamination. Hot section components for land-based turbines are constructed typically in superalloys, protected by coatings that are resistant to oxidation and corrosion which can be overlayed by thermal barrier coatings. The corrosion resistance of the protective coatings arise from their capacity to form protective oxide surface layers at elevated temperatures. Gas turbines generally operate in relatively oxidising gases that contain significant levels of oxygen, typically about 14% WI, However, lower levels of oxygen, such as those in the off-gas from para-xylene oxidation, can prevent or inhibit the formation of protective oxides on coatings. Also, small levels of HBr, up to 100 ppm w/w, can promote the formation of volatile bromides of alloy and coating constituent elements. The off-gas from para-xylene oxidation typically comprises an oxygen concentration less than about 5% w/w, and oxidation catalyst co-factor and by-products comprising organobromides, bromine and acidic bromides.
SUMMARY OF THE INVENTION
The consequence of these combined problems is the need to protect the internal components of a gas turbine against corrosion or degradation due to the composition of off-gas streams from para-xylene oxidation. It is therefore an object of the invention to provide suitable materials of construction for a standard gas turbine to cost- effectively improve power recovery on a PTA production plant.
Disclosed is a coating composition that protects components of a gas turbine against corrosion when in contact with off-gas from para-xylene oxidation. Such streams include the off gas from the oxidation reactor, comprising reduced concentrations of oxygen and corrosive contaminants including oxidation catalyst co-factor and by-products, such as HBr, MeBr and Br 2 . Surprisingly, the present invention can be characterised by gas turbine components constructed in nickel- and cobalt-based superalloys, protected by aluminide and MCrAIY coatings that can be overlayed, where required by thermal barrier coatings to reduce enhanced corrosion in combustion gases containing low concentrations of oxygen or in para-xylene oxidation off-gases comprising oxygen and oxidation catalyst co-factors and by products, including HBr.
DETAILED DESCRIPTION
The present invention can be characterised by gas turbine components constructed in nickel- and cobalt-based superalloys protected by aluminide and MCrAIY coatings which can be overlayed, where required by thermal barrier coatings, to reduce enhanced corrosion in combustion gases comprising low concentrations of oxygen such as para-xylene oxidation off-gases comprising oxygen and oxidation catalyst co-factor and by products, including HBr.
In a TA production plant power recovery using an expander is typically carried out at temperatures from about 150-750 ° C., including 450° C. Improved power recovery may be achieved by heating the gaseous stream from the oxidation reaction to a temperature between 800-1300° C., including between 800-1100° C. and about 1050° C., and recovering energy through an expander. At such temperatures expanders provide significantly improved power recovery relative to expanders at about 450° C. The improved power recovery more than offsets the additional cost of heating the off-gas and the additional power recovered from the higher temperature gaseous stream can be recovered, e.g. utilised elsewhere in the oxidation process or to generate electricity. The expander can be an integral component of a gas turbine, such as an ICOCGT, comprising a compressor, a combustor and a turbine.
A gas turbine can be beneficially integrated into a TA production plant where the compressor stage of the ICOCGT compresses the oxidant feed to the reactor (at greater than atmospheric pressure) thereby by at least partially offsetting the cost of providing the high temperature and pressure reaction conditions in the reactor. The turbine stage of the ICOCGT expands the heated gaseous stream from the oxidation reactor recovering energy to power the compressor and a hot gas stream, from which energy can be recovered downstream of the ICOCGT, as disclosed in publication WO 09/136146.
The mechanical properties for the materials used to construct the turbine and hot section components in an 1 COCGT must be durable to operate at the above conditions. For land-based turbines nickel- and cobalt-based alloys can be used. Turbine blade/bucket alloys typically can be nickel-based containing up to about 20% w/w chromium, up to about 20% w/w cobalt and other alloying elements, comprising in any combination molybdenum, titanium, tantalum, aluminium, tungsten and niobium.
Nozzles/vanes are subjected to higher temperatures than blades/buckets and are constructed in nickel-based alloys containing typically up to about 20% w/w cobalt, or cobalt-based alloys containing typically up to about 20% w/w nickel. All alloys that can be used also contain up to about 28% w/w chromium and other alloying elements, including in any combination molybdenum, titanium, tantalum, aluminium, tungsten and niobium.
Combustion system materials are also commonly constructed in nickel-, cobalt- or iron-based alloys, comprising up to about 24% w/w chromium and other alloying elements, including in any combination molybdenum, titanium, aluminium and tungsten. Typically, nickel-based alloys that can be used comprise up to about 24% w/w chromium and up to about 20% w/w cobalt and other alloying elements, including molybdenum, iron and aluminium.
Discs can be constructed in high strength, low alloy steels or nickel-based alloys, depending on the operating temperature. Typically, nickel-based alloys that can be used comprise up to about 21% w/w chromium, up to about 18% w/w iron and other alloying elements, including niobium and molybdenum.
In normal operation, the alloys used to construct the internal components of a gas turbine require further protection against oxidation, corrosion and high temperatures, typically by the application of protective coatings. Different types of coatings can be applied to protect the superalloys already described, however, to protect the components against oxidation and corrosion two types of coatings are preferred.
1. Diffusion coatings applied at high temperatures at which aluminium and/or chromium and/or silicon are diffused into the surface of the alloy from a surrounding vapour. The vapour is commonly created by the thermal decomposition of particulate source materials. The coating consists of intermetallic products of reaction between the substrate and diffused elements. Coatings produced by the diffusion of aluminium consist principally of nickel and cobalt aluminides containing typically about 35-40% w/w aluminium. In some cases, co-diffusion of silicon produces coatings that also contain about 5% w/w silicon. 2. MCrAIY coatings, comprising M=cobalt and/or Ni, can be applied by spray processes, such as high velocity oxy-fuel (HVOF) or plasma in air (APS) or at low pressures (LPPS) or under vacuum (VPS). The composition of the coating can vary dependent on the combination of materials selected for spraying. Nickel- and/or cobalt-based coatings comprise about 25% w/w chromium, about 15% w/w aluminium and about 0.5% w/w yttrium.
For thermal barrier coatings yttria stabilised zirconia (YSZ) can be used. The coating can be applied in thicknesses up to about 200 microns by processes including plasma spray in air (APS), low pressure plasma spray (LPPS) or electron beam physical vapour deposition (EBPVD). Thermal barrier coatings offer little or no resistance to oxidation/corrosion and can be typically applied over oxidation/corrosion resistant aluminide or MCrAIY coatings.
The hot section of gas turbines normally operates in relatively oxidising gases that contain significant levels of oxygen, typically up to about 14% w/w. However, when coupled to a TA production plant the off-gas composition fed to a gas turbine is significantly different and the risk of corrosion of turbine components in service is increased. The increase is due to a reduced oxygen concentration and oxidation catalyst co-factor and byproducts in the TA off-gas. Significantly lower levels of oxygen, as low as about 1% w/w, can prevent or inhibit the formation of protective oxides on coatings and alloy substrates and small levels of HBr, up to about 100 ppm w/w, can promote the formation of volatile bromides of alloy and coating constituent elements.
EXAMPLES
The following examples further illustrate the disclosed compositions.
EXAMPLE 1
Thermodynamic stability has been calculated to estimate the performance of a range of metals in the alternative range of conditions. Calculations have been made for 950, 1000and 1050° C. and 16 bara for the metallic elements Al, Cr, Co, Cu, Fe, Nb, Ni, Mo, Mn, Si and W to determine the equilibrium composition in a gas with the following composition that contains more than 1.5×the maximum anticipated level of HBr in service:
TABLE 1
Gas composition for thermodynamic stability calculations
Basis
N2
CO2
O2
CO
H2O
HBr
% v/v
86.6
7.9
0.5
0.01
5.0
30 ppm
(balance)
% w/w
84.2
12.1
0.6
0.01
3.1
166 ppm
(balance)
Phase diagrams have been calculated for a range of oxygen and bromine fugacities, from a gas bromine level of 10 −6 to 10 −2 bar; the higher fugacities to illustrate the potential effects of bromine concentration at the bases of cracks in protective oxides/coatings.
The calculations predicted copper forms volatile bromides across the whole range of bromine concentrations. No other metal formed critical amounts of bromides at the lower bromine level. However, at the higher bromine level cobalt, nickel, molybdenum and iron form bromides with activities in the range 10 −4 to 10 −5 bar, indicating possible formation of metal halide and possible corrosion.
EXAMPLE 2
Experimental Tests—1
A series of tests was undertaken at 1 bara, with a gas composition as shown in Table 2. The HBr level is about 3×the maximum anticipated level of HBr in service:
TABLE 2
Gas composition for experimental tests - 1
Basis
N2
CO2
O2
CO
H2O
HBr
% v/v
84.5
4.0
0.5
0.03
11.0
100 ppm
(balance)
% w/w
85.8
6.4
0.6
0.03
7.2
294 ppm
(balance)
Samples of the alloy/coating systems in Table 3 were tested in an unloaded condition for a total of 1000 h. Samples were subjected to daily cooling to temperatures below 200° C. for 3 hours and re-heating up to temperatures between 850 and 1050° C. for 21 hours.
TABLE 3
Test conditions for experimental tests - 1
Representative
Tempera-
Component
Alloy
Coating
tures ° C.
Blades/buckets
Ni-based
Uncoated
950/1050
Aluminised
950/1050
HVOF MCrAlY
950/1050
Ni-based
Uncoated
850/950
Chromised
850/950
Nozzles/vanes
Ni-based
Uncoated
950/1050
Aluminised
950/1050
Co-based
Uncoated
950/1050
Aluminised
950/1050
Combustors/
Ni-based
HVOF MCrAlY
950/1050
ducts
HVOF MCrAlY + TBC
950/1050
Discs
Ni-based
Uncoated
850/950
Chromised
850/950
Mass changes during the test were measured for all samples and macroscopic evidence of coating spallation and other changes were recorded. At the conclusion of the tests, cross sections of all specimens were prepared and the microstructures observed with regard to scale thickness, spallation, depth of inward directed oxidation and depletion. The oxide scales and thicknesses of the internally oxidised and nitrided zones were measured. Element mapping of sections was undertaken using electron probe microanalysis (EPMA).
The results from the experimental test for the materials used to fabricate gas turbine components indicated:
1. There is no apparent loss of protection of aluminide or MCrAIY coatings arising from the low oxygen content of the gas. Chromide coatings are unprotective because of the formation of volatile CrO 4 H 2 in gases containing both H 2 O and O 2 at temperatures above about 650° C. 2. HBr content. There is no evidence of significant deterioration arising from the formation of volatile bromides, nor any evidence of bromine uptake in any of the sections, within the detection limits of the EPMA technique.
EXAMPLE 3
Experimental Tests—2
A series of tests were undertaken at 1 bara gases to investigate whether cracks in protective oxides/coatings are sites of increased corrosion risk. Three gas compositions were used:
low oxygen gas (Table 1) laboratory air containing up to 4% v/v water to simulate a typical combustion gas with relatively high oxygen content from a conventional application intermediate oxygen concentration and containing more than 3×the maximum anticipated level of HBr in service (Table 4)
TABLE 4
Gas composition for experimental tests - 2
Basis
N2
CO 2
O 2
CO
H 2 O
HBr
% v/v
74.1
4.0
6.9
50 ppm
15
100 ppm
(balance)
% w/w
75.7
6.4
8.1
50 ppm
9.8
295 ppm
(balance)
In these three environments, samples of different alloy/coating systems were tested.
i) A commercial diffusion coating formed from an applied slurry comprising about 36% w/w aluminium and about 6% w/w silicon. ii) MCrAIY/LPPS a commercial, cobalt-based coating comprising about 32% w/w nickel, about 21% w/w chromium, about 8% w/w aluminium and about 0.5% w/w yttrium.
TABLE 5
Test conditions for experimental tests - 2
Representative
Temperature
Component
Alloy
Coating
° C.
Blades/ buckets
Ni-based
MCrAlY/LPPS
1000
Nozzles/vanes
Ni-based
Diffused slurry
1000
Co-based
MCrAlY/LPPS
1000
Samples were strained in a creep-testing rig at a strain rate higher than about 10 −8 S −1 . Above this strain rate, regarded as a critical creep rate, access of the environment to the substrate alloy can occur and any cracks formed cannot heal by oxidation. Samples were exposed to 5 cycles of heating to 1000° C. and cooling down every 100 hours for a total exposure time of 500 hours. Accumulated strains at the completion of the tests were in the range about 5-12%. To introduce coating cracks prior to exposure some samples were pre-cracked by straining up to about 2% total strain at room temperature. Crack formation was monitored by acoustic emission (AE). At the conclusion of the tests samples were examined using metallographic and microanalytical procedures.
Neither the pre-cracking treatment nor the significant straining at elevated temperatures produced visible, through thickness cracks in the coatings. The results indicate:
1. Low oxygen content. Both coatings form protective oxides in all three environments. The MCrAIY coating exhibits particularly high corrosion resistance, but the performance of the diffused slurry coating is adequate. 2. HBr content. There was no evidence of significant deterioration from the formation of volatile bromides. Also, there was no evidence of bromine uptake in any of the sections, within the detection limits of the EPMA technique. The coatings, if applied correctly, remain highly protective in the HBr-containing environments.
Thermodynamic calculations and experimental tests in gases with a low oxygen concentration and a significant HBr content have demonstrated that gas turbine components constructed in nickel- and cobalt-based superalloys protected by aluminide and MCrAIY coatings have satisfactory corrosion resistance in the following applications:
1. Combustion gases containing levels of oxygen as low as 0.6% w/w. 2. PTA oxidation reactor off-gas containing levels of oxygen as low as 0.6% w/w and levels of HBr as high as about 300 ppm w/w.
While the invention has been described in conjunction with specific embodiments thereof, it is evident the many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, the invention is intended to embrace all such alternatives, modifications and variations as fall within the spirit and scope of the claims.
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The present invention relates to a means to protect gas turbine components against corrosion from a gaseous stream, produced from an oxidation reaction the reaction being conducted in a continuous oxidation reactor
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BACKGROUND OF THE INVENTION
The present invention relates to a device for arranging conductive particles in a preselected pattern for the connection of electric circuit boards or electric parts. More particularly, the present invention is concerned with a device for surely and efficiently transferring solder bumps to the electrode pads of a semiconductor chip or the leads of a TAB (Tape Automated Bonding) tape, and a conductive particle transferring method using the same.
It is a common practice with, e.g., LSI (Large Scale Integration) circuits and LCDs (Liquid Crystal Displays) to connect electric circuit boards by using conductive particles. After electric conduction has been set up between the circuit boards by the conductive particles, the circuit boards are fixed by an adhesive. Specifically, after the conductive particles have been arranged on either one of the circuit boards, an adhesive is applied and then set after the alignment of electrodes. To arrange the particles on the circuit board, they may be simply sprayed, as taught in, e.g., Japanese Patent Laid-Open Publication Nos. 2-23623 and 3-289070.
With the spraying scheme, however, it is difficult to control the positions and the number of the particles on the electrodes. Particularly, when the electrodes are arranged at a fine pitch, the particles are apt to short the electrodes or to render the connection resistance irregular due to the irregular number thereof on the electrodes. Although the particles may be arranged on the electrodes while having their positions controlled, such an approach needs a sophisticated control system.
For the electrical connection of the electrode pads of a semiconductor chip and outside leads, a wire bonding system, a TAB system and a flip-chip bonding system are typical systems available at the present stage of development. The TAB system and flip-chip bonding system each uses conductive particles in the form of solder bumps (simply bumps hereinafter) for electrical connection. Specifically, in the TAB system, bumps intervene between the electrode pads of a semiconductor chip and the film-like leads of a TAB tape. In the flip-chip bonding system, bumps intervene between the electrode pads of a semiconductor chip and the leads of a circuit board.
Today, the following methods are extensively used to form bumps. In one method, the exposed portions of electrode pads provided on a semiconductor chip are covered with barrier metal. After a solder film pattern has been formed on the barrier metal, reflow and annealing are effected in order to cause the solder film to shrink on the barrier metal due to its own surface tension. In another method, bumps are formed on the electrode pads one by one by a wire bonder. Recently, a transfer bump method has been proposed which is advantageous over the above direct methods from the step and cost standpoint. The transfer bump method forms bumps on an exclusive transfer substrate by an electrolytic plating scheme. The bumps on the transfer substrate are aligned with the leads of a TAB tape in the TAB system or with the electrode pads of a semiconductor chip in the flip-chip bonding system. Then, the bumps are bonded by heat and transferred to the leads or the electrode pads. It is not too much to say that the transfer bump method has broadened the applicable range of the TAB system.
However, the problem with the bumps formed by the electrolytic plating scheme is that they have flat surfaces and cannot be evenly transferred unless they have exactly the same height. In light of this, Japanese Patent Publication No. 7-27929 discloses a device capable of arranging spherical bumps on a transfer substrate. However, while the electrolytic plating scheme is capable of defining positions for forming the bumps beforehand, the spherical bumps are produced at random. Therefore, the key to the spherical bump scheme is how efficiently the bumps can be arranged in preselected positions. For the efficient arrangement of the bumps, the above document teaches that the diameter of the spherical bumps is strictly controlled. However, because the diameter of the bumps decreases with a decrease in the pitch of the electrode pads or that of the leads, it is extremely difficult to provide the bumps with the same diameter. As a result, the accuracy required of the flatness of the leads of a TAB tape, the flatness of a bonding tool and the parallelism of a transfer substrate and a TAB tape increases. The adjustment of such factors will become more difficult in the future in parallel with the progress of dense mounting.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a simple, low cost device capable of arranging conductive particles adequately.
It is another object of the present invention to provide a method capable of transferring conductive particles to a semiconductor chip, TAB tape or intermediate transfer member more surely and easily without increasing accuracy required of a device for practicing it.
In accordance with the present invention, a device for arranging conductive particles for connecting electric circuit boards includes a mask formed with openings in a preselected pattern for arranging the conductive particles. A squeegee is spaced from the mask by a preselected distance and movable over the mask in a preselected direction for filling the conductive particles in the openings of the mask. A stage is positioned below the mask for holding the conductive particles filled in the openings of the mask. A vacuum suction mechanism is positioned below the stage for sucking, via the stage, the conductive particles being moved on the mask by the squeegee into the openings of the mask.
Further, in accordance with the present invention, a device for arranging conductive particles includes a feeding section for feeding the conductive particles. A stage is implemented as a porous flat plate having opposite major surface. One of the opposite major surfaces expected to arrange the conductive particles is implemented as fine irregular surface for restricting the movement of the conductive particles, A mask is formed with openings in a preselected pattern for defining an arrangement of the conductive particles on the stage. A sucking mechanism sucks the conductive particles via the other major surface of the stage to thereby retain the conductive particles on the one major surface of the stage. A drive source is drivably connected to at least one of the stage and mask for selectively moving the one major surface of the stage and a major surface of the mask toward or away from each other.
Moreover, in accordance with the present invention, a method of transferring conductive particles includes the step of positioning a stage comprising a porous flat plate having one of opposite major surfaces thereof expected to arrange the conductive particles implemented as a fine irregular surface for restricting the movement of the conductive particles and a mask formed with openings in a preselected pattern for defining an arrangement of the conductive particles on the stage close to each other and parallel or substantially parallel to each other. In this condition, the conductive particles are from above the mask to thereby cause the openings of the mask to trap the conductive particles. Then, excess conductive particles other than the conductive particles trapped in the openings are removed from the mask. Subsequently, the mask and stage are separated from each other. Finally, the conductive particles arranged on the stage are transferred to another surface.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings in which:
FIG. 1 is a sectional side elevation showing a first embodiment of the conductive particle arranging device in accordance with the present invention;
FIGS. 2-7 are sectional side elevations each showing a particular modification of a squeegee included in the first embodiment;
FIG. 8 is a sectional side elevation showing a modification of a mask also included in the first embodiment;
FIG. 9 is a sectional side elevation showing a modification of a pedestal and stage further included in the first embodiment;
FIG. 10 is a section showing a conventional conductive particle arranging device;
FIG. 11 is a section showing Example 1 of a second embodiment of the present invention;
FIGS. 12-17 are sections each showing Example 2 of the second embodiment in a particular condition;
FIG. 18 is a section showing Example 3 of the second embodiment;
FIGS. 19 and 20 are sections each showing Example 4 of the second embodiment in a particular condition;
FIG. 21 is a section showing Example 5 of the second embodiment;
FIGS. 22 and 23 are sections each sowing Example 5 in a particular condition;
FIG. 24 is a section showing Example 6 of the second embodiment;
FIGS. 25-28 are sections each showing Example 6 in a particular condition; and
FIG. 29 is a section showing Example 7 of the second embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be described hereinafter.
1st Embodiment
This embodiment relates to a conductive particle arranging device applicable to the bump forming step stated earlier. As shown in FIG. 1, the device, generally 10, includes a base 12 on which a guide rail 14 is mounted. A slider 16 is slidably mounted on the guide rail 14 and moved in the right-and-left direction, as seen in FIG. 1, by an air cylinder, not shown. A stage 18 is mounted on the slider 14 and shiftable up and down over a distance of about 10 mm by being driven by, e.g., an air cylinder.
A pedestal 20 is mounted on the stage 18 and implemented as a box-like or hollow cylindrical top-open member. The pedestal 20 has a bore 20a fluidly communicated to a vacuum pump, not shown, via a passageway 20b. A stage 22 is mounted on the pedestal 20, closing the open top of the pedestal 20. The stage 22 is implemented by a sintered ceramic body. The pedestal 20 carrying the stage 22 thereon has its bore 20a evacuated by the vacuum pump via the passageway 20b.
A mask 24 is held on and in contact with the top of the stage 22. The mask 24 is implemented as a metal mask by way of example and formed with openings, not shown, in a preselected pattern for arranging conductive particles. If conductive particles to be arranged by the device 10 have a diameter of, e.g., 40 μm, then the above openings each has a diameter of 50 μm and a depth of 40 μm. A frame 22a retains the peripheral portion of the mask 22 while a guide frame 26 guides and holds the peripheral portion of the mask 22. The mask 24 with the openings is mounted on the stage 22 which is, in turn, mounted on the pedestal 20, as stated above. Therefore, when the bore 20a of the pedestal 20 is evacuated, vacuum is developed in the openings of the mask 24 via the stage 22.
A frame 30 is supported by posts 28 above the mask 24. Sliders 32 and 34 are mounted on the frame 30 and driven horizontally by an air cylinder or a stepping motor, not shown, in directions perpendicular to each other. A pair of squeegees 38 and 40 are affixed to the slider 34 facing the mask 24 via a jig 36. The jig 36 is made up of a Z axis stage implementing adjustment in the vertical direction (Z direction), as seen in
FIG. 1, and a goniometer implementing the adjustment of the angles of the squeegees 38 and 40, although not shown specifically.
The squeegees 38 and 40 are positioned above and at a preselected distance from the mask 24. When the sliders 32 and 34 are moved in the horizontal direction, the slider 34 moves the squeegees 38 and 40 in the horizontal direction. Conductive particles are fed to the mask 24 via the gap between the squeegees 38 and 40.
The device 10 having the above construction will be operated as follows. Initially, the squeegees 38 and 40 are located at their initial position or home position defined at the right-hand side or the left-hand side of the openings of the mask 24. Conductive particles are present between the squeegees 38 and 40. The stage 18 is held in its elevated position, maintaining the stage 22 in contact with the mask 24. The bore 20a of the pedestal 20 is evacuated by the vacuum pump.
In the above condition, the squeegees 38 and 40 are moved over the openings of the mask 24 at the same time by the sliders 32 and 34. As a result, the squeegees 38 and 40 move away from the home position while sequentially filling the openings of the mask 24 with the conductive particles. Because the bore 20a of the pedestal 20 is evacuated, air is sucked out of the openings of the mask 24 via the stage 22. Consequently, the particles fed to the mask 24 are surely introduced into and held in the openings of the mask 24.
When the movement of the squeegees 38 and 40 ends, the evacuation of the bore 20a is interrupted while the stage 18 is lowered. As a result, the mask 24 and stage 22 are separated from each other. When the slider 16 is moved along the guide rail 14, the conductive particles have been adequately arranged on the stage 22 in the desired pattern.
As shown in FIG. 2, the illustrative embodiment allows the distance between the mask 24 and the squeegees 38 and 40 to be smaller than the diameter of a conductive particle 42. Specifically, in the illustrative embodiment, the mask 24 and squeegees 38 and 40 (only the squeegee 38 is shown) are spaced from the mask 24 by a distance α smaller than the diameter of the particle 42. The distance α should preferably be one-half to one-fourth of the diameter of the particle 42. In such a configuration, the particle 42 is prevented from escaping via the gap between the mask 24 and the squeegees 38 and 40. This allows the particle 42 to be surely filled in the opening of the mask 24 and frees the mask 24 from wear or breakage.
As shown in FIG. 3, the thickness of the squeegees 38 and 40 (only the squeegee 38 is shown) may be reduced below the diameter of the particle 42. Specifically, in the illustrative embodiment, each of the squeegees 38 and 40 has at least its lower edge provided with a thickness smaller than the diameter of the particle 42. With this configuration, the squeegees 38 and 40 can move the particle 42 smoothly on and along the mask 24.
More specifically, assume a squeegee 38a shown in FIG. 4 and having a thickness greater than the diameter of the particle 42. Then, it is likely that the particle 42 gets between the squeegee 38a and the mask 24 and cannot smoothly move on the mask 24. By contrast, the squeegee 38 shown in FIG. 3 allows the particle 42 to easily slip away upward and smoothly move on the mask 24. Therefore, even when the particle 42 is implemented as a resin particle plated with metal, it can smoothly move on the mask 24 and adequately enters the opening of the mask 24 without being damaged.
As shown in FIG. 5, the angle between each of the squeegees 38 and 40 (only the squeegee 38 is shown) and the mask 24 may be selected to be less than 30 degrees inclusive. The flat squeegee 38 is inclined relative to the mask 24 by an angle β of less than 30 degrees inclusive. This also allows the conductive particle 42 to easily slip away upward, i.e., prevents it from getting between the squeegee 38 and the mask 24 and being damaged thereby. Therefore, even when the particle 42 is implemented as a resin particle plated with metal, it can smoothly move on the mask 24 and adequately enter the opening of the mask 24 without being damaged.
As shown in FIGS. 6 and 7, projections 44 and 46 may be provided on the lower edge of each of the squeegees 38 and 40 (only the squeegee 38 is shown) facing the mask 24, so that an adequate distance can be maintained between the squeegees and the mask 24. In the illustrative embodiment, the projections 44 and 46 are positioned at opposite ends of the lower edge of each of the squeegees 38 and 40. The projections 44 and 46 each has a height which is less than one-half of the diameter of the conductive particle 42 inclusive. Specifically, when the diameter of the particle 42 is 40 μm, resin beads whose diameter is 10 μm to 20 μm may be affixed to the above positions of the lower edge of the squeegee by, e.g., an adhesive.
When the squeegees 38 and 40 are moved above the mask 24 with their projections 48 and 40 contacting the mask 24, a preselected distance is surely maintained between the squeegees 38 and 40 and the mask 24. This is an economical, yet adequate, implementation for preventing the particle 42 from escaping and causing the mask 24 to wear.
As shown in FIG. 8, the mask 24 may be provided with a thickness smaller than the diameter of the particle 42, but greater than one-half of the same. Specifically, the mask 24 is formed with a plurality of openings 24a. In the illustrative embodiment, the thickness of the mask 24 is selected to be smaller than the diameter of the particle 42, but greater than one-half of the same. Therefore, when such particles 42 are introduced into the openings 24a of the mask 24 laid on the stage 22, the particles 42 rest on the top of the stage 22. In this condition, less than one-half of each particle 42 protrudes from the top of the mask 24. The particles 42 received in the openings 24a of the mask 24 are delivered to the next step. In the next step, a transfer head, not shown, is lowered onto the mask 24 with the result that the particles 42 each protruding from the top of the mask 24 are transferred to the head.
With the configuration shown in FIG. 8, it is possible to deliver the mask 24 and stage 22 to the next step together, i.e., without lowering the stage 18 in order to separate the mask 24 and stage 22. This reduces the number of steps of the device 10 and thereby promotes smooth and adequate arrangement of conductive particles.
FIG. 9 shows an alternative configuration of the pedestal 20. As shown, the box-like or hollow cylindrical pedestal, labeled 48, has a center bore 48a and a peripheral bore 48b surrounding the center bore 38a, i.e., a double bore structure. The pedestal 48 is formed with a passageway 48c communicated to the peripheral bore 48b and a passageway, not shown, communicated to the center bore. The passageway 48c and the other passageway, not shown, each is fuidly communicated to a respective vacuum pump, not shown, and evacuated thereby.
The stage 22 implemented as a sintered ceramic body is mounted on the top of the pedestal 48, closing the center bore 48b and peripheral bore 48b. The mask 24 with the openings 24a is mounted on the stage 22, although not shown specifically. The conductive particles 42 are received in the openings 24a of the mask 24 positioned above the center bore 48a.
The center bore 48a and peripheral bore 48b of the pedestal 48 each is evacuated by the respective vacuum pump, as stated above. When the mask 24 having the particles 42 in its openings and the stage 22 are separated from each other, the pump communicated to the center bore 48a above which the particles 42 are arranged is turned on while the other pump communicated to the peripheral bore 48b is turned off. As a result, the particles 42 are prevented from being displaced. This can be done with miniature vacuum pumps at a low cost.
While the mask 24 has been shown and described as comprising a metal mask, it may alternatively be implemented by, e.g., a polyimide film or similar resin film. With a polyimide film, it is possible to form the openings 24a and therefore to arrange the particles 42 more accurately than with a metal mask when use is made of an excimer laser. It is to be noted that the openings 24a formed by an excimer laser are tapered. From the accuracy standpoint, therefore, the particles 42 should preferably be directly transferred to a transfer head without the mask 24 being separated.
As stated above, the first embodiment achieves the following advantages.
(1) The device is capable of arranging conductive particles adequately with a simple, low cost structure.
(2) The particles are prevented from escaping via a gap between squeegees and a mask and causing the mask to wear or break.
(3) The particles are prevented from getting between the squeegees and the mask. Therefore, even when the particles are implemented as resin particles plated with metal, they are free from breakage.
(4) The squeegees are constantly spaced from the mask by a preselected distance during movement.
(5) The particles received in the openings of the mask can be directly transferred to a transfer head, so that the number of steps is reduced.
(6) When the stage is separated from the mask, only the portion around the particles is evacuated in order to prevent the particles from being displaced.
(7) The openings of the mask can be formed m ore accurately than the openings of a metal mask.
2nd Embodiment
To better understand this embodiment, reference will be made to FIG. 10 showing the conventional arrangement taught in Japanese Patent Publication No. 7-27929 mentioned earlier. The arrangement to be described addresses irregular transfer particular to the transfer bump method which forms conductive particles, i.e., bumps on an exclusive transfer substrate by electrolytic plating, and then transfers the bumps to the electrode pads of a semiconductor chip or the leads of a TAB tape. As shown in FIG. 10, a transfer substrate 50 is formed with through holes 53. The holes 53 each has a smaller diameter than a bump bp at its bottom, but has a greater diameter than the bump bp at its top. With this configuration, the substrate 50 itself plays the role of a jig for positioning the bumps bp. The bottom side of the substrate 50 is depressurized in order to retain the bumps bp in the holes 53 by suction. Specifically, a bore 57 formed between the substrate 50 and a holder 56 supporting it is evacuated via an tubing 58.
More specifically, the substrate 50 is implemented as a laminate of two flat sheets 51 and 52. The sheets 51 and 52 are respectively formed with openings 54 having a diameter d 1 smaller than the diameter of the bumps bp, and openings 55 having a diameter d 2 greater than the same. The openings 54 and 55 are aligned with each other, constituting the through holes 53. The holes 53 each has such a depth that less than one-half of the bump bp, inclusive, introduced therein protrudes from the top of the substrate 50. In practice, the thicknesses t 1 and t 2 of the sheets 51 and 52, respectively, are optimized. The bumps bp arranged on the substrate 50 are transferred to, e.g., the leads of a TAB tape. Subsequently, the TAB tape is bonded to a semiconductor chip.
The bumps bp each is assigned to one electrode pad or one lead. Therefore, if the transfer of the bump to even one of several tens to a hundred and tens of electrodes or leads fails, the semiconductor chip is rejected. The conventional device transfers the bumps bp while retaining them in the holes 53, so that the amount of protuberance of the bumps bp necessary for transfer is not achievable without resorting to strict control over the diameter of the bumps bp. However, the bumps decrease in diameter with a decrease in the pitch between nearby electrode pads or leads, making it more difficult to evenly control the diameter of the bumps bp.
The embodiment to be described realizes easy and sure transfer of bumps or conductive particles to a semiconductor chip or a TAB tape.
Basically, in this embodiment, the support for the conductive particles and the definition of a particle arrangement each is assigned to one of two independent members. The two members are moved toward each other for particle arrangement and then moved away from each other for particle transfer, so that the particles can be transferred in their fully exposed position. Assume that the particles are bumps. Then, this embodiment is capable of surely transferring the bumps with a high throughput without resorting to strict control over the height of the bumps, the flatness of the leads of a TAB tape, and the flatness of a bonding tool.
A conductive particle arranging device embodying the above concept needs a stage for laying conductive particles, a mask for defining a particle arrangement, and drive means drivably connected to at least one of the stage and mask. For the simplest construction and control, the drive means may be connected only to the stage in order to move the stage up and down relative to the mask fixed in place.
The particles can be fixed in place on the stage to a certain degree if the stage is implemented as a flat porous plate, and if suction is applied to the rear of the stage. In this embodiment, the stage is additionally provided with an irregular surface for arranging the particles, so that the particles can be prevented from being displaced when the stage and mask are separated from each other. The irregular surface may be implemented by fine lugs formed on the above surface or by a mesh whose mesh size is smaller than the diameter of the particles.
The fine lugs may be formed in either one of a regular pattern and an irregular or random pattern. A simple method for forming the irregular pattern consists in spraying a solution of thermosetting resin or that of ultraviolet (UV) curable resin onto the particle arranging surface of the stage, and curing the resulting fine drops by use of heat or UV rays. On the other hand, to form the regular pattern most simply, use may be made of the patterning of photoresist. With the patterning scheme, it is possible to freely select even the relation between the pitch of the fine lugs and that of the particles. If the pitch of the lugs is greater than the pitch of the particles, each particle will be trapped between two nearby lugs. If the former is smaller than the latter, each particle will be caught by a plurality of adjoining lugs.
The fine lugs or the mesh may at least partly be provided with tackiness to act on the particles. For this purpose, the lugs themselves may be formed of an adhesive material, or an adhesive material may be applied to the mesh. The adhesive material may be implemented by a silicone resin or an acryl resin. If desired, the mesh may be selectively provided with tackiness in its region corresponding to the region of the mask adjoining the openings, but not provided with it in the peripheral regions of the stage. This protects the mask from needless contamination.
In the illustrative embodiment, the drive means may include a tilting mechanism for causing the major surface of the stage and that of the mask to tilt by a small angle from their parallel position. When the stage and mask are separated from each other after the arrangement of the particles, the tilting mechanism reduces the sharp inflow of air and thereby prevents the particles from being displaced or flying about.
A bump arranging device with high practicability is achievable if the openings of the mask each is so sized as to trap a single particle, and if the particle is implemented as a conductive particle for forming a solder bump.
In the illustrative embodiment, two different particle arranging methods are available for the transfer of the particles to another surface, depending on the operating timing of the above tilting mechanism. A first method is to slightly lower the degree of parallelism of the stage and mask at the time of arrangement of the particles. A second method is to arrange the particles while maintaining the stage and mask parallel to each other, slightly lower the degree of parallelism at least in the initial stage of separation of the stage and mask, and then restore the original parallelism when the danger of the sharp inflow of air has decreased. In any case, when the drive means is connected to the stage, the stage will be caused to tilt relative to the horizontal mask.
It is to be noted that "another surface" to which the particles are to be transferred refers to a TAB tape having leads, a semiconductor chip having bare pad electrodes, or an intermediate transfer member preceding the TAB tape or the semiconductor chip.
Examples of the second embodiment are as follows.
EXAMPLE 1
FIG. 11 shows a conductive particle arranging device including a stage having fine lugs formed by spraying and then curing a UV curable resin. As shown, the device, generally 60, includes a movable stage 62 and a fixed mask 72. The stage 62 is movable along a guide rail 64. A bump arranging section 60A and a bump transferring section 60B are respectively arranged at one end (right-hand side as seen in FIG. 11) and the other end (left-hand-side as seen in FIG. 11) of the guide rail 64. Drive means, not shown, moves the stage 62 back and forth between the two sections 60A and 60B in a direction indicated by an arrow C. As a result, the arrangement of bumps Bp on the stage 62 and the transfer of the bumps Bp to a transfer head 66 are effected alternately.
The bump arranging section 60A is surrounded by a frame 68 whose one end is open in the form of a gate 68a for the ingress and egress of the stage 62. The mask 72 is supported by a mask holder 70 which is, in turn, supported by the frame 68. The bumps Bp are fed from above the mask 72 via a piping 74. A squeegee 76 collects the bumps Bp not arranged on the mask 72, i.e., excess bumps Bp. A guide rail 78 allows the squeegee 76 to move therealong only in a direction indicated by an arrow A. The squeegee 76 is driven by drive means, not shown.
The mask 72 is implemented as an about 40 μm thick nickel sheet and formed with openings 72a each being so sized as to trap a single bump Bp. The bumps Bp had a mean diameter of about 40 μm while the openings 72a had a diameter of about 50 μm. In Example 1 the mask 72 is fixed in its horizontal position.
The gap between the squeegee 76 and the mask 72 is selected to be less than one-half of the diameter of the bumps Bp inclusive, i.e., less than 20 μm inclusive, so that the squeegee 76 can collect all the excess bumps Bp.
In the bump transferring section 60B, the transfer head 66 includes optics 80 for exposure. A quartz window 82 coated with an adhesive paint is provided on the surface of the head 66 which will face the stage 62. The optics 80 fixes the bumps Bp to the electrode pads of an LSI chip, not shown, by using a UV curable adhesive. For this purpose, the optics 80 includes a light source for feeding optical energy for the curing reaction of the adhesive, and an optical fiber for evenly guiding light issuing from the light source to the quartz window 82.
The head 66 is movable up and down in a direction indicated by an arrow D in order to adhere the bumps Bp of the stage 62 to the quartz window 82 and then transfer the bumps Bp to the LSI chip, not shown, at another place.
The stage 62 is formed of ceramics or similar porous material. A great number of fine lugs 84 each being about 10μm high are formed on the surface of the stage 62. The lugs 84 not only restrict the movement of the bumps Bp on the particle arranging surface of the stage 62, but also prevent the particle arranging surface and mask 72 from closely contacting each other. The above specific height of the lugs 84 was selected in order to prevent two or more bumps Bp from gathering at a single position. In Example 1, the lugs 84 were formed by spraying a UV curable resin dissolved in a suitable solvent onto the stage 62, and then curing the drops of the solution by UV radiation.
The stage 62 is supported by the stage holder 86 along its edges. A chamber 90 is formed between the rear of the stage 62 and the stage holder 86 and fluidly communicated to an evacuating unit 88. In this configuration, the bumps Bp each being trapped in one opening 72a of the mask 72 are restricted in position on or between the lugs 84, and additionally restricted by suction acting from the rear of the stage 62.
The stage holder 86 is fixed to an elevatable base 91 engaged with the guide rail 64 stated earlier. The base 90 is moved in the direction C while carrying the stage 62 thereon.
The base 91 is extendable in a direction indicated by an arrow B and allows the distance between the stage 62 and the mask 72 to be adjusted when they are conveyed to the bump arranging section 60A. The amount of extension in the direction B does not have to be uniform over the entire stage 62. For example, an actuator may be used to cause the base 91 to extend more at one end of the stage 62 than at the other end of the stage 62. This allows the particle arranging surface of the state 62 to slightly tilt from horizontal in a direction E when the bumps Bp are arranged on the stage 62 or when the stage 62 carrying the bumps Bp is moved away from the mask 72.
In the above configuration, the transfer of the bumps Bp is effected without regard to the mask 72. Therefore, all the bumps Bp arranged on the stage 62 can be transferred to another surface without resorting to sophisticated control over the height of the bumps Bp, as measured from the surface of a substrate, and bump diameter.
EXAMPLE 2
In Example 2, the particle arranging device 60 was used to actually transfer the bumps Bp to the electrode pads of an LSI chip. The transfer will be described with reference to FIGS. 12-17.
First, as shown in FIG. 12, the mask 72 and stage 62 are positioned close to each other, and each is held in its horizontal position. The bumps Bp each is received in one of the openings 72a. The bumps Bp are implemented as resin beads plated with Ni (nickel) and Au (gold) in a laminate structure. The excess bumps Bp not received in the openings 72a are collected by the squeegee 76 moving back and forth in the direction A.
Subsequently, as shown in FIG. 13, the elevatable base 91 is operated to move the stage 62 away from the mask 72. In the initial stage of the separation, the tilting movement stated earlier may be effected in order to prevent air from sharply flowing into the gap between the mask 72 and the stage 62. This maintains the accurate arrangement of the bumps Bp. Thereafter, the stage 62 is lowered in the direction B to a level at which the stage 62 can be conveyed out of the bump arranging section 60A. It is to be noted that the stage 62 can be restored to its horizontal position at the time when the influence of the stream of air has become negligible.
FIG. 14 shows a condition wherein the stage 62 is fully separated from the mask 72, and the bumps Bp are arranged on the stage 62. Because the fine lugs 84 are irregularly arranged on the stage 62, some bumps Bp are trapped between nearby lugs 84 while the other bumps B rest on a plurality of nearby lugs 84. Although the height above the stage surface slightly differs from one bump Bp to another bump Bp, the difference is only less than 10 μm.
Subsequently, the base 91 is moved in the direction C in order to convey the stage 62 out of the bump arranging section 60B. Then, as shown in FIG. 15, the transfer head 66 was lowered in the direction D until the bumps Bp adhered to the surface of the quartz window 82 applied with the adhesive material. In Example 2, the bumps Bp existed on the stage 62 in their bare state. This, coupled with the fact that the adhesive material absorbed the difference in height between the bumps Bp and sufficiently contacted all the bumps Bp, allowed the bumps Bp to be shifted to the head 66 without exception.
As shown in FIG. 16, the head 66 was moved to a position above an LSI chip 92 in order to align the bumps Bp with the electrode pads 94 of the chip 92. Then, the head 66 was lowered in the direction 66. The surfaces of the electrode pads 94 are covered with UV curable adhesive layers 96 beforehand. After the bumps Bp on the head 66 contacted the adhesive layers 96, UV rays hv were radiated from the optics 80. The UV rays hv caused the adhesive layers 96 to set via the quartz window 82. As a result, the bumps Bp were fixed to the electrode pads 94, as shown in FIG. 17.
Finally, the head 66 is raised away from the chip 92. This is the end of the bump transfer procedure of Example 2.
EXAMPLE 3
In Example 3, the stage 62 is slightly tilted from the horizontal at the time of arrangement of the bumps Bp thereon in order to protect the arrangement of the bumps Bp from a stream of air. Specifically, as shown in FIG. 18, the bumps Bp were arranged on the stage 62 inclined by an angle of θ from the horizontal via the base 91. The angle θ is free to choose so long as the bumps Bp do not escape from the openings 72a of the mask 72. After the arrangement of the bumps Bp, the stage 62 and mask 72 may be separated from each other by the method described in relation to Example 2.
EXAMPLE 4
As shown in FIGS. 19 and 20, in this example, the fine lugs 84 on the stage 62 are replaced with fine lugs 84a formed in a regular pattern by photolithography. Specifically, the lugs 84a are implemented as a resist pattern formed by the selective exposure and development of a photoresist film provided on the stage 62.
As shown in FIG. 19, when the pitch P 2b of the lugs 84a is sufficiently smaller than the pitch P B of the bump Bp, the bumps Bp rest on the lugs 84a without contacting the particle arranging surface of the stage 62. As shown in FIG. 20, when the pitch P 2b is sufficiently greater than the pitch P B , the bumps Bp contact the particle arranging surface of the stage 62 between the adjacent lugs 84b.
EXAMPLE 5
In this example, the fine lugs on the stage 62 are provided with tackiness. As shown in FIG. 21, the fine lugs are constituted by an adhesive resin buried layer 98 which may be formed by use of a silicone resin. A method of forming the layer 98 will be described with reference to FIGS. 22 and 23.
First, as shown in FIG. 22, conventional resist patterning was effected on the stage 62 in order to form a resist pattern 100. Then, as shown in FIG. 23, the adhesive resin buried layer 98 was formed such that a silicone resin filled the spaces of the resist pattern 100. After the setting of the silicone resin, the resist pattern 100 was removed by a peeling liquid. As a result, only the layer 98 was left on the stage 62, as shown in FIG. 21.
The fine lugs formed by the above procedure have tackiness themselves and retain the bumps Bp more positively than the fine lugs implemented by the previously stated UV curable resin. Therefore, even when a flow of air occurs at the time of separation of the stage 62 and mask 72, the disturbance to the arrangement of the bumps Bp can be minimized. In addition, to obviate the flow of air, the tilting angle of the stage 62 can be increased.
EXAMPLE 6
In this example, the fine lugs with tackiness are not formed over the entire particle arranging surface of the stage 62, but formed only in the region of the stage 62 adjoining the openings 72a of the mask 72. Specifically, as shown in FIG. 24, the fine lugs are constituted by an adhesive resin buried layer 98b and a resist pattern 100c. The layer 98b is selectively formed in a region M adjoining the openings 72a of the mask 72. For the layer 98b, use may be made of a silicone resin. The resist pattern 100c surrounds the above region M and is formed of a conventional positive type photoresist material. With this configuration, it is possible to free the mask 72 from contamination when the mask 72 and stage 62 are brought into contact.
FIGS. 25-28 show a procedure for forming the fine lugs of this example by two consecutive photolithographic steps. First, as shown in FIG. 25, a positive type photoresist film 102 formed on the stage 62 was subjected to the first selective exposure via a photomask 104. The photomask 104 is made up of a substrate 106 transparent for exposing light, and a Cr (chromium) film or similar light intercepting film pattern 108 formed on the substrate 106. The pattern 108 defines a position for forming the layer 98b (FIG. 27) in the region M. While the exposure is shown as being proximity exposure in FIG. 25, it may be contact exposure or projection exposure, if desired.
Subsequently, the exposed region of the photoresist film 102 was removed by the first development in order to form a resist pattern 100b shown in FIG. 26. Then, as shown in FIG. 27, the adhesive resin buried layer 98b was formed such that the spaces of the resist pattern 100b were filled with a silicone resin.
As shown in FIG. 28, after the setting of the above layer 98b, the resist pattern 100b on the stage 62 was subjected to the second selective exposure via a photomask 110. The photomask 110 is also made up of a substrate 112 transparent for exposing light, and a Cr film or similar light intercepting film pattern 114 formed on the substrate 112. The pattern 114 causes a new resist pattern 100c shown in FIG. 28 to be formed in the peripheral region around the region M. At the same time, the pattern 114 defines an exposure area for causing the resist pattern 100b existing in the region M to be removed.
After the second selective exposure, the second development was effected so as to produce the stage 62 shown in FIG. 24. As shown, the stage 62 has two different kinds of fine lugs each being confined in a respective region.
EXAMPLE 7
In this example, the fine lugs for retaining the bumps Bp are replaced with a mesh 116 laid on the stage 62. As shown in FIG. 29, the mesh 116 is laid on the stage 62 such that the bumps Bp trapped in the openings 72a of the mask 72 are arranged on the mesh 116. The mesh 116 is formed of, e.g., stainless steel. The mesh size of the mesh 116 is selected to be sufficiently smaller than the diameter of the bumps Bp, yet to surely retain the bumps Bp. In Example 7, the apertures of the mesh were about 20 μm.
The bumps Bp may be arranged on the stage 62 and then transferred by the previously stated procedure.
While this example maintains both the stage 62 and mask 72 horizontal at the time of arrangement of the bumps Bp, the stage 62 may be slightly tilted from the horizontal via the elevatable base 91 in the same manner as in Example 3. Further, when the stage 62 and mask 72 are separated from each other, the stage 62 may advantageously be lowered while being tilted, as in Example 1.
The illustrative embodiment is not limited to Examples 1-7 shown and described. For example, the bumps Bp arranged on the stage 62 and brought to the bump transferring section 60B may be directly bonded to the leads of a TAB tape by a conventional bonding tool, i.e., without using the transfer head 66. The kinds and sizes of the bumps Bp, the sizes of the openings of the mask and mesh, the dimension of the fine lugs, and the details of the particle arranging device shown and described are only illustrative. In addition, this embodiment is applicable not only to the bumps Bp but also to other various kinds of particles.
In summary, in the illustrative embodiment, bumps can be easily and surely arranged and transferred without resorting to strict control over the diameter of the bumps, the flatness of the leads of a TAB tape, the flatness of a bonding tool, and the parallelism of a stage and a TAB tape or an LSI chip. This successfully increases the yield of bonding using the TAB system or the flip-chip bonding system, and thereby enhances the productivity of semiconductor devices.
Various modifications will become possible for those skilled in the art after receiving the teachings of the present disclosure without departing from the scope thereof.
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A process for manufacturing a device for arranging conductive particles in a preselected pattern for the connection of electric circuit boards or electric parts is disclosed. Particularly, a device capable of surely and efficiently transferring, e.g., solder bumps to the electrode pads of a semiconductor chip or the leads of a TAB (Tape Automated Bonding) tape and a conductive particle transferring method using the same are disclosed.
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BACKGROUND OF THE INVENTION
The present invention relates to a flat knitting machine having function for adjusting knock-over timing capable of adjusting the knock-over timing when knitting depending on the characteristics of knitting threads and knitted texture of the knit facric.
Generally, as knock-over timing of knitting in a flat knitting machine, after the knitting needle planted in the needle bed is related to a position capable of clearing the stopped former loop, the knitting thread supplied into the hook of this knitting needle is pulled in and lowered, and the new loop surpasses the former loop to form a stitch. In other words, the former loop stopped on the knitting needle is, when forming a next new loop, knocked over together with the knitting needle in its pulling-in process, so that a complete stitch is formed.
This knock-over timing is automatically determined by the position of a hole drilled near the front tip of the sinker in order to install the knitting thread stopping wire rod. It means that the ratio of the sinker loop and needle loop forming the stitch to one stitch is constant in the stitches of the continuously knitted courses.
However, the knock-over timing is significantly influenced by the characteristics of the knitting threads and others. For example, slipping of knitting thread, elongation, twist, dyeing property, and difference in after-treatment may affect whether the materials are the same or different. They are also found to affect the shapes of the sinker loop and needle loop forming the stitches at the same time.
Hitherto, therefore, whenever the type or thickness of the knitting thread is changed, the knitting parameters that are considered to affect the timing (thead feed tension, waxing, knit fabric winding-down tension, needle hook shape) have been revised or modified to adjust to proper suited knitting paramenters.
This work, however, required much skill and labor, and in spite of the skill and labor spent, sufficient effects could not be obtained.
OBJECT AND SUMMARY OF THE INVENTION
The invention is devised in the light of the above problems and it is hence a primary object of the invention to present a flat knitting machine having a function for adjusting knock-over timing in order to obtain a high quality knit fabric excellent in knitting performance (ease of knitting), by variably adjusting the knock-over timing when knitting, depending on the characteristics of the knitting threads and the knitted texture of the knit fabric.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view for explaining the portion relating to the invention of a flat knitting machine,
FIG. 2 is an explanatory drawing showing the knock-over state of essential parts relating to the invention,
FIG. 3 is a front view showing a sinker 1a in a first embodiment,
FIG. 4 is an enlarged view of essential parts in FIG. 3,
FIG. 5 is a front view showing a sinker 1b in a second embodiment,
FIG. 6 is an enlarged view of essential parts in FIG. 5, and
FIG. 7, FIG. 8 are enlarged explanatory drawings of a sinker 1c in a third embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 to FIG. 8, some of the preferred embodiments of the invention are described in detail below.
As shown in FIG. 1, in a flat knitting machine, sinkers 1 are fixed on the top of a needle bed at specific intervals in parallel with each other. Multiple knitting needles 4 are mounted on a needle bed slidably along the sinkers 1 and needle plates 9, each of the knitting needles 4 being controlled by a cam mechanism of a carriage (not shown) running on the needle bed in a longitudinal direction by means of a select jack 2 and a jack 3. A knitting thread stopping wire rod 5 is provided below hook portions of the knitting needles 4 in operation of knock-over and it pierces through the sinkers 1 to be orthogonal to the sliding direction of the knitting needles 4. Sinkers 1a, 1b, 1c in the individual embodiments shown in FIG. 3 to FIG. 8 are individually disposed as the sinkers 1 in FIG. 1, and the knitting thread stopping wire rod 5 is designed to be freely set in and out of the holes pierced in the sinkers 1a, 1b or 1c.
That is, in the sinker la of the first embodiment as shown in FIG. 3 and FIG. 4, large and small holes 6a, 6b are pierced near the front tip of the sinker by deviating the position slightly in the sliding direction of the knitting needles 4. In the sinker 1b of the second embodiment shown in FIG. 5 and FIG. 6, large and small communicating holes 6c in a snowman shape on the whole are opened near the front tip of the sinker as shown in the drawings By putting the knitting thread stopping wire rods 5 into these holes 6a, 6b, holes 6c, depending on the characteristics of the knitting threads and knitted texture of knit fabric, the abutting position to the knitting thread stopping wire rod 5 of the knitting thread loop A may be changed as showned in FIG. 2, thereby making it possible to adjust to the optimun knock-over timing when the knitting thread loop A (former loop) is cleared from the hook 4a of the knitting needle 4 when forming a stitch.
The embodiment shown in FIG. 7, and FIG. 8 is a third embodiment, and in this embodiment, in order to adjust the knock-over timing depending on the characteristics of knitting threads and knitted texture of knit fabric, the knitting thread stopping wire rod 5 in an elliptical section is inserted in the hole 6d pierced near the front tip of the sinker 1c, and by attaching by arbitrarily varying the attaching position in the hole 6d of this knitting thread stopping wire rod 5a, that is, the inserting angle (method) of the knitting thread stopping wire rod 5a as shown in the drawing, the abutting position of the knitting thread loop A and the knitting thread stopping wire rod 5a when knitting may be properly changed in the longtudinal direction of the sinker 1c. In this embodiment, meanwhile, the hole 6d may be disposed in a plurality same as in the foregoing embodiments, or plural communicating holes may be opened, and the knitting thread stopping wire rod 5a in the elliptical shape may be set in the desired hole or in the desired position of the communicating holes.
By properly setting the knitting thread stopping wire rods 5, 5a in the holes of the sinkers 1a, 1b, 1c in the foregoing embodiments, the following actions and effects may be obtained (see FIG. 2 to 6).
More specifically, even in the same knitted texture, if differing in the characteristics of knitting threads, for example, in the case of the knitting thread low in stretchability or the knitting thread of excellent slipping property (small in surface friction coefficient), by setting the knitting thread stopping wire rod 5 in the hole closer to the front tip of the sinkers 1a, 1b in the first and second embodiments, a beautiful knit fabric with uniform stitches will be obtained.
That is, as shown above, by setting the knitting thread stopping wire rod 5 in the hole 7 closer to the front tip of the sinkers 1a, 1b, the knock-over timing of the knitting loop A is quickened, while the stitch being formed presently is less affected by the winding-down tension. Owing to the quickness of knock-over by these characteristics of the knitting thread itself, it is possible to form the stitch more natually than in the state of easier winding-down effect by keeping the knitting thread stopping wire rod 5 away from the front tip of the needle bed (the state in which the winding-down tension may directly affect the stitch formation), and therefore the stitches become very orderly and neat, and a knit fabric of high quality may be obtained.
On the other hand, even in the same knitted texture, in the case of the knitting thread high in stretchability or poor in slipping performance (large in surface friction coefficient), if knitted by setting thread stopping wire rod 5 in the hole 7 closer to the front tip of the sinkers 1a, 1b of the first embodiment and second embodiment as mentioned above, the frictional resistance increases at the contact point of the loops A and B when the new loop B rides over the former loop A (knitting thread loop A) at the time of knock-over, and the knock-over timing of the former loop A (knitting thread loop A) is delayed by the corresponding portion, and the ratio of the needle loop and sinker loop may be disturbed or the movement of the knitting thread still moving in the formed loop may be influenced, thereby adversely affecting the uniformity of the stitches.
Accordingly, by setting the knitting thread stopping wire rod 5 in the hole 8 opened at a position remote from the front tip of the needle bed, stitches may be formed in a state where the winding-down tension may take effect easily, and therefore the delay of the knock-over due to poor slipping property of the knitting thread itself may be compensated by the positive utilization of the winding-down tension, and hence knit fabrics of high quality may be obtained by eliminating the above adverse effects.
Next, when the knitted texture is different although the knitting threads are the same, for example, in a fashioning knit for sequentially widening or narrowing the knitting width, particularly when narrowing the knitting width, if the knitting thread stopping wire rod 5 is set in the hole 8 opened at a position remote from the front tip of the sinkers 1a, 1b, the effect of the winding-down tension is large, and as the knitting width becomes narrower and narrower, it bocomes difficult to adjust the winding-down tension, and it also becomes difficult to reduce the stitches at both ends of the knit fabric, further it is likely to be broken.
Accordingly, by setting the knitting thread stopping wire rod 5 in the hole 7 opened at a position close to the front end of the sinkers 1a, 1b, the effect of the winding-down tension becomes less, and therefore even if some strong winding-down tension is actuated, the chance of immediate adverse effect on the knit fabric is low.
On the other hand, even by the same knitting threads, in the case of knitted texture mixing rib stitch and plain stitch at various locations in the wale direction such as in the knit-in pattern, if the knitting thread stopping wire rod 5 is placed in the hole 7 made at a position closer to the front tip of the sinkers 1a, 1b, as known from the example above, the winding-down tension hardly acts on the knit fabric, and hence the plain stitch loop in a loosened state as compared with the rib stitch loop may finally lead to double biting even if knocked over from the hook part of the needle front end.
Accordingly, by setting thread stopping wire rod 5 in the hole 8 drilled at a position remote from the front tip of the sinkers 1a, 1b, the effect of the winding-down tension is increased, and such double biting may be avoided, and a knit fabric of excellent high quality may be obtained.
Incidentally, in order to obtain the above action and effect by the sinker 1a and knitting thread stopping wire rod 5a in the third embodiment, as mentioned above, instead of setting the knitting thread stopping wire rod 5 in the hole 8 made in a position remote from the front the front end of the sinkers 1a, 1b, for example, the knitting thread stopping wire rod 5a which has an elliptical section may be inserted as shown in FIG. 7, so that the same action and effect may be obtained.
Moreover, instead of setting the knitting thread stopping wire rod 5 in the hole 7 opened in a position close to the front tip of the sinkers 1a, 1b, for example as shown in FIG. 8, by inserting the knitting thread stopping wire rod 5a which has an ellipical section, the same action and effect may be obtained.
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The invention relates to a flat knitting machine capable of obtaining a high quality knit fabric excellent in knitting property (ease of knitting), by variably adjusting the knock-over timing when knitting, depending on the characteristics of knitting threads and knitted texture of the knit fabric. The characteristics of the knit fabric depends upon the sinkers which have at least one aperture near a tip end of the sinkers. A knitting thread stopping wire rod is passed through one aperture near the tip end of the sinker. The knit fabric depends upon which aperture near the tip end that the knitting thread stopping wire rod is passed.
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