The disclosure is a probelike apparatus (16) for spectroscopic analysis of a fluid medium (19) by attenuated reflection. Two light beams from a light source (11) impinge upon the boundary (18) between a prism (17) and the medium (19) to be analyzed and the intensities of the light beams reflected at the boundary are measured in a detector unit (22). The two light beams differ in their angle of incidence on the boundary and/or in their polarization state. Measurement is preferably carried out under total reflection.

1. Field of the Invention
The present invention relates to an apparatus for spectroscopic analysis of a fluid medium by attenuated reflection, preferably by internal reflection spectroscopy and especially by attenuated total reflection (ATR).
The invention relates particularly to a novel apparatus for continuous reaction monitoring, for example for in-situ or on-line reaction monitoring in the chemical industry.
2. Discussion of the Background
Optical analytical methods such as transmission spectroscopy have hitherto only been used to a very limited extent for the continuous monitoring of reactions on an industrial scale. Owing to the high concentrations arising in manufacturing processes, coupled with large extinction coefficients in some cases, the pathlengths of the measuring cells would have to be on the order of 1 micrometer to obtain useful absorption spectra. It is therefore necessary to take samples and to prepare them, for example by dilution, for a measurement in the laboratory. But this process of sample preparation may alter the chemical equilibrium of the sample, so that lab results are not necessarily applicable to conditions in the reactor.
It is known that these transmission spectroscopy problems can be avoided by conducting measurements utilizing the well known optical phenomenon of the total reflection of light. When light traveling within a first medium having a refractive index n1 impinges upon a boundary between that medium and a medium of lower refractive index n2, it is totally reflected, i.e., does not pass into the second medium, when the sine of the angle of incidence xcex8 is greater than the ratio of the refractive index of the second medium to the refractive index of the first medium (sin xcex8 greater than n2/n1). Although the reflection is referred to as total, the light, owing to its wave nature, does penetrate a short distance into the second medium. The depth of penetration is usually on the order of the wavelength of the light. If the light does not interact with the second medium, then the coefficient of reflection, i.e., the ratio of the intensity of the reflected light to the intensity of the incident light, is 1 and the reflection is indeed xe2x80x9ctotalxe2x80x9d. If, however, a portion of the light which penetrates into the second medium (the so-called evanescent wave) is absorbed or scattered therein, this results in a reduced coefficient of reflection and the effect is known as xe2x80x9cattenuated total reflectionxe2x80x9d. Computing the negative decadic logarithm of the degree of transmission, i.e., the reciprocal of the coefficient of reflection R, gives the quantity of decadic extinction customary in absorption spectroscopy, which is usually known as the absorbance A:   A  =            -      log                  xe2x80x83                  (              1        R            )
Methods and apparatuses utilizing this simple relation so as to carry out absorption measurements by attenuated total reflection in chemical analysis are known. European Patent Application EP-A-0 206 433, for example, describes an ATR probe for measuring the concentration of a light absorbing substance in a fluid medium. An optical fiber is used to couple light at a certain angle into an ATR prism where it is totally reflected one or more times at a boundary between the prism and the medium to be analyzed. The reflected light emerges from the prism via a second optical fiber which transmits the light to two detectors via a bandpass filter each. One of the filters has a transmission wavelength at which no absorption is expected in the medium, and is used as reference signal, while the other filter has a transmission wavelength at which absorption does take place in the medium. The concentration measurement is effected by comparing the measured intensity ratio with calibration measurements carried out on solutions of known concentrations.
European Patent Application EP-A-0 221 011 discloses a method for analyzing dye solutions by attenuated total reflection. This reference also describes a probelike apparatus for spectroscopic analysis of a fluid medium by attenuated total reflection. It comprises a prism which is mounted in a holder and which shares with the medium to be analyzed one or more boundaries at which incident light is totally reflected and then transmitted to a detection unit. The reference proposes various applications in the chemical industry, especially in dye manufacture.
However, existing processes and apparatuses have disadvantages. For example, absorption spectra obtainable according to the prior art depend not only on the absorption coefficient of the sample, but also on its refractive index, which may vary, for example owing to temperature changes.
It is also well known that absorption spectra obtained via ATR measurements exhibit a bathochromic shift, i.e., a shift to longer wavelengths, compared with transmission spectra. This shift is due to the fact that the refractive index n of the absorbing medium to be analyzed and hence the depth of penetration of the evanescent light is wavelength-dependent (Harrick, J. Opt. Soc. Am. 55, 851-857, 1965). Accordingly, a single determination of the coefficient of reflection of the totally reflected light is not sufficient for accurate sample analysis.
From German Patent 12 69 816 C2 a device for measuring attenuated total reflection is known comprising a goniometer which allows for changing the angle of incidence of a single light beam. The time consuming mechanical adjustment of the angle of incidence does not allow for continuously monitoring chemical reactions.
It is an object of the present invention to provide an apparatus for continuous spectroscopic analysis of fluid mediums which permits precise and economical in-line monitoring of industrial reaction processes. The apparatus of the invention shall be useful in particular in an aggressive environment at comparatively high temperatures.
We have found that this object is achieved by the apparatus of the accompanying main claim. The present invention accordingly provides an apparatus for spectroscopic analysis of a fluid medium by attenuated reflection, comprising first means for directing a first light beam onto a boundary or interface of the medium to be analyzed and means for measuring the intensity of the first light beam reflected at the boundary. The apparatus according to the invention further includes second means for directing a second light beam onto a boundary of the medium to be analyzed and means for measuring the intensity of the second reflected light beam, the first and second light beams differing in their respective polarization state and/or in their angle of incidence upon the boundary.Said first and second light beams are directed substantially simultaneously onto said boundary.
By xe2x80x9cangle of incidencexe2x80x9d is means herein, as is customary in optics, the angle between the incident light beam and the perpendicular to the boundary. By xe2x80x9clightxe2x80x9d is meant in the present context not just visible light. The apparatus of the invention is also useful in the IR region or in the UV region. The preferred wavelength region for using the method of the invention ranges from 200 nm to 20,000 nm.
The invention is predicated on the concept that the reflection of a light beam at the boundary between two dielectric media is describable by the classic Fresnel equations. It is found that the coefficient of reflection is dependent, inter alia, on the angle of incidence of the light and on its polarization state.
The apparatus of the invention makes it possible to carry out two different, mutually independent reflection measurements, so that it is possible to determine decoupled dispersion spectra n(xcex) and absorption spectra k(xcex) of the medium. These spectra, unlike those produced by conventional ATR spectroscopy, are not bathochromically shifted, since the influence of the different depths of penetration of the evanescent light on the measured reflection spectra can be corrected.
Unlike the apparatuses known from EP-A-0 206 433 and EP-A-0 221 011, the apparatus of the invention is not restricted to angles of incidence which are larger than the limiting angle of total reflection. This is because Fresnel""s equations show that, for smaller angles too, the coefficient of reflection is dependent not only on the refractive index n(xcex) but also on the absorption coefficient k(xcex) of the medium to be analyzed, i.e., when absorption occurs in the medium it is not just the beam passing through the medium which is attenuated but also the beam reflected at the boundary.
In a first embodiment of the apparatus of the invention, the angle of incidence of the first light beam on the boundary is xcex81 and the angle of incidence of the second light beam on the boundary is xcex82, which differs from xcex81. Both the beams are reflected at the boundary and conducted to suitable detection means.
This apparatus makes it possible, for example, to measure the total intensity in the case of beams reflected at these two angles. The wavelength-dependent coefficients of reflection for the two angles can be used, as will be shown hereinafter, to assign numerical values to n(xcex) and k(xcex). There is no need for polarizers, so that the apparatus is relatively inexpensive to manufacture and can be used especially under harsh conditions in chemical reaction monitoring, for example at high temperatures and pressures and in an aggressive environment. Since it is only total intensities which are still measured in a polarization-independent way, there is no need either for costly polarization-preserving optical fibers. The apparatus of the invention provides an exact determination of the refractive index n and of the absorption coefficient k, which depends only on the accuracies of the reflection measurements and of the calculation and therefore permits in particular the exact description of an absorption spectrum or a dispersion curve of the medium to be analyzed. Simple optical components can be used, especially relatively inexpensive multimode optical fibers.
xe2x80x9cTotal intensityxe2x80x9d for the purposes of the present invention is to be understood as meaning a measurement of the polarization-independent intensity of the reflected light.
The angles of incidence of the two light beams preferably differ by an amount in the range from 5 to 20xc2x0, particularly preferably by about 10xc2x0.
In one variant, the angle xcex81 is larger than the limiting angle of total reflection while the angle xcex82 is smaller than the limiting angle of total reflection. In this case, the intensity of the first reflected beam is more dependent on k(xcex), while the intensity of the second reflected beam is more dependent on n(xcex).
In a particularly preferred variant, however, both the angles xcex81 and xcex82 are larger than the limiting angle of total reflection. This represents the case of an ATR probe, but the ATR probe of the invention differs from prior art probes in that it utilizes two measuring beams.
The apparatus of the invention is preferably constructed as an elongate probe comprising a cylindrical protective housing at whose free end face is disposed a prism having at least one face which is wettable by the medium to be analyzed and which forms the boundary for the reflection of the two light beams. The prism/medium boundary is a clearly defined, planar surface, as is preferred for the impingement of light on an air/medium boundary.
However, there may also be a separate boundary with the medium for each light beam. These two boundaries may be realized by one prism or else by two prisms.
Advantageously the prism is mounted replaceably in the probe. For each measuring problem it is then possible to select an appropriate prism. Different prism geometries make it possible, for example, to use different angles of incidence. Different prism materials permit a selection with regard to transmission properties and refractive index.
The cylindrical protective housing is advantageously formed of chemically resistant metallic or ceramic materials. In this way it is possible to realize dip probes up to 2.5 m in length for use on an industrial production scale. In a particularly preferred embodiment, the prism is forced by suitable elastic means, for example compression springs, against sealing means surrounding an opening in the end face of the cylindrical housing. The compression springs serve to compensate the longitudinal expansion of the probe in the event of an increase in the temperature and maintain a good seal with regard to the prism, since the necessary contact pressure is ensured even at high temperatures. The probe of the invention can therefore also be used in the case of process temperatures of 200xc2x0 C. or more or in the case of wildly fluctuating temperatures. An example of a useful sealing means is a gasket in the shape of a circular ring. This design makes it possible to fabricate dip probes more than two meters in length with just one seal. Such comparatively long probes are preferably installed in customary dip tubes, i.e., gas inlet tubes, so as to obtain good mechanical stability in stirred vessels, for example.
The prism is preferably a crystal which, for measurements in the UV to near IR region, is composed of materials which have a high refractive index and are substantially chemically resistant, such as quartz glass, sapphire or diamond, zirconium oxide or zirconia (doped zirconium oxide). For infrared measurements it is preferable to employ semiconductor crystals, for example ZnSe crystals. Preferably the entire optical device is fixedly mounted, eliminating the need for reconfiguration and adjustment.
For an ATR prism composed of quartz and refractive indices in the range from 1.2 to 1.7 for the mediums to be analyzed, the angles of incidence are preferably in the range from 55 to 60xc2x0 for the first beam and in the range from 65 to 70xc2x0 for the second beam. Preferably the prism has an essentially frustoconical shape and comprises a light entry and exit face parallel to the boundary, a first pair of mirror-symmetrically opposite side faces which form an angle of xcex81/2 with the normal to the boundary, and a second pair of mutually opposite mirror-symmetrical side faces which form an angle of xcex82/2 with the normal to the boundary.
In this embodiment of the apparatus according to the invention, the two light beams pass essentially vertically through the horizontal light entry and exit face into the prism, are reflected at one of the side faces of the first or second side-face pair and impinge at an angle of xcex81 or xcex82, respectively, upon the boundary, where they are diverted to the other side face of each pair. There, they are vertically reflected upward and emerge from the prism with a parallel offset relative to the incident beam. To avoid light loss, the reflection at the side faces is total as well. In one variant, the prism is arranged in such a way that one or both of the side faces of a pair are likewise wetted by the medium to be analyzed, so that each light beam undergoes two or three xe2x80x9cattenuatedxe2x80x9d reflections. In a particularly preferred variant, however, only the lower boundary is wetted by the medium. In this case, the prism holder will be constructed in such a way that no absorption of the evanescent light takes place at the side faces in order that the measurement of the medium may not be distorted.
Advantageously the first side-face pair is twisted by 90xc2x0 around a normal to the boundary relative to the second side-face pair, resulting in a particularly compact apparatus.
In a second embodiment of the apparatus according to the invention, the optical path of the first light beam includes pre-boundary a polarizer for perpendicularly polarized light and/or post-boundary an analyzer for perpendicularly polarized light and the optical path of the second light beam includes pre-boundary a polarizer for parallel-polarized light and/or post-boundary an analyzer for parallel-polarized light. As light is reflected at the boundary, a certain amount of depolarization may occur. It is therefore preferable in this case to use both a polarizer and an analyzer for each light beam.
What is measured in this embodiment is not, as in the prior art, the total intensity of the reflected light, but, separately, the intensities of the two polarization directions of the light parallel to the plane of incidence Ip and perpendicular to the plane of incidence Is. For this case, Fresnel""s equations have been analytically solved for the desired parameters of the medium, i.e., for the refractive index n and the absorption coefficient k (Querry, xe2x80x9cDirect Solution of Generalized Fresnel Reflectance Equationsxe2x80x9d, J. Opt. Soc. America, 59 (1969), 876-877). The angles of incidence of the two beams may be identical. In principle it would also be possible here to use just one light beam and to switch the polarizers and analyzers or, for example in the case of the use of polarizing films, turn them by 90xc2x0 between two successive measurements.
This embodiment of the probe according to the invention is advantageous in that it makes use of the known analytical solutions to enable the desired spectra to be calculated directly and rapidly from the measurements. However, the use of polarizers or analyzers is mandatory.
In a third embodiment of the apparatus according to the invention, the optical path of the first and second light beams include pre-boundary polarizers for perpendicularly polarized light and/or post-boundary analyzers for perpendicularly polarized light. The light beams impinge upon the boundary at different angles of incidence. Again, it is preferable to use both polarizers and analyzers.
For this case of a reflection measurement with perpendicularly polarized light and two different angles of incidence, an iteration method has been described for solving the Fresnel equations (Fahrenfort and Visser in Spectrochim. Acta 18, 1103-1116 (1962)).
In the probe of the invention, the light is advantageously not focused on the boundary; instead the light should impinge upon the boundary in as parallel a state as possible, for exact compliance with the chosen angle of incidence. It is therefore particularly advantageous to provide first optical fibers for passing the incident light beams onto the boundary and second optical fibers for directing the light beams reflected at the boundary to the means for measuring the light intensities, in which case collimating means are disposed between the light exit faces of the first optical fibers and the boundary, and between the boundary and the light entry faces of the second optical fibers, respectively for coupling the light beams in and out, respectively.
In an embodiment of the apparatus according to the invention, which for cost reasons is particularly preferred for use as a monitoring probe in chemical production, the measurement is carried out polarization-independently at two different angles. This is because high quality polarizers capable of withstanding temperatures of above 200xc2x0 C. are very costly and therefore uneconomical for many monitoring duties. Also, the use of reflection probes in process monitoring has gained popularity in recent years especially because the use of optical fibers made it possible to have the probe head with the prism and the actual measuring unit (spectrometer, sensor and microprocessor) far apart. Polarization-dependent measurements would therefore also require the use of costly polarization-preserving single mode fibers.
A measuring process using a probe according to the invention will now be more particularly described by way of example. A polarization-independent measurement is carried out at two different angles of incidence. Total reflection shall occur at both angles of incidence, i.e., an ATR probe is used.
A first light beam is in a conventional manner allowed to impinge under total reflection upon the boundary between the prism and the medium to be analyzed, at a first angle of incidence xcex81. The total intensity I1 of the totally reflected light beam is measured at a certain wavelength l. According to the invention, in addition, a second light beam is allowed to impinge under total reflection upon the boundary at an angle of incidence xcex82, which differs from the first angle of incidence xcex81, and the total intensity I2 of the totally reflected second light beam is measured. The two measurements are then used to calculated the absorption coefficient k(xcex) and/or the refractive index n(xcex).
When used for monitoring industrial chemical processes, each beam is usually totally reflected at the boundary only once. In thin, weakly absorbing mediums, however, multiple total reflection at the boundary may also be provided for in one variant. A measuring arrangement suitable for this purposexe2x80x94albeit for measurements at only one angle of incidencexe2x80x94is described in EP-A-0 206 433, for example.
The accuracy of wavelength measurement depends on the particular purpose. For spectroscopic studies, for example, the need for a higher resolution will require the use of a grating spectrograph positioned in front of a diode array or other polarization-independent detection means. If, for example, there is only interest in monitoring the formation of a certain reaction component, then there is no need to record a spectrum and instead, for example, suitable bandpass filters can be used to isolate a characteristic wavelength range in which the absorption characteristics of the properties are expected to change as the reaction proceeds.
The two light beams are preferably measured simultaneously or substantially simultaneously, for example by providing a separate detection array for each reflected light beam.
Such a setup can also be used to simultaneously measure a plurality of wavelengths, i.e., to record a larger region of the spectrum. Useful sensitive diode arrays are known and typically have 256, 512 or 1024 diodes (the MMS or MCS arrays from Zeiss, for example). The signals from the diodes are amplified and processed by a microprocessor. The choice of diode arrays can be influenced by numerous factors, for example the desired resolution, the time available for on-line evaluation, the computing power, the accuracy required for measurement and computation, etc.
To calculate the constants n and k of interest, the present example utilizes polarization-independent detectors to measure the total intensity of the reflected light. The coefficient of reflection for a given angle of incidence is then made up as per             R      θ                  (              n        ,        k            )        =                    R        s            2                  xe2x80x83                  (              1        +                              R            p                                R            s                              )
from the perpendicularly polarized fraction Rs and the parallel-polarized fraction Rp. According to Fresnel""s formulae, the coefficient of reflection is also dependent on the angle of incidence xcex8, so that different coefficients of reflection Rxcex81 and Rxcex82 result for the two light beams. An analytical solution of Fresnel""s formulae for n and k is not possible for this case. The actual values of n and k have to satisfy the following two relations simultaneously:
Rxcex81(n,k)=R1
and
Rxcex82(n,k)=R2
i.e., the theoretical coefficient of reflection Rxcex81 has to be equal to the measured coefficient of reflection R1 of the first light beam for n and k. A corresponding relation has to be satisfied for the second light beam for the same n and k.
To solve this nonlinear system of equations, the invention proposes forming a function F(n,k) of the following structure:
F(n,k)=(Rxcex81(n,k)xe2x88x92R1)2+(Rxcex82(n,k)xe2x88x92R2)2
i.e., the sum of the advantageously squared differences of the two theoretical coefficients of reflection Rxcex8 and of the respective measured coefficient of reflection R, and numerically minimizing F. The squaring of the difference terms leads to a continuous function F, facilitating minimization. Rxcex8 is obtained from Fresnel""s formulae by the following relation:                     R        θ                          (                  n          ,          k                )              =                  1        2                          xe2x80x83                                                              (                              a                -                                  cos                                                        xe2x80x83                                                      θ                                            )                        2                    +                      b            2                                                              (                              a                +                                  cos                                                        xe2x80x83                                                      θ                                            )                        2                    +                      b            2                                            xe2x80x83                          (                  1          +                                                                      (                                      a                    -                                          sin                                                                    xe2x80x83                                                                  θ                                                                    xe2x80x83                                                                  tan                                                                    xe2x80x83                                                                  θ                                                        )                                2                            +                              b                2                                                                                (                                      a                    +                                          sin                                                                    xe2x80x83                                                                  θ                                                                    xe2x80x83                                                                  tan                                                                    xe2x80x83                                                                  θ                                                        )                                2                            +                              b                2                                                    )                                where                          xe2x80x83                        a            -              ⅈ                          xe2x80x83                        b              =                            m          2                -                              sin            2                              θ                          m    =                  (                  n          -                      ⅈ                                      xe2x80x83                                    k                          )                    n        0
where m is the complex refractive index of the medium and n0 is the refractive index of the optical element, i.e., of the prism, for example. Algorithms for minimizing a nonlinear function having two parameters are known. Particular preference is given to using a Broyden-Flatcher-Goldfarb-Shanno minimization algorithm (unconstrained quasi-Newton minimization) as described for example in the standard work xe2x80x9cNumerical Recipes in Cxe2x80x9d and implemented in the MATLAB Optimization Toolbox, The Math Works Inc.
The MATLAB Toolbox optimization technique requires a computing time of about 19 seconds on a 133 MHz Pentium computer (PENTIUM(copyright) is a registered trademark of Intel) for 256 spectral points and an estimated error of 10xe2x88x924 in the determination of n and k.
The evaluation time can be reduced, depending on requirements. For example, it is possible to use faster processors or to use a plurality of processors in a parallel array.
Advantageously the coefficients of reflection R1 and R2 following r1 and r2 total reflections (usually: r1=r2=1) are determined from the measured intensities I1 and I2 according to the following relation:             R              1        ,        2                        (      λ      )        =            (                                    I                          1              ,              2                                                      (            λ            )                                    I          ref                    )              1              r1        ,        2
The reference intensity Iref corresponds essentially to the intensity I0 of the light source used. Since a light source may be subject to intensity fluctuations in the course of a measurement, it is advantageous to measure the reference intensity continuously as well. This may be accomplished, for example, by incorporating in the spectrometer a third diode array for wavelength-dependent measurement of the intensity I0. For particularly accurate measurements, the intensity I0 will be additionally weighted using the transmission curve of the entire optical system, advantageously by also taking account of the grating function of the spectrometer. This is because the transmission curve of the measuring system will generally also show a certain degree of wavelength dependence, which will be particularly noticeable when the region of the spectrum measured is relatively large. The corresponding transmission curve Itrans(xcex) is determined once for a given setup and can then be stored for the evaluation of later measurements.
The apparatus of the invention is particularly useful for applications in the chemical industry. Typical examples are continuous concentration measurements or absorption-spectroscopic studies of chromophoric systems in dye synthesis, in the manufacture of paints and generally in the processing of highly concentrated organic substances. The method of the invention provides for the first time the possibility of precise in-situ concentration measurements of substances which absorb strongly in the UV region, such as hydrosulfite, benzaldehyde or styrene, by preparing linear calibration curves.
The reflection measurements which can be performed using the probe of the invention are insensitive to solid particles more than a few micrometers in diameter, which is particularly advantageous in the case of measurements where there is a danger that comparatively large particles will distort the measurement. On the other hand, fine pigment dispersions in paints or printing inks can be reliably investigated.

Apparatus for spectroscopic analysis of a fluid medium by attenuated reflection


A porting apparatus in an internal combustion engine delivers and exhausts gas in a combustion space. A pair of cylinders each have a cylinder wall mounted for rotation within a head of an engine block. The cylinders each provide a pair of apertures in diametrically opposing and axially offset positions through the wall of the cylinder. A pair of rotatable manifold rods, each axially oriented, are each positioned within one of the cylinders. The manifold rods each provide a through port adapted for alignment with the pair of apertures of a corresponding one of the cylinders, such that within each of the cylinders and corresponding through ports, a gas flow is enabled for communication from one of the pair of apertures to the other of the pair of apertures through the through port upon each full rotation of the cylinders which are driven in coordination with the engine.

1. Field of the Invention
This invention relates generally to the porting of gases in and out of an internal combustion engine, and more particularly to a rotary valve system enabled for efficient gas flow, throttling of gas flow, improved mixing of gas flow and timing of gas flow.
2. Description of Related Art
The following art defines the present state of this field:
Ferrer Beltran, U.S. Des. 289,915 describes a rotary valve shaft design.
Calkins et al., U.S. Pat. No. 1,097,166 describes the combination of the cylinder and the rotating cylindrical valve at the outer end thereof, of a sectional bearing chamber for the valve, one of the sections of the chamber being connected to the cylinder, and the other section being movable toward and from the first-named section, means in connection with the engine for transmitting the pressure from the combustion chamber of the cylinder to the movable bearing section to cause the pressure exerted by the said section on the valve to vary with the variations of pressure in the combustion chamber, springs normally pressing the movable section toward the fixed section, means for varying the, tension the valve and the bearing chamber, the said lining consisting of similar semi-cylindrical sections, each section having a radial dowel pin, one of the sections of the lining being arranged adjacent to each section of the bearing chamber, each of the said bearing chamber sections having an opening for receiving the dowel pin to fix the lining with respect to the bearing chamber section.
Brower, U.S. Pat. No. 1,171,834 describes the combination with a plurality of engine cylinders provided each with an intake port in the head thereof, of a relatively fixed supply tube extending through the heads of all the cylinders and provided with inlet ports registering with the intake ports of the individual cylinders, fuel supply connection to the opposite ends of the said supply tube, a rotary valve concentrically disposed with respect to the supply tube provided with valve ports therein to register with the inlet ports in the supply tube and the intake ports in the cylinders, and means for rotating the said valve in time with the functions of the different cylinders of the engine.
Hollmann, U.S. Pat. No. 1,213,873 describes a rotary sleeve valve having internal and external bearing surfaces and ports for the passage of gas, and having in its external face circumferential recesses made therein at points coincident with the ports respectively.
Wehr, U.S. Pat. No. 1,252,753 describes the combination with a valve-casing, of a rotary valve arranged therein, a lining for aid casing shiftably arranged in the latter and ahving a concave portion forming the seat for said valve and completely surrounding the latter, and means engaging said lining and said casing for causing a continuous contact between said seat and said valve.
Thayer, U.S. Pat. No. 1,299,264 describes the combination with the cylinder of an internal-combustion engine, of a valve-casing having a port communicating with said cylinder, a plurality of concentric rotary valve-members located in said casing and provided with diametric ports adapted to register with each other and with said casing-port, and means intermittently moving said valve-members in the same direction but at different speeds respectively.
Fronk U.S. Pat. No. 1,360,107 describes a rotary valve mechanism for internal combustion engines, comprising a poart closing an end of the cylinder and provided with three ports, one in communication with the cylinder, the second constituting the exhaust port and the port Opening into the cylinder being in the same plane and disposed quartering and the intake port being in a different relative plane, and a rotary valve mounted in said part and having three ports in communication at their inner ends, two of the ports being in the same plane and set quartering and adapted to register with the exhaust port and the port opening into the cylinder formed in the part in which the valve is mounted and the third port being in a different relative plane and diametrically opposite on of the said two ports and adapted to register with the intake port only during each complete revolution of the valve.
Wallace, U.S. Pat. No. 1,386,477 describes the combination with an engine cylinder, of a valve mechanism comprising a casing with a curved seat and connected with the engine cylinder by a port, a pair of curved valves concentrically arranged in the said casing, the valves having oprts, means for moving the valves to cause their ports to register with teach other and with the port leading to the engine cylinder with a frequency required by the cycle on which the engine operates, and an adjustable curved valve mounted between the said movable valves and arranged to vary the effective size of the opening to the engine cylinder the latter valve being normally stationary and means for adjusting the said normally stationary valve.
Casna, U.S. Pat. No. 1,578,581 describes the combination with a cylinder having a piston therein and also having an inlet port, of a rotary tubular valve controlling said port, a tubular control member within said valve, a shaft extending axially of the valve and having a radial arm, a throttle member carried by said arm and engaging the inner wall of the control member, said control member being turnable about its axis and co-operating with the throttle member to vary the time of cut off.
Pope, Jr., U.S. Pat. No. 1,677,460 describes the combination of a cylinder having a combustion chamber, a rotary valve having a combustion chamber, a rotary valve having a port adapted to communicate with said combustion chamber during the intake and exhaust strokes of the engine, and a uniplanar sealing ring engaging said valve, the plane of said ring being at an angle with the cylinder axis and the ring being positioned to pass entirely below the valve port and to seal the valve port from the combustion chamber during the compression and firing strokes.
Danford, U.S. Pat. No. 1,702,816 describes a valve for use in multi-cylinder engines, a valve casing formed with an outlet opening leading to each cylinder and formed with a plurality of inlet openings, each inlet opening serving two outlet openings, and a valve mounted for rotation in the casing and formed with a pair of ports therethrough in each of two right angled diametric positions of the valve, the ports of each pair being in parallelism and inclined to the longitudinal and transverse axis of the valve, the respective ports of a pair cooperating with different inlets and different outlets of the valve casing at intervals indicated by a half revolution of the valve, the valves of one pair being arranged between the valves of the other pair and at directly opposite inclination to the valves of such other pair, each pair of ports opening through the surface of the valve in direct longitudinal alignment axially of the valve.
White, U.S. Pat. No. 1,740,758 describes a valve means for internal combustion engines comprising a valve chamber, a sleeve within said chamber but disposed with slight clearance therefrom, a stationary core member disposed with slight clearance within said sleeve, said sleeve and said core having staggered inlet and exhaust ports, packing rings arranged on said core member between adjacent inlet and exhaust ports, and trunnion means for supporting said sleeve independently of said core and said chamber.
Hansen, U.S. Pat. No. 1,890,326 describes the combination of a piston chamber, separate intake and exhaust valves therefor, each of said valves comprising a cylindrical casing having diametrically disposed port openings therethrough and communicating with said chamber, and comprising also a rotatable, hollow cylindrical valve member within said casing and having diametrically disposed openings there through for registry with said port openings, means of communication between the inside of each of said valve members and the outside of said casing for intake and exhaust, and means for rotating said valve members in properly timed sequence, said valves being so constructed and operated that the impact of the explosions individually upon the valves will be counter-balanced upon diametrically opposite sides of each of said valves.
Baker, U.S. Pat. No. 1,967,734 describes a rotary valve element having one or more ports, a ported casing surrounding said valve element, a cam rotatable with said valve element, a cam follower mounted in said casing for radial movement toward and away from the valve element, and yielding means for forcing said cam follower toward engagement with said cam.
Cross, U.S. Pat. No. 2,169,631 describes a cylindrical valve surmounting said cylinder, a housing for said valve divided into inner and outer floating parts, the inner floating part being movable toward the valve under the action of pressure developed in the cylinder, and a lever system through which said movement of the inner floating part causes the outer floating part to press on the valve with a force which is a controlled fraction of the force applied to the inner floating part by the gas pressure.
Large, U.S. Pat. No. 2,183,024 describes a rotary valve structure for engines, comprising a unitary engine head having thereon at least a pair of spaced valve housings and a bearing housing disposed intermediate of and spaced from said valve housings, said housings having aligned ports therein, a rotor passing through and jounaled in said bearing and valve housings, valving means in said rotor and positioned within said valve housings for controlling the flow of a fluid under pressure through the valve housings, means to supply oil under pressure to aid bearing housing, and the spaces between the spaced valve and bearing housings being maintained at a constant pressure differing from the pressure of the fluid passing through said valve housings and the pressure of the oil in said bearing housing.
Berlyn, U.S. Pat. No. 3,171,425 describes a housing having a valve bore with port means adapted to communicate therewith, a cylindrical rotary valve mounted in a free fit for continuous rotary motion in said valve bore, means for reciprocating said valve axially upon its rotation, a lattice of seals on the periphery of said rotary valve, said lattice of seals comprising at least four circumferential and four longitudinal sealing elements, said valve having a diametral valving duct and at least two pairs of pressure balancing ducts connecting diarnetrally opposed zones of equal area as defined by said lattice of seals, internal cooling means within said rotary valve, and means for applying lubricant to the periphery of said rotary valve outside the perimeter of said lattice.
Yasuda, U.S. Pat. No. 3,547,094 describes a rotary-valve engine in which there are provided rotary bodies each of a circular shape in section and a notch on one part thereof, the rotary bodies are each disposed in opposite to the intake and exhaust ports of the cylinder of the engine, and the rotary bodies make rotation thereby alternately opening and closing the intake and exhaust ports at desired time intervals.
Guenther, U.S. Pat. No. 3,948,227 describes an apparatus for applying a stratified charge to a reciprocating internal combustion engine. The apparatus comprises a cylindrical rotary valve body disposed for rotation within the head of an internal combustion engine. The valve body defines diametrically extending inlet and exhaust passages which, during rotation of the valve body, place a cylinder of the engine in sequential communication with an inlet manifold and an exhaust manifold secured to the head. The inlet manifold comprises a double-passage gallery and a rich fuel air charge in a second passage. Rotation of the inlet passage into communication with the cylinder also brings the inlet passage into sequential communication with the first throat and then the second throat for transporting the first lean charge and then the second rich charge to the cylinder. Means are also provided for shielding the exhaust passages from excessive exhaust head; for sealing the rotary valve body and for controlling the timing of the valve in response to engine demand.
Negre et al., U.S. Pat. No. 4,506,636 describes a device for controlling the evacuation of exhaust gases of a combustion chamber in an internal combustion engine. A rotary valve performs a continuous or alternate turning movement and synchronized with the rotation of the motor about an axis parallel to the axis of rotation of the motor and issues at the level of its transversal channel on one side on an orifice connected to the exhaust towards the outside. The invention is applied to the control of the exhaust of two stroke engines.
Eickmann, U.S. Pat. No. 4,546,743 describes a rotary valve with an axially extending passage revolving in a bed of a valve bearing body which has inlet passage means and a fluid transfer channel. The valve controls the periodic flow of fluid from the inlet means to the transfer channel. Fluid pressure containing pockets are provided diametrically of the transfer channel to let the rotary valve member float between opposed pressure fields. Accessory means can be provided to the rotary valve to secure equal forces at equal times on diametrically opposed portions of the outer face of the rotary valve member.
Giocastro et al., U.S. Pat. No. 4,556,023 describes a pair of rotary valves for an internal combustion engine positioned in a cylinder head over a cylinder block. The rotary valves include a pair of rotatable shafts, and a pair of sleeve supports having ports opening to the cylinder or cylinders of the engine. The pair of rotatable shafts can be either hollow or solid. The hollow intake shaft brings in a fuel mixture to an inlet passage that rotates into alignment with an intake opening in the intake shaft to the piston cylinder. The hollow exhaust shaft allows exhaust of burned gases from the piston chamber through an exhaust opening from the piston cylinder to an exhaust passage in the exhaust shaft and to the atmosphere. The solid rotatable shafts are provided with a diametrical intake channel and a diametrical exhaust channel that aligns with the openings to the piston cylinder and to the fuel mixture and to the atmosphere. Drive and timing gearing between the crankshaft and the intake and exhaust shafts are provided.
Hedelin, U.S. Pat. No. 4,572,116 describes an internal combustion engine having at least one chamber where there is a moving working member, an inlet valve and an outlet valve as well as a compression regulation device. In an inlet channel there is arranged a regulating valve upstream of the inlet valve, said regulating valve being open only during a portion of the motion cycle of the working member. This regulating valve has a rotatable valve body provided with at least one inlet passage, the rotational speed of the body being proportional to that of the engine.
Krugger, U.S. Pat. No. 4,739,737 describes that in order to produce a rotary valve with short and small cross-sectional dimensions, fresh gas or exhaust gas ducts of the rotary valve are associated with adjacent cylinders and extend in some regions in a common cross-sectional plane, in different halves of the cross section of the rotary valve outside the longitudinal axis thereof, the plane also contains two diametrically opposite fresh gas and, respectively, exhaust gas openings in the rotary valve housing.
Hansen, U.S. Pat. No. 4,782,656 describes a rotary internal combustion engine having a housing with an elliptical inside surface surrounding an elliptical rotor forming with the housing combustion chambers. Valve and ignition assemblies connected to a source of air under pressure and injectors for introducing fuel into the air supply sequentially allows the air and fuel mixture to flow into the combustion chambers and ignite the air and fuel mixture therein. Vane and seal assemblies on the rotor and housing are controlled with cam and linkages to provide positive effective gas seals between the housing and rotor. A slack adjuster maintains lateral sealing relationships between the housing vane and seal assemblies and opposite side walls of the housing.
Schiattino, U.S. Pat. No. 5,309,876 describes an automatic variator for use in an internal combustion engine and other engines which use valve-type distribution systems, to operate a twin set of double-effect distribution sequential valve shafts for the purpose of regulating the valve overlap and the valve opening section while the engine is running. A motor reducer advances a spindle against the valve shaft with a grooved screw at one end of same, causing the shaft to turn and move, thereby varying the valve overlap and the valve section.
Baird, U.S. Pat. No. 5,410,996 describes an improved rotary valve assembly that is rotated by chain, belt or gears that are driven by a reciprocating engine which has intake and exhaust rotary valves that have ports and interior channels that are sequentially positioned to allow the intake and exhaust of gases and alternatively seals the combustion chamber. The rotary valve ports and intake and exhaust ports may be varied axially and circumferential to change the engine time and gas volume capacity of the engine.
Trotter, U.S. Pat. No. 5,579,730 describes a rotary valve head assembly including a split head assembly, a rotary spool assembly,spool drive assemblies, and bearing and spool lubrication components. The split head assembly has bores for containing the spool assembly, bearings and spool seals, and defines passages for coolant and lubricant to pass therethrough. The head assembly is separable to provide unencumbered access to the components contained therein. The spool assembly is cylindrical and extends the length of the head assembly. The spool assembly has two ports for each combustion chamber. Each port is provided with a port relief to control the duration it is open. A separate and independent spool drive assembly provides each spool assembly rotating action. Each drive assembly effectively changes the timing of a corresponding spool assembly via instructions from the engine management system, allowing intake and exhaust timing can be controlled independently. The drive system simultaneously allows the engine to function as a compressor, thus providing an engine brake. The bearing and spool lubrication components provide support and lubrication for the spool assembly. Spring loaded lubricant control seals are mounted in the bearings and maintain contact with the spool assembly. The seals are also provided with a chamfer to control oil consumption while maintaining effective combustion chamber sealing. The instant invention eliminates the need for intake and exhaust valves and related actuation hardware, such as cams, lifters, rocker arms, and pushrods.
Duve, U.S. Pat. No. 5,711,265 describes an improved drive mechanism for rotary valves of the type used in internal combustion engines indexing the valves in selected attitudes of rotation to align the valve passage with an inlet or exhaust port and holding the valve in alignment for a selectable duration of crankshaft rotation. In like fashion, the valves are also indexed to close off an inlet or exhaust port for a selected duration of crankshaft rotation. Flow into and out of an engine cylinder is improved because each valve is held for a longer period of time in a full open position while compression and power strokes are made more efficient by the gas seal maintained while the valves are positioned to close off the intake and exhaust ports.
The prior art teaches the use of rotating through ports for providing flow of a gas into an internal combustion engine but does not teach such using a fixed port and a rotating sleeve so as to improve gas flow dynamics. The present invention fulfills these needs and provides further related advantages as described in the following summary.
The present invention teaches certain benefits in construction and use which give rise to the objectives described below.
A porting apparatus in an internal combustion engine delivers and exhausts gas in a combustion space. A pair of valving cylinders each have a cylinder wall mounted for rotation within a head of an engine block. The cylinders each provide a pair of apertures in diametrically opposing and axially offset positions through the wall of the cylinder. A pair of rotatable manifold rods, each axially oriented, are each positioned within one of the valving cylinders. The manifold rods each provide a through port adapted for alignment with the pair of apertures of a corresponding one of the cylinders, such that within each of the cylinders and corresponding through ports, a gas flow is enabled for communication from one of the pair of apertures to the other of the pair of apertures through the port upon each full rotation of the valving cylinders which are driven in coordination with the engine. One advantage of the present invention is that a manifold vane and mixing baffles may be placed in the through port to adjust gas flow as necessary to optimize gas dynamics. A further advantage is that the valving cylinders may be adapted to rotate at one-half the rate of the engine instead of at one-forth so that reduction gears may be significantly reduced in size. A further advantage is that the inlet channel (through port) directs gas flow at an angle into the combustion chamber thereby causing improved mixing.
A primary objective of the present invention is to provide an apparatus and method of use of such apparatus that provides advantages not taught by the prior art.
Another objective is to provide such an invention capable of controlling gas flow into and out of an internal combustion engine.
A further objective is to provide such an invention capable of throttling the gas flow into and out of an internal combustion engine.
A still further objective is to provide such an invention capable of adjusting gas flow timing to an internal combustion engine.

Rotary sleeve port for an internal combustion engine


A method for funding the production of a movie by presenting a storyboard synopsis of the yet-to-be-produced movie on a production company""s Internet Web site, and allowing interested potential viewers of the movie to purchase a share of the production company""s stock prior to production of the movie. Accompanying the storyboard synopsis is an offer which includes an opportunity to participate in the making of the movie by xe2x80x98votingxe2x80x99 for certain options related to the movie""s production, as well as the opportunity to view the production of the movie via video transmission over the Internet. The purchase of a share of production company stock provides the shareholder the right to obtain a free copy of the completed movie as a dividend. The stock purchase is effected preferably by an electronics fund transfer, such as by the entering of a credit card number via the Web site. Production of the movie is not commenced until the number of shares of stock in the production company sold is sufficient to cover the estimated cost of making the movie.

1. Technical Field
The present invention relates generally to the production and distribution of movies, and more particularly, to a method of pre-selling movies to end users of the movies prior to the actual production thereof.
2. Statement of the Problem
There are presently several-problems related to the production of feature length movies, including high production costs, high investment risk, and a high instance of financial failure. Revenues generated from a movie""s distribution are often much less than the cost of production. The high cost of producing and distributing feature length movies continues to escalate each year. These ever increasing costs create a commensurate increase in risk for movie investors. A significant percentage of box office failures is largely due to the inability of movie producers to accurately predict the number of tickets that will be purchased. Although various market surveys are presently performed by the movie industry, movie producers have been unable to use these methods to determine what the exact size of the audience for a specific movie will be, and consequently cannot determine whether the number of tickets sold will pay for the cost of production of the movie. Thus, only a small percentage of movies are now profitable.
Furthermore, even in cases where particular movies turn out to be profitable on paper, filmmakers and film investors are often unable to collect their profit share from the distributors of their movies. Distributors of feature films often use xe2x80x9ccreative accountingxe2x80x9d methods for reporting the profits of a movie. Furthermore, the filmmakers and film investors have little or no control over expenses charged against the movie by the distributors. In many instances, a movie""s distributor makes a considerable profit, but after the distributor""s xe2x80x9cexpensesxe2x80x9d are deducted, the filmmakers and investors do not.
Another significant problem for all filmmakers is xe2x80x9ccreative meddlingxe2x80x9d by a studio or distributor. In order to secure financing for their movie, filmmakers are often forced to accept choices for creative elements in a film that prove to be undesirable to the audience. For example, a studio may require a filmmaker to use a certain star in the film, because that star is under contract to the studio or that star can get them greater foreign sales guarantees, and not because that star would best serve the story. Significant creative choices in the making of a movie are often made arbitrarily, by a single individual, without input from the potential audience. To date, there has never been an accurate method for determining if these creative choices in the making of a film are those most desired by the audience.
Since presently known methods of surveying the audience cannot determine, in and of themselves, exactly how many tickets will be purchased for a particular movie, a method is needed for assuring the financial success of a movie, in advance of the movie""s production. In addition, a method is needed to insure a movie""s critical success by keeping creative choices made by the filmmakers in line with those of the intended audience.
The present invention overcomes the aforementioned problems of the prior art and achieves an advance in the field by providing a method for funding the production of a movie by presenting a storyboard synopsis of the movie on a production company""s Internet Web site, and allowing interested potential viewers of the movie to purchase a share of the production company""s stock prior to production of the movie. The purchase of a share of stock provides the shareholder the right to obtain a free copy of the movie, when completed, as a dividend.
In an effort to secure financing for a movie, xe2x80x9cStoryboard synopsesxe2x80x9d (realistically drawn, sequential series of drawings depicting the action of the story, running concurrently with a narrative description) and xe2x80x9cTrailersxe2x80x9d (edited sequences filmed from the screenplay that summarize the story) have been shown to potential investors prior to completion of a movie, but never to end user viewers. End user viewers have not heretofore been shown storyboard synopses as a means of securing their investment, because prior to the advent of the Internet, there has never been a cost-effective way to expose an audience to a movie""s story line, and then advertise for, and transact, enough individual stock sales to pay for the movie""s production costs.
Traditionally, movie producers do not reveal a movie""s complete story line and other significant elements thereof in advance of distribution. High risk exists from the producers standpoint because the ultimate audience has no input into the creation of the product, and therefore, the movie content, the specific actors participating in the movie, and the directing thereof, may not be suitable to a sufficiently large number of potential viewers to make the movie profitable. The method of the present invention exposes a movie""s ultimate audience to its story line and adapts the story line according to input received from them. In addition, the present method also allows the participants to help determine other aspects of the movie, such as casting, the final story line, selection of the filming location, and the shooting schedule.
In accordance with the present invention, a storyboard synopsis of an unproduced (i.e., uncompleted) movie is first displayed to a potential end user viewer thereof via the Internet Web site of a movie production company. Accompanying the storyboard synopsis is an offer which includes an opportunity to participate in the making of the movie by xe2x80x98votingxe2x80x99 for certain options related to the movie""s production, as well as the opportunity to view the production of the movie via live video transmission over the Internet. A potential viewer who decides to participate in the offer then purchases a share of stock in the production company, which entitles the purchaser to receive, in addition to the above opportunities, a free copy of the movie (when completed) as a dividend. The stock purchase is effected preferably by an electronics fund transfer, such as by the entering of a credit card number via the Web site.
The participants in the offer, who, in part, comprise the ultimate audience, use the storyboard synopsis to determine whether to make a purchase of the movie in advance of production. The participants who decide to purchase the stock, and thereby a copy of the movie, become the end users of a product they themselves help create. Production of the movie is not commenced until the number of xe2x80x98ticketsxe2x80x99 (i.e., shares of stock in the production company) sold is sufficient to cover the cost of making the movie.
The financial success of the movie is therefore essentially guaranteed because a section of the ultimate movie audience assures that sufficient funding is available to produce the movie by purchasing stock, and thereby copies of the movie prior to production. Upon completion of the movie and delivery to shareholders, the movie""s cost of production is paid for, and any future revenues received from screening the movie in worldwide markets are therefore, essentially, gross profit.
The present invention thus provides a method for allowing a filmmaker to maintain financial control of a movie, while eliminating all financial risk from the standpoint of the movie studio investor. Traditionally, a movie studio (xe2x80x98studioxe2x80x99) provides xe2x80x98front moneyxe2x80x99 for the production and distribution expenses of a typical movie. According to one aspect of the present method, a studio and/or a movie distributor (xe2x80x98studio/distributorxe2x80x99) invests in a filmmaker""s project (i.e., an unproduced movie) by buying stock in the filmmaker""s production company. The studio/distributor buys stock in a production which is essentially pre-sold, and therefore owns stock in a project which is already into a profitable phase. If the completed movie is a xe2x80x98hitxe2x80x99, then the production company""s stock price would appreciate significantly, thus producing greater profits for the movie studio investor than those derived solely from the usual rentals of a given movie. Furthermore, as described above, a film that does not acquire xe2x80x98hitxe2x80x99 status would still be profitable, because it had already been pre-sold prior to its production.
The purchase of production company stock by studios and distributors is in addition to the purchase of stock by individuals, who may purchase the stock primarily to observe the production of a movie, and to receive a copy of the movie when it is completed. A distributor, such as a video movie rental store chain, may purchase stock primarily for the purpose of acquiring copies of the movie for rental or resale to home viewers, since a free copy of the movie is (ultimately) provided with each share of stock purchased.
An additional advantage provided by the present method is the ability of the production company to maintain control over the creative elements of a movie by retaining the right to decide ultimately which aspects of the movie are tailored in accordance with the options selected by the voting participants. Even though a studio/distributor investor (which may own many thousands of shares of stock) might cast their large voting share for certain options, the individual (public) participants, who collectively control more shares than the studio/distributor, may decide that they want options different from those chosen by the studio/distributor (e.g., different actors). The present method allows the production company to be the ultimate arbiter of which options are to be employed in the actual production of the movie.

Method for the sale of movies prior to the production thereof