A chromium-free process for phosphatizing a metal surface provides for applying to the surface an aqueous acidic solution having pH 1.5 to 3.0 and containing phosphate; a metal cation of valence two or greater; molybdate, tungstate, vanadate, niobate or tantalate ions; and drying the solution on the surface without rinsing.

The invention relates to a process for the preparation of metal surfaces for the subsequent application of organic coatings by applying a phosphate coating by means of wetting with a phosphatizing liquid, containing at least 2-valent cations, and subsequent drying in situ of the liquid film as well as to its use for the treatment of aluminum surfaces.
The so-called three-step processes are increasingly gaining in importance for the chemical surface treatment of metals, for example as preparation for the application of paints, adhesives and plastics. In the first step, the metal surface is cleaned in order to free it from oil, dirt and corrosion products. The second step represents rinsing with water, in which residues of chemicals from the first step are removed from the metal surface. Finally, in the third step, the metal surface is wetted with an aqueous chemical reaction solution and the liquid film dried in situ.
By means of the process described above, a thin non-metallic coat is formed on the metal, which can decisively improve surface quality, with suitably selected composition of the treatment liquid and reaction condition. Thus, for example, coatings of paints, adhesives and plastics can be distinguished by materially greater adhesion and considerably increased anti-corrosive protection, if they are applied to metal pretreated in this way.
West German Examined Patent Application (Auslegeschrift) No. 17 69 582, for example, describes a process, in which an aqueous solution, containing hexavalent chromium trivalent chromium alkali ions and silicon dioxide in definite quantitative ratios, is dried on the metal in situ. The coatings formed are very suitable, for example, as electrical insulation, as anti-corrosive protection and as primer for paints and the like.
Another process is known from U.S. Pat. No. 2,030,601, in which highly concentrated aqueous solutions, containing from 10 to 20% by weight of phosphoric acid and from 10 to 15% by weight of sodium dichromate, optionally with addition of silica, are brushed on to iron surfaces and subsequently dried in situ. This treatment serves for protection against rust formation.
Furthermore, it is known to produce coatings on metal surfaces with the aid of coating agents, containing a compound of hexavalent chromium and a polymeric organic substance,--so-called primers,--and subsequently dried in situ or stoved, (Euratom Patent Specification No. 197 164).
All the above-mentioned processes have the disadvantage in common that, as a result of the presence of 6-valent chromium, special precautionary measures are required in the application of the coating agent and in the handling of the coated metal and that, when metals, coated in this manner, are used as container material for foodstuffs and beverages, influence on the content of the container cannot be excluded. If the coating agents possess organic components, a further disadvantage is the low shelf-life (pot-life) of the treatment liquids.
In order to avoid the disadvantages connected with the use of treatment liquids containing 6-valent chromium, it is already known to wet the cleaned metal surface, especially of iron, zinc and aluminum, with an acidic aqueous solution containing chromium (III) ions, phosphate ions and finely divided silica, optionally also acetate ions, maleinate ions, zinc ions and/or manganese ions, and to dry the film of solution in situ, (West German Unexamined Patent Application (Offenlegungsschrift) No. 27 11 431). Although this process possesses considerable advantages over those mentioned above, it is a shortcoming that, when the coated metals are employed as a container material, a certain influence on foodstuffs and beverages cannot be totally excluded, as a result of the chromium (III)-content of the layer, and that the treatment liquid tends towards instability through the formation of sparingly soluble chromium phosphate.
Other patents of relevance are U.S. Pat. No. 3,450,577; U.S. Pat. No. 3,819,385; U.S. Pat. No. 2,502,441; and U.S. Pat. No. 3,586,543.
It is the object of the invention to provide a process, which avoids the known, especially the above-mentioned, shortcomings and can, nevertheless, be carried out in a simple manner and without additional expense.


A method for fully supporting floating point multiplication using a combination of partial hardware support and partial software support traps to software when a subnormal operand is encountered and gross underflow cannot be determined without determining the leading zeros in the subnormal mantissa. A simplified hardware multiplier does not require leading zero detection or left or right shifting. The partial hardware support circuit allows single and double precision operands. The hardware multiplier unit only partially supports subnormal operands. If one of the operands is subnormal, the hardware multiplier unit will output zero and a gross underflow signal if the multiplication would result in gross underflow. There is a small minority of operand permutations that are not supported in hardware and thus require a greater time to compute by resorting to software. However, the vast majority of operand permutations gain reduced latency. So long as the fraction of operand permutations that occurs when a typical instruction stream is executing that are not supported in hardware is small, a performance gain is achieved. An alternative embodiment of the present invention, the gross underflow output is computed in parallel with the resulting exponent computation. An implementation of the gross underflow detection circuit can be used for either single or double precision operands.

1. Field of the Invention
The present invention relates to the field of floating point units in microprocessors. Specifically, the present invention relates to hardware floating point multipliers and the support of subnormal operands in floating point multiplications.
2. Discussion of the Related Art
Multiplier units are commonly found in digital signal processors and more recently in RISC-based processors. Double precision floating point operations involve the inherently slow operation of summing 53 partial products together to produce the product. IEEE compliant multiplication also involves the correct rounding of the product adjustment to the exponent and generation of correct exception flags. Multiplier units imbedded in modern RISC-based processors must also be pipelined, small and fast. Judicious functional and physical partitioning are needed to meet all these requirements. FIG. 1 shows the standard IEEE floating point data formats. The floating point the value definitions according to IEEE standards corresponding to the floating point data formats shown in FIG. 1 are given below.
s=sign PA1 e=biased exponent PA1 f=fraction PA1 E=number of bits in exponent (8 for single, 11 for double) PA1 F=number of bits in fraction (23 for single, 52 for double) PA1 B=exponent bias (127 for single, 1023 for double) PA1 Normalized Value (0<e<2.sup.E-1): PA1 Subnormal Value (e=0): PA1 Zero:
(-1).sup.s .times.2.sup.e-B .times.1.f PA2 (-1).sup.s .times.2.sup..sup.1-B .times.0.f PA2 (-1).sup.s .times.0
A floating point number is analogous to a number in scientific notation with the primary difference being in the IEEE standard, the number is in a base 2 number representation system whereas in standard scientific notation, numbers are represented in base 10. Thus, a floating point number has an exponent which represents the binary order of magnitude by which its mantissa must be multiplied. In a normalized floating point number, the implicit leading 1 as well as all F fractions bits are significant. Therefore, the mantissa of a normalized floating point number always has F+1 significant binary digits in the mantissa.
The IEEE standard for floating point numbers includes two different precisions for floating point numbers. As depicted in FIG. 1, the first type, single precision floating point numbers, have 23 fraction bits (FRACTION[22:0]) and 8 exponent bits (EXP[7:0]); whereas the second type, double precision floating point numbers, have 52 fraction bits (FRACTION[51:0]) and 11 exponent bits (EXP[11:0]).
Because the exponent is represented by a fixed number of bits according to the IEEE standard, upper and lower limits exist to the absolute values of numbers which can be represented in normalized form. The minimum value for the exponent is defined to be one, However, supporting subnormal numbers allows the expansion of the lower absolute value range of representable numbers in floating point format. Because the leading one in a normalized number and the leading zero in a subnormal number are implied rather than explicitly included in the data stored, this leading bit cannot be used to distinguish normalized from subnormal numbers. Instead, one exponent value, zero, is reserved to indicate that the corresponding mantissa is from a subnormal number, therefore the leading bit is a zero. Therefore, every subnormal number has the minimum possible representable exponent field, zero, and has a mantissa with fewer significant digits than in a normalized number. Although the exponent field for a subnormal number is zero, this is simply a code to indicate that the number is subnormal in order to distinguish subnormal numbers from normal numbers. The value of the exponent for a subnormal number is interpreted as being one, as indicated in equation 2.
Because it is generally desirable to maintain the full precision of mantissa, subnormal numbers having fewer significant digits are only allowed when the exponent has reached its minimum value such that it is necessary to sacrifice precision in order to expand the range of representable numbers. Thus, the absolute value of any subnormal number is less than the absolute value of any normalized number. By permitting subnormal numbers to be represented, the range of representable numbers is increased by F binary orders of magnitude. Thus, between zero and the smallest positive normalized number, there are F binary orders of magnitude of representable subnormal numbers.
Binary multiplication of two floating point numbers M1 and M2 is analogous to the multiplication of two base 10 numbers in scientific notation. The mantissas of the operands M1 and M2 are multiplied by each other to produce the resultant mantissa while the exponents e1 and e2 of the operands M1 and M2 are added to produce the resulting exponent er. Typically, a hardware multiplier unit supports all possible operand combinations. Therefore, a typical hardware multiplier will support the multiplication of two normalized operands and the multiplication of one normalized operand and a second subnormal operand. Typical hardware multipliers will not support the multiplication of two subnormal operands, because such a multiplication will always produce a result which is smaller than the smallest subnormal number.
Each multiplication takes two operands, M1 and M2. If both M1 and M2 are normalized floating point numbers, then the mantissa for M1 is 1.f1, and the mantissa for M2 is 1.f2. Because each normalized number has an implicit leading 1, every normalized number has F+1 significant bits. The result output by the mantissa multiplier 200 takes the form 1.fr, where the number of bits in the fraction part fr is either 2F or 2F+1, depending upon the sizes of f1 and f2. When the number of bits in the fraction part is 2F, this is described as "non-overflow." When the number of bits in the fraction part is 2F+1, this is described as "overflow."
The overflow-non-overflow distinction is easily understood with a base 10 analogy. 11*11=121. In scientific notation, this is 1.1.times.10.sup.1 *1.1.times.10.sup.1 =1.21.times.10.sup.2. Here the number of fraction digits in the output is twice the number of fraction digits in the inputs--this is non-overflow. 99*99=9801. In scientific notation, this is 9.9.times.10.sup.1 *9.9.times.10.sup.1 =98.01.times.10.sup.2 =9.801.times.10.sup.3. Here the number of fraction digits in the output is one plus twice the number of fraction digits in the inputs--this is overflow. In the overflow situation, the exponent must be incremented by one. Usually, it is desirable that the result R produced by a multiplication will have the same precision (the same number of significant bits) as each of the operands M1 and M2.
If the mantissa multiplier 200 array produces 2F significant mantissa fraction bits, while the result R can include only F significant mantissa fraction bits, the least significant F mantissa bits output by the multiplier are used only to produce the three rounding bits--the guard, round, and sticky bits--for rounding purposes. The least significant F mantissa bits output from the mantissa array are then discarded.
A subnormal number takes the form 0.f. Since the most significant bit of any subnormal number is an implicit zero, a subnormal number has at most F significant bits. However, a subnormal number can have as few as only 1 significant bit, if the only non-zero fraction bit is the least significant bit of the fraction. The positive subnormal number having only 1 significant bit is the smallest non-zero positive representable number.
FIG. 2 illustrates the logical structure of a typical floating point multiplier unit. With high modern clock frequencies, a typical modern floating point unit will include pipeline registers at various points. The illustration of these registers is omitted for simplicity. Multiplier units that handle subnormal operands and results often require the determination of leading zeros, adjustments to the input and output mantissas (shifting), adjustment to the output exponent, and rounding. The calculation of the resultant exponent er is complicated by the supporting of subnormal numbers. The exponent e in a floating point number is biased by an exponent bias B. In a subnormal number, there is an implicit leading zero and there may be up to F-1 additional leading zeros. For purposes of multiplication, when one or more of the operands is subnormal, that subnormal operand is converted into a normalized mantissa before being input into the mantissa multiplier array 200.
FIG. 2 illustrates the hardware necessary to support all the possible input combinations. In FIG. 2, a leading zero detector 201 determines if one of the operands M1 is subnormal, and if so, how many leading zeros are in the mantissa. The number of leading zeros is referred to as z. FIG. 3 illustrates one way a leading zero detector can be implemented. The latency of the leading zero detector in FIG. 3 is proportional to the log.sub.2 N, where N is the of the number of inputs (I0 through I15 in FIG. 3). The silicon area required to implement the hardware in FIG. 3 is proportional to Nlog.sub.2 N. The leading zero detector 201 in FIG. 3 produces an encoded left shift output (z3, z2, z1, and z0). The encoded output 202 (in FIG. 2) is necessary to properly adjust the output exponent er according to Equation 2. Inverter 206 converts the encoded output 202 of the leading zero detector 201 into its one's complement. By hooking the carry input Cin to the carry-save adder 207 to a one, the negative of z in two's complement form is supplied to the carry save adder 207. The encoded output 202 is also necessary to drive the left shifter 203. FIG. 4 illustrates one way to implement a left shifter. The left shifter shown in FIG. 4, a barrel shifter, is constructed of an array of 2-to-1 multiplexors. The left shifter 203 converts a subnormal mantissa into a normalized mantissa, so that the most significant one in the subnormal mantissa is shifted into the most significant output 400 (in FIG. 4) of the left shifter 203. The latency of the left shifter in FIG. 4 is proportional to log.sub.2 N. The silicon area required to implement the hardware in FIG. 4 is proportional to Nlog.sub.2 N.
Because the result R may be subnormal, the output 204 of the mantissa multiplier 200 is input into a right shifter 205. The right shifter 205 is implemented similarly to the left shifter 203. The quantity rshift is input to the right shifter 205, and is calculated according to Equations 2 and 3 by the rshift logic block 208.
By fully supporting multiplication in hardware when one of the operands is subnormal, the hardware requirements for the resultant mantissa and exponent calculations are substantial. In FIG. 2, the carry-save adder 207 exists only to add in the two's complement of z. Additionally, the rshift logic 208 is necessary to control the right shifter 205. If the multiplier unit is implemented as shown in FIG. 2, the rshift logic 208 is of non-trivial complexity. The leading zero detector 202, the left shifter 203, the right shifter 205, the rshift logic 208, the inverter 206, and the carry-save adder 207 are all necessary to support multiplication where one of the operands is subnormal.
As is apparent from the above discussion, it is desirable to avoid overly complicating the multiplier hardware. There is a need for an efficient hardware multiplier that reduces size and latency. As long as a the fraction of multiplication operand permutations that are not supported in hardware is statistically insignificant, a performance gain could be achieved.

Method and apparatus for partially supporting subnormal operands in floating point multiplication


A fuel shut-off valve is particularly adapted for fuel systems using alcohol fuel wherein the alcohol fuel is typically pumped via an on-off valve to a fuel injection system and recirculated back to the alcohol fuel tank. The fuel shut-off valve of the invention is located between the fuel pump and the fuel injection system and is adapted to receive excess fuel from the injectors and direct it back to the fuel pump. In addition, a bypass valve arrangement directs fuel from the fuel pump to either the fuel injection system in the on or open position or back to the fuel pump when the valve is closed. The fuel shut-off valve also has a positive locking mechanism which retains the valve in the open or closed position.

In the prior art, it is well known to use alcohol fuel in modified engines for such applications as drag racing, tractor pulling or the like. Typically, these alcohol fuel systems employ an on/off valve which provides fuel from a fuel pump at maximum pressure to fuel injectors or the like.
Referring now to FIG. 1, a typical prior art alcohol fuel system is generally designated by the reference numeral 10 and includes a fuel tank 1, fuel pump 3, on/off valve 5, fuel injection system 7 and engine 9. Other conventional components such as fuel filters and fuel injection metering valves are not shown for clarity purposes.
The fuel system 10 also includes recycle or recirculating lines 11 which recirculate fuel back to the tank 1 which is not used in the engine 9. Since the on/off valve 5 is either fully open or fully closed, the amount of fuel in the recirculating lines 11 controls the fuel input to the engine 9. That is, if the fuel rate is high in recirculating lines 11, the fuel mixture to the engine will be lean. Likewise, if the recirculating fuel flow is low, the fuel mixture to the engine will be rich.
One of the problems with these types of fuel systems is fuel aeration in the fuel tank. Since the fuel is recirculated to the fuel tank, the fuel therein becomes agitated and air bubbles are entrained therein. This aerated fuel mixture, necessarily having a lower BTU or fuel value, is then fed to the fuel injection system. The lower fuel value results in poorer engine performance.
Recirculating the fuel back to the fuel tank is also costly since long runs of the recirculating fuel lines are needed. The lines being made of braided stainless steel surrounding a high pressure rubber hose. Moreover, since modern fuel injection systems use three or four fuel injectors, each injector having its own recirculating line 11, a large quantity of hose is required for recirculation.
The prior art fuel system is also disadvantageous in that the on/off valve can slip out of the fully on position and starve the fuel injection system and engine of necessary fuel.
In view of the disadvantages noted above, a need has developed for an improved alcohol-based fuel system. In response to this need, the present invention provides a unique fuel shut-off valve which eliminates the need for extensive lengths of recirculating hose line, aerated fuel and improperly functioning on/off valves. The present invention provides a fuel shut-off valve which recirculates unused fuel from both the fuel pump and fuel injection system directly to the fuel pump rather than the fuel tank. The inventive valve also includes a positive locking mechanism to maintain the valve in its on or off position.


The invention relates to a method for determining midpoint coordinates of an image of a point-symmetrical structure stored in a volume data record, comprising: extracting a partial volume data record from the volume data record which contains the image of the point-symmetrical structure, selecting a set of points whose coordinates lie in the partial volume data record, determining a measure for each point of the set wherein the measure for each of the points of the set characterizes in each case the symmetry of the partial volume data record in relation to this point, selecting a point as a midpoint of the point-symmetrical structure that point of the set in relation to which the partial volume data record has the greatest symmetry on the basis of the previously determined measures, and storing the coordinates of the midpoint in a computer unit.

During recent years, magnetic resonance tomography (MR tomography) has established itself as a significant imaging method in medicine. MR imaging systems which generate sectional views of an object to be examined, in particular a human body or body part, using nuclear magnetic resonances are known per se. In this type of activity, the body to be examined is introduced into a strong homogeneous static magnetic field, this being known as the main magnetic field, which effects an alignment of the nuclear spin of atomic nuclei within the body, in particular hydrogen atomic nuclei (protons) which are bound to water. Said nuclei are then excited into a precessional motion by means of high-frequency excitation pulses. After the end of a corresponding high-frequency (HF) excitation pulse, the atomic nuclei precess with a frequency (the so-called Larmor frequency) which depends on the strength of the main magnetic field, and then settle down after a predefined tissue-dependent relaxation time into the preferred direction which is predetermined by the main magnetic field. Using computational and/or metrological analysis of the integral high-frequency nuclear signals, a picture relating to a body layer can be generated from the spatial spin density or the distribution of the relaxation times. The assignment of the nuclear resonance signal, which can be seen as a result of the precessional motion, to the location of its occurrence is done by applying linear field gradients. For this, corresponding gradient fields are superimposed on the main magnetic field and controlled such that an excitation of the nuclei only occurs in a layer which is to be depicted. An HF coil apparatus is required both for the HF excitation of the nuclear spin and for the detection of the nuclear response signal. Imaging systems which are based on these physical effects are also referred to using the terms nuclear-spin tomography, nuclear magnetic resonance (NMR) tomography or magnetic resonance imaging (MRI).
Variations of the magnetic fields, in particular the spatial distribution of the magnetic field strengths, from their theoretically predetermined and calculated values cause geometric distortions in the picture. In particular, methods which are based on a quantitatively precise geometric representation of the areas to be examined are considerably impaired in respect of their quality as a result of such distortions.
It is possible primarily to identify four different causes which result in geometric distortion:
The magnetic susceptibility varies in the case of different materials and thus gives rise to a slight material-dependent modification of the main magnetic field.
Static magnetic field homogeneities are largely equalized by the so-called shimming of the magnetic field, but slight residual inhomogeneities can nonetheless remain.
Non-linearities of the gradient coils cause distortions in all directions. Gradient coils are usually designed in such a way as to minimize such distortions in the isocenter of the device. Consequently, such effects primarily occur in the marginal areas of MRT pictures.
Eddy currents are always produced in conductive materials when modifications of the magnetic fields are carried out. This primarily occurs when switching the gradient fields. In this case the strength and the spatial distribution of the eddy currents depend on the MRT sequence which is applied. In turn, the eddy currents themselves cause magnetic fields which overlie other magnetic fields and therefore cause geometric distortions.
One possibility for detecting geometric distortions which occur in the case of a specified MRT sequence is the use of a phantom. Such phantoms generally have a three-dimensional lattice of structures which are shown clearly in an MRT picture. Using an image of the phantom, the image of the three-dimensional lattice can be compared with the original lattice. This allows the creation of a distortion map which identifies the strength and the direction of the geometric distortions at various spatial points. This distortion map is used for correcting geometric distortions in the context of pictures which are subsequently recorded using the same MRT sequence.
Phantoms which are suitable for such a method generally exhibit structures which are easily and reliably identified, e.g. spheres, at the lattice points. An exact and reproducible specification of the position of the spheres, e.g. their midpoints, in an image of the phantom is necessary in this case in order to capture distortions.
Phantoms whose three-dimensional lattice is formed of spheres are disclosed in M. Breeuwer et al., "Detection and correction of geometric distortion in 3D MR images", Proc. SPIE 4322, 1110-1120, 2001, and in M. Holden et al. "Sources and correction of higher order geometrical distortion for serial MR brain imaging", Proc. SPIE 4322, 69-78, 2001. In these documents, as a midpoint of the spheres, only the central area of the sphere is specified in the image of a sphere, after the image of a sphere has been modified by a series of morphological erosion and dilatation operations to such an extent that additionally interfering structures—such as connections between the spheres—are removed from the image. However, the images of the spheres are also modified as a result of the erosion and dilatation operations, presenting the risk that the central area of the sphere will also be displaced in the case of spheres which are depicted in a distorted manner.
U.S. Pat. No. 5,545,995 A discloses a calibration method for correcting geometrical imaging errors, which are caused by gradient field non-linearities and by magnetic field inhomogeneities, in an MR image with reference to a three-dimensional scan of a phantom. The phantom contains an array of conical rods which generate an array of corresponding images in reconstructed picture layers. The size of the corresponding images and their position allow the measurement of positional errors and the creation of correction factors for subsequently acquired images of patients.
US 2005/0024051 A1 likewise discloses a method for correcting distorted pictures whose distortions are caused by non-linear gradient fields and translational, rotational, and/or winding or design errors of gradient coils. In this context, developments of surface spherical harmonics of the gradient fields and rapid Fourier transformation techniques are used in order to produce corrected pictures.
DE 101 07 421 A1 and the corresponding US 2002/0110268 A1 disclose in each case a method for detecting imaging distortions in an image. A first region of the imaging volume is shown free of distortion in the imaging, while a second region is distorted. The method works using at least three markings which show a known spatial position relative to each other and of which two markings are located in the first region of the imaging volume. Distortions in the image can be inferred from the position of the markings relative to each other.

Method for determining midpoint coordinates of an image of a point-symmetrical structure


An antiskid braking device for a motorcycle includes a single pump unit which is used to repressurize braking mechanisms of front and rear wheels of the motorcycle and mounted almost in a central portion of a body frame of the motorcycle and a master cylinder of the front wheel. Middle portions of front wheel brake pipes connecting the pump unit to the braking mechanisms are formed of metallic pipes, both ends of the metallic pipes are connected to the braking mechanisms, the master cylinder and the pump unit through flexible brake hoses, and the metallic pipes are arranged along an inside face of a pair of bilateral tank rails of the body frame extending rearward from a head pipe of the motorcycle. The pump unit is mounted so as to extend in a longitudinal dimension thereof along a longitudinal direction of the motorcycle and a brake pipe port section faces front and rear directions of the body of the motorcycle.

The present invention relates to an antiskid braking device for a motorcycle having an improved mounting structure.
Regarding an antiskid braking device which brakes over the shortest possible distance and stops a motorcycle without locking the wheels when braking suddenly or braking on a slippery road, a control device detects an indication that the wheels may lock and reduce the master cylinder pressure applied to the braking mechanism (brake caliper and the like) preventing the wheel from locking. When the indication that the wheel may lock diminishes, the control device actuates the pump unit to repressurize the control mechanism with an appropriate pressure. By repeating the aforementioned operation steps quickly, it is possible to brake and stop the motorcycle after it travels over the shortest possible distance.
Generally, in an antiskid braking device provided on a motorcycle, a single pump unit is employed to repressurize the braking mechanism on the front and rear wheels. Because the pump unit is relatively heavy, it is arranged almost in a central portion of the body frame so that the pump unit is located near the center of gravity of the body. Brake pipes extend to the back and the front of the body from the pump unit and, then, are connected to the control mechanisms and the master cylinders of the front and rear wheels.
The front wheel brake pipes which connect the braking mechanism and the master cylinder of a motorcycle to the pump unit extend a relatively long distance. Thus, generally, the middle portions of the brake pipes are formed of metallic pipes to avoid expansion of the pipes due to brake fluid pressure, and both ends of the metallic pipes are connected to the front wheel braking mechanism, the master cylinder and the pump unit through flexible brake hoses.
In one aspect, since the metallic pipe sections of the front wheel brake pipes extend a long distance from the front of the body to the rear as described above, there is a fear that the metallic pipes may hit the ground and be damaged when a motorcycle falls down.
Further, an electric wire harness which extends from the front to the rear of the body of the motorcycle is placed along the metallic pipes on the body frame of the motorcycle. Thus, the mounting space for the metallic pipes is reduced, but the electric wire harness is likely to interfere with the metallic pipes when assembled to the body frame, thereby hindering the assembly process.
Furthermore, in conventional motorcycles, since connecting sections which connect the front ends of the metallic pipes of the front wheel brake pipes to the brake hoses are arranged in a relatively forward position, the brake hoses are made short. Thus, there is a fear that the brake hose may be forcibly bent when steering, thereby leading to damage or leakage of brake fluid.
In another aspect, a prior art provides an antiskid braking device such as disclosed in Japanese Patent Application Laid-Open No. 2-11448, for example, in which the pump unit is mounted perpendicularly to the length of the body of a motorcycle and the brake pipe port section of the pump unit faces the side of the body. To facilitate connecting the brake pipes, the brake pipe port section protrudes from the side of the body frame.
In such prior art, since the pump unit is mounted perpendicularly to the longitudinal direction of the body and the brake pipe port section protrudes from the side of the body frame, when a motorcycle falls down or is hit on the side, there is a fear that the pump unit or the brake pipes may be damaged. In addition, since the brake pipes are grouped on the side of the pump unit, it is difficult to flexibly structure the brake pipes, thus providing a bad layout thereof.
Furthermore, since the pump unit is mounted perpendicularly to the longitudinal direction of the body, it is necessary to enlarge the width of the body frame to support the pump unit and place it above the drive chain to avoid interfering with the drive chain. Thus, the width and height of the driver's seat are necessarily increased so that foot contact to a pedal or ground becomes less accessible.
Still further, the heavy pump unit is offset from the center of the body along the width thereof, thus the bilateral weight balance of the motorcycle body can be adversely affected.
In such a motorcycle structure, the pump unit is fastened to the body frame via fixing brackets provided on the body frame. However, since the internal space of the motorcycle is limited, it is difficult to provide the body frame with a number of fixing brackets and, further, to fix the pump unit firmly. If fixing brackets are provided on a body frame, when the body frame is adapted to a motorcycle having no antiskid braking device easily, all the fixing brackets will be wasted.


A method for configuring hardware modules in an automation system includes the steps opening or creating a project in a project configuration software package, opening or generating, in the project, where a station has a number of slots, opening a hardware catalog that includes a plurality of hardware module master data records, inserting at least one hardware module master data record for a hardware module from the hardware catalog (into the station, wherein a customization step is performed for the at least one hardware module master data record, where at least one environmental parameter is specified which represents the ambient conditions at the deployment location of the at least one hardware module, and saving the station having the at least one hardware module master data record inserted into the station and with its at least one environmental parameter.

1. Field of the Invention
The invention relates to configuration systems and, more particularly, to a method for configuring hardware modules in an automation system, comprising opening or creating a project in a project configuration software package, opening or generating, in the project, a station having a number of slots, opening a hardware catalog comprising a plurality of hardware module master data records, and inserting at least one hardware module master data record for a hardware module from the hardware catalog into the station.
2. Description of the Related Art
Automation systems have one or more interconnected stations. Each of the stations preferably has a modular construction and can comprise different hardware modules. As a general rule, the hardware modules form the smallest unit of the automation system and are combined in a hardware catalog for a plant commissioning engineer. In the catalog, each hardware module is assigned an order number, for example. The project management and configuration of hardware modules in the automation system can be performed, for example, by a project configuration software package, such as Step 7 from Siemens, for example. This means that after the project configuration software package is called a corresponding user interface is opened. A project is then generated for the plant to be automated, for the machine or for each station. The hardware modules are then configured in this project, in other words, a slot in the station is assigned to the hardware modules to be parameterized. Following successful configuration and parameterization, this configuration is saved and loaded into the automation system. The corresponding methodology is known, for example, from the "Einführung in den SIMATIC-Manager" (Introduction to the SIMATIC Manager) by Walter, 14.05.2003.
EP 1 480 092 B1 also discloses a method for project management of an automation system.
Special requirements apply to the technology employed for hardware modules in the automation technology sector. The hardware modules are normally installed directly in a production environment, for example in control cabinets or directly on a machine.
On account of the deployment location of the hardware modules, special requirements exist, for example, with respect to electromagnetic compatibility, shock, vibrations, as are also described inter alia in International Electrotechnical Commission (IEC) standard 61131-2. It has furthermore become established as a quality standard that automation components or the hardware modules are capable of being used at high ambient temperatures up to 60° C. or even 65° C. On account of the harsh industrial environment, free convection cooling is resorted to as a general rule for heat dissipation from the hardware modules because built-in fans in the device tend, on the one hand, to suffer from soiling and, on the other hand, significantly reduce the MTBF of the devices. In addition to the high ambient temperatures and the requirement for passive cooling, the requirements relating to shock and vibration also render the design of the cooling for powerful electronic components considerably more difficult in the industrial environment.
Electrical and electronic components built into the hardware modules, such as for a multi-core processor system, are frequently only specified up to ambient temperatures of 85° C. or housing temperatures of less than 100° C. Accordingly, on account of the high ambient temperatures permitted in industrial environments only slight temperature differences from the specified maximum temperatures of the components used are therefore available. A maximum permissible power loss in the system is thereby also greatly limited. A limitation of the maximum permissible power loss directly limits the available computing power of the processor system employed in each case or of the entire hardware module.
From the product world of personal computers, it is known to dynamically customize the computing power of a system to the currently prevailing conditions. These methods referred to, for example, as turbo modes, on the one hand, or as throttling, on the other hand, are employed, for example, with laptops and other mobile devices.
With this known method it is, however, disadvantageous that these methods result in considerable fluctuations in the available computing power depending on the currently prevailing conditions. Such types of methods are not as a rule suitable for hardware modules in the automation technology sector because a constant computing power and therewith a stable cycle time or constant response times for the production process are of vital importance for the applications running in the hardware modules.
Hardware modules for the automation technology sector are, as a rule, currently designed such that with respect to a processor clock, the number of processor cores used and the memories used can be reliably cooled in the event of maximum guaranteed ambient conditions. At lower ambient temperatures and therewith a higher permissible power loss the hardware modules could be operated at a considerably higher performance level.
A dynamic customization of the computing power based on the currently prevailing ambient conditions is not performed in the case of industrial modules. This is intended to avoid the situation in which the computing power of the hardware module, and thus also of the production process to be automated, is not influenced by the ambient conditions and problems are therefore avoided in the production process.
A maximum achievable computing power of the hardware module or of an automation component employed is therefore influenced essentially by the maximum guaranteed ambient temperature. Even a slight reduction in the maximum ambient temperature for a particular application enables a significant increase in the computing power of the hardware module.

Method and configuration system for configuring hardware modules in an automation system


A process for fractionating deacylated glycerophospholipids of the formula (I): ##STR1## wherein R is a negative charge; a hydrogen atom; a CH.sub.2 CH.sub.2 NR.sup.1 R.sup.2 residue wherein R.sup.1 and R.sup.2, which are the same or different, are H or C.sub.1 -C.sub.4 alkyl; a CH.sub.2 CH.sub.2 N.sup.+ (CH.sub.3).sub.3 residue; a CH.sub.2 CH(NH.sub.2)COOH residue or a residue of the formula: ##STR2## and X is OH or 0.sup.-, is described. The process involves subjecting an aqueous or hydroalcoholic mixture of two or more of the deacylated glycerophospholipids to electrodialysis in an electrolytic cell comprising a number of compartments. The compartments are separated by cation-exchange membranes, anion-exchange membranes or both cation-exchange and anion-exchange membranes, at a pH effective to differentiate the deacylated glycerophospholipids.

The present invention refers to a new process for the fractionation of deacylated glycerophospholipids of the formula (I) ##STR3## wherein R is a negative charge, a hydrogen atom, a CH.sub.2 CH.sub.2 NR.sup.1 R.sup.2 residue (wherein R.sup.1 and R.sup.2, which are the same or different, are H or C.sub.1 -C.sub.4 alkyl), a CH.sub.2 CH.sub.2 N.sup.+ (CH.sub.3).sub.3 residue, a CH.sub.2 CH(NH.sub.2)COOH residue or a residue of the formula ##STR4## and X is OH or O.sup.-, starting from aqueous or hydroalcoholic mixtures, having two or more components, of said deacylated glycerophospholipids and of possible impurities of a non-glycerophospholipidic kind.
The process is characterized in that said mixtures are subjected to electrodialysis in electrolytic cells having a number of compartments, separated by cation exchange and/or anion-exchange membranes, in pH conditions suited to differentiate, depending on the positive, negative or neutral charge, the deacylated glycerophospholipids to be separated or other impurities of a non-glycerophospholipidic kind.
In the following description, the following abbreviations will be used:
GPA for the compound of formula (I) wherein R=H; PA1 GPE for the compound of formula (I) wherein R=CH.sub.2 CH.sub.2 NH.sub.2 ; PA1 GPC for the compound of formula (I) wherein R=CH.sub.2 CH.sub.2 N.sup.+ (CH.sub.3).sub.3 ; PA1 GPS for the compound of formula (I) wherein R=CH.sub.2 CH(NH.sub.2)COOH; PA1 GPI for the compound of formula (I) wherein R is a myoinositol residue. PA1 1) (-)cathode/catholyte/M.sup.- /compartment A/M.sup.+ /compartment B/M.sup.- /anolyte/anode (+) PA1 2) (-)cathode/catholyte/M.sup.+ /compartment C/M.sup.- /compartment A/M.sup.+ /anolyte/anode (+) PA1 3) (-)cathode/catholyte/M.sup.+ /compartment C/M.sup.- /compartment A/M.sup.+ /compartment B/M.sup.- /anolyte/anode (+) PA1 4) (-)cathode/catholyte/M.sup.+ /compartment A/M.sup.+ /compartment B/M/anolyte/anode (+) PA1 cathode: H.sup.+ +e.sup.- .fwdarw.1/2 H.sub.2 PA1 anode: 1/2 H.sub.2 O .fwdarw.1/4 O.sub.2 +H.sup.+ +e.sup.- PA1 MC 3470 (cation-exchange) and PA1 MA 3475 (anion-exchange) PA1 [Supplier CYBRON CHEM INC. (G.B.)] PA1 or PA1 CMT SELEMION (cation-exchange) PA1 AMR SELEMION (anion-exchange) PA1 [Supplier ASAHI GLASS CO. (J)] PA1 or PA1 CSP (cation-exchange) PA1 ADP (anion-exchange) PA1 [Supplier MORGANE (F)]. PA1 or PA1 NAFION 324 (cation-exchange) PA1 [Supplier DUPONT].
The compounds (I) may be of a fully synthetic origin or they may be obtained by deacylation, according to known methods, of acylated phospholipids of vegetal origin (e.g. soy lecithin) or of animal origin (e.g. egg yolk or bovine brain). In both instances, in the mixture of compounds (I) to be subjected to electrodialysis, impurities of a non-glycerophospholipidic kind can be present, which may be removed during the fractionation process or subsequently according to conventional techniques, such as crystallization, liquid/liquid extraction or chromatography.
The process surprisingly attains an effective fractionation of the compounds (I) using, in comparison with known methods, smaller amounts of chemical reagents or solvents, giving smaller amounts of waste to be disposed of, allowing to obtain compounds (I) with higher productivity.
Compounds (I) are characterized in that they may be positively or negatively charged or they may be electrically neutral according to the pH value of the solution. For instance, GPC is positively charged at pH values <1 and amphotheric at pH values higher than 4, whereas GPE is positively charged at pH values <1, amphotheric in the pH range from 5 to about 8 and negatively charged at pH values >10. Similarly, such pH values of the solution can be found as to differentiate the species (I) in the mixture by means of the positive, negative or neutral charge. By the same method, it is possible to separate the compounds (I) from any other possible impurities in the starting mixtures.
Therefore, if a mixture of compounds (I), in aqueous or hydroalcoholic solution, is introduced at a suitable pH in a compartment of the electrolytic cell (hereinafter defined as compartment A), delimited by cation-exchange membranes and/or anion-exchange membranes, and an electrical potential is applied through the cell, it is possible to cause the migration of the negatively charged species to the anode through the anion-exchange membrane (having fixed positive charges and hereinafter referred to as M.sup.+) in an adjacent compartment (hereinafter referred to as compartment B), whereas the positively charged species migrate to the cathode through the cation-exchange membrane (having fixed negative charges and hereinafter referred to as M.sup.-) in an adjacent compartment (hereinafter referred to as compartment C) and leaving in compartment A the electrically neutral species.
According to the kind of mixture to be fractionated it is possible to carry out the separation working sequentially at different pH values.
The basic scheme of the cell, formed of a number of compartments, depends on the kind of mixture to be separated; in any case the electrodes, cathode and anode are present, in contact with electrolytic solutions of salts and/or inorganic acids or bases, respectively referred to as catholyte and anolyte, having a suitable composition and concentration compatible with the requirements of electrodic and fractionation processes. In compartments A, B and/or C, inorganic salts may also be present from the beginning or they may be subsequently added in order to increase conductivity whenever the presence of the charged species (I) would not be sufficient. The nature of the catholyte and anolyte is connected with that of the said inorganic salts, or to the kind of mixture of compounds (I) present in compartments A, B and C. The inorganic salts, acids or bases in the cell are dissociated in cations and anions and they may cross in their turn the membranes having opposite charge and they are repelled by the membranes having the same charge, competing in transport with the charged species (I). The compartments separated by the cationic and/or anionic membranes are in sufficient number to allow the introduction of the mixture of compounds (I) and the recovery of the fractionated species; the basic scheme may be repeated in series to increase the process productivity by connecting compartments of the same kind together.
For instance, cells of the following composition may be used:
For the sake of simplicity, the characterizing elements of these possible schemes of a cell are schematized, the inlets and outlets from and to the cell exterior having not been indicated.
Cells 1 and 2 are suited to the construction of a two-compartment stack, delimited by membranes of opposite sign as a repetive unit. Cell 3 is suited to the construction of a three-compartment stack, delimited by membranes of opposite sign. Cell 4 is suited to the construction of a more complex stack because of the membrane configuration, but it offers the advantage of securing a suitable conductivity even when the negatively charged species (I) have almost completely moved from compartment A to compartment B.
The process is characterized by the following electrodic reactions:
As a consequence, the electrodes conventionally used in electrolytic cells may be installed. Even simpler cells, having only one membrane (M.sup.+ or M.sup.-) are possible; in this case, the starting mixture and the fractionated species (I) are directly in contact with the electrodes. Therefore the fractionation conditions must be such that the species involved are stable with regards to the electrodic reactions, i.e. towards the development of oxygen and hydrogen. The membranes which can be used in this process are for example:
The cation-exchange membranes are permeable to the positively charged species (I) and to the inorganic cations present; the anion-exchange membranes are permeable to the negatively charged species (I) and to the inorganic anions present. Both kinds of membranes have good resistance to the operative pH values as well as mechanical and heat resistance, they are scarcely prone to clogging and they may be re-cycled after optional washings with water, with an hydroalcoholic solution, with a diluted acidic solution, with a diluted basic solution, again with water or with a saline aqueous solution according to the conventional method.
The starting concentration of the inorganic salts in the compartments ranges from 0 to 5M so as to obtain the best current density.
The process may be carried out at a current density from 20 to 3,000 A/m.sup.2, referred to the surface of each installed membrane. The following examples further illustrate the invention.

Process for the preparation of glycerophospholipids


First and second cam shafts arranged in first and second cylinder heads of a V-shaped internal combustion engine are respectively arranged so as to be offset toward the inner side of the internal combustion engine in the width directions of the first and second cylinder heads. First and second exhaust valves and first and second spark plugs are arranged so as to be almost parallel to first and second cylinder center lines of first and second cylinder banks, respectively.

In an internal combustion engine, particularly, in a 4-cycle internal combustion engine, a valve moving mechanism and spark plugs are provided for the cylinder head. Such a cylinder head structure has been disclosed in JP-A-1-193009 and JP-A-1-280605. According to the cylinder head structure disclosed in JP-A-1-193009, a hydraulic tappet is provided for a rocker shaft to axially support one of the rocker arms, and the other rocker arm is pivotally supported by the hydraulic tappet, thereby simplifying the working of the cylinder head. According to cylinder head structure disclosed in JP-A-1-280605, the forming position of an intake valve and the forming position of an exhaust valve in the width direction perpendicular to the longitudinal direction of the cylinder head are fixed and the cylinder head for the moving valve system is constructed, thereby enabling the outer shape of the cylinder head and the working equipment to be commonly constructed irrespective of the number of intake and exhaust valves and enabling the parts which are used to be also commonly constructed and reducing the costs.
Internal combustion engines are classified into the straight-type, opposed-type, V-type, and the like in accordance with the arrangement of the cylinders. For instance, as shown in FIG. 4, a V-shaped internal combustion engine 102 is constructed in a manner such that first and second cylinder heads 106-1 and 106-2 are mounted on an almost V-shaped cylinder block 104 and first and second cylinder banks 108-1 and 108-2 are arranged in an almost V-shape. One first cam shaft 1101 and one second cam shaft 110-2 are arranged in the first and second cylinder heads 106-1 and 106-2 of the internal combustion engine 102 in the longitudinal direction, respectively. First and second intake valves 112-1 and 112-2 are arranged in the first and second cylinder heads 106-1 and 106-2 on the inner side of the internal combustion engine 102 in the width direction, respectively. First and second exhaust valves 114-1 and 114-2 and first and second spark plugs 116-1 and 116-2 are arranged on the outer edge side of the internal combustion engine 102 in the width direction, respectively. Reference numerals 118-1 and 118-2 denote first and second cylinders; 120-1 and 120-2 first and second intake cams; 122-1 and 122-2 first and second exhaust cams; 124-1 and 124-2 first and second rocker arms; and 126-1 and 126-2 third and fourth rocker arms, respectively.
As shown in FIG. 4, however, the first and second exhaust valves 114-1 and 114-2 and the first and second spark plugs 116-1 and 116-2 are arranged on the outer edge side of the internal combustion engine 102 in the width direction of the first and second cylinder heads 106-1 and 106-2, respectively, so as to be inclined from first and second cylinder center lines 118-1L and 118-2L of the first and second cylinders 118-1 and 118-2. That is, as shown in FIG. 5, the second exhaust valve 114-2 and the second spark plug 116-2 are arranged on the outer edge side of the internal combustion engine 102 in the width direction of the second cylinder head 106-2 in a manner such that a second exhaust valve center line 114-2L and a second spark plug center line 116-2L are inclined from the second cylinder center line 118-2L of the second cylinder 118-2.
Therefore, there is a disadvantage in that the width of the internal combustion engine 102 is enlarged because the first and second exhaust valves 114-1 and 114-2 and the first and second spark plugs 116-1 and 116-2 project from the outer edge side of the internal combustion engine 102. There is also a disadvantage in that the weight of the internal combustion engine 102 is increased, an increase in the size of the engine room of the vehicle is required, and the weight of the vehicle is increased. Since the first and second spark plugs 116-1 and 116-2 are obliquely arranged, there is a problem such that it is difficult to easily attach and detach them. Thus, maintenance efficiency is deteriorated. Further, when an accessory 128 such as a radiator or the like exists on an extension in the spark plug attaching/detaching direction, the attaching/detaching of the first and second spark plugs 116-1 and 116-2 is difficult and the maintenance efficiency is deteriorated. In order to assure the maintenance efficiency of the internal combustion engine 102, the accessory 128 must therefore be located away from the engine. There is consequently a disadvantage in that an enlargement of the engine room is required and the weight of vehicle is increased
In an attempt to solve the above disadvantages, according to the invention, in a cylinder head structure of an internal combustion engine in which first and second cylinder heads are mounted on an almost V-shaped cylinder block and first and second cylinder banks are arranged in an almost V-character shape, wherein a first cam shaft and a second cam shaft are respectively arranged in the longitudinal directions of the first and second cylinder heads of the internal combustion engine, first and second intake valves are respectively arranged on the inner side of the internal combustion engine in the width directions of the first and second cylinder heads, and first and second exhaust valves and first and second spark plugs are respectively arranged on the outer edge side of the internal combustion engine in the width directions of the first and second cylinder heads, the cylinder head structure is characterized in that the first and second cam shafts are respectively arranged so as to be deviated to the inner side of the internal combustion engine in the width directions of the first and second cylinder heads, and the first and second exhaust valves and the first and second spark plugs are respectively arranged so as to be almost parallel to respective center lines of the first and second cylinders.
According to the invention, the first and second cam shafts are respectively arranged so as to be deviated to the inner side of the internal combustion engine in the width directions of the first and second cylinder heads. The first and second exhaust valves and the first and second spark plugs are arranged so as to be almost parallel to the cylinder center lines of the first and second cylinders, respectively. Consequently, the width of the internal combustion engine can be reduced and the spark plugs can be attached/detached from positions over the internal combustion engine on extensions of the cylinder center lines.

Cylinder head structure of internal combustion engine


A method and apparatus for adaptive service interworking include processing that begins by obtaining connection information of a receiving end-point network switch in response to receiving a setup message from a sending party. The setup message identifies a receiving party, which is operably coupled to the receiving end-point switch. Such connection information may be obtained by sending an enhanced traffic descriptor appended to the setup message and receiving an enhanced traffic descriptor that was appended to a connection message from the receiving end-point switch. The connection information is then interpreted to determine whether the receiving end-point switch is capable of supporting a transparent link. If the end-point network switch is capable of supporting the transparent link, the transparent link is established and utilized to transport data between the sending and receiving parties.

Communication between a calling party and a called party may be established over a communication network. Such a communication network may include a plurality of network switches that transport data in one of a variety of data transport protocols. For example, the data transport protocol may be frame relay, asynchronous transfer mode (ATM), IP (internet protocol), where frame relay includes a plurality of subset protocols. Some network switches provide for a conversion between frame relays protocols and ATM protocols. Such transformation is known as service interworking. One such switch is manufactured and sold by Newbridge Network Corporation and has a product number of 36170.
Many standards have been generated to regulate and unify data transportation via network switches. One such standard for frame relay to ATM protocol conversion is RFC 1483. The RFC 2483 standard provides a finite set of frame relay data transport protocols that can be converted to an ATM data transport protocol. As such, a problem arises when the frame relay data transport protocol being supported by an end-point switch is not listed in the RFC 1483 standard. As such, a communication, or switched virtual call (i.e., a communication between network switches), using a frame relay interface not specified in the standard cannot be supported by an ATM back bone.
Therefore, a need exists for a method and apparatus that provides a comprehensive service when frame relay to frame relay communications, or switch virtual calls, are used with any type of frame relay protocol without compromising frame relay to ATM switch virtual calls, or communications.

Method and apparatus for adaptive service interworking


Provided are a print control apparatus and a non-transitory computer-readable storage medium storing a color calibration control program. A print control apparatus includes an information storage processing section which stores measured color values into a database which stores history information of color measurement, where the measured color values are obtained by measuring colors in a color chart by using a printing device. The print control apparatus further includes a color defining section which defines a specific color by referring to the database, and a color calibration controlling section which, while the printing device is processing a print job, causes the printing device to measure the specific color, determines whether to calibrate the printing device on the basis of a change with time in the measured color value of the specific color, and calibrates the printing device according to the determination result.

Printing devices such as a copier and an MFP (Multi-function Peripheral) having a color printing function are now widespread. To perform color printing using such a printing device, there is a need to calibrate the printing device so as to accurately reproduce colors contained in pages of a print job (also referred to as color calibration). A method of such a color calibration includes a step of forming an image of a color chart in which color patches are arrayed on a sheet of paper; a step of measuring colors of the color patches formed on the sheet with an inline sensor provided in the printing device; a step of obtaining an amount of change in colors in the color chart by comparing the measured color values given by the inline sensor with the corresponding reference values (a target color value set for each patch); and performing feedback continually so that the amount of change in colors falls within an appropriate range.
As an example relating to such a color calibration, Japanese Unexamined Patent Publication (JP-A) No. 2010-201819 discloses a printing device including: a conveyance unit for conveying a printing medium in a predetermined conveying direction; a printing unit that can print an image onto the printing medium during the conveyance on the basis of printing data expressing the image; a color measuring unit for measuring colors in a region extending in the conveying direction on the printing medium; an analysis unit for analyzing a change in measured color values in the region obtained by the color measurement; and an adjustment processing unit for performing a predetermined adjustment processing about the printing unit and/or the color measuring unit according to the result of the analysis.
As another example, JP-A No. 2006-201613 discloses an image forming apparatus that adjusts an image forming condition by measuring the density of a pattern for image density measurement formed on a recording material by using an optical measuring unit. The image forming apparatus includes: a formation unit for forming a test pattern in a region designated on the recording material before adjusting the image forming condition using the pattern for image density measurement; a density difference obtaining unit for obtaining a density difference between the density of the test pattern measured by the optical measuring unit and a reference density corresponding to the test pattern; a density fluctuation determination unit for determining an existence of a density fluctuation on the basis of the density difference; and a determination unit for determining whether or not to adjust the image forming condition that uses the pattern for image density measurement, according to the determination result of the density fluctuation determination unit.
A conventional color calibration technique includes a step of printing a color chart periodically (once in a certain number of sheets or once in a certain period of time), a step of comparing measured color values of colors in the color chart with the corresponding reference values, and a step of performing color calibration if an amount of change in color exceeds a certain value. However, this method has a problem of wastes of consuming resources and time.
That is, in a conventional color calibration technique, when the prescribed number of output sheets or prescribed elapsed time is reached, a printing device prints out a color chart irrespective of a necessity of color calibration. It makes problems of increase in unusable print sheets (waste or spoiled sheets), increase in the amount of consumption of consumables, increase in waiting time for printing, or the like. Further, before the prescribed number of output sheets or prescribed elapsed time is reached, the printing device does not print out a color chart irrespective of a necessity of color calibration. Accordingly, when the printing device passed into a state that the printing device needs to be calibrated during that period, the printing device makes outputs with the color reproducibility insufficiently secured. It creates a certain number of waste or spoiled sheets and re-print processing wastes additional consumables and time, which are problems. The present invention seeks to solve the problems.

Apparatus and computer program product controlling printer color calibration using color chart history information


A locking device for joining first and second mating connectors together comprises a pair of first locking members and a pair of second locking members respectively retained in opposite sides of the first and second connectors. Each first locking member has a globular engaging portion extending beyond the first connector. Each second locking member has a latch extending beyond the second connector which includes an opening and a transverse bar at a free end thereof. The transverse bar defines an inclined surface and has an arcuate construction for facilitating guidance of a corresponding engaging portion of the first locking member into the opening of the latch. The pair of engaging portions of the first locking members is accommodated in the pair of openings of the second locking members, thereby securely engaging the first and second locking members together.

1. Field of the Invention
The present invention relates to a locking device for joining first and second mating connectors together.
2. Description of the Prior Art
Electrical connection between two mating connectors is often adversely effected by vibration or an unexpected external force. In order to protect the connection from such disturbances, the mating connectors often have engageable locking devices for securely joining the two connectors together. U.S. Pat. Nos. 5,401,189 and 5,971,790, and Taiwan Patent Application No. 84201383 disclose such connectors.
Referring to FIG. 4, a conventional connector comprises a dielectric housing 70, a plurality of conductive contacts 71 received in the housing 70, a shield 72 enclosing a front portion of the housing 70 and a pair of locking members 73 for joining the connector and a mating connector (not shown) together. The housing 70 defines a pair of apertures 74 in opposite sides thereof for securely receiving the corresponding locking members 73. The shield 72 defines a pair of cutouts 78 and a pair of through holes 79 at positions corresponding to the apertures 74 of the housing 70. Each locking member 73 forms a cantilevered arm 76 having a hook 77 at a free end thereof and a cavity 75 corresponding respectively to the cutout 78 and the through hole 79 of the shield 72. Each locking member 73 is received in the corresponding aperture 74 of the housing 70 with the arm 76 extending through the corresponding cutout 78 of the shield 72. The locking member 73 is attached to the housing 70 and the shield 72 by a fastening member such as a screw (not shown), extending through the cavity 75 and the through hole 79.
However, since the locking member 73 is relatively large, the aperture 74 of the housing 70 weakens the integrity of the housing 70. In addition, since the hook 77 only engages with a locking member of the mating connector (not shown) at a predetermined position, any deviation therebetween will hinder proper engagement. Further, disengagement between the two mated connectors is complicated since the locking members 73 are not provided with an accessible disengaging device. Hence, an improved electrical connector is required to overcome the disadvantages of the prior art. The copending applications of Ser. Nos. 09/361,686 filed Jul. 27, 1999 and 09/364,172 filed Jul. 07, 1999 both of which have the same inventor and the same assignee with the invention, disclose some approaches.

Device for locking two mating connectors


A technique allows a smart meter to receive a mask. The smart meter may receive the mask from a utility company or an escrow service. The smart meter may apply the mask to original metered data on a continuous schedule, on a periodic schedule, or on a determined schedule, or on a randomized schedule to conceal the original metered data. The smart meter may apply different masks at different times. The smart meter transmits the concealed metered data as augmented metered data remotely to an electric utility via a communication network.

Modern electrical grid systems are based on electric utilities and interconnected networks that deliver one-way flow of electricity from suppliers to consumers. However, increasing demand for energy, depleting fossil-based resources and a changing climate are emerging as challenges to continued and uninterrupted supply of electric power from electric utilities. As green energy sources such as, for example, solar, wind and geothermal sources emerge as a source of energy generation at residential homes, modernized systems must allow energy from these small distributed energy sources to be supplied to the grid. Therefore, as today's grid architecture is transformed into a smart grid, two-way flow of electricity and two-way flow of information is needed.
To achieve this two-way flow of information, electric utilities have installed smart meters at residential homes. Smart meters record near-real time information on consumer electricity usage in the home. The recorded information is subsequently transmitted to utilities on a predetermined schedule as metered data via a communication network. Transmitted metered data (i.e., electricity usage data) for a home may offer a window into the lives of people inside the residence by revealing the occupants' daily schedules, current occupancy level, use of individual appliances or the like.
Recently, transmitted metered data has raised confidentiality issues with respect to protecting personal privacy and safeguarding proprietary information from unauthorized access. For example, metered data that is transmitted over a communication network may potentially be subject to interception or theft by unauthorized third parties or hackers. Malicious attacks by hackers, who may eavesdrop on these communication networks, can gain access to personal and/or proprietary information, for example, access to consumer usage information or customer confidential account information. Additionally, metered data may provide appliance usage patterns that can shed light on an occupant's behavior inside the home that may potentially compromise his privacy in the home.
Conventional methods to protect personal and/or confidential information have relied on cryptography. For example, the ZigBee® Smart Energy Profile (SEP) standard from the ZigBee® Alliance has been adapted in some home area networks. The ZigBee® SEP implementation uses a certificate for providing security of metered data that is transmitted from a smart meter. However, the ZigBee® SEP implementation is limited as it neither provides certificate revocation nor certificate renewal capability. Other methods to safeguard metered data or information may include Advanced Encryption Standards (AES), RSA or Elliptic Curve cryptography, which are computationally intensive. Attackers could still glean usage patterns over encrypted data in transit and where they have physical access to the Smart Meters, they could gain encryption keys and see the usage data. Additionally, detailed personal usage information is available to the electric utility from which occupants' behaviors in the home through the persons' energy consumption could be derived. A system and method for ensuring confidentiality of metered data on a device and transmitted from a smart meter over a communication network would be desirable.

Smart home security of metered data using a mask


A press-contact type semiconductor device having multiple semiconductor substrates, a periphery of which being enclosed by a chip frame of insulating resin a first electrode plate and a second electrode plate. The semiconductor substrates are arranged on a plane so as to abut against the chip frame. The semiconductor substrates are press-contacted from the upper and the lower sides by the first electrode plate and the second electrode plate.

1. Field of the Invention
The present invention relates to a press-contact type semiconductor device, more particularly, relates to MOS gate drive switching devices such as IGBT (Insulated Gate Bipolar Transistor) having a plurality of semiconductor substrates.
2. Description of the Related Art
Conventionally, the structure of the press-contact type semiconductor device has been only one which press-contacts a single semiconductor substrate (hereinafter referred to as "chip"). For example, in the press-contact type device of the anode short type GTO (Gate Turn-Off) thyristor, the disc type chip includes N-type emitter layer, P-type base layer, N-type base layer and P-type emitter layer, from the chip surface which is the cathode toward the back face of the chip which is the anode.
N-type emitter region on the chip surface is formed as a plurality of mesas on P-type base layer. These N-type emitter regions has an aluminum cathode electrode on the top portion of said mesas, and a plurality of gate electrodes composed of aluminum are provided in P-type base layer exposed by said mesa processing. On the back face of the chip, a plurality of P-type emitter regions having a planar structure are formed within the surface of a flat N-type base layer, and the anode short type GTO thyristor is formed by providing the anode electrode composed of aluminum on the whole face thereof, extending over said N-type base layer and P-type emitter regions. The side face of the chip is coated with, for example, silicone resin for the insulation protection.
On the cathode electrode of the top portion of said mesas, the cathode external electrode is press-contacted, and on the anode electrode, the anode external electrode is press-contacted. The above-mentioned press-contact type device of the anode short type GTO thyristor is disclosed in KOUKAI, "Press-contact type semiconductor device", HEI, 4-137561 (12 May, 1992).
Recently, IGBT has appeared as a MOS gate drive type switching device. This device is characterized in that it has an advantage that it makes high voltage and high current operation easy, which the bipolar transistor has, and an advantage that driving is easy. As the switching device using this IGBT, a RC (Reverse Conduction) type switching device incorporating FRD (Free Wheel Diode) is known. This device is the one which connects FRD to IGBT in inversely parallel, and used in a module structure. This module is assembled by forming an electrode pattern used as given collector electrode, emitter electrode, emitter control electrode and gate electrode on the insulation substrate, and by solder mounting a plurality of IGBT back-face collectors and FRD chips, respectively, on said collector electrode pattern. The emitter on the upper face of the chip, emitter control and respective electrodes of the gate, and the corresponding electrode patterns on the insulation substrate are connected by a bonding wire, respectively.
The surface of IGBT chip mounted on the switching device of this module structure is coated with a passivation film such as polyimide, except for the bonding pad of the gate and emitter. The square shaped silicon chip of IGBT forms the collector electrode of the metal multilayer film over the whole surface of the back face of the chip in order to facilitate soldering.
For example, since the press-contact type semiconductor device composed of the conventional GTO thyristor has only one structure to press-contact one chip, there are defects described below:
(1) High current operation of the element is difficult. Namely, in order to increase the current rating of the element, it has been necessary to make the chip size large. However, if the chip size is increased, such problems are caused that in the high-speed power element such as MOS gate type switching devices of IGBT, the possibility to contain unrestorable defects which make fine processing difficult is increased to increase the failure rate. PA0 (2) Highly functionalizing and high value-adding are difficult. For example, when RC type IGBT device is produced, two different kinds of device structures, IGBT and FRD have to be produced in one wafer, thereby the production process is complicated and production becomes difficult. PA0 (1) Reliability for the Power Cycle of Bonding PA0 (2) Reliability for the Thermal Fatigue of the Soldering Layer PA0 (3) Reliability for Cooling of the Element PA0 (4) Reliability for High Temperature Operation PA0 (5) Reliability for High Voltage Operation PA0 (6) Reliability for Wiring
Furthermore, when the conventional module type semiconductor device is used to be mounted on a vehicle (for traction applications), such problems described below are caused:
It is required that semiconductor devices for traction applications have to be endurable to the power cycle of 6 million cycles at a temperature variation of 25.degree. C., but in the current technology, it can only endure 3 million cycles.
It is required that the soldering layer has to be endurable, as in said bonding, to the power cycle of 75,000 cycles at a temperature variation of 70.degree. C., but in the current technology, it can only endure about 25,000 cycles.
Conventional module type semiconductor devices are cooled on the only one face from the collector side, and cooling from the emitter electrode side is almost impossible. Therefore, in order to enhance the heat dissipation, the outside diameter of the element has to be increased. For example, in the RC type IGBT module of 1200 A-2500 V class, the outside diameter becomes 130.times.260.times.40 mm.
In semiconductor devices for traction applications, the operating temperature in use is had to be insured in the range -40.degree. C. -150.degree. C., but the resin of the case material is not endurable against such temperature.
Since the case material is a resin and easy to cause tracking, it is not endurable against high voltage operation.
Since wiring within the module is fine and complicated, there are such problems as noise generation in the gate circuit due to the wiring inductance, and generation of the spike voltage at the time of diode recovery.

Press-contact type semiconductor devices


A programmable apparatus for applying pressure-sensitive transfer tape in selective lengths to sheet material at high speed, which is adaptable for other sheet preparation purposes.

In recent years, advertising and other forms of printed literature in sheet form have been distributed to the ultimate user with adhesive applied to the margins thereof in the form of strips of adhesive transfer tapes each comprising a backing strip having a loosely held layer of adhesive material on the side thereof which is face down upon the sheet material and a non-tacky outer face which permits stacking of similar sheets without the sticking together of adjacent sheets in the stack. When the ultimate user desires to apply the sheet material to a vertical wall surface, he peels the backing strip from the sheet material, leaving the adhesive layer upon the sheet material. The sheet material may then be adhesively secured to a vertical wall surface by applying the adhesive-coated side of the sheet material against the wall surface involved.
The machinery heretofore used to apply the adhesive transfer tape at high speeds to the sheet material was single-purpose and very costly and only a relatively few sheet processing plants were available for applying the adhesive transfer tape to sheet material. Other machines were needed to perforate stock, to blade-slit stock, to crease and score stock, and to rotary-slit stock. The sheet material involved was first processed by the printer who provided individual printed sheets in the usual manner. Then, the sheets were usually delivered to the nearest plant having the above mentioned tape-applying machinery, which plant, in many cases, was located hundreds of miles away from the printing plant and from the distributor of the printed material. This procedure was costly in both time and money.
It is apparent that the spacing of the areas of transfer tape applied to the sheets of material fed through the machine varies with the size of the sheet material involved. Another variable with which the machine must deal is the form or pattern of the areas of adhesive transfer tape applied to the sheet material. For example, the tape can be applied in long strips or in spots. In the latter case, the size and spacing of the spots can vary. The tape-applying machines heretofore made are not readily adaptable to these varying conditions. Moreover, difficulty is encountered in operating the machines at high speeds, particularly where the sheet material is thin and fragile, and for any relative movement between the tape and the sheet material in the process of applying such tape will tear the sheet material.
It is, accordingly, an object of the present invention to provide a machine which can be readily adapted to programmably apply pressure-sensitive transfer tape and adjusted to receive sheet material and pressure-sensitive adhesive tape of widely varying widths and lengths and to apply the tape to a number of areas of the sheet material with a variety of patterns and special arrangements in a single pass of the sheet material through the machine. A related object of the invention is to provide a tape-applying machine which can selectively apply a strip of adhesive tape extending the full length of the sheet material involved or in spots thereon. Furthermore, two or more different programs can apply spots simultaneously. Another object of the present invention is to provide a machine for applying strips of adhesive tape at high feeding rates to even thin, fragile sheet materials. It shall also be adaptable to readily accommodate heads to perforate stock, heads to blade-slit stock, heads to crease-score stock, and heads to rotary-slit stock.

High speed programmable pressure-sensitive transfer tape applicator


A sheet having an image of a document formed by a copying unit on one side is sequentially stacked in a stacking section of a two-sided/multiple copy unit. Such sheets are picked up by pick-up rollers one by one and conveyed to the copying unit by a plurality of conveying rollers which are arranged along a conveying path. A detection switch is provided on the conveying path to detect abnormality which may occur during conveyance of the sheet. If such abnormality is detected by the switch, then a door is opened by the operator and a caught sheet is removed from the rest of the machine. Upon the closure of the door, the door switch detects that the door is closed. At this time, the sheet is picked up from the stacking section by the pick-up roller prior to a copying operation by the copying unit and conveyed past a conveying path to a location near the copying unit. When a start-to-copy instruction is supplied to an operation panel, the sheet which is stopped near the copying unit is supplied to the copying unit where a document image is copied on the sheet.

1. Field of the Invention
The present invention relates to a copying machine capable of automatically copying an image on each side of a copying sheet or a plurality of images on one side of a copying sheet, and in particular an improved control unit for a two-sided/multiple copy conveying unit for conveying a copying sheet with an image formed on one side.
2. Description of the Related Art
A copying machine capable of automatically copying a document image on each side of a copying sheet or a plurality of document images on one side of a copying sheet has been developed in this art. This copying machine comprises a copying section for copying an image corresponding to a document image on a sheet, a stacking section for stacking those imaged sheets from the copying section and a conveying unit which, in the case of a two-sided copy mode, conveys the stacked sheet to the copying section in an "inverted" state and, in the case of a multiple copy mode, conveys the stacked sheet to the copying sheet in an non-inverted fashion.
In the aforementioned copying machine, in the two-sided copy mode, a document image is transferred to one side of the sheet at the copying section and conveyed to the stacking section. Then the imaged sheet is taken out of the stacking section and transferred to the copying section in an "inverted" fashion where, for example, another document image is transferred to that side of the sheet.
In the multiple copying mode, a document image is transferred to a half of one side of the sheet and then conveyed to the stacking section. The stacked sheet is conveyed, in that posture, via the conveying unit to the copying section where, for example, another document image is transferred to the remaining half of the sheet.
For the two-sided copy or multiple copy mode, the sheet which is taken out of the stacking section is once stopped at the conveying unit. The sheet thus stopped is responsive to the copying operation of the copying section to be transferred to the copying section. In the copying machine, however, when a plurality of copying sheets are imaged in a continuous copying mode, if the sheet which is taken out of the stacking section is jammed or caught at the location of the conveying unit, the copying operation is stopped until the cause of the jamming is removed. When, in this case, a start-to-copy instruction is issued from an operation panel in the copying machine after the jammed sheet has been removed, the succeeding sheet is taken out of the stacking section and, in this way, a copying operation is started.
In this way, after the interruption of the copying section, the sheet is being held in the stacking section, leaving a long distance from the stacking section to the copying section. For this reason, a long time is taken from the picking up of the sheet from the stacking section subsequent to the issuance of the start-to-copy instruction to the conveyance of the sheet to the copying section. It takes a long time to start a copying operation at the location of the copying section.

Control apparatus for a two-sided/multiple copy conveying unit


The electrocatalysts in certain fuel cell systems can be poisoned by impurities in the fuel stream directed to the fuel cell anodes. Introducing a variable concentration of oxygen into the impure fuel stream supplied to the fuel cells can reduce or prevent poisoning without excessive use of oxygen. The variation may be controlled based on the voltage of a carbon monoxide sensitive sensor cell incorporated in the system. Further, the variation in oxygen concentration may be periodic or pulsed. A variable air bleed method is particularly suitable for use in solid polymer fuel cell systems operating on fuel streams containing carbon monoxide.

Electrochemical fuel cells convert reactants, namely fuel and oxidant, to generate electric power and reaction products. Electrochemical fuel cells generally employ an electrolyte disposed between two electrodes, namely a cathode and an anode. An electrocatalyst typically induces the desired electrochemical reactions at the electrodes. In addition to electrocatalyst, the electrodes may also comprise a porous electrically conductive sheet material, or "electrode substrate", upon which the electrocatalyst is deposited. The electrocatalyst may be a metal black, an alloy or a supported metal catalyst, for example, platinum on carbon.
Solid polymer electrolyte fuel cells employ a membrane electrode assembly ("MEA") which comprises a solid polymer electrolyte or ion-exchange membrane disposed between the two electrode layers. Separator plates, or flow field plates for directing the reactants across one surface of each electrode substrate, are disposed on each side of the MEA. Solid polymer fuel cells operate at relatively low temperatures (circa 80.degree. C.) compared to other fuel cell types.
A broad range of reactants can be used in electrochemical fuel cells. For example, the fuel stream may be substantially pure hydrogen gas, a gaseous hydrogen-containing reformate stream, or methanol in a direct methanol fuel cell. The oxidant may be, for example, substantially pure oxygen or a dilute oxygen stream such as air.
The fuel stream may contain impurities that do not contribute to, and may actually inhibit, the desired electrochemical reaction. These impurities may, for example, originate from the fuel stream supply itself, or may be generated, for example, as intermediate species during the fuel cell reactions, or may be impurities entering the fuel stream from elsewhere in the system. Some of these impurities may be chemically adsorbed or physically deposited on the surface of the anode electrocatalyst, blocking the active electrocatalyst sites and preventing these portions of the anode electrocatalyst from inducing the desired electrochemical fuel oxidation reaction. Such impurities are known as electrocatalyst "poisons" and their effect on electrochemical fuel cells is known as "electrocatalyst poisoning". Electrocatalyst poisoning thus results in reduced fuel cell performance, where fuel cell performance is defined as the voltage output from the cell for a given current density. Higher performance is associated with higher voltage for a given current density or higher current for a given voltage.
In the absence of countermeasures, the adsorption or deposition of electrocatalyst poisons may be cumulative, so even minute concentrations of poisons in a fuel stream, may, over time, result in a degree of electrocatalyst poisoning which is detrimental to fuel cell performance.
Reformate streams derived from hydrocarbons or oxygenated hydrocarbons typically contain a high concentration of hydrogen fuel, but typically also contain electrocatalyst poisons such as carbon monoxide. To reduce the effects of anode electrocatalyst poisoning, it is known to pre-treat the fuel supply stream prior to directing it to the fuel cell. For example, pre-treatment methods may employ catalytic or other means to convert carbon monoxide to carbon dioxide. However, known pretreatment means for reformate streams cannot efficiently remove 100% of the carbon monoxide. Even trace amounts less than 10 ppm can eventually result in electrocatalyst poisoning which causes a reduction in fuel cell performance.
Substances other than carbon monoxide are also known to poison fuel cell electrocatalysts. Poisons may also be generated by the reaction of substances in the reactant streams with the fuel cell component materials. For instance, carbon monoxide or other impurities can be generated from carbon dioxide in the presence of an electrocatalyst. This can occur when there is a relative abundance of carbon dioxide and a relatively low concentration of carbon monoxide such that equilibrium conditions favor some limited carbon monoxide formation. What constitutes a poison may depend on the nature of the fuel cell. For example, whereas methanol is the fuel in a direct methanol fuel cell, in a hydrogen fuel cell operating on a methanol reformate stream, traces of unreformed methanol can be detrimental to the electrocatalyst performance.
Conventional methods for addressing the problem of anode electrocatalyst poisoning include purging the anode with an inert gas such as nitrogen. However, such purging methods involve suspending the generation of power by the fuel cell, thus a secondary power source may be needed to provide power while the fuel cell anode is being purged.
Another approach for removing poisons from an electrocatalyst comprises introducing a "clean" fuel stream containing substantially no carbon monoxide or other poisons to a poisoned fuel cell anode. Where the adsorption is reversible, an equilibrium process may result in some rejuvenation of the electrocatalyst. However, a disadvantage of this approach is that it is generally not effective against irreversibly adsorbed poisons. Furthermore, the recovery of the anode electrocatalyst by such an equilibrium process can be very slow, during which time the fuel cell is not able to operate at full capacity.
Another technique to counteract carbon monoxide electrocatalyst poisoning is to continuously introduce a low concentration of oxygen into the fuel stream upstream of the fuel cell, as disclosed in U.S. Pat. No. 4,910,099. Therein, oxygen levels from about 2% to 6% were injected into fuel streams having carbon monoxide levels from about 100 to 500 ppm. However, such an oxygen bleed into the fuel stream results in some consumption of hydrogen and hence a reduction in fuel efficiency. Further, an oxygen bleed results in undesirable localized exothermic reactions at the anode, particularly near the fuel inlet, which may damage fuel cell membranes and reduce fuel cell lifetime. Further still, since in practice oxygen bleed is typically obtained by compressing air (it is often drawn from a compressed air stream provided as a fuel cell oxidant), use of an oxygen bleed may result in an additional parasitic load on a fuel cell system. Thus, the use of an excessive amount of oxygen bleed is undesirable.
To efficiently and effectively counteract carbon monoxide poisoning, it is desirable to know the approximate concentration of carbon monoxide in the fuel stream. However, directly measuring the concentration of carbon monoxide in a fuel stream can be difficult in practice. Thus, while a sensor for directly measuring carbon monoxide is desirable in a fuel cell system, often the concentration is inferred based on the known operating conditions of the fuel cell system (e.g., carbon monoxide concentrations can be determined under various operating conditions in a laboratory and can then be inferred for a fuel cell system operating under similar conditions in actual use). While many early fuel cell applications may have had relatively constant operating conditions and therefore relatively consistent levels of carbon monoxide in the fuel stream, the potential applications for fuel cells are expanding. As a result, the carbon monoxide concentration in the fuel streams now tends to vary for many reasons (e.g., depending on reformer temperature, or fuel cell and/or reformer load demand conditions).
A low output voltage from one or more of the fuel cells in a fuel cell system might be used as an indicator of carbon monoxide poisoning. Preferably perhaps, a sensor cell might be incorporated in the fuel cell system for this purpose. As described in U.S. Provisional Patent Application Ser. No. 60/091,531 filed Jul. 2, 1998, by the same applicant as the present application and previously incorporated herein by reference in its entirety, a sensor cell can be incorporated whose performance is more sensitive to carbon monoxide poisoning than other fuel cells in the fuel cell system. Thus, a sensor cell can be used to indicate an abnormal or undesirable operating condition (e.g., high level of CO) before it affects the performance of the other fuel cells.
U.S. patent application Ser. No. 08/998,133, filed Dec. 23, 1997, by the same applicant as the present application, discloses a fuel cell operating method in which a substantially fuel-free liquid (which may contain oxygen) is periodically introduced into the fuel stream in order to cause a fuel starved condition.

Method for operating fuel cells on impure fuels


The invention is an improved cooling system for an internal combustion engine wherein an expansion and degasification tank is placed in the cooling system allowing the liquid containing gases to enter the degasification portion of the tank tangentially thereby creating a swirling vortex flow of the coolant containing gases. The coolant is permitted to leave the degasification portion through a peripheral annular gap in the lower part of the tank created by a conical deflector which collects the gases in the coolant and is arranged so as to permit the gases to pass to the expansion of the tank. A check valve mounted in the outlet of the expansion tank prevents any backflow of liquid. Further, the gases are allowed to escape into the atmosphere through a pressure release valve mounted to the top portion of the expansion chamber. The expansion chamber and the degasification chamber may be separated so as to place the degasification chamber at any height in relation to the engine and the radiator without adversely affecting its function.

1. Field of the Invention
The present invention concerns an improved cooling system for an internal combustion engine.
2. Description of the Prior Art
The cooling systems of internal combustion engines which are found today on modern industrial vehicles almost all include systems ensuring both the degasification of the cooling liquid and the recovery of the liquid in an expansion tank.
Such systems are well known, for example by the application for a French patent made by the present applicant on May 28, 1975 with the number 75 16 888, in which an attempt was made to reduce the dimensions of the expansion tank to facilitate its installation on the vehicle.
In fact, it is well known that this is a major difficulty, especially in the case of vehicles with forward cabs. It is difficult to locate the degasification tanks above the level of the radiator.

Cooling system for an internal combustion engine