A cyclic internal combustion engine having at least one working piston and cylinder arrangement which includes separate compression, combustion, and expansion chambers that perform respective compression combustion and expansion cycles. The compression cycle is advanced up to 180xc2x0 in relation to the expansion cycle, so as to extend the combustion cycle during the exhaust stroke to reduce the formation in the combustion cycle of polluting gases.

The invention relates to a cyclic internal combustion engine with an independent and constant-volume combustion chamber.
Cyclic internal combustion engines with an independent combustion chamber and separate compression and expansion chamber as described in French Patents 2319769 or alternatively 2416344 allow a certain number of improvements to be made to the operation compared with conventional engines. In this type of engine, inlet and compression take place in a chamber controlled by a piston, whereas expansion and exhaust take place in another chamber; the independent combustion chamber is connected to these chambers by ducts equipped with shutters. However, the variable volumes of these two chambers are controlled cyclically in phase and the time available for the combustion and transfer of the gaseous masses is particularly short and does not allow complete combustion to be achieved as is achieved in conventional engines.
The engine according to the invention makes it possible to alleviate this shortcoming and to make a considerable improvement in the operation of this type of engine; it is characterized by the means employed, and more specifically by the fact that the compression chamber cycle, which comprises inlet and compression, is advanced in relation to the expansion chamber cycle which comprises expansion and exhaust so that it is possible to obtain a combustion time which is far longer than in conventional engines; as a tangible example, in a conventional engine and in the engines described in the aforementioned patents, the combustion of their charge takes place over approximately 30 to 45xc2x0 of rotation of their engine shaft, whereas with the engine procedure according to the invention there are up to 180xc2x0 of rotation available (during the exhaust stroke) in which to fill the chamber and burn the mixture, and this, depending on the mode of filling used, may allow combustion periods of the order of 150xc2x0 or even 160xc2x0 of rotation of the engine shaft. Furthermore, and in order to avoid heat loss through the walls during this lengthy combustion, the chamber will or may be coated with a thermal barrier made of ceramic or other heat-insulating materials so as not to lose heat through the walls which can thus be very hot; likewise it will be particularly advantageous, this also for the same reasons, for the walls of the expansion chamber (piston crown, roof of the chamber, transfer duct, etc.) to be coated with a thermal barrier made of ceramic or other heat-insulating materials.
The operation of the engine according to the invention and the improvements made over conventional engines and over the engines described in the aforementioned patents will now be understood. The interdependency, in particular, in terms of compression chamber and expansion chamber cycle, and the thermal protection of the combustion chamber and/or of the expansion chamber allow combustion periods 3 to 4 times longer than those of conventional engines to be achieved without significant heat loss, and thus allow the efficiency to be improved; incidentally, it is also possible with this arrangement to be able to produce a combustion chamber which does not depend, at its base, on the diameter of the piston, and thus to approximate to or to achieve the ideal spherical shape without roughnesses or xe2x80x9ccornersxe2x80x9d in which the gases do not burn and produce unburnt hydrocarbons.
These combined advantages of a long combustion period, of a compact combustion chamber shape close to that of a sphere without roughnesses or corners, thermally insulated with hot walls make it possible to obtain emissions of pollutants in the exhaust which are far lower than in conventional engines.
According to another embodiment of the invention, it is possible to form between the compression chamber and the combustion chamber a buffer volume in which compressed air is accumulated which will make it possible to avoid surge effects and pressure drops due to the dead transfer volumes and to the expansion during the filling of the combustion chamber.
The mode of operation of the compressor can therefore vary without this in any way altering the principle of the invention; although in common practice it seems convenient to employ a reciprocating compressor, any other mode of producing compressed air may be usedxe2x80x94a single or multi-stage reciprocating compressor, a rotary vane compressor, a Roots-type blower or Lyshom type compressor or a turbocompressor driven by the exhaust gases. Likewise, for certain applications it is possible to employ a reserve of air from a cylinder (or other container) which will be expanded in the combustion chamber, or even compressed air from a main (in the example of a stationary engine used in a factory employing compressed air from a main).
The mode of operation of the expansion chamber can also vary without this in any way altering the principle of the invention; although in practice it also seems convenient to employ a piston sliding in a cylinder and driving a crankshaft via a connecting rod, any rotary encapsulation system can also be usedxe2x80x94rotary with radial vanes, with rotary piston such as the path of a conchoid of a circle or of a trochoid, etc.
The engine according to the invention operates with homogeneous air-fuel mixtures and the mixing can be achieved using a carburetor prior to inlet into the compressor, but it is preferable to have a fuel-injection (electronic or mechanical) system between the compressor and the combustion chamber, although direct injection into the combustion chamber can also be used without that in any way altering the operating principle.
The engine according to the invention also operates with heterogeneous self-igniting mixtures like in diesel engines. In this case, the spark plug fitted into the chamber is omitted and a direct diesel injector supplied by a pump and its equipment of a type commonly used in diesel engines is fitted into the said combustion chamber.
Incidentally, there may be inserted at least two separate combustion chambers operating in exactly the same way as the one described hereinabove and which can be supplied together, separately or alternately in order to improve the thermodynamic efficiency at light loadxe2x80x94for example using just one chamber for used power levels below half the total power of the engine, and using both chambers above that value.

Internal combustion engine with constant-volume independent combustion chamber


An inflated floating bridge piece is provided for use on eyeglass frames to increase comfort, reduce slippage and allow for height adjustment of the glasses. The bridge piece is in the form of a resilient, hollow member having one or more air chambers in an inverted U shape adapted to fit over the bridge of the nose in place of conventional eyeglass bridges. The inner wall of the bridge is thinner than the outer wall to provide control over bridge pressure and an adjustment plate bears against the cross piece to selectively adjust the pressure in the chamber or chambers.

1. Field of the Invention
This invention relates generally to nose pieces for eyeglasses and more particularly is directed towards a new and improved, variable pressure, inflated bridge piece for eyeglass frames.
2. Description of the Prior Art
A conventional eyeglass frame is supported on the bridge of the nose by means of a bridge piece which may be an integral part of the frames or may be in the form of pads fixed or on a swivel to provide some self adjustment between the frames and the nose. In either event, bridge pieces on conventional eyeglass frames have a number of disadvantages in that frequently they will allow the frame to slip down the nose so that the lenses move out of optimum optical position with respect to the eyes. Furthermore, conventional bridge pieces tend to be uncomfortable particularly after wearing the glasses for a long period of time and most such standard pieces cannot be adjusted as to width and height with the result that, unless the glasses are fitted properly and exactly at the outset, there is very little that can be done to correct for a poor fit.
While various types of devices have been proposed to improve the comfort and to provide some form of adjustability, none has been satisfactory from the standpoint of practicality, simplicity, cost and effectiveness.
Accordingly, it is an object of the present invention to provide a new and improved nose piece for eyeglass frames. Another object of this invention is to provide a nose piece for an eyeglass frame which is both comfortable and adjustable to permit the frames to be raised or lowered selectively for optimum lens position. A further object of this invention is to provide a nose piece for eyeglass frames which is comfortable, adjustable, simple and low cost and adapted to prevent the glasses from slipping along the nose.


A process plant data collection and viewing system uses a common or integrated navigational tree structure and one or more common display formats to enable a user to view, in a similar and consistent manner, information obtained from different applications or data sources within a process plant at any desired level of integration, even though the actual data from the multiple different data applications or data sources may be collected and organized in different manners by different data sources. Because a common visualization of information is provided at different levels of data integration, a user can easily navigate through the data stored in the database or collected by the different data sources at higher or lower levels of data integration without having to contend with or encounter multiple different viewing formats for the same type of data.

Process plants, such as those used in chemical, petroleum or other industries, typically include one or more centralized or decentralized process controllers communicatively coupled to at least one host or operator workstation and to one or more process control and instrumentation devices, such as field devices, via analog, digital or combined analog/digital buses. Field devices, which may be, for example valves, valve positioners, switches, transmitters, and sensors (e.g., temperature, pressure and flow rate sensors), perform functions within the process such as increasing or decreasing fluid flow and measuring process parameters. The process controller receives signals indicative of process measurements or process variables made by or associated with the field devices and/or other information pertaining to the field devices, uses this information to implement a control routine and then generates control signals which are sent over one or more of the buses or other communication lines to the field devices to control the operation of the process. Information from the field devices and the controller is typically made available to one or more applications executed by operator workstations to enable an operator to perform desired functions with respect to the process, such as viewing the current state of the process, modifying the operation of the process, etc.
While a typical process plant has many process control and instrumentation devices, such as valves, transmitters, sensors, etc. connected to one or more process controllers which execute software that controls these devices during the operation of the process, there are many other supporting devices which are also necessary for or related to process operation. These additional devices include, for example, power supply equipment, power generation and distribution equipment, rotating equipment such as turbines, etc., which are located at numerous places in a typical plant. While this additional equipment does not necessarily create or use process variables and, in many instances, is not controlled or even coupled to a process controller for the purpose of affecting the process operation, this equipment is nevertheless important to and ultimately necessary for proper operation of the process.
As a result, many process plants, and especially those which use smart field devices, include applications that are used to help monitor and maintain the devices within the plant regardless of whether these devices are process control and instrumentation devices or are other types of devices. For example, the Asset Management Solutions (AMS) application sold by Emerson Process Management, enables communication with and stores data pertaining to field devices to ascertain and track the operating state of the field devices. An example of such a system is disclosed in U.S. Pat. No. 5,960,214 entitled "Integrated Communication Network for use in a Field Device Management System." In some instances, the AMS application may be used to communicate with devices to change parameters within the device, to cause the device to run applications on itself, such as self calibration routines or self diagnostic routines, to obtain information about the status or health of the device, etc. This information may be stored and used by a maintenance person to monitor and maintain these devices. Likewise, there are other types of applications which are used to monitor other types of devices, such as rotating equipment and power generation and supply devices. These other applications are typically available to the maintenance persons and are used to monitor and maintain the devices within a process plant. In many cases, however, outside service organizations may perform services related to monitoring process performance and equipment. In these cases, the outside service organizations acquire the data they need, run typically proprietary applications to analyze the data and merely provide results and recommendations to the process plant personnel.
Still further, many process plants have other computers associated therewith which execute applications related to business functions or maintenance functions. For example, some plants include computers which execute applications associated with ordering raw materials, replacement parts or devices for the plant, applications related to forecasting sales and production needs, etc.
Typically, the functions associated with the process control activities, the device and equipment maintenance and monitoring activities, and the business activities are separated, both in the location in which these activities take place and in the personnel who typically perform these activities. Furthermore, the different people involved in these different functions generally use different tools, such as different applications run on different computers, to perform the different functions. In many instances, these different tools collect or use different types of data associated with or collected from the devices or equipment within the process and are set up differently to collect the data they need. For example, process control operators who generally oversee the day to day operation of the process and who are primarily responsible for assuring the quality and continuity of the process operation typically affect the process by setting and changing set points within the process, tuning loops of the process, scheduling process operations such as batch operations, etc. These process control operators may use available tools for diagnosing and correcting process control problems within a process control system, including, for example, auto-tuners, loop analyzers, neural network systems, etc. Process control operators also receive process variable information from the process via one or more process controllers which provide information to the operators about the operation of the process, including alarms generated within the process. Still further, it is typical to provide control optimizers, such as real time optimizers, within a plant to optimize the control activities of the process plant. Such optimizers typically use complex models of the plant to predict how inputs may be changed to optimize operation of the plant with respect to some desired optimization variable such as, for example, profit. While this information may be provided to the process control operator via standard user interface devices, the process control operators are generally interested in viewing and accessing the information within the applications based on how the process plant is set up and configured from a control standpoint.
On the other hand, maintenance personnel who are primarily responsible for assuring that the actual equipment within the process is operating efficiently and for repairing and replacing malfunctioning equipment, use tools such as maintenance interfaces, the AMS application discussed above, as well and many other diagnostic tools which provide information about operating states of the devices within the process. Maintenance persons also schedule maintenance activities which may require shut down of portions of the plant. For many newer types of process devices and equipment, generally called smart field devices, the devices themselves may include detection and diagnostic tools which automatically sense problems with the operation of the device and automatically report these problems to a maintenance person via a standard maintenance interface. For example, the AMS software reports device status and diagnostic information to the maintenance person and provides communication and other tools that enable the maintenance person to determine what is happening in devices and to access device information provided by devices. Typically, maintenance interfaces and maintenance personnel are located apart from process control operators, although this is not always the case. For example, in some process plants, process control operators may perform the duties of maintenance persons or vice versa, or the different people responsible for these functions may use the same interface. None-the-less, maintenance personnel are typically interested in viewing and accessing the information from the applications available thereto based on how the equipment is set up or located in the plant, or on other logical bases related to the equipment within the plant. This organization is typically different than the control organization.
Still further, some tasks, such as monitoring equipment, testing the operation of devices, determining if the plant is running in an optimal manner, etc. are performed by outside consultants or service companies who measure the data needed, perform an analysis and then provide only the results of the analysis back to the plant personnel. In these cases, the data is typically collected and stored in a proprietary manner and may be organized in a still different manner as the organization of the data is geared to the particular application that is collecting, generating and using the data.
Many of the different applications discussed above use a navigational tree or other similar structure for organizing and enabling a user of the application to view and access the different data or information within or available to the application. In most cases, these navigational tree structures are similar in nature to the navigational tree structures used in Microsoft Outlook™, Windows™, etc., and are provided in these applications to enable a user to access or drill down into a relevant area, subarea, etc., of the plant to perform functions using the application. Usually, although not always, the applications use a navigational tree structure with nomenclature provided by the S88 standard, which logically divides a process plant into smaller and smaller entities, as, starting at the highest level, Enterprise, Site, Area, Process Cell, Unit, Equipment Module and Control Module. Applications using a navigational tree structure based on the S88 standard may provide some or all of these headings within a navigational tree to enable a user to access information or perform functions associated with the process plant.
Unfortunately, each of the different applications is generally different in the manner in which it uses and applies this navigation tree structure, including the names and, sometimes, the meaning of the names used therein, and is different in the manner in which it provides views of the data collected by that application. Thus, system level software applications provided for different uses within a plant, such as control applications, maintenance applications, optimization applications, power equipment monitoring applications, efficiency or plant monitoring applications, etc., may and generally do have a different way of organizing the data associated therewith. Moreover, customers may have a still different preferred manner of organizing the information pertaining to their plant, that may differ from any organization provided in any of the applications used in the plant.
Currently, plant operators, maintenance personnel, etc. must become accustomed to and remember the different manner in which the same or different information for a plant is available in and organized within the different applications used in the plant, even though, in some instances, some of the same information is stored in and used by those different applications. This makes cross use of these applications tedious and sometimes confusing. Furthermore, it makes it very difficult to organize the information provided from different applications in a single and consistent manner, or to enable a user to view the information from different sources, i.e., applications, using a single navigational tool.
However, there is currently a need by some users, such as persons responsible for business applications, like those which order parts, supplies, raw materials, or which assist in making strategic business decisions such as choosing which products to manufacture, what variables to optimize within the plant, etc., to have access to data from more than one of the applications discussed above, to thereby understand or view the operation of the plant from a higher level than provided by any of the individual applications within the plant. While, in the past, these persons have not had much access to the actual data generated within the plant by the different applications, U.S. patent application Ser. No. 10/087,308, entitled "Data Sharing in a Process Plant," filed Mar. 1, 2002 and assigned to the assignee hereof, the disclosure of which is hereby expressly incorporated herein, discloses a method of combining the data from various different sources of data in a central database to make that data available on a more general basis to business personnel, as well as to the different users and applications within the process plant.
However, as noted above, the different applications collecting this data are designed to be used within the process plant to perform very different functions on, typically, a subset of the devices or equipment within the plant. The applications are, therefore, developed to organize and provide viewing of the data collected and generated thereby in sometimes slightly different and in sometimes very different manners. As a result, while these applications can share data with one another and with a centralized database, there is no simple technique of organizing the shared data in a manner that makes sense or is easy to use by a person viewing or accessing all of the data from the different applications or a way of presenting that data to a user in an organized and easily understood manner.

Data visualization within an integrated asset data system for a process plant


A sump-lubricated internal combustion engine equipped with exhaust gas recycle, lubricated with (a) an oil of lubricating viscosity, (b) 0.05 to 1 percent by weight of an amide of an aliphatic carboxylic acid, and (c) at least one additional dispersant, detergent, or anti-wear agent, exhibits reduced temperature of the lubricant in the sump.

The present invention relates to lubricating an internal combustion diesel engine which is equipped with an exhaust gas recirculation system (exhaust gas recycle) with a lubricant which includes an amide, leading to lower sump temperature of the lubricant.
Various techniques to abate emissions of such materials as nitrogen oxides and particulate matter, from engines, and in particular, heavy duty diesel engines, have been also developed. One of these methods is the installation of exhaust gas recirculation (EGR) systems. An EGR system recycles part of exhaust gases into the intake air stream. EGR has been used for the control of nitrogen oxide emissions for light duty diesel and gasoline engines. However, this approach has not been widely adopted for heavy duty diesel engines because of various problems, such as decreased durability and reliability of the engine and deterioration of the lubricant which have been associated with EGR. These and related difficulties are believed to arise, in part, because of the increased engine and lubricant temperatures encountered in such engines, due to the recycling of a portion of hot exhaust gas.
The present invention, therefore, addresses the problem of excessive lubricant sump temperature in diesel engines with an exhaust gas recirculation system by including within the lubricant an amide of an aliphatic carboxylic acid. This permits reduction of the lubricant temperature, leading to an increase in its useful lifetime, or, alternatively, recycling of a larger fraction of the exhaust gas without an unacceptable increase in the lubricant temperature.
The use of aliphatic amides as a friction modifier component of engine lubricants is generally known and are disclosed, for example, in U.S. Pat. No. 5,652,201 However, the use of aliphatic amides in engines without EGR has been shown to tend to lead at times to valve train wear, and thus such materials are not often used. It has now been observed that, for reasons that are not entirely understood, valve train wear is not such a problem in engines with EGR when aliphatic amide is present. This opens the possibility for use of such amines, as in the present invention, for the reduction of oil temperature, a possibility which is precluded in practice for engines without EGR.
The present invention provides a method for lubricating a sump-lubricated internal combustion diesel engine equipped with an exhaust gas recirculation system, comprising supplying to said engine a lubricating oil composition comprising:
(a) an oil of lubricating viscosity;
(b) about 0.05 to about 1 percent by weight of an amide of an aliphatic carboxylic acid, said acid containing 6 to 28 carbon atoms; and
(c) at least one additional additive selected from the group consisting of dispersants, detergents, anti-wear agents;
whereby the oil-sump temperature or the piston liner temperature is reduced under operating conditions, compared to that of a comparable composition without component (b).
Various preferred features and embodiments will be described below by way of non-limiting illustration.
The present invention is particularly suitable for use in a diesel engine with exhaust gas recycle, such as a passenger car diesel engine or, especially, a heavy duty diesel engine with exhaust gas recycle. The construction of such engines and such exhaust gas recycle systems is well known and is described in detail, for example, in Leet et al., SAE Technical Paper 980179, xe2x80x9cEGR""s Effect on Oil Degradation and Intake System Performance,xe2x80x9d Feb. 23-26, 1998, especially pages 57-59, and McKinley, SAE Technical Paper 970636, xe2x80x9cModeling Sulfuric Acid Condensation in Diesel Engine EGR Coolers,xe2x80x9d Feb. 24-27, 1997, especially page 207; and references cited in each.
Diesel engines typically consume hydrocarbon fuels, normally referred to as diesel fuels. Recently, water-blend fuels (hydrocarbons blended with up to e.g. 20% water, with appropriate emulsifiers and other additives) have been used. The method of the present invention is useful for engines consuming any of these fuels, including low sulfur diesel fuels and diesel fuels obtained from a Fischer-Tropsch process. Low sulfur diesel fuels can contain 15 or less parts per million sulfur.
The present invention relates to sump-lubricated engines, that is, those in which the lubricant is retained in a sump or reservoir from which it is circulated to and through the engine. This is in contrast to systems, characteristic of certain two-stroke cycle engines, in which the lubricant is mixed with the fuel and the fuel-lubricant mixture passes through the engine only once before being consumed.
The engines in which the present invention can be used are typically compression-ignited (diesel) engines. It is especially useful in heavy duty diesel engines, although benefits are also observed in other engines including small diesel engines. The distinction between heavy duty and small diesel engines is principally one of piston displacement within the engine cylinders. Small diesel engines, typically used in passenger cars, particularly in Europe, normally have a displacement of less than 3L, typically up to 2.5L, and commonly below 2L. In contrast, heavy duty diesel engines are typically used in trucks and off-road vehicles and will normally have a displacement of 3L or greater, typically 6 to 12 L or even greater, particularly for certain off-road vehicles.
The first component of the lubricant is an oil of lubricating viscosity, including natural or synthetic or semisynthetic lubricating oils and mixtures thereof. Natural oils include animal oils, vegetable oils, mineral lubricating oils of paraffinic, naphthenic, or mixed types, solvent or acid treated mineral oils, and oils derived from coal or shale. Synthetic lubricating oils include hydrocarbon oils, halo-substituted hydrocarbon oils, alkylene oxide polymers (including those made by polymerization of ethylene oxide or propylene oxide), esters of dicarboxylic acids and a variety of alcohols including polyols, esters of mono-carboxylic acids and polyols, esters of phosphorus-containing acids, polymeric tetrahydrofurans, and silicon-based oils (including siloxane oils and silicate oils). Included are unrefined, refined, and rerefined oils. Specific examples of the oils of lubricating viscosity are described in U.S. Pat. No. 4,326,972.
Lubricating oils have also been categorized as API Groups I, II, III, IV, and V, on the basis of parameters such as sulfur content, saturate content, and viscosity index. Group III oils are generally considered superior, in these categories to Group II, which is turn is superior to Group I. Group IV comprises all polyalphaolefins, and Group V comprises oils not included in the other groups. Group III base oils are also sometimes considered to be synthetic base oils, and for the purposes of this invention they can be considered to be included within the definition of xe2x80x9csynthetic base oils.xe2x80x9d Group III base oils are defined by the API Base Oil Interchange Guidelines as having the following minimum characteristics: xe2x89xa60.03% sulfur, xe2x89xa790% saturates, and xe2x89xa7120 viscosity index. These are generally oils which are derived from natural stocks (as opposed to being derived from synthetic sources), but are so highly refined that they can exhibit the performance and viscosity parameters of other synthetic base oils. The present invention can be used with any of these oils, although it is particularly useful with Groups II, III, and IV or with oils comprising groups III, IV, and V. It is also useful in base oils prepared by a Fischer-Tropsch process.
The lubricating oil will normally comprise the major amount of the composition used for the present invention. Thus it will normally be at least 50% by weight of the composition, preferably about 83 to about 98%, and most preferably about 88 to about 90%.
The lubricant composition will include at least one or more of the additives which are conventional for use in an engine oil lubricant, and in particular for a lubricant for diesel engines. A description of common lubricant additives can be found, for example, in Smalheer, Lubricant Additives, 1967 Lezius-Hiles Company, Cleveland. Among important additives are detergents, dispersants, corrosion inhibitors, antioxidants, pour point depressants, extreme pressure additives, and such miscellaneous additives as rust inhibitors and anti-foam agents. Numerous additives are also disclosed in European Patent Application 386 803A. Viscosity index improvers are also important and are often considered additives, although they are sometimes also considered as a part of the base oil, particularly when a multigrade oil is designated. In particular, the lubricant of the present invention will include at least one additive selected from the group consisting of dispersants, detergents, anti-wear agents. Preferably at least one of each of these components will be present.
Dispersants are well known in the field of lubricants and include primarily what are sometimes referred to as xe2x80x9cashlessxe2x80x9d dispersants because (prior to mixing in a lubricating composition) they do not contain ash-forming metals and they do not normally contribute any ash forming metals when added to a lubricant. Dispersants are characterized by a polar group attached to a relatively high molecular weight hydrocarbon chain.
One class of dispersant is Mannich bases. These are materials which are formed by the condensation of a higher molecular weight, alkyl substituted phenol, an alkylene polyamine, and an aldehyde such as formaldehyde. Such materials may have the general structure
(including a variety of isomers and the like) and are described in more detail in U.S. Pat. No. 3,634,515.
Another class of dispersant is high molecular weight esters. These materials are similar to the above-described Mannich dispersants or the succinimides described below, except that they may be seen as having been prepared by reaction of a hydrocarbyl acylating agent and a polyhydric aliphatic alcohol such as glycerol, pentaerythritol, or sorbitol. Such materials are described in more detail in U.S. Pat. No. 3,381,022.
Other dispersants include polymeric dispersant additives, which are generally hydrocarbon-based polymers which contain polar functionality to impart dispersancy characteristics to the polymer.
A preferred class of dispersants is the carboxylic dispersants. Carboxylic dispersants include succinic-based dispersants, which are the reaction product of a hydrocarbyl substituted succinic acylating agent with an organic hydroxy compound or, preferably, an amine containing at least one hydrogen attached to a nitrogen atom, or a mixture of said hydroxy compound and amine. The term xe2x80x9csuccinic acylating agentxe2x80x9d refers to a hydrocarbon-substituted succinic acid or succinic acid-producing compound (which term also encompasses the acid itself). Such materials typically include hydrocarbyl-substituted succinic acids, anhydrides, esters (including half esters) and halides.
Succinic based dispersants have a wide variety of chemical structures including typically structures such as
In the above structure, each R1 is independently a hydrocarbyl group, preferably a polyolefin-derived group having an {overscore (M)}n of 500 or 700 to 10,000. Typically the hydrocarbyl group is an alkyl group, frequently a polyisobutyl group with a molecular weight of 500 or 700 to 5000, preferably 1500 or 2000 to 5000. Alternatively expressed, the R1 groups can contain 40 to 500 carbon atoms and preferably at least 50, e.g., 50 to 300 carbon atoms, preferably aliphatic carbon atoms. The R2 are alkylene groups, commonly ethylene (C2H4) groups. Such molecules are commonly derived from reaction of an alkenyl acylating agent with a polyamine, and a wide variety of linkages between the two moieties is possible beside the simple imide structure shown above, including a variety of amides and quaternary ammonium salts. Succinimide dispersants are more fully described in U.S. Pat. Nos. 4,234,435 and 3,172,892.
The polyalkenes from which the substituent groups are derived are typically homopolymers and interpolymers of polymerizable olefin monomers of 2 to 16 carbon atoms; usually 2 to 6 carbon atoms.
The olefin monomers from which the polyalkenes are derived are polymerizable olefin monomers characterized by the presence of one or more ethylenically unsaturated groups (i.e.,  greater than Cxe2x95x90C less than ); that is, they are mono-olefinic monomers such as ethylene, propylene, 1-butene, isobutene, and 1-octene or polyolefinic monomers (usually diolefinic monomers) such as 1,3-butadiene, and isoprene. These olefin monomers are usually polymerizable terminal olefins; that is, olefins characterized by the presence in their structure of the group  greater than Cxe2x95x90CH2. Relatively small amounts of non-hydrocarbon substituents can be included in the polyolefin, provided that such substituents do not substantially interfere with formation of the substituted succinic acid acylating agents.
Each R1 group may contain one or more reactive groups, e.g., succinic groups, thus being represented (prior to reaction with the amine) by structures such as
in which y represents the average number of such succinic groups attached to the R1 group. In one type of dispersant, y=1. In another type of dispersant, y is greater than 1, preferably greater than 1.3 or greater than 1.4; and most preferably y is equal to or greater than 1.5. Preferably y is 1.4 to 3.5, especially is 1.5 to 3.5 and most especially 1.5 to 2.5. Fractional values of y, of course, can arise because different specific R1 chains may be reacted with different numbers of succinic groups.
The amines which are reacted with the succinic acylating agents to form the carboxylic dispersant composition can be monoamines or polyamines. In either case they will be characterized by the formula R4R5NH wherein R4 and R5 are each independently hydrogen, or hydrocarbon, amino-substituted hydrocarbon, hydroxy-substituted hydrocarbon, alkoxy-substituted hydrocarbon, amino, carbamyl, thiocarbamyl, guanyl, and acylimidoyl groups provided that only one of R4 and R5 is hydrogen. In all cases, therefore, they will be characterized by the presence within their structure of at least one Hxe2x80x94N less than  group. Therefore, they have at least one primary (i.e., H2Nxe2x80x94) or secondary amino (i.e., Hxe2x80x94N less than ) group. Examples of monoamines include ethylamine, diethylamine, n-butylamine, di-n-butylamine, allylamine, isobutylamine, cocoamine, stearylamine, laurylamine, methyllaurylamine, oleylamine, N-methyl-octylamine, dodecylamine, and octadecylamine.
The polyamines from which (C) is derived include principally alkylene amines conforming, for the most part, to the formula
wherein t is an integer preferably less than 10, A is a hydrogen group or a hydrocarbyl group preferably having up to 30 carbon atoms, and the alkylene group is preferably an alkylene group having less than 8 carbon atoms. The alkylene amines include principally methylene amines, ethylene amines, hexylene amines, heptylene amines, octylene amines, other polymethylene amines. They are exemplified specifically by: ethylene diamine, triethylene tetramine, propylene diamine, decamethylene diamine, octamethylene diamine, di(heptamethylene) triamine, tripropylene tetramine, tetraethylene pentamine, trimethylene diamine, pentaethylene hexamine, di(-trimethylene) triamine. Higher homologues such as are obtained by condensing two or more of the above-illustrated alkylene amines likewise are useful. Tetraethylene pentamines is particularly useful.
The ethylene amines, also referred to as polyethylene polyamines, are especially useful. They are described in some detail under the heading xe2x80x9cEthylene Aminesxe2x80x9d in Encyclopedia of Chemical Technology, Kirk and Othmer, Vol. 5, pp. 898-905, Interscience Publishers, New York (1950).
Hydroxyalkyl-substituted alkylene amines, i.e., alkylene amines having one or more hydroxyalkyl substituents on the nitrogen atoms, likewise are useful. Examples of such amines include N-(2-hydroxyethyl)ethylene diamine, N,Nxe2x80x2-bis(2-hydroxyethyl)-ethylene diamine, 1-(2-hydroxyethyl)piperazine, monohydroxypropyl)-piperazine, di-hydroxypropyl-substituted tetraethylene pentamine, N-(3-hydroxypropyl)-tetra-methylene diamine, and 2-heptadecyl-1-(2-hydroxyethyl)-imidazoline.
Higher homologues, such as are obtained by condensation of the above-illustrated alkylene amines or hydroxy alkyl-substituted alkylene amines through amino radicals or through hydroxy radicals, are likewise useful.
The carboxylic dispersant composition (C), obtained by reaction of the succinic acid-producing compounds and the amines described above, may be amine salts, amides, imides, imidazolines as well as mixtures thereof. To prepare the carboxylic dispersant composition (C), one or more of the succinic acid-producing compounds and one or more of the amines are heated, optionally in the presence of a normally liquid, substantially inert organic liquid solvent/diluent at an elevated temperature, generally in the range of 80xc2x0 C. up to the decomposition point of the mixture or the product; typically 100xc2x0 C. to 300xc2x0 C.
The succinic acylating agent and the amine (or organic hydroxy compound, or mixture thereof) are typically reacted in amounts sufficient to provide at least one-half equivalent, per equivalent of acid-producing compound, of the amine (or hydroxy compound, as the case may be). Generally, the maximum amount of amine present will be about 2 moles of amine per equivalent of succinic acylating agent. For the purposes of this invention, an equivalent of the amine is that amount of the amine corresponding to the total weight of amine divided by the total number of nitrogen atoms present. The number of equivalents of succinic acid-producing compound will vary with the number of succinic groups present therein, and generally, there are two equivalents of acylating reagent for each succinic group in the acylating reagents. Additional details and examples of the procedures for preparing the nitrogen-containing compositions of the present invention by reaction of succinic acid-producing compounds and amines are included in, for example, U.S. Pat. Nos. 3,172,892; 3,219,666; 3,272,746; and 4,234,435.
The dispersants may be borated materials. Borated dispersants are well-known materials and can be prepared by treatment with a borating agent such as boric acid. Typical conditions include heating the dispersant with boric acid at 100 to 150xc2x0 C. The dispersants may also be treated by reaction with maleic anhydride as described in PCT patent publication WO00/26327.
The amount of dispersant in the compositions used for the present invention can be 1 to 8 percent by weight, typically 3 to 5 percent by weight, and preferably 2 to 6 percent by weight.
Detergents are generally salts of organic acids, which are often overbased. Overbased salts of organic acids are typically metal salts, although non-metallic overbased salts are known. Overbased salts are widely known to those of skill in the art and generally include metal salts wherein the amount of metal present exceeds the stoichiometric amount. Such salts are said to have conversion levels in excess of 100% (i.e., they comprise more than 100% of the theoretical amount of metal needed to convert the acid to its xe2x80x9cnormalxe2x80x9d or xe2x80x9cneutralxe2x80x9d salt). They are commonly referred to as overbased, hyperbased or superbased salts and are usually salts of organic sulfur acids, organic phosphorus acids, carboxylic acids, phenols or mixtures of two or more of any of these. As a skilled worker would realize, mixtures of such overbased salts can also be used.
The terminology xe2x80x9cmetal ratioxe2x80x9d is used in the prior art and herein to designate the ratio of the total chemical equivalents of the metal in the overbased salt to the chemical equivalents of the metal in the salt which would be expected to result in the reaction between the organic acid to be overbased and the basic reacting metal compound according to the known chemical reactivity and stoichiometry of the two reactants. Thus, in a normal or neutral salt the metal ratio is one and, in an overbased salt, the metal ratio is greater than one. The overbased salts used as component (A) in this invention usually have metal ratios of at least 3:1. Typically, they have ratios of at least 12:1. Usually they have metal ratios not exceeding 40:1. Typically, salts having ratios of 12:1 to 20:1 are used.
Overbased compositions are well known. Overbased compositions can be prepared based on a variety of other well known organic acidic materials including sulfonic acids, carboxylic acids (including substituted salicylic acids), phenols, phosphonic acids, and mixtures of any two or more of these.
Preferred overbased materials include overbased phenates derived from the reaction of an alkylated phenol, preferably wherein the alkyl group has at least 6 aliphatic carbon atoms. The phenate is optionally reacted with formaldehyde or a sulfurization agent, or mixtures thereof, to provide a bridged or linked structure.
Other preferred overbased materials include metal overbased sulfonates derived from an alkylated aryl sulfonic acid wherein the alkyl group has at least about 15 aliphatic carbon atoms. Yet other preferred overbased materials include metal overbased carboxylates derived from fatty acids having at least about 8 aliphatic carbon atoms.
The basically reacting metal compounds used to make these overbased salts are usually an alkali or alkaline earth metal compound (i.e., the Group IA, IIA, and IIB metals excluding francium and radium and typically excluding rubidium, cesium and beryllium), although other basically reacting metal compounds can be used. Compounds of Ca, Ba, Mg, Na, K, and Li, such as their hydroxides and alkoxides of lower alkanols are usually used as basic metal compounds in preparing these overbased salts but others can be used as shown by the prior art referred to herein. Overbased salts containing a mixture of ions of two or more of these metals can be used in the present invention.
Overbased materials are generally prepared by reacting an acidic material (typically an inorganic acid or lower carboxylic acid, preferably carbon dioxide) with a mixture comprising an acidic organic compound, a reaction medium comprising at least one inert, organic solvent (such as mineral oil, naphtha, toluene, or xylene) for said acidic organic material, a stoichiometric excess of a base (typically a metal base), and a promoter. The acidic material used in preparing the overbased material can be a liquid such as formic acid, acetic acid, nitric acid, or sulfuric acid. Acetic acid is particularly useful. Inorganic acidic materials can also be used, such as HCl, SO2, SO3, CO2, or H2S, preferably CO2 or mixtures thereof, e.g., mixtures of CO2 and acetic acid.
A promoter is a chemical employed to facilitate the incorporation of metal into the basic metal compositions. The promoters are diverse and are well known in the art. A discussion of suitable promoters is found in U.S. Pat. Nos. 2,777,874, 2,695,910, and 2,616,904. These include the alcoholic and phenolic promoters, which are preferred. The alcoholic promoters include the alkanols of one to twelve carbon atoms such as methanol, ethanol, amyl alcohol, octanol, isopropanol, and mixtures of these. Phenolic promoters include a variety of hydroxy-substituted benzenes and naphthalenes. a particularly useful class of phenols are the alkylated phenols of the type listed in U.S. Pat. No. 2,777,874, e.g., heptylphenols, octylphenols, and nonylphenols. Mixtures of various promoters are sometimes used.
Patents specifically describing techniques for making basic salts of acidic organic compounds generally include U.S. Pat. Nos. 2,501,731; 2,616,905; 2,616,911; 2,616,925; 2,777,874; 3,256,186; 3,384,585; 3,365,396; 3,320,162; 3,318,809; 3,488,284; and 3,629,109.
One useful detergent compound is a metal saligenin derivative. Such materials have been described in detail in U.S. Pat. No. 6,310,009. These materials can be useful if a low-sulfur or sulfur-free detergent is desired. Other low-sulfur or sulfur free detergents include those formed from carboxylic acids, substituted phenols, and substituted salicylates. Also in this category are overbased calixarates, which are described, for example, in U.S. Pat. No. 6,174,844.
The amount of detergent in the compositions useful in the present invention can be 0.2 to 6 percent, typically 0.5 to 5 percent, preferably 1 to 3 percent by weight. The amount of detergent may also be 0%, or 0% metal-containing detergent, if an ashless formulation is desired.
Anti-wear additives include sulfur-, phosphorus-, or sulfur- and phosphorus-containing antiwear agents and boron-containing anti-wear agents. The term antiwear agent refers to compounds which provide wear protection properties to lubricating compositions and functional fluids. The antiwear agent is useful in controlling wear and may also act as an extreme pressure agent. These antiwear agents include sulfurized organic compounds, hydrocarbyl phosphates, phosphorus-containing amides, phosphorus-containing carboxylic esters, phosphorus-containing ethers, and dithiocarbamate-containing compounds.
In one embodiment, the antiwear agent is a sulfurized organic composition, preferably a sulfurized olefin such as a mono-, or disulfide or mixtures thereof. These materials generally have sulfide linkages having from 1 to 10 sulfur atoms, preferably 1 to 4, more preferably 1 or 2. Materials which can be sulfurized to form the sulfurized organic compositions of the present invention include oils, fatty acids or esters, olefins or polyolefins made thereof, terpenes, or Diels-Alder adducts. Details of methods of preparing some such sulfurized materials can be found in U.S. Pat. Nos. 3,471,404 and 4,191,659.
In one embodiment, the antiwear agent is a hydrocarbyl phosphate, such as a mono-, di- or trihydrocarbyl phosphate. Hydrocarbyl phosphates can be prepared by reacting a phosphorus acid or anhydride, preferably phosphorus pentoxide with an alcohol at a temperature of 30xc2x0 C. to 200xc2x0 C., preferably 80xc2x0 C. to 150xc2x0 C. The phosphorus acid is generally reacted with the alcohol in a ratio of 1:3.5, preferably about 1:3.
The hydrocarbyl phosphate can also be a hydrocarbyl thiophosphate. Thiophosphates may contain from one to three sulfur atoms, preferably one or two sulfur atoms. Thiophosphates are prepared by reacting one or more of the above-described phosphites with a sulfurizing agent including sulfur, sulfur halides, and sulfur containing compounds, such as sulfurized olefins, sulfurized fats, and mercaptans.
Metal salts of the formula
wherein R8 and R9 are independently hydrocarbyl groups containing 3 to 30 carbon atoms are readily obtainable by the reaction of phosphorus pentasulfide (P2S5) and an alcohol or phenol to form an O,O-dihydrocarbyl phosphorodithioic acid corresponding to the formula
The reaction involves mixing at a temperature of 20xc2x0 C. to 120 or 180xc2x0 C., four moles of an alcohol or a phenol with one mole of phosphorus pentasulfide. Hydrogen sulfide is liberated in this reaction. The acid is then reacted with a basic metal compound to form the salt. The metal M, having a valence n, generally is aluminum, lead, tin, manganese, cobalt, nickel, zinc, or copper, and most preferably zinc. The basic metal compound is thus preferably zinc oxide, and the resulting metal compound is represented by the formula
The R8 and R9 groups are independently hydrocarbyl groups that are preferably free from acetylenic and usually also from ethylenic unsaturation. They are typically alkyl, cycloalkyl, aralkyl or alkaryl group and have 3 to 20 carbon atoms, preferably 3 to 16 carbon atoms and most preferably up to 13 carbon atoms, e.g., 3 to 12 carbon atoms. The alcohols which react to provide the R8 and R9 groups can be one or more primary alcohols, one or more secondary alcohols, a mixture of secondary alcohol and primary alcohol. A mixture of two secondary alcohols such as isopropanol and 4-methyl-2-pentanol is often desirable.
Such materials are often referred to as zinc dialkyldithiophosphates or simply zinc dithiophosphates. They are well known and readily available to those skilled in the art of lubricant formulation.
In another embodiment, the antiwear agent can be a phosphorus-containing amide. Phosphorus-containing amides are generally prepared by reacting a phosphorus acids such as a phosphoric, phosphonic, phosphinic, or thiophosphoric acid with an unsaturated amide, such as an acrylamide. Preferably the phosphorus acid is a dithiophosphorus acid prepared by reacting a phosphorus sulfide with an alcohol or phenol to form dihydrocarbyl dithiophosphoric acid. Phosphorus-containing amides are known in the art and are disclosed in U.S. Pat. Nos. 4,876,374, 4,770,807 and 4,670,169.
Alternatively, the antiwear agent can be a dithiocarbamate-containing compound such as dithiocarbamate esters, dithiocarbamate amides, dithiocarbamic ethers, or alkylene-coupled dithiocarbamates. The dithiocarbamate amides, ether, and esters are prepared in a manner similar as that described above for phosphorus-containing amides and esters. Generally, the dithiocarbamic acid is reacted with an unsaturated amide, ether, or ester to form the dithiocarbamate-containing compounds. The dithiocarbamates used in making the dithiocarbamate-containing compound are prepared by reacting an amine with carbon disulfide or carbonyl sulfide. The dithiocarbamates are reacted with an unsaturated compound at 25xc2x0 C. to 125xc2x0 C., preferably 70xc2x0 C. to 90xc2x0 C. in the presence or absence of solvent. Lubricants containing alkylene dithiocarbamic compounds are described, for example, in U.S. Pat. No. 3,876,550.
Another type of anti-wear agent which can be used is a borate ester. The borate esters are well known to those skilled in the art and can be prepared by reacting of one or more of boron compounds with one or more alcohols. Typically, the alcohols contain from 6 to 30, or from 8 to 24 carbon atoms. The methods of making such borate esters are known to those in the art. Various types of borate esters and their methods of preparation are disclosed in greater detail in U.S. Pat. No. 5,883,057.
The amount of the antiwear agent can be typically 0.01 to 10 percent by weight of the composition, more commonly 0.1 to 2 percent. If the antiwear agent is a phosphorus-containing agent, it is frequently convenient to express its amount as the percent phosphorus contributed thereby to the composition. On that basis, the antiwear agent typically contributes 0.025 to 0.17 percent by weight phosphorus, preferably 0.05 to 0.143 percent, and more preferably 0.05 to 0.08 percent to the composition.
The total amount of the dispersant, detergent, and antiwear additive components in the present lubricants will typically be 3 to 15 percent by weight, preferably 4 to 10 percent, more preferably 5 to 9 percent.
The lubricating oil compositions of the present invention also may contain, particularly when the lubricating oil compositions are formulated into multi-grade oils, one or more viscosity modifiers. Viscosity modifiers generally are polymeric materials, typically hydrocarbon-based polymers generally having number average molecular weights between 25,000 and 500,000, more often between 50,000 and 200,000. Examples of suitable hydrocarbon polymers include homopolymers and copolymers of two or more monomers of C2 to C30, e.g., C2 to C8 olefins, including both alphaolefins and internal olefins, which may be straight or branched, aliphatic, aromatic, alkyl-aromatic, or cycloaliphatic. Frequently they will be copolymers of ethylene with C3 to C30 olefins, particularly preferred being the copolymers of ethylene and propylene. Other polymers can be used such as polyisobutylene, homopolymers and copolymers of C6 and higher alphaolefins, atactic polypropylene hydrogenated polymers and copolymers and terpolymers of styrene, e.g., with isoprene and/or butadiene.
Hydrogenated styrene-conjugated diene copolymers are another class of commercially available viscosity modifiers for motor oils. These polymers include polymers which may be described as hydrogenated or partially hydrogenated homopolymers, and random, tapered, star, or block interpolymers (including terpolymers and tetrapolymers). Examples of styrenes include styrene, alpha-methyl styrene, ortho-methyl styrene, meta-methyl styrene, para-methyl styrene, and para-tertiary butyl styrene. Preferably the conjugated diene contains four to six carbon atoms. Examples of conjugated dienes include piperylene, 2,3-dimethyl-1,3-butadiene, chloroprene, isoprene, and 1,3-butadiene, with isoprene and butadiene being particularly preferred. Mixtures of such conjugated dienes can also be used.
These copolymers are typically hydrogenated in solution so as to remove a substantial portion of their olefinic double bonds. It is preferred that these copolymers, for reasons of oxidative stability, contain no more than 5% and preferably no more than 0.5% residual olefinic unsaturation on the basis of the total number of carbon-to-carbon covalent linkages within the average molecule. These copolymers typically have number average molecular weights in the range of 30,000 to 500,000, preferably 50,000 to 200,000. Such hydrogenated copolymers have been described in U.S. Pat. Nos. 3,551,336; 3,598,738; 3,554,911; 3,607,749; 3,687,849; and 4,181,618.
Esters obtained by copolymerizing styrene and maleic anhydride in the presence of a free radical initiator and thereafter esterifying the copolymer with a mixture of C4-18 alcohols also are useful as viscosity modifying additives. The styrene esters generally are considered to be multi-functional premium viscosity modifiers. The styrene esters in addition to their viscosity-modifying properties also are pour point depressants and exhibit dispersancy properties when the esterification is terminated before its completion leaving some unreacted anhydride or carboxylic acid groups. These acid groups can then be converted to imides by reaction with a primary amine.
Polymethacrylates (PMA) are also used as viscosity modifiers. These materials are prepared from mixtures of methacrylate monomers having different alkyl groups. The alkyl groups may be either straight chain or branched chain groups containing from 1 to 18 carbon atoms. Most PMA""s are viscosity modifiers as well as pour point depressants.
When a small amount of a nitrogen-containing monomer is copolymerized with alkyl methacrylates, dispersancy properties are also incorporated into the product, and the resulting materials are often referred to as dispersant viscosity modifiers. Thus, such a product has the multiple function of viscosity modification, pour point depressancy and dispersancy. Such products have been referred to in the art as dispersant-type viscosity modifiers or simply dispersant-viscosity modifiers. Vinyl pyridine, N-vinyl pyrrolidone and N,Nxe2x80x2-dimethylaminoethyl methacrylate are examples of nitrogen-containing monomers. Polyacrylates obtained from the polymerization or copolymerization of one or more alkyl acrylates also are useful as viscosity modifiers.
The amount of the viscosity index modifier will typically be 0.5 to 7 percent by weight, or 0.5 to 2 percent, or 2 to 5 percent. In a synthetic base oil, the amount of viscosity modifier can often be reduced. The viscosity modifiers can be employed in varying amounts in various viscosity base oils in a known manner, to prepare multigrade oils of a variety of viscosities, including such grades as 0W-30, 5W-30, 10W-30, 10W-40, 15W-40, and others. Unmodified monogrades such as 20W, 30W, 40W, or 50W can also be used.
The formulation as thus far described can be considered to be a typical lubricant formulation for use in lubricating engines, in particular, diesel engines. Specific formulations of this type are disclosed for instance in U.S. Pat. Nos. 4,981,602, 5,328,620 and 5,595,964.
In addition to the components normally found in an engine lubricant, the lubricants suitable for use in the present invention also include a minor amount of an amide of an aliphatic carboxylic acid, said acid containing 6 to 28 carbon atoms. The amide can be based on such an acid and either an amine (secondary or, preferably, primary) or ammonia, although amides based on ammonia, that is, N-unsubstituted amides, are preferred.
The aliphatic carboxylic acids which form the amide can preferably contain 8 to 24, carbon atoms, or 12 to 20 carbon atoms, and preferably 14, 16, or 18 carbon atoms, or mixtures thereof. Acids with 18 carbon atoms, such as stearic acid and oleic acid, are useful. The resulting amides, if prepared with ammonia, are stearamide and oleamide. Commercial mixtures of amides, such as Armid O(trademark) from Akzo Nobel Chemicals can be used.
The amount of the amide in the lubricant is typically 0.05 to 1 percent by weight, preferably 0.1 to 0.6 percent by weight, and more preferably 0.1 or 0.2 to 0.4 percent by weight.
The compositions used in the present invention, may, if desired, be made compatible with diesel engine after treatment devices such as particulate filters or oxidation catalysts. Since such devices may require a low level of phosphorus and/or a low level of sulfated ash, the formulations of the present invention can be prepared using low phosphorus or phosphorus-free components and low ash or ashless components.
As used herein, the term xe2x80x9chydrocarbyl substituentxe2x80x9d or xe2x80x9chydrocarbyl groupxe2x80x9d is used in its ordinary sense, which is well-known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Examples of hydrocarbyl groups include:
hydrocarbon substituents, that is, aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic-, aliphatic-, and alicyclic-substituted aromatic substituents, as well as cyclic substituents wherein the ring is completed through another portion of the molecule (e.g., two substituents together form a ring);
substituted hydrocarbon substituents, that is, substituents containing non-hydrocarbon groups which, in the context of this invention, do not alter the predominantly hydrocarbon substituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulfoxy);
hetero substituents, that is, substituents which, while having a predominantly hydrocarbon character, in the context of this invention, contain other than carbon in a ring or chain otherwise composed of carbon atoms. Heteroatoms include sulfur, oxygen, nitrogen, and encompass substituents as pyridyl, furyl, thienyl and imidazolyl. In general, no more than two, preferably no more than one, non-hydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group; typically, there will be no non-hydrocarbon substituents in the hydrocarbyl group.
It is known that some of the materials described above may interact in the final formulation, so that the components of the final formulation may be different from those that are initially added. For instance, metal ions (of, e.g., a detergent) can migrate to other acidic sites of other molecules. The products formed thereby, including the products formed upon employing the composition of the present invention in its intended use, may not susceptible of easy description. Nevertheless, all such modifications and reaction products are included within the scope of the present invention; the present invention encompasses the composition prepared by admixing the components described above.

Use of an amide to reduce lubricant temperature


A system is provided for improving photoplethysmographic analyte measurements by de-emphasizing motion-contaminated data and/or emphasizing motion-free data. The system 100 is used in a measurement instrument which includes at least illumination source 104 for transmitting at least two light signals at two center wavelengths through a patient""s appendage 106 and a sensor 108 for converting the light signals transmitted through the appendage into electrical output signals. The system 100 includes a first buffer 116 configured to temporarily store at least one pulse cycle of output signals received from the sensor 108. A motion estimator 122 quantifies an amount of motion associated with the output signals stored in the first buffer 116 by performing a principal component analysis on differential absorption values derived from the output signals. Based on the amount of motion estimated, a weight application module 118 is configured to associate a weight with the output signals in the first buffer. The weighted output signals are transferred into a second buffer 120 which contains weighted output signals collected over multiple pulse cycles. An analyte computing module 126 computes blood analyte related values based on the weighted output signals stored in the second buffer 120.

The present invention generally relates to photoplethysmographic measurement systems, and, in particular, to a method and system for improving photoplethysmographic analyte measurements by preprocessing measurement data to compensate for measurement artifact such as by de-weighting motion-contaminated data.
In the field of photoplethysmography, light pulses from different portions of the electromagnetic spectrum are used to noninvasively determine various blood analyte related values, such as blood oxygen saturation, in test subjects. Typically, photoplethysmographic measurement systems, such as pulse oximeters, include a probe for releasably attaching to the tip of a patient""s appendage (e.g., a finger, earlobe or the nasal septum). The probe directs light signals into the appendage where the probe is attached. Some portion of the light is absorbed by the tissue and a remaining portion of the light passes through patient tissue. The intensity of light passing through the tissue is monitored by a sensor typically contained in the probe. The intensity related signals produced by the sensor are used to compute blood analyte related values.
During a medical examination, measurements such as blood oxygen saturation levels computed by the pulse oximeter can be distorted by various factors including movement of the appendage where the probe is attached. For example, the movement of the patient may affect source/detector alignment, ambient light levels, blood volume fluctuation or other factors, thus resulting in potential measurement errors. Some instrument designs have attempted to address such artifact through the use of hardware such as filters to screen the detector signals. However, such approaches have generally had a limited ability to distinguish artifact components of the signal from desired information, resulting in loss of information and/or admission of substantial artifact into the data used for calculations.
There is a particular need for a photoplethysmographic measurement instrument that is capable of accurately analyzing the quality of output signals produced by an instrument sensor so that appropriate steps may be taken to improve photoplethysmographic analyte related measurements computed by the instrument. In particular, there is a need for a system with improved ability to distinguish artifact from desired information and to preprocess the data based on such distinction so as to enhance overall instrument performance.
The present invention is directed to a system and corresponding method for use in a pulse oximeter to improve the way in which data output by a pulse oximeter sensor, such as data representing a pulse waveform, is preprocessed prior to the computation of blood oxygen saturation levels. The present system quantifies artifactual components (e.g., motion artifact) contained in a set of data aggregated over a certain time interval (e.g., one or more pulse cycles or portions thereof or simply a given predetermined time interval) and preprocesses the set of data such that the effect of artifactual components is reduced. The blood oxygen saturation levels may be computed based on multiple sets of preprocessed data so as to improve the accuracy of the pulse oximetry measurements.
In accordance with one aspect of the present invention, an apparatus for evaluating the reliability of output signals produced by a pulse oximeter sensor is provided. Electrical output signals produced by the sensor may be captured at a defined interval. Each captured set of signals may be analyzed independently to estimate a degree of artifactual component reflected in the set of output signals. Unreliable sets of output signals can be addressed in a variety of ways. In one embodiment, a weight metric may be generated which accurately reflects the degree of artifactual component in the output signals. The weight metric may then be used to relatively emphasize or de-emphasize each set of output signals in proportion to the degree of artifactual component estimated such that the sets of output signals used in the blood analyte computation are dominated by output signals with a relatively small artifactual component. In another embodiment, sets of output signals that are deemed to be unreliable, i.e., the degree of artifactual component associated therewith exceeds a certain threshold, may be excluded from the blood analyte computation.
In accordance with a related aspect of the present invention, motion affected data is identified based on a numerical or mathematical analysis of the data. The electrical output signals generated by the photodetector may be separated into red and infrared data by a hardware or software based demultiplexer. The reliability of output signals may be evaluated on the basis of data points derived from separated red and infrared pulse waveforms. The motion contained in output signals produced by the pulse oximetry sensor may be quantified based on spread of the data points, e.g., from a regression model such as a best-fit linear regression line. In one embodiment, the red and infrared pulse waveforms are used to acquire differential absorption values dAx and dAy respectively. Each pulse cycle is represented by a set of data points, where each data point represents a pair of corresponding differential absorption values dAx and dAy obtained at a specific point in time within each pulse cycle. A principal component analysis (xe2x80x9cPCSxe2x80x9d) may be performed on each set of data points to estimate an amount of motion affecting the data. First and second principal components derived from the PCA account for different amounts of variation among the set of data points. The first principal component may describe the cluster of data points disposed along a longitudinal axis and the second principal component may describe the amount of spread of the data points with respect to the longitudinal axis. An amount of motion associated with a set of data points may be approximated by multiplying the RMS (Root Mean Square) variation along the axis of the first principal component by the RMS variation along the axis of the second principal component.
According to another related aspect of the invention, a method is provided for distinguishing motion artifact from the plethysmographic signal. It has been recognized that the artifact due to motion can be distinguished from other data anomalies because motion affects tend to be relatively evenly distributed over multiple channels (a channel being the electronic or digital data received from any given emitter in a photoplethysmographic system). Accordingly, motion effects can be identified and quantified by mathematically accounting for a corresponding bias or tendency in the data. For example, if two channels of data are plotted against one another over a set of samples, motion effects tend to be reflected by a slant, e.g., an approximately 45-degree bias in the data spread since some common types of motion tend to induce similar amounts of artifact into each channel (actually into the dA""s calculated from the channel data), while the plethysmographic signal will tend to spread the data at some other angle determined by blood analyte levels. It will be appreciated that such effects may be identified mathematically rather than graphically. In this regard, each data point generally includes a plethysmographic content and a motion content. The motion content of a data point may be represented by a shift of the data point at a 45-degree angle, the amount of shift indicating the degree of motion affecting the data point. Simultaneously, the data will also be spread along some other angle which is determined by blood analyte levels. The random spreading of points in two directions expands the area occupied by the points. Thus, motion artifact present in a data point may be quantified based on the area filled by the spreading of the points. Typically, a set of data points may be characterized by a parallelogram, the boundary of which encompasses a majority of data points. The amount of motion associated with such set of data points may be estimated by approximating the area of the parallelogram which outlines the data points.
According to another aspect of the invention, one or more buffers or data storage units may be utilized to temporarily store data generated by a pulse oximeter so that the data may be accessed and manipulated by processing modules to improve the accuracy of analyte related computation such as an oxygen saturation level computation. In a preferred embodiment, dual buffer system architecture is utilized. A first buffer is used to temporarily store a set of data representing at least one pulse cycle or other time period of data from a pulse oximetry sensor. A first processing module accesses the raw data stored in the first buffer to preprocess the raw data and yield preprocessed data. The preprocessed data can then be used, on a set-by-set or aggregated basis, to make the desired analyte related computations. For example, each set of preprocessed data may be transferred into a second buffer which is adapted to temporarily store multiple sets of preprocessed data most recently received from the first processing module.
The dual buffer system architecture of the present invention may be used for various purposes. For example, the data output by the sensor may be processed to eliminate, de-weight, or otherwise address data components that are not representative of the desired analyte related values, such as electronic noise, environmental noise, motion, or other artifact. In one embodiment, the first processing module may include a combination of a motion estimator and a weight application module. The motion estimator quantifies an amount of motion associated with the raw data stored in the first buffer by performing a principal component analysis on differential absorption values derived from the output signals. Based on the amount of motion estimated, the weight application module is configured to associate a weight with the raw data in the first buffer and transfer the weighted data to the second buffer. A second processing module may then assess multiple pulse cycles of improved data accumulated in the second buffer to perform its oxygen saturation level computation.
According to a further aspect of the invention, buffered or preprocessed data may be utilized to reduce the effect of artifactual component, such as motion artifact, in raw signal output by a pulse oximeter. A quantity of motion artifact identified in a set of input data, representing raw signals produced by a pulse oximeter sensor during a defined time period, may be utilized to selectively emphasize and/or de-emphasize the set of data based upon the quality of the data. In order to improve the accuracy of blood oxygen saturation computed by the pulse oximeter, the effect of data sets that are contaminated by an unacceptable amount of artifactual component may be substantially minimized or eliminated from the final computation thereof.
In one embodiment, a threshold value is used to distinguish between acceptable data (relatively free of motion) and unacceptable data (affected by motion). Data collected over each pulse cycle is considered in the blood analyte computation if the degree of motion associated therewith is below a threshold value. Otherwise, if the degree of motion exceeds the threshold, the data is discarded from further consideration in the final computation. In a preferred embodiment, weighting is used to either emphasize or de-emphasize data depending on the quantity of motion associated with the data. A quantity of motion content is estimated for each set of data stored in the first buffer. Then, a weight parameter is assigned to each set of data such that a motion-affected set of data may be relatively de-emphasized and/or a motion-free set of data is relatively emphasized. The blood analyte levels may be computed by performing a linear regression analysis on the weighted sets of data collected over multiple pulse cycles. In this regard, the slope of the best-fit line equation derived from the linear regression analysis provides an accurate blood oxygen level since the weighted sets of data are dominated by those with relative low motion content.
According to yet another aspect of the invention, processing logic may be utilized to compensate for motion-affected data. The process of estimating a quantity of motion and associating a weight parameter in proportion to the quantity of motion estimated may be embodied in the form of a software program or an executable set of instructions running on a processor. For example, a stream of pulse waveforms provided by the photodetector may be processed by a software routine configured to determine the quantity of motion artifact present in the raw data and manipulate the raw data in such a way as to produce an improved preprocessed data which more accurately reflects the actual blood oxygen saturation levels by reducing the effect of or eliminating raw data contaminated by undesirable artifactual content, i.e., due to movement of the patient.

Method and system for improving photoplethysmographic analyte measurements by de-weighting motion-contaminated data


The present invention relates to pharmaceutical compositions, kits, and methods of use thereof, comprising, a mutant human herpes simplex-type 1 virus, which is cytopathic to susceptible hyperproliferative cells, such as neoplastic cells. Preferably, the virus does not produce a fully functionally active wild-type ICP0 polypeptide coded for the IE gene 1.

From the early part of this century, viruses have been used to treat cancer. The approach has been two-fold; first, to isolate or generate oncolytic viruses that selectively replicate in and kill neoplastic cells, while sparing normal cells. Here investigators initially used wild type viruses, and this approach met with some, albeit, limited success. While oncolysis and slowing of tumor growth occurred with little or no damage to normal tissue, there was no significant alteration in the course of the disease. See, Smith et al., Cancer 9: 1211-1218 (1956), Cassel, W. A. et al., Cancer 18: 863-868 (1965), Webb, H. E. et al., Lancet 1: 1206-1209 (1966). See, also, Kenney, S and Pagano, J. J. Natl. Cancer Inst., vol. 86, no. 16, p.1185 (1994).
More recently, and because of the reoccurrence of disease associated with the limited efficacy of the use of wild type viruses, investigators have resorted to using recombinant viruses that can be delivered at high doses, and that are replication competent in neoplastic but not normal cells. Such viruses are effective oncolytic agents in their own right, and further, can be engineered to carry and express a transgene that enhances the anti neoplastic activity of the virus. An example of this class of viruses is an adenovirus that is mutant in the E1B region of the viral genome. See, U.S. Pat. No. 5,677,178, and Bischoff, J. R., D. H. Kim, A. Williams, C. Heise, S. Horn, M. Muna, L. Ng, J. A. Nye, A. Sampson-Johannes, A. Fattaey, and F. McCormick. 1996, Science. 274:373-6.
It is important to distinguish the use of replication competent viruses, with or without a transgene for treating cancer, from the second approach that investigators have used to treat cancer, which is a non-replicating virus that expresses a transgene. Here the virus is used merely as a vehicle that delivers a transgene which, directly or indirectly, is responsible for killing neoplastic cells. This approach has been, and continues to be the dominant approach of using viruses to treat cancer. It has, however, met with limited success, and it appears to be less efficacious than replicating viruses.
As mentioned above, to avoid damage to normal tissues resulting from the use of high dose viral therapy it is preferred that the virus have a mutation that facilitates its replication, and hence oncolytic activity in tumor cells, but renders it essentially harmless to normal cells. This approach takes advantage of the observation that many of the cell growth regulatory mechanisms that control normal cell growth are inactivated or lost in neoplastic cells, and that these same growth control mechanisms are inactivated by viruses to facilitate viral replication. Thus, the deletion or inactivation of a viral gene that inactivates a particular normal cell growth control mechanism will prevent the virus from replicating in normal cells, but such viruses will replicate in and kill neoplastic cells that lack the particular growth control mechanism.
The use of genetically engineered replication-competent herpes simplex virus-type 1 (HSV-1) has been reported as an anti-tumor agent. See, Martuza et al., Science 252: 854 (1991). Specifically, it was shown that HSV-1 thymidine kinase-deficient mutant, dlsptk, exhibited anti-tumor activity towards human malignant glioma cells in an animal brain tumor model. Unfortunately, the HSV-1 dlsptk virus produced significant encephalitis at the doses required to kill the tumor cells adequately. See, Markert et al., Neurosurgery 32: 597 (1993).
U.S. Pat. No. 5,585,096 describes a mutated, replication-competent herpes simplex virus-type 1 (HSV-1) which contains mutations in two genes, is sensitive to antiviral agents such as acyclovir, is not neurovirulent and does not replicate in non-dividing cells, yet can kill nervous system tumor cells. This herpes simplex virus mutant is incapable of expressing both a functional gamma 34.5 gene product and ribonucleotide reductase.
U.S. Pat. No. 5,728,379 describes a method for killing tumor cells in vivo with a replication competent herpes simples virus by the regulated expression of an essential immediate-early viral gene product.
U.S. Pat. No. 5,804,413 describes cell lines that express complementing levels of certain herpes simplex virus essential immediate early proteins
Although progress has been made in identifying and using viruses for treating disease, particularly cancer, there is obviously still a great need for more effective viruses.
An aspect of the invention is the description of a method for treating unwanted hyperproliferative cell growth in a cell population with an amount of a mutant herpes simplex virus which is lytic to the cells, wherein the virus does not produce a functionally active wild-type ICP0 polypeptide coded for by the IE gene 1.
Another aspect of the invention is the description of a method for treating neoplastic cells which over express Beta-catenin as compared to normal cells of the same histological type with an effective amount of a mutant human herpes simplex virus, wherein the virus does not produce a functionally active wild-type ICP0 polypeptide coded for by the IE gene 1.
A further aspect of the invention is the description of pharmaceutical compositions consisting of a mutant human herpes simplex virus, wherein the virus does not produce a functionally active wild-type ICP0 polypeptide coded for the IE gene 1.
Another aspect of the invention is a method of identifying cells which overexpress Beta-catenin by administering to the cells an effective amount of a mutant human herpes simplex virus, wherein the virus does not produce a functionally active wild-type ICP0 polypeptide coded for the IE gene 1.
These and other aspects of the invention will become apparent upon a full consideration of the disclosure set forth herein.

Herpes simplex virus for treating unwanted hyperproliferative cell growth


An alternator having a plurality of positive and negative diodes, is disclosed. The alternator further includes a plurality of stator windings each of the plurality of stator windings has a first end and a second end, and a first diode plate for fixing one of the plurality of positive and plurality of negative diodes in a first orientation. Further, the alternator includes a second diode plate for fixing the other of the plurality of negative and plurality of positive diodes in a second orientation. Each of the anodes of the positive diodes are connected to each of the cathodes of the negative diodes and to at least one end of each of the plurality of stator windings to form a rectifier bridge circuit.

The present invention relates generally to alternator rectifiers and the electrical connection of the alternators rectifier bridge circuit.
An alternator is put to use in many applications, including generating alternating current in an automobile. Conventional alternators include a rotor, a stator, a rectifier bridge, housing, and a cooling fan. The rotor is typically a claw pole configuration that contains a field coil. The start and end leads of the coil are attached to slip rings that are insulated from the rotor shaft. Insulated stationary carbon brushes communicate the generated field current to the slip rings. The brushes and slip rings provide a means of maintaining electrical continuity between the stationary DC electrical supply and the rotating rotor. Direct current from the batteries is applied to the rotating field through the field terminal and insulated brushes.
The rotor is disposed within the stator. An air gap is maintained between the rotor and stator. The rotors magnetic field energizes the coils or windings of the stator at the same time to maximize the magnetic force. Since the battery and electrical system of a vehicle cannot accept or store an AC voltage, a rectifier bridge is provided to convert AC current to DC current. A rectifier bridge includes both positive and negative diodes. The diodes act as a one-way check valve switching current back and forth so that the current flows only in one direction. More specifically, when AC current reverses itself, the diode blocks the current and no current flows. Typically, AC generators or alternators use a pair of diodes for each stator winding. For example, in a three-phase alternator, three of the diodes are positive biased and another three diodes are negative biased. The use of diodes that are reversed biased with respect to each other allows for rectification of both sides of the AC sign wave.
In order to electrically interconnect the positive and negative diodes, generally a circuit board is employed. The anode of the positive diodes, the cathode of the negative diodes, and the stator windings lead are electrically interconnected to the circuit board. This arrangement requires multiple electrical interconnects reducing reliability of the overall alternator assembly, increasing manufacturing complexity and cost.
Therefore there is a need for a new and improved alternator assembly for electrically interconnecting the positive, negative, and stator windings start and end leads to form a rectifier bridge. The new and improved assembly should reduce the number of electrical interconnects, reduce manufacturing complexity, and cost.
In an aspect of the present invention, an alternator includes a plurality of positive diodes and negative diodes having an anode electrode and a cathode electrode. The alternator further includes a plurality of stator windings that have a first end and a second end. Further, a first diode plate is provided that fixes one of the plurality of positive diodes in a first orientation. Further, the alternator includes a second diode plate for fixing the negative diodes in a second orientation. Each of the anodes of the positive diodes are connected to each of the cathodes of the negative diodes and to at least one end of each of the plurality of stator windings to form a rectifier bridge circuit.
In another aspect of the present invention, a plurality of stator windings include three stator windings.
In yet another aspect of the present invention, the first diode plate is planar and the first orientation is axially oriented.
In yet another aspect of the present invention, the second diode plate is cylindrical and the second orientation is radially oriented.
In still another aspect of the present invention, the first diode plate fixes the plurality of positive diodes in the first orientation.
In still another aspect of the present invention, the second diode plate fixes the plurality of negative diodes in the second orientation.
In still another aspect of the present invention, the first diode plate fixes the plurality of negative diodes in the first orientation.
In still another aspect of the present invention, the second diode plate fixes the plurality of positive diodes in the second orientation.
These and other aspects and advantages of the present invention will become apparent upon reading the following detailed description of the invention in combination with the accompanying drawings.

Diode interconnection in an alternator rectifier