Patent Publication Number: US-8122902-B2

Title: Apparatus and method for unclogging a pipe

Description:
FIELD OF THE INVENTION 
     The present invention relates to a method and apparatus for unclogging an obstructed conduit such as a wastewater pipe. 
     BACKGROUND OF THE INVENTION 
     Clogs in pipes are a nuisance, especially underground. Releasing the clogs typically requires time, manpower, tools and/or machinery, and may cause annoyances such as blocking roads and delays until manpower is available. 
     Some methods and mechanisms for dealing with obstructions in piping systems for sewage drainage or rain water runoff and the like have been devised. DE 3300489 discloses an apparatus comprising a screen for retaining and removing substances that may clog an outlet opening; and DE 3822555 relates to a throttle device for an outflow opening of a rainwater-retention chamber in a drainage system. 
     U.S. Pat. No. 5,967,175 describes a waste-line stoppage detector and automatic water shutoff system that is utilized to prevent the overflow of raw sewage from a plumbing fixture. Electronic shutoff valves are electronically connected to a waste line stoppage detector. The electronic waste line stoppage detector may be electronic, use a diaphragm or float ball with a switch. 
     U.S. Pat. No. 4,083,661 discloses a pneumatic sewage ejector that includes a tank for holding fluid sewage. When the sewage reaches a predetermined high level in the tank, it is ejected by pressurized air forced into the tank through a valve located inside the tank. The ejection of the fluid is initiated by a float which responds to the high fluid level in the tank by ascending and thereby moving the valve to an air-input position to admit pressurized air into the tank to expel the sewage. The valve remains in the air-input position until the fluid reaches a low level, at which time the float descends and moves the valve to a vent position to vent the pressurized air to the atmosphere. The float moves the valve between the air-input position and the vent position in one discrete step so that the valve cannot stop in an intermediate position. 
     The above-mentioned references are incorporated herein by reference in their entirety. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention there is provided a method of unclogging an obstruction in a conduit or pipe, comprising thrusting, ejecting or forcing a fluid into the pipe in order to remove the obstruction. 
     According to another aspect of the invention there is provided an apparatus adapted to unclog an obstruction in a conduit or pipe, comprising at least one tube for thrusting or ejecting a fluid into the conduit, and a supply pipe for providing the fluid to the at least one tube. 
     According to one aspect of the invention there is provided a junction comprising an apparatus adapted to unclog an obstruction in a conduit or pipe, comprising at least one tube for thrusting or ejecting a fluid into the conduit or pipe, and a supply pipe for providing the fluid to the at least one tube. 
     According to one aspect of the invention there is provided a kit comprising components for unclogging an obstruction in a conduit or pipe. In some embodiments the components comprise one or more tube sections for disposing in the conduit or pipe, connectors for connecting the tube sections, a fluid supply pipe, and a valve with a regulating mechanism for controlling the fluid supply. Optionally the kit comprises one or more chemicals to add to the fluid. Optionally, the kit comprises a tank for the fluid. 
     The obstruction typically resides in an effluent pipe, which may be, without limiting, sewage, wastewater, rain water, or other effluent fluid such as industrial or environmental fluids. 
     For brevity and clarity, in the specification and claims, unless otherwise specified, the following terms, or inflections thereof, denote or relate to the following respective designations: 
     effluent—any flowing material that may contain an obstruction; 
     drain pipe—any pipe or conduit that may contain an obstruction; 
     flush—thrusting, ejecting or forcing a fluid into a drain pipe; and 
     water or flushing water—any fluid usable for unclogging an obstruction. 
     In some embodiments of the invention, the flushing water comprises one or more supplementary ingredients, such as a surfactant or alkaline compound, which may assist in disintegrating or decomposing the obstruction. 
     In some embodiments of the invention, one or more tubes are disposed in a drain pipe and water is flushed under pressure in or into the drain pipe from the one or more tubes, wherein the flush pressure is greater than the pressure of the effluent flow. 
     In some embodiments, the water, optionally with supplementary ingredients, is provided from a municipal or regional water supply. 
     In some embodiments, the flushing pressure is obtained from a municipal or regional water supply. Optionally or alternatively, the pressure is obtained, or augmented, by a pump or a compressor or by other methods such as a container with pressurized gas such as air, or by a hydrostatic column. 
     In some embodiments, the water is flushed toward the clog and/or in the clog substance. Optionally, the water is ejected after the clog, effecting a flow that pulls and releases at least a part of the clog. 
     In some embodiments of the invention, water is flushed into an outlet drain pipe. Optionally or alternatively, the water is flushed into an inlet drain pipe. In some cases, the inlet flow is slow relative to the flushing water so that the flushing flow may unclog an obstruction even when that flushing water is directed in the opposite direction of the inlet flow. In some cases, the inlet flow is intermittent so that the flushing flow may unclog an obstruction when little of no effluent is flowing in the inlet pipe. 
     In some embodiments of the invention, flushing water into the drain pipe is effected manually. According to other embodiments, flushing water into the drain pipe is automatic. 
     According to an aspect of some embodiments of the present invention there is provided an apparatus for unclogging an obstruction in a drain pipe, comprising: 
     at least one tube disposed in the drain pipe; and 
     a fluid supply pipe for providing fluid from a fluid source, the supply pipe connected to the at least one tube that delivers the fluid to unclog the obstruction. 
     In some embodiments the apparatus is configured to flush the fluid from the at least one tube into the drain pipe. 
     In some embodiments the apparatus is further comprises a mechanism that regulates the fluid delivery automatically. 
     In some embodiments the mechanism regulates the pressure of the fluid. 
     In some embodiments the mechanism regulates the fluid flow rate. 
     In some embodiments the mechanism comprises a valve. 
     In some embodiments the mechanism comprises an element for automatically controlling the valve according to an effluent level in a chamber into which the drain pipe connects. 
     In some embodiments the mechanism comprises an element for automatically controlling the valve according to an effluent level in the drain pipe. 
     In some embodiments the mechanism comprises an element for automatically controlling the valve according to an effluent flow rate in a chamber into which the drain pipe connects. 
     In some embodiments the mechanism comprises an element for automatically controlling the valve according to an effluent flow rate in the drain pipe. 
     In some embodiments the element comprises a float linked to the valve. 
     In some embodiments the element comprises at least one of a fluid level sensor, a flow rate meter and a flow velocity meter. 
     In some embodiments the apparatus further comprises a pump for pressurizing the fluid. 
     In some embodiments the apparatus further comprises a tank connected to the supply pipe for providing supplementary ingredients to the fluid. 
     In some embodiments the fluid is water. 
     In some embodiments the supply pipe connects to a water source. 
     In some embodiments the water source is a regional water supply. 
     According to an aspect of some embodiments of the present invention there is provided a method for unclogging an obstruction in a drain pipe, comprising: 
     disposing at least one tube into the drain pipe; 
     providing a fluid to the at least one tube; and 
     flushing the fluid in the drain pipe for at least partially unclogging the obstruction. 
     In some embodiments the fluid is water. 
     In some embodiments the method further comprises supplementing the fluid with ingredients for assisting in unclogging the obstruction. 
     In some embodiments the method further comprises pressurizing the fluid to a pressure above the pressure in the drain pipe. 
     In some embodiments pressurizing comprises obtaining pressure from a regional water supply. 
     In some embodiments the method further comprises automatically regulating the flushing according to a determined clogging in the drain pipe. 
     In some embodiments the method further comprises automatically regulating the flushing according to an effluent level in a chamber into which the drain pipe connects. 
     In some embodiments the method further comprises automatically regulating the flushing according to an effluent level in the drain pipe. 
     In some embodiments the method further comprises automatically regulating the flushing according to an effluent flow rate in a chamber into which the drain pipe connects. 
     In some embodiments the method further comprises automatically regulating the flushing according to an effluent flow rate in the drain pipe. 
     According to an aspect of some embodiments of the present invention there is provided a junction having a plurality of pipe stubs, comprising: 
     at least one tube disposed in at least one pipe stub; and 
     a fluid supply pipe for providing fluid from a fluid source, the supply pipe connected to the at least one tube, whereby the fluid is deliverable to unclog an obstruction in a pipe connected to the at least one pipe stub. 
     In some embodiments the junction further comprises a valve in the supply pipe. 
     In some embodiments the junction further comprises a mechanism for automatically regulating the valve according to effluent level in the junction. 
     In some embodiments the junction further comprises a mechanism for automatically regulating the valve according to effluent flow rate in the junction. 
     In some embodiments the junction further comprises a mechanism for automatically regulating the valve according to effluent level in a pipe stub. 
     In some embodiments the junction further comprises a mechanism for automatically regulating the valve according to effluent flow rate in a pipe stub. 
     In some embodiments the mechanism comprises a float linked to the valve. 
     In some embodiments the mechanism comprises a sensor for detecting at least one of fluid level, fluid flow and fluid velocity. 
     According to an aspect of some embodiments of the present invention there is provided a kit for unclogging an obstruction in a drain pipe, comprising: 
     a plurality of tube sections for disposing in the drain pipe; 
     connectors for connecting the tube sections; 
     a fluid supply pipe; and 
     a valve with a regulating mechanism for controlling the fluid supply. 
     In some embodiments the mechanism comprises a float pivotally linked to the valve. 
     In some embodiments the kit further comprises at least one chemical to aid in unclogging the obstruction. 
     In some embodiments the kit further comprises at least one tank for holding flushing fluid. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may be understood upon reading of the following detailed description of non-limiting exemplary embodiments thereof, with reference to the following drawings. 
       Identical and/or equivalent and/or similar structures, elements, or parts that appear in more than one drawing are generally labeled with the same reference numeral. Dimensions of components and features shown in the figures are chosen for convenience or clarity of presentation and are not necessarily shown to scale or true perspective. For clarity, some structures are shown only partially or without perspective. 
         FIGS. 1A-1C  schematically show some embodiments of an apparatus of the present invention; 
         FIG. 1D  schematically shows a flushing pipe according to another embodiment of the invention; 
         FIG. 2A  and  FIG. 2B  schematically show a further embodiment of the apparatus the present invention adapted for automatic operation, in an inactive and active position, respectively; 
         FIG. 3  schematically shows an exemplary kit for flushing an obstruction according to an embodiment of the invention; and 
         FIG. 4  shows a flowchart of an exemplary method of the invention for unclogging an obstruction in a drain pipe. 
     
    
    
     DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     The invention will be described with respect to the unclogging of a drain pipe such as is commonly found underneath street manhole covers and used to drain water from homes, apartment buildings, or other locations such as streets. Typically such drain pipes connect to a junction distribution box (hereinafter in the specification and claims: “junction”). However, it should be understood that the invention can be adapted by a person of ordinary skill in the art for use with a wide variety of conduits, pipes, tubes or junctions, and in a variety of settings. 
       FIGS. 1A ,  1 B and  1 C illustrate a typical, non-limiting example of a junction  100  comprising three inlet pipe stubs  102  (two visible), an outlet pipe stub  104 , and a cylindrical wall  106  with a base  108  defining a cavity or chamber  110 . Extending from pipe stubs  102  and  104  are pipes  102 A and  104 A, respectively. Effluent flow reaches chamber  110  via inlet pipes  102 A and continues to drain into outlet pipe  104 A. 
     Chamber  110  allows access to pipe stubs  102  and  104  and pipes  102 A and  104 A, and is used in the specification as a non-limiting framework for examples of embodiments of the invention. The number and relative diameters of inlet pipes  102 A or outlet pipes  104 A shown are merely exemplary and any practical number of inlet pipes  102 A or outlet pipes  104 A and diameters thereof may be used in accordance with embodiments of the invention. 
       FIGS. 1A-1C  further show an embodiment of an apparatus  120  for unclogging an obstruction in a drain pipe. Apparatus  120  comprises a fluid supply pipe  124  and one or more flushing tubes, represented by four flushing tubes  126 A- 126 D which are shown disposed in one of the inlet pipes  102 A and outlet pipe  104 A. In some embodiments, flushing tubes  126  are inserted in all or some of inlet or outlet pipes  102 A and  104 A, respectively. Supply pipe  124  is fitted with a valve  128  for controlling the flow of flushing water, in terms of flow rate (volume per time) and/or velocity and/or pressure. 
     In some embodiments of the invention, in order to install apparatus  120 , chamber  110  is exposed, such as by opening a manhole cover under which such junction  100  is typically located, as illustrated in  FIGS. 1A and 1B . In other embodiments of the invention, as illustrated in  FIG. 1C , wall  106  of junction  100  is opened, such as by drilling, and supply pipe  124  is installed in chamber  110  through an opening  132  in wall  106 . Additionally, pipe  124  and other pipes (or tubes)  126  are installed via top or side of junction  100 . 
     However, pipe  124  can be disposed in any appropriate location and manner. For retrofitting, supply pipe  124  may be installed through opening  132  made in wall  106 ; whereas in other embodiments the apparatus includes junction  100  or the junction is pre-formed with a suitable opening to accommodate supply pipe  124 . 
     Valve  128  can be operated manually, or by other means such as an electro-mechanical mechanism (e.g., a locally or remotely controlled actuator, such as by a solenoid, not shown). In this regard, a system of apparatuses can be operated remotely to flush a series of drain pipes. Valve  128  may be located in the vicinity of junction  100  (e.g. within or adjacent the junction) or outside the vicinity of junction  100 . Optionally, the function of valve  128  is carried out by a plurality of valves. 
     When valve  128  is opened, the water provided by supply pipe  124  is flushed into inlet or outlet pipes  102 A or  104 A thereby clearing or at least partially clearing the obstruction. 
     In order to provide water for flushing, flushing tubes  126 A-D are connected to a water source (not shown), such as a regional water supply system or a reservoir, through supply pipe (or pipes)  124 . The water is optionally supplemented with additional ingredients to assist in unclogging, such as surfactants and/or alkali or acidic chemicals. The pressure for flushing the water into pipes (or tubes)  126  is provided by the water supply system or a reservoir, for example, a reservoir in a sufficiently high location relative to junction  100 . Optionally or alternatively, the pressure is provided, or augmented, by a pump  130 . Pump  130  is manually operated, or operated by other methods such an electro-mechanical mechanism (e.g., a locally or remotely controlled actuator). 
     The water from supply pipe  124  is fed to flushing tubes  126  via a pipe  118 . Pipe  118  is, optionally, constructed as a manifold that distributes water from supply pipe  124  to flushing tubes  126 . 
     Flushing tubes  126  are disposed in inlet or outlet pipes  102 A and  104 A, respectively, and constructed such that they do not hinder effluent flow in pipes  102 A or  104 A, or at least not significantly. Typically, the outer diameters of water flushing tubes  126 A-D are small relative to the inner diameters of inlet pipes  102 A and outlet pipes  104 A; however any appropriate diameter for the flushing pipes can be used. Likewise, according to the present embodiment, flushing tubes  126 A-D can be of varying lengths. 
     In some embodiments of the invention, water flushing tubes  126  have an outer diameter of 5% to 10% of the inner diameter of pipes  102 A and/or  104 A. Optionally, water flushing tubes  126  have a diameter of 10% to 20%, or larger or smaller of pipes  102 A and/or  104 A. In some embodiments of the invention, water flushing tubes  126  are disposed in a drainage pipe for some length down an outlet pipe and/or up an inlet pipe. Optionally, the length of flushing tube  126  is in the order of 2 cm to 50 cm; optionally, the length is in the order of 50 cm to 1 m; optionally, the length is in the order of 1 m to several meters such as 2 m, 2.5 m, 3 m or more, or any intermediate length of the recited length ranges. In some embodiments of the invention, a plurality of flushing tubes  126  are disposed in a drainage pipe  102 A or  104 A, optionally each flushing tube  126  has a different length and/or diameter. 
     As illustrated in  FIG. 1D , in some embodiments of the invention, flushing tubes  126  comprise a plurality of sections  144  that are fastened to each other, for example, by threaded connections  146  or the like, for ease of assembly and.or installation and/or manufacturing. In some embodiments, flushing tubes  126  are constructed by sections of different diameters, for example, tube  126  is narrower at the end from which flushing water exits than at the end adjacent junction  100 .  FIG. 1D  schematically shows flushing tube  126  comprising a relatively large diameter section (or sections)  142  and narrow sections (or section)  144  connected together. Optionally, tube  126  is fitted with a nozzle  148  to thereby eject flushing water in a jet or fast stream in order to unclog an obstruction. 
     Optionally or alternatively, in some embodiments of the invention, flushing tubes  126  are flexible, or partially flexible, to ease installation thereof. 
     In some embodiments of the invention, apparatus  120  comprises a tank  112  which can be used to store chemicals that may be added to flushing water in flushing tube  126  from a tank  112  for example via a pipe  114  and regulated by a valve  116 . 
     The embodiments shown in  FIGS. 2A ,  2 B and  2 C illustrate a manually operated apparatus. According to other embodiments, described herein below, the apparatus is operated automatically. In other words, an obstruction is automatically detected or determined (directly or indirectly) and flushing water is automatically ejected to clear the obstruction. 
       FIGS. 2A and 2B  schematically show an apparatus  120 A adapted for automatic operation and unclogging of a drain pipe. In this embodiment, and certain others to be described, the apparatus comprises a mechanism  200  for detecting or determining that a drain pipe is clogged based on the premise that if and/or when the obstruction is disruptive enough, the effluent flow will be hindered and accumulate (back up) in chamber  110  whereby the effluent level will rise in the chamber. 
     In some embodiments of the invention, mechanism  200  comprises a valve  204  (optionally different and/or a variant of valve  128 ) and a float  210 , both of which are pivotally connected by an arm  206 . 
     Valve  204  is constructed such that it can open or close water supply pipe  124  according to the height of effluent level  212  in chamber  110 , and consequently, the level of float  210 , as described below. 
     When effluent level  212  in chamber  110  is low ( FIG. 2A ), that is, closer to a lower part of outlet pipe  104  than to an upper part of outlet pipe  104 , indicating that effluent flow is not significantly hindered, then float  210  positions arm  206  such that valve  204  is closed and flushing water is not supplied to flushing tubes  126 . 
     When effluent level  212  in chamber  110  is high ( FIG. 2B ), that is, closer to an upper part of outlet pipe  104  than to a lower part of outlet pipe  104 , indicating that a drain pipe is clogged, at least partially, then float  210  floats on accumulated effluent and positions arm  206  such that valve  204  is open and water is supplied to flushing tubes  126  for unclogging. 
     In some embodiments of the invention, the water supply from source pipe  124  is regulated according to the effluent level  212  and, accordingly, according to the flow (or clogging) of an outlet pipe  104 . Optionally, the rate of flow or pressure in flushing tubes  126  is regulated according to the level of float  210  (i.e. effluent level  212 ) by opening or closing valve  204  responsive to the level of the float  210 . Optionally, the opening or closing valve  204  is not linear with float  210  level and, for example, a relatively small or partial rise of float  210  affects an essentially complete opening of valve  204  in order to flush tubes  126 . In this manner, even a relatively minor obstruction can be removed before it becomes a more significant obstruction. 
     In some embodiments, the operation of float  210 , arm  206  and valve  204  (mechanism  200 ) is similar to the operation of a toilet flushing mechanism (though in an opposite manner, such that when float  210  is high valve  204  is opened). The embodiment shown in  FIGS. 2A and 2B  is provided as a non-limiting example, and other mechanisms may be used for controlling and/or regulating valve  204 , and accordingly, of water flow in flushing tubes  126 . For example, electrically operated valve controlled by a water (or other fluid) sensor  214  located in chamber  110  on base  108  or other locations in chamber  110 , or a sensor for the flow rate or velocity of effluent flow in chamber  110  or in outlet stub  104  or inlet stub  102 . 
     It can be recognized that the operation responsive to the level of float  210  may be practical for an obstruction in the effluent flow of outlet pipe  104 A. However, by placing a water (or other fluid) sensor or detector  212  in inlet pipe  102 A, a clog in inlet pipe  102 A may also be determined. For example, a low effluent level in inlet stub  102 , e.g. below the level of a sensor  216 , can indicate that an obstruction is present upstream of the sensor. Sensor  212  is operably connected to valve  204 , whereby a reduced flow, detected by the sensor, opens valve  204 . Optionally, a plurality of sensors  212  may be disposed at several levels in inlet stub  102  or inlet pipe  102 A, and valve  204  will open (or close) responsive to the lowest (or highest) level of a sensor  212 . Optionally, the rate of flushing in flushing tubes  126  is determined is response to the effluent level detected by sensor  214  and/or  216 . 
     The water sensor(s)  214  and/or  216  may comprise, for example, two electric electrodes with different electric potentials, such that when covered with water/effluent (or other conductive medium) electric current flows under the potential difference, which effects (e.g. by using an amplifier) the opening or closing of valve  204 . 
     In some embodiments of the invention, sensor(s)  214  and/or  216  comprise a flow rate meter and/or flow velocity meter disposed in inlet stub  102  or outlet stub  104 , so that valve  204  is opened or closed according to the flow in inlet stub  102  or outlet stub  104 . For example, when the effluent flow rate is lower than typically expected, valve  204  is opened to flush tubes  126  in inlet pipe  102 A or outlet pipe  104 A. 
     In some embodiments, the water sensor or flow meter  212  is disposed in chamber  110 , and functions as described above. When the drain is not conductive, other sensors sensitive to the effluent composition may be used. 
     In some embodiments, valve  204  and/or the sensors described above are used to regulate the pressure of the flushing water. For example, by regulating pump  130  or by other methods such as regulating the water supply pressure by an auxiliary valve. 
     In some embodiments of the invention, apparatus  120  is installed on an ad-hoc basis. For example, when a clog is identified or suspected, junction  100  is accessed (e.g., by opening a cover of manhole in which the junction is placed) and apparatus  120  is installed to provide water from supply pipe  124  to tubes  126 . Optionally or alternatively, apparatus  120  is left installed for future use, optionally with valve  208  closed to save water and it may be assembled with mechanism  200  and/or tank  112 . In some embodiments of the invention, apparatus  120  or  120 A is installed as a preventive measure, that is, to be ready in case of a clogging and, particularly for apparatus  120 A, to operate automatically when clogging is determined or identified. 
     In some embodiments of the invention, junction  100  is manufactured and/or supplied with apparatus  120  and/or  120 A, at least partially. In some embodiments of the invention, junction  100  comprises a section of supply pipe  124  and/or manifold  118  and/or sections of tubes  126  in inlet and/or outlet stubs  102  and  104 , and/or optionally valve  128  or  204 . Optionally, the chemicals are supplied as part of junction  100 , optionally in a bag or container such as tank  112 . 
     In some embodiments of the invention, apparatus  120  and/or  120 A, at least partially, are provided as a kit. For example, maintenance personnel may acquire the kit and install it in a drain pipe or junction such as junction  100  or other such plumbing system. Optionally, additional pipes or pipe (or tube) sections may be acquired in order to extend pipes  126 , as well as chemicals and pumps.  FIG. 3  schematically shows an exemplary kit  300  for flushing an obstruction in a drain pipe, comprising supply pipe  124 , valve  204 , arm  206  and float  210 , as well as tube  126  sections  142 ,  144 , connection sections  146  and ejection nozzle  148 . Optionally, the kit comprises at least one chemical for aiding in unclogging an obstruction. Optionally, the kit comprises a tank, for example, such as tank  112  for holding flushing fluid. 
       FIG. 4  shows a flowchart of an embodiment of a method for unclogging an obstruction in a drain pipe, comprising: disposing at least one tube into a drain pipe ( 402 ), providing water for flushing the drain pipe ( 404 ), and flushing the water into the drain pipe via the at least one tube ( 406 ). 
     The terms ‘vertical’, ‘perpendicular’, ‘parallel’, ‘opposite’, ‘straight’, ‘planar’, ‘rectangular’, ‘square’, ‘circular’, ‘round’, ‘elliptical’, ‘oval’, ‘cylindrical’, ‘sphere’ and other angular and geometrical shapes and relationships and inflections thereof imply also imprecise yet functional and/or practical respective relationships. 
     The terms ‘about’, ‘approximate’, ‘substantial’, ‘significant’ and inflections thereof denote, unless otherwise specified or implied in the context, a sufficiently close functional and/or practical respective relation or measure or amount or quantity or degree according to the context in which the terms or their inflections appear. 
     The terms “comprises”, “comprising”, “includes”, “including”, “having” and their inflections and conjugates denote “including but not limited to”. 
     The present invention has been described using descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. The described embodiments comprise various features, not all of which are necessarily required in all embodiments of the invention. Some embodiments of the invention utilize only some of the features or possible combinations of the features. Alternatively and additionally, portions of the invention described/depicted as a single unit may reside in two or more separate physical entities which act in concert to perform the described/depicted function. Alternatively and additionally, portions of the invention described/depicted as two or more separate physical entities may be integrated into a single physical entity to perform the described/depicted function. Variations of embodiments of the present invention that are described and embodiments of the present invention comprising different combinations of features noted in the described embodiments can be combined in all possible combinations including, but not limited to use of features described in the context of one embodiment in the context of any other embodiment. 
     In the specifications and claims, unless otherwise specified, when a range of values is recited, it is merely for convenience or brevity and includes all the possible sub-ranges as well as individual numerical values within that range. Any numeric value, unless otherwise specified, includes also practical close values enabling an embodiment or a method, and integral values do not exclude fractional values. A sub-range values and practical close values should be considered as specifically disclosed valued.