Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35USC§119(e) of U.S. provisional patent application 61/365,942 filed on Jul. 20, 2010, the specification of which is hereby incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This description relates to the field of engines and compressors. More particularly, this description relates to rotary type engines and compressors. 
       BACKGROUND 
       [0003]    An engine is a machine designed to convert energy into mechanical motion. A compressor is a device used for increasing pressure of a gas by reducing its volume. 
         [0004]    Various types of engines exist. Among them, internal combustion engines with reciprocating pistons are most popular in cars today. Another type of internal combustion engine is the Wankel engine in which triangular shaped rotor and an epotrochoid-shaped casing interact to create compression and expansion chambers. Yet another type of engines is a rotary engine which is an internal combustion engine where the radially-mounted cylinders and pistons rotate around a fixed crankshaft. 
         [0005]    There are also various types of compressors, namely reciprocating, rotary, centrifugal and axial. 
         [0006]    Existing engines and compressors all have inefficiencies which are constantly being reduced. 
         [0007]    There is therefore a need for a rotating and reciprocating efficient piston device. 
       SUMMARY 
       [0008]    There is described herein a rotating and reciprocating piston device which can be used in an engine application, a compressor or a pump application. 
         [0009]    According to an embodiment, there is provided a rotating and reciprocating piston device comprising: chambers disposed about a chamber axis, the chambers having two ends and a port for passage of a fluid at each one of the ends of the chambers; pistons having two ends, each one of the pistons slidably positioned within a respective one of the chambers thereby determining a space at either end of each piston within its respective chamber; a track forming a closed circuit through which the chamber axis passes; and guiding devices, each one of the guiding devices for guiding a respective one of the pistons along the track; wherein during operation: the device cycles through a plurality of stages wherein a position of a piston within its respective chamber determines the stage for that piston and hence the space on either side thereof; each piston slides within its respective chamber and thereby continuously varies the space at either end of each piston within its respective chamber; and each port admits or exhausts the fluid respectively to or from the space depending on the stage of the plurality of stages. 
         [0010]    According to an aspect, one of the chambers and the track is static, and the other one of the chambers and the track is free to rotate about the chamber axis. 
         [0011]    According to an aspect, the rotating and reciprocating piston device further comprises a transmission device for transmitting energy to or receiving energy from the rotating and reciprocating piston device. 
         [0012]    According to an aspect, the transmission device comprises one of a shaft, a belt, a chain, a gear mechanism, a wheel, and an electro-magnetic device. 
         [0013]    According to an aspect, the rotating and reciprocating piston device further comprises a track plate on which the track is located. 
         [0014]    According to an aspect, the chambers are located substantially with a chamber plane and wherein the track plate comprises a first track plate and a second track plate, each track plate comprising a track, the first track plate located on one side of the chamber plane and the second track plate located on the opposite side of the chamber plane. 
         [0015]    According to an aspect, the first track plate and the second track plate are connected via a gear device. 
         [0016]    According to an aspect, the first track plate further comprises a shaft receptor portion located in the chamber axis for mounting a rotatable shaft to the first track plate, the rotatable shaft for transmitting or receiving energy to or from the rotating and reciprocating piston device. 
         [0017]    According to an aspect, the second plate comprises a void substantially at a center thereof for providing access to the end of the chambers closest to the chamber axis. 
         [0018]    According to an aspect, the gear device comprises a gear device axis about which it rotates during operation and shaft receptor portion located in the gear device axis for mounting a rotatable shaft to the gear device, the rotatable shaft for transmitting or receiving energy to or from the rotating and reciprocating piston device. 
         [0019]    According to an aspect, the rotating and reciprocating piston device further comprises a chamber block located substantially within a chamber plane, the chambers being formed in the chamber block. 
         [0020]    According to an aspect, the piston chamber block further comprises a shaft receptor portion in the central axis for connecting a rotatable shaft to the track plate. 
         [0021]    According to an aspect, the track comprises one of a groove and a protrusion. 
         [0022]    According to an aspect, the track comprises a symmetrical shape. 
         [0023]    According to an aspect, the symmetrical shape is either centered on the chamber axis or off center from on the chamber axis. 
         [0024]    According to an aspect, the rotating and reciprocating piston device further comprises valves for controlling the passage of fluid through the ports. 
         [0025]    According to an aspect, the rotating and reciprocating piston device further comprises a valve track forming a closed circuit through which the chamber axis passes, the valve track controlling the operation valves. 
         [0026]    According to an aspect, the rotating and reciprocating piston device further comprises spark plugs, a respective one of the spark plugs located at each of the two ends of each of the chambers. 
         [0027]    According to an aspect, the number of pistons is equal to the number of chambers. 
         [0028]    According to an embodiment, there is provided a rotating and reciprocating piston device comprising: chambers disposed about a chamber axis, the chambers having two ends and a port for passage of a fluid at each one of the ends of the chambers; pistons having two ends, each one of the pistons slidably positioned within a respective one of the chambers thereby determining a space at either end of each piston within its respective chamber; and a track forming a closed circuit through which the chamber axis passes, the track for determining a position of a piston within its respective chamber and hence the space on either side thereof. 
         [0029]    According to an embodiment, there is provided a rotating and reciprocating piston device comprising a track plate comprising a track forming a closed circuit, a piston chamber block having defined therein chambers having two ends and an air admission or an exhaust port at each one of the ends of the chambers, pistons having two ends, each one of the pistons being located within a respective one of the chambers, guiding devices, each one of the guiding devices mounted to a respective one of the pistons, the guiding devices adapted to travel along the track; wherein during operation, the device cycles through a plurality of stages, each piston travels within its respective chamber and thereby creates spaces of continuously varying sizes within its respective chamber at either end of each piston, and the spaces within the chambers on either side of each the pistons admit or exhaust gases depending on the stage of the plurality of stages within which are the pistons, the track, via each guiding device, determines a position of each piston within its respective chamber. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    Further features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which: 
           [0031]      FIG. 1  is a schematic diagram showing a top plan view of an embodiment of a rotating and reciprocating piston device without one of its covers; 
           [0032]      FIG. 1   a  is a cut out view of the track plate of  FIG. 1 ; 
           [0033]      FIG. 1   b  is a diagram showing a top elevation view of an embodiment of a piston for use with the rotating and reciprocating piston device; 
           [0034]      FIG. 1   c  is a diagram showing a front elevation view of an embodiment of a piston for use with the rotating and reciprocating piston device; 
           [0035]      FIG. 1   d  is a schematic diagram showing a side elevation view of an embodiment of a piston for use with the rotating and reciprocating piston device; 
           [0036]      FIG. 2  is a schematic diagram showing a top plan view of an embodiment of a piston chamber block of a rotating and reciprocating piston device; 
           [0037]      FIG. 2   a  is a side view of the piston chamber block of  FIG. 2 ; 
           [0038]      FIG. 3  is a schematic diagram showing an embodiment for a track for a 12-stage rotating and reciprocating piston device; 
           [0039]      FIG. 4  is a schematic diagram showing a top plan view of an embodiment of the track plate of a rotating and reciprocating piston device; 
           [0040]      FIG. 4   a  is a schematic diagram showing a side elevation view of an embodiment of the track plate of a rotating and reciprocating piston device; 
           [0041]      FIG. 4   b  is a schematic diagram showing a cross-sectional view of an embodiment of the track plate of a rotating and reciprocating piston device; 
           [0042]      FIG. 4   c  is a schematic diagram showing a top plan view of an embodiment of the track plate with its track of a rotating and reciprocating piston device; 
           [0043]      FIG. 4   d  is a schematic diagram showing a side elevation view of the device of  FIG. 4   c;    
           [0044]      FIG. 4   e  is a schematic diagram showing a cross-sectional top plan view of an embodiment of the track plate with its track of a rotating and reciprocating piston device; 
           [0045]      FIG. 5  is a schematic diagram showing a top plan view of another embodiment of a piston chamber block of a rotating and reciprocating piston device used in a four-stroke engine application; 
           [0046]      FIG. 6  is a side view of the piston chamber block of a rotating and reciprocating piston device of  FIG. 5 ; 
           [0047]      FIG. 7  is a side elevation view of a piston of  FIG. 5 ; 
           [0048]      FIG. 8  is a top elevation view of a piston of  FIG. 5 ; 
           [0049]      FIG. 9  is a schematic diagram showing a top plan view of the track plate of the rotating and reciprocating piston device of  FIG. 5 ; 
           [0050]      FIG. 10  is a side cutout view along line A-A of the track plate of  FIG. 9 ; 
           [0051]      FIG. 11  is a schematic diagram showing a top plan view of another embodiment of a rotating and reciprocating piston device in an electric generator or hybrid engine application; 
           [0052]      FIG. 12  is a side cutout view along line B-B of the rotating and reciprocating piston device of  FIG. 11 ; 
           [0053]      FIG. 13  is a side elevation view of the rotating and reciprocating piston device of  FIG. 11 ; 
           [0054]      FIG. 14  is a schematic diagram showing a top plan view of another embodiment of a rotating and reciprocating piston device; 
           [0055]      FIGS. 15 and 16  are cutout views along line C-C of the piston chamber block of the rotating and reciprocating piston device of  FIG. 14  at different moments; 
           [0056]      FIG. 17  is a top elevation view of a piston of  FIG. 14 ; 
           [0057]      FIG. 18  is a front elevation view of a piston of  FIG. 14 ; 
           [0058]      FIG. 19  is a side view of a piston of  FIG. 14 ; 
           [0059]      FIG. 20  is a schematic diagram showing a top plan view of another embodiment of a rotating and reciprocating piston device; 
           [0060]      FIGS. 21 to 24  are various cutout views along line D-D of the track plate of the rotating and reciprocating piston device of  FIG. 20 ; 
           [0061]      FIG. 25  is a schematic diagram showing a top plan view of another embodiment of a rotating and reciprocating piston device; 
           [0062]      FIG. 26  is a cutout view along line E-E of the track plate of the rotating and reciprocating piston device of  FIG. 25 ; 
           [0063]      FIG. 27  is a side elevation view of the rotating and reciprocating piston device of  FIG. 25 ; 
           [0064]      FIG. 28  is a schematic diagram showing a top plan view of another embodiment of a rotating and reciprocating piston device; 
           [0065]      FIGS. 29 to 32  are various cutout views along line F-F of the housing of the rotating and reciprocating piston device of  FIG. 28 ; 
           [0066]      FIG. 33  is a schematic diagram showing a top plan view of another embodiment of a rotating and reciprocating piston device; 
           [0067]      FIG. 33   a  is a schematic diagram showing a side cutout view of the rotating and reciprocating piston device of  FIG. 33 ; 
           [0068]      FIG. 34  is a schematic diagram showing a top plan view of the track plate with its track of the rotating and reciprocating piston device of  FIG. 33 ; 
           [0069]      FIG. 35  is a schematic diagram showing a top plan view of the piston chamber block of the rotating and reciprocating piston device of  FIG. 33 ; 
           [0070]      FIG. 36  is a schematic diagram showing a top plan view of another track plate with its track of the rotating and reciprocating piston device of  FIG. 33   
           [0071]      FIG. 37  is a schematic diagram showing a top plan view of another embodiment of the piston chamber block of the rotating and reciprocating piston device of  FIG. 33 ; 
           [0072]      FIG. 38  is a schematic diagram showing a top plan view of the piston chamber block with the track plate of the rotating and reciprocating piston device of  FIG. 33 ; 
           [0073]      FIG. 39  is a picture of rotating and reciprocating piston device in accordance with an embodiment; 
           [0074]      FIG. 40  is a picture of a rotating and reciprocating device in accordance with an embodiment; 
           [0075]      FIG. 41  is a picture showing a cover for a rotating and reciprocating piston device in accordance with an embodiment showing a rotatable shaft; 
           [0076]      FIG. 42  is a picture of a piston chamber block with its pistons (without its cover) of a rotating and reciprocating piston device; 
           [0077]      FIG. 43  is a picture showing a track plate with its track for a rotating and reciprocating piston device in accordance with an embodiment; 
           [0078]      FIG. 44  is showing a piston chamber block with its shaft of a rotating and reciprocating piston device; and 
           [0079]      FIG. 45  is a picture showing a partial view in accordance with an embodiment of piston chamber block and pistons placed therein the cover. 
       
    
    
       [0080]    It will be noted that throughout the appended drawings, like features are identified by like reference numerals. 
       DETAILED DESCRIPTION 
       [0081]    Many interesting applications for rotating and reciprocating piston device  10  exist. These applications include a four-stroke engine ( FIG. 5 ), an electric generator ( FIG. 11 ), a hybrid engine, a compressor ( FIG. 39 ), and, in combination with a compressed air tank, an energy reservoir. 
         [0082]    Referring now to the drawings, and more particularly to  FIGS. 1 ,  1   a ,  1   b ,  1   c ,  1   d ,  4 ,  4   a ,  4   b ,  4   c ,  4   d ,  4   e  and  39 , there is shown a rotating and reciprocating piston device  10  in accordance with an embodiment. Device  10  comprises a top track plate  14   a , and a shaft  15 . The device  10  comprises a ring  11  and top and bottom track plates  14   a  and  14   b.    
         [0083]    Now referring to  FIG. 1 , there is shown a partial view of an embodiment of a rotating and reciprocating piston device  10  without the top track plate  14   a  (first track plate). The bottom track plate  14   b  (second track plate) is present. Device  10  comprises a stationary ring  11  having an interior portion and a hole  28  at the center of the interior portion. 
         [0084]    The top track plate  14   a  is for covering the interior portion. The top track plate  14   a  has a hole  28  which, when the top track plate  14   a  is installed on the ring  11 , is aligned with the hole  28  in the bottom track  14   b.    
         [0085]    Device  10  further comprises a rotatable shaft  15  for mounting through hole  28  in top and bottom track plates  14   a  and  14   b.    
         [0086]    Device  10  further comprises a piston chamber block  16  mounted on the rotatable shaft  15  within the interior portion of the track plate  12 . The piston chamber block  16  has defined therein chambers  26 . 
         [0087]    Device  10  comprises two or more pistons  20  (seven pistons are shown in the embodiment depicted in  FIG. 1 ) having two ends  21   a ,  21   b . Each one of the pistons  20  is located within a respective one of the chambers  26 . 
         [0088]    According to an embodiment, each piston  20  comprises a guiding device  22 . Guiding device  22  may comprise a ball bearing. The device  10  further comprises a track  18  (aka, a groove) in at least one of the track plate  12 . The guiding device  22  travels within the track  18  and thereby determines a position of each piston  20  within its respective chamber  26 . 
         [0089]    During rotation of piston chamber block  16 , the device  10  cycles the two or more pistons  20  through a plurality of stages. In the embodiment shown in  FIG. 1 , stages  1  through  4  are shown. Each piston  20  travels within its respective chamber  26  and thereby creates spaces of continuously varying sizes within its respective chamber  26  at either end of each piston  20 . The spaces within the chambers  26  on either side of each of the pistons  20  admit or exhaust gases depending on the stage of the plurality of stages within which are the pistons  20 . 
         [0090]    Now referring to  FIGS. 4 ,  4   a ,  4   b ,  4   c ,  4   d , and  4   e  ring  11  further comprises external inlet/outlet passages  24   a ,  24   b ,  24   c ,  24   d  and internal inlet/outlet passages  30   a ,  30   b ,  30   c ,  30   d . As will be described later, the passages have ports which act as inlets or outlets for gases to the outside of the device  10 . The passages or ports may be blocked depending on the application. 
         [0091]    Now referring to  FIGS. 2 and 2   a , there is shown an embodiment of a piston chamber block  16  of a rotating and reciprocating piston device  10 . Piston chamber block  16  is circular in shape and comprises chambers  26  within which pistons (not shown) may travel. The cross-section of the chambers  26  and corresponding pistons can be of any suitable for a given application, such as round, square, triangular, oval, etc. At the exterior end of each chamber is a hole  32 . The holes  32  provide a passage for air or gases to travel between the chambers  26  and whichever inlet or outlet passages the holes  32  are in fluid communication with. 
         [0092]    Now referring to  FIG. 3 , there is shown an embodiment for a groove for a 12-stage rotating and reciprocating piston device. For a compressor application, using such a star-shaped configuration for the track will result in a compressor with 6 stages of air admission from the inlets at the external end of the piston chamber block and 6 stages of air evacuation to the outlets at the external end of the piston chamber block along with 6 stages of air admission from the inlets at the internal end of the piston chamber block and 6 stages of air evacuation to the outlets at the internal end of the piston chamber block. 
         [0093]    Now referring to  FIG. 4 , there is shown a top plan view of an embodiment of a track plate  12  of a rotating and reciprocating piston device. Track plate  12  comprises mid-portions  27  which act as separators between the external end passages  24   a ,  24   b ,  24   c  and  24   d . Each passage includes a port  25   a ,  25   b ,  25   c  and  25   d  through which air/gases may travel from the outside to the inside or vice versa. 
         [0094]    The operation of device  10 , when used as a compressor, will now be described using the embodiment shown in  FIG. 1 . Starting with piston  20  in chamber  26  at the 3 o&#39;clock position. At this position, piston  20  is entering stage  1  of the compressor when the piston chamber block  16  starts its rotation in a clockwise direction. In a compressor application, shaft  15  is powered by an external motor such as an electric motor (not shown). Guiding device  22  will follows the track  18  and force piston  20  to move toward the center (interior) of the piston chamber block  16  therefore admitting fresh air through air passage  24   b . At the same time, air which is present in chamber  26  at the other end (or opposite side) of piston  20  will be forced out through air passage  30   b  to a compressed air tank (not shown) or to another device or tools that need air to drive it. The same piston will finish stage  1  at the 6 o&#39;clock position where the reverse process for the piston  20  takes place; i.e., fresh air will enter from air passage  30   c  and exit through passage  24   c . Stage  3  will be the same as stage  1  and stage  4  will be the same as stage  2 . 
         [0095]    This embodiment can also be used in a hybrid engine application. For example, when the brakes are applied on a car, the energy to drive the compressor to fill a compressed air tank can be used to help in slowing down the car. On the other hand, during acceleration of the car, the stored compressed air in the tank can be used to drive the compressor and hence help in accelerating the car. 
         [0096]    Now referring to  FIGS. 5 ,  6 ,  7 ,  8 ,  9 , and  10 , another embodiment of the rotating and reciprocating piston device  110  will be described. This embodiment is for a four-stroke engine. Since most components are similar or the same as those described in the previous embodiments, the emphasis will be placed on the differences between the embodiments. 
         [0097]      FIGS. 5 and 6  show piston chamber block  116 .  FIGS. 7 and 8  show piston  120 .  FIG. 9  shows a cover  114   a  or  114   b .  FIG. 10  shows track plate  112  with covers  114   a  and  114   b  and ring  111 . 
         [0098]    In this embodiment of device  10 , one or both spaces in the chambers  126  at either end of the pistons  120  can be used. There are provided means for admitting fuel along with air in the external space of chamber  126  during stage  3  and in the internal (center) space of chamber  126  during stage  4 . There are provided means for igniting an air-fuel mixture  140  (aka, spark plug) at the external space of chamber  126  during stage  1  and at the internal space of chamber  126  during stage  2 . For the external chamber, the four-stages would be as follows: stage  3 : intake; stage  4 : compression; stage  1 : ignition; and stage  2 : exhaust. For the internal chamber, the four-stages would be as follows: stage  4 : intake; stage  1 : compression; stage  2 : ignition; and stage  3 : exhaust. 
         [0099]    Using the embodiment shown in  FIG. 5  in which ten piston-chamber pairs are shown, the total process would then result in 20 ignitions for each full rotation of the piston chamber block  116 . 
         [0100]    Now referring to  FIGS. 11 to 32 , other embodiments of the rotating and reciprocating piston device  290  will be described. It is contemplated that the device  290  can be used as an electric generator by placing electro-magnets  250  and permanent magnets  260  at appropriate positions around (or on) the piston chamber block  296  and track plate  292 . There is also shown ( FIG. 21 ) a cover  294  for track plate  292 . In  FIGS. 25 and 26 , there is shown a housing  298  and its cover  300 . This housing  298  and cover  300  assembly are used to house the track plate  292  and its cover  294 . 
         [0101]    In an exemplary embodiment, the device  290  can be used, in combination with a car engine, to store energy in a battery (not shown). The stored energy can then be used for different purpose such as utility purposes in the car or to drive the car&#39;s wheels. 
         [0102]    Other uses include 1—using energy to drive the device  290  to produce compressed air in a compressed air tank, or  2 —in combination, the energy of the piston and electrical energy can be used to increase a performance of an engine. 
         [0103]    Referring now to  FIG. 33 , there is shown another embodiment of a rotating and reciprocating piston device  500 . The device  500  comprises a track plate  12  having a track  18  forming a closed circuit. The device  500  also comprises a piston chamber block  16  having defined therein chambers  26  having two ends and an air admission or an exhaust port at each one of the ends of the chambers  26 . The device  500  also comprises pistons  20  having two ends  21   a  and  21   b , each one of the pistons  20  being located within a respective one of the chambers  26 . Moreover, the device  500  comprises guiding devices  22 , where each one of the guiding devices  22  is mounted to a respective one of the pistons  20 . The guiding devices  22  are adapted to travel along the track  18 . 
         [0104]    During operation of the device  500 , the device  500  cycles through a plurality of stages and each piston  20  travels within its respective chamber  26  and thereby creates spaces of continuously varying sizes within its respective chamber  26  at either end  21   a  or  21   b  of each piston  20 . Also, during operation of the device  500 , the spaces within the chambers  26  on either side of each the pistons  20  admit or exhaust gases depending on the stage of the plurality of stages within which are the pistons  20 . Additionally, the track  18 , via each guiding devices  22 , determines a position of each piston  20  within its respective chamber  26 . 
         [0105]    It is to be noted that in the case the top and bottom track plates  14   a  and  14   b  are rotating, the piston chamber block  16  is statically mounted. On the other hand, in the case the piston chamber block  16  is rotating, the track plate  12  is statically mounted. 
         [0106]    There is shown in  FIG. 33  that the track  18  is rotating, while the piston chamber block  16  is statically mounted and the shaft  15  is connected to the track plate  12 . Moreover, in the embodiment of  FIG. 33 , the piston chamber block  16  is static and track  18  is rotating. Indeed, a first track plate  12  rotates while engaging the shaft  15  and a second track plate  12  rotates while engaging the first track plate  12  via a gear device  700 . 
         [0107]    Now referring to  FIG. 33   a , there is presented a schematic diagram showing a side cutout view of the rotating and reciprocating piston device  500  of  FIG. 33 . The rotating and reciprocating piston device  500  comprises a piston chamber block  16  located in a chamber plane (perpendicular to drawing). A first track plate  12  is located above the piston chamber block  16  (on on side of the chamber plane) and a second track plate  12  is located below the piston chamber block (on the other side of the chamber plane). A gear device  700  drives both the first track plate  12  and the second track plate  12 . A cover  14   a  for mounting over the first plate  12  which is located above the piston chamber block  16 . A bearing  900  is provided in cover  14   a  to enhance the stability of shaft  15 . 
         [0108]    Referring now to  FIG. 34 , there is shown a schematic diagram showing a top plan view of the track plate  12  with its track  18  and its gears  700  of the rotating and reciprocating piston device  500  of  FIG. 33 . 
         [0109]    Referring now to  FIG. 35 , there is shown a schematic diagram showing a top plan view of the piston chamber block  16  of the rotating and reciprocating piston device  500  of  FIG. 33 . There is also shown that the piston chamber block  16  further includes a shaft receptor portion  800  for connecting to track plate  12 . 
         [0110]    Referring now to  FIG. 36 , there is a shown a schematic diagram showing a top plan view of the second track plate  12  with its track  18  of the rotating and reciprocating piston  500  device of  FIG. 33 . There is also shown that the piston chamber block  16  further includes a shaft receptor portion  800  for connecting to track plate  12 . 
         [0111]    Referring now to  FIG. 37 , there is shown a schematic diagram showing a top plan view of another embodiment of the piston chamber block  16  of the rotating and reciprocating piston device  500  of  FIG. 33 . 
         [0112]    Finally, Referring now to  FIG. 38 , there is shown a schematic diagram showing a top plan view of the piston chamber block  16  with the track plate  12  of the rotating and reciprocating piston device  500  of  FIG. 33 . 
         [0113]    While preferred embodiments have been described above and illustrated in the accompanying drawings, it will be evident to those skilled in the art that modifications may be made without departing from this disclosure. Such modifications are considered as possible variants comprised in the scope of the disclosure.

Technology Category: 2