Abstract:
An internal combustion engine or other internal pressure driven engine of the type capable of converting reciprocal linear powered motion into unidirectional rotary motion, the engine having at least one pair of first and second cylinders with each cylinder having a pair of opposed pistons therein forming a pressure chamber therebetween. Outer ends of each piston carries a piston rod connected to a pivot arm of a respective one way clutch which causes the clutch to oscillate back and forth when the piston moves in and out due to pressure or combustion in the pressure chamber. Alternatively, the piston rods may be configured as gear racks in direct operative engagement with pinion gears of the one way clutches. The clutches are parallel and spaced apart from each other near each end of the cylinders. Each clutch carries a gear on one end which intermeshes with a gear rack assembly having gears and a gear rack which drives a crankshaft and auxiliary flywheel operatively connected to a starter. Once the starter is turned on the kinetic energy of the flywheel and gear rack keeps the on/off clutches in continuous oscillation. The oscillating clutches turn unidirectional drive shafts connected through pinion gears to a main output shaft and main flywheel.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to an internal pressure driven engine for converting reciprocal linear motion of a pair of opposed pistons in each cylinder into unidirectional rotary motion acting on an output shaft. The term internal pressure driven engines can include internal combustion engines, diesel engines, steam engines or fluid pressure driven engines. 
       BACKGROUND OF THE INVENTION 
       [0002]    It is known to use a pair of opposed pistons in each cylinder of an internal combustion engine and to convert the linear reciprocating motion of the pistons into a rotary motion of a drive shaft. 
         [0003]    Such an engine having opposed pistons in each cylinder operating a crank shaft on opposite ends of the cylinder is shown in U.S. Pat. No. 876,870 (Gordon). 
         [0004]    It is also known to use a pair of opposed pistons in each cylinder operating through a rack and pinion gear to convert the reciprocating movement to rotary motion and shown in U.S. Pat. No. 2,079,289 (Janicke) and U.S. Pat. No. 3,384,057 (Boone). 
       ASPECTS OF THE INVENTION 
       [0005]    It is an aspect of the invention to increase the power of the engine by linking each piston rod of the pistons to a respective pivot arm of a one way clutch mechanism to cause reciprocating movement of each clutch mechanism and each clutch mechanism being operatively connected through a gear and rack to a crankshaft mechanism with an auxiliary flywheel to provide continuous rotational movement of an output shaft operatively connected to each clutch. The invention contemplates piston power transmission to the clutch mechanisms through pivoting arms and piston rods in one instance, and pinion gears driven by piston rods configured as gear racks in another—the latter providing increased efficiency over the former. 
       SUMMARY OF THE INVENTION 
       [0006]    An internal pressure driven engine of the type capable of converting reciprocal linear powered motion into unidirectional rotary motion for acting on an output drive, comprising: an engine block having at least one pair of first and second cylinders with each cylinder having an annular interior cylinder wall; a pair of opposed pistons within each cylinder, each piston having an inwardly facing end and an outwardly facing end; the pistons and the cylinder wall forming a pressure chamber between inwardly facing ends of the pistons; means creating pressure within the pressure chamber to cause both pistons to move axially in a reciprocating movement to and from each other; a piston rod pivotally attached to the outer end of each piston and extending axially outwardly from the outer end of the cylinder; each piston rod having an outer end pivotally connected to a pivot arm on a respective one way clutch to cause reciprocal rotation of the one way clutch with the clutch and pivot arm reversing direction of rotation with each outward and inward stroke of the piston; each first and second cylinder of the pair being parallel to each other and spaced apart a sufficient distance from each other so that the end of a piston rod extending from one end of the first cylinder is pivotally connected to a first pivot arm on an adjacent first one way clutch and the end of the piston rod extending from an adjacent end of the second cylinder is pivotally connected to a second pivot arm on the adjacent first one way clutch with one of the piston rods moving in an outward stroke while the other is moving in an inward stroke; the piston rods extending from opposite ends of the first and second cylinders being pivotally connected to pivot arms on a second one way clutch to cause it to simultaneously rotate in a direction opposite to the first one way clutch and both the first and second pivot arm each connected through a clutch mechanism to an output shaft and drive gear with the clutch alternating between engage and disengage position to convert the reciprocating movement of the first and second pivot arm to continuous unidirectional rotation. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a top plan view of one embodiment of the invention; 
           [0008]      FIG. 2  is a side elevational view of the invention; 
           [0009]      FIG. 3  is a cross section view of the invention taken on line  3 - 3  of  FIG. 1 ; 
           [0010]      FIG. 4  is an end elevational view of the invention looking toward the right end of  FIG. 2 ; 
           [0011]      FIG. 5  is a cross sectional view through one of the one way clutches used in the invention; 
           [0012]      FIG. 6  is a top plan view of another embodiment of the invention similar to  FIG. 1  but having two pairs of cylinders; 
           [0013]      FIG. 7  is an end elevational view of the embodiment of the invention shown in  FIG. 6  and having two pairs of cylinders; 
           [0014]      FIG. 8  is a top plan view of an embodiment of the invention employing gear racks and pinion gears for piston power transmission; 
           [0015]      FIG. 9  is a front elevational view of the embodiment of the invention of  FIG. 8  taken at a different point in time; 
           [0016]      FIG. 10  is a side elevational view of the embodiment of  FIGS. 8 and 9 ; 
           [0017]      FIG. 11  is a top plan view of another embodiment of the invention wherein the piston rods are gear racks directly driving pinion gears; 
           [0018]      FIG. 12  is a front elevational view of the embodiment of  FIG. 11 ; and 
           [0019]      FIG. 13  is a side elevational view of the starter mechanism portion of the embodiment of  FIGS. 11 and 12 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    Referring now to the drawings and in particular to  FIGS. 1-4 , the internal pressure driven engine is indicated as a whole by the numeral  10 . The engine  10  has an upper cylinder  12  and a lower cylinder  14  in an engine block  16 . 
         [0021]    For simplifying the drawings, the detailed shape of the engine block  16  will not be shown since the block may be of any shape needed to contain the various engine components which will later be described herein. The drawings will show the various components of the engine in their relative locations with respect to each other and how they are operatively interconnected with each other. It will be understood that suitable openings in the engine block will be provided for mounting bearings, gears, clutches and various other components of the engine. 
         [0022]    The engine  10  shown in  FIGS. 1-4  will be described as an internal combustion engine, however the overall arrangement of the working parts of this engine could apply equally to diesel engines, steam engines or other types of fluid pressure driven engines. 
         [0023]    The cylinders  12  and  14  can be bored in the engine block  16  or made as separate parts and fastened to the block. The cylinders may contain conventional spark plugs, intake and exhaust ports or valves (not shown for simplicity). 
         [0024]    The upper cylinder  12  has opposed pistons  18 L and  18 R therein with a combustion or pressure chamber  20  therebetween and the lower cylinder  14  has opposed pistons  22 L and  22 R with combustion or pressure chamber  24  therebetween. 
         [0025]    The pistons  18 L and  18 R have respective piston rods  26 L and  26 R pivotly connected to the outer ends thereof and extending axially outwardly therefrom, the outer ends of the piston rods  26 L and  26 R being respectively connected to pivot arms  28 L and  28 R which are respectively connected to clutches  30 L and  30 R to cause the clutches to rotate a predetermined distance in a reciprocating motion as the pistons move inwardly and outwardly within the cylinder  12 . The clutches  30 L and  30 R are conventional commercially available cam clutches such as shown in  FIG. 5  which will be described in further detail later. 
         [0026]    Likewise the pistons  22 L and  22 R have respective piston rods  34 L and  34 R pivotally connected to the outer ends thereof and extending axially outwardly therefrom, the outer ends of the piston rods  34 L and  34 R being respectively connected to pivot arms  36 L and  36 R which are respectively connected to the clutches  30 L and  30 R to cause the clutches to rotate back and forth a predetermined distance in a reciprocating motion as the pistons move inwardly and outwardly within the cylinder  14 . 
         [0027]    It may be seen in  FIG. 2  that pivot arms  28 L and  36 L extend in opposite directions from each other and pivot arms  28 R and  36 R also extend in opposite directions so that when the pistons  18 L and  18 R are moving axially outwardly due to combustion, the pistons  22 L and  22 R are moving axially inwardly producing compression within the cylinder  14 . 
         [0028]    Referring now to  FIG. 1 , the clutch  30 L has a gear  38 L attached to the opposite end from the pivot arm  36 L to move back and forth with the reciprocating movement of the clutch  30 L. Similarly the clutch  30 R has a gear  38 R attached to the opposite end from the pivot arm  36 R to move back and forth with the reciprocating movement of the clutch  30 R. Extending from each end of clutches  30 L and  30 R are center shafts  40 L and  40 R which are operatively connected to the clutches  30 L and  30 R in such manner as to rotate continuously in one direction regardless of the back and forth reciprocal motion of the clutches. The shafts  40 L and  40 R have respective bearings  42  on each end thereof. The shafts  40 L and  40 R respectively have gears  44 L and  44 R affixed to one end thereof and intermeshing with a main drive gear  46  which is connected to a drive shaft  48  on which is mounted a flywheel  50 . The gear  46  and shaft  48  are mounted in a suitable bearing  52 . 
         [0029]    The clutches  30 L and  30 R are both of the type shown in cross section in  FIG. 5  and are commercially available Morse cam clutches of the type shown in U.S. Pat. No. 3,542,442 (Kent) which is incorporated herein in its entirety for the purposes of reference to the detailed working of the clutch. As shown in  FIG. 5 , the clutches  30 L and  30 R have an outer race  54  and an inner race  56  secured to shaft  40 L or  40 R by a key  58  to cause the inner race  56  and shaft to rotate together. A pair of bearings  60  are located between the inner and outer race. 
         [0030]    When the clutch is engaged, the outer race  54 , the inner race  56  and the shaft  40 L or  40 R rotate together in the same direction. When the clutch is disengaged the outer race  54  rotates in the opposite direction as the inner race  56  and shaft  40 L or  40 R. The timing of engage and disengage of the clutches is such that the clutch is engaged when the outer race  54  is moving in one direction but is disengaged when the outer race  54  is moving in the opposite direction. Thus it can be seen the inner race  56  and the shafts  40 L and  40 R are moved only in one direction by step by step intermittent engagement with the outer race  54  but the inner race  56  and shafts  40 L and  40 R rotate continuously in one direction by forward momentum as will be explained. 
         [0031]    In order to start the engine and provide continuous unidirectional rotation of the shafts  40 L and  40 R a gear and gear rack assembly  62  intermeshes with gears  38 L and  38 R as will be further described with respect to  FIGS. 1 and 3 . 
         [0032]    Referring now to  FIGS. 1 ,  3  and  4 , the gear rack assembly  62  has a pair of intermediate gears  64 L and  64 R which respectively intermesh with gears  38 L and  38 R and with teeth  68 L and  68 R on a vertical gear rack  66 . The gear rack  66  is pivotally connected to a connecting rod  70  which in turn is connected to a crankshaft  72  mounted in bearings  74 . The crankshaft  72  carries an auxiliary flywheel  76  on one end thereof. The auxiliary flywheel  76  has a ring gear  78  around its periphery. An electric starter  80  has a driving gear  82  which intermeshes with the ring gear  78 . When the starter  80  is turned on, the driving gear  82  rotates and causes rotation of the ring gear  78  and thereby causes the auxiliary flywheel  76  to rotate along with the crankshaft  72 . This combination of rotation and oscillation causes the gear rack  66  to move up and down and rotate intermediate gears  64 L and  64 R, as well as gears  38 L and  38 R, one way clutches  30 L and  30 R, pivot arms  28 L and  28 R and pivot arms  36 L and  36 R with piston rods  26 L,  26 R,  34 L,  34 R moving with pistons  18 L,  18 R,  22 L and  22 R. This movement of the above described parts activates intermittent combustion or pressurization within the cylinders  12  and  14  along with the intermittent engagement and disengagement of the clutches  30 L and  30 R. 
         [0033]    After combustions in cylinders  12  and  14 , the starter  82  stops and gears  82  and  78  disengage. The engine  10  continues to rotate due to stored kinetic energy in the flywheel  76  and combustion or injection of pressure continues in cylinders  12  and  14 . Combustion in cylinders  12  and  14  creates pressure which is applied to the inner ends of the pistons. The pistons  18 L and  18 R are driven outwardly with equal pressure force and simultaneously pistons  22 L and  22 R are driven inwardly. 
         [0034]    When the piston  18 L is pressure driven outwardly, it drives connecting rod  26 L which drives pivot arm  28 L and engaged one way clutch  30 L which is transmitting torque onto shaft  40 L. At the same time piston  18 R is driven with equal pressure force as is piston  18 L. Piston  18 R drives connecting rod  26 R which drives pivot arm  28 R and disengaged one way clutch  30 R and pinion gear  38 R. Pinion gear  38 R drives pinion gear  64 R which drives gear rack  66 , connecting rod  70 , crankshaft  72  and flywheel  76 . As gears  38 L and  38 R mounted on clutches  30 L and  30 R are caused to intermittently rotate back and forth in an oscillating motion, they in turn, transfer the same oscillation motion to the intermediate gears  64 L and  64 R which causes the gear rack  66  to move up and down causing continuous movement of the connecting rod  70 , rotation of the crankshaft  72  and the flywheel  76 . 
         [0035]    The clutches  30 L and  30 R are timed so that when one is engaged the other is disengaged. The intermeshing of the gears of the gear and rack assembly  62  is such that even though only one of the one way clutches  30 L or  30 R is transmitting rotational force at any one time, this force is transferred through the gears of the assembly and the gear rack  66  to the opposite gear. Once the crankshaft  72  and the flywheel  76  are set in motion, the momentum or kinetic energy of the rotating flywheel  76  causes continuous rotational force to be transferred as continuous oscillating force to the one way clutches  30 L and  30 R which covert the oscillating motion to continuous rotation of the shafts  40 L and  40 R, gears  44 L,  44 R and  46  and ultimately the main drive shaft  48  and the main flywheel  50 . 
         [0036]    Thus it may be seen that the gear rack assembly  62  serves not only to transfer the rotational force of the starter to the clutches  30 L and  30 R, but it also operatively interconnects the movement of the piston rods  26 L and  34 L with piston rods  26 R and  34 R to assure continuous oscillating movement of the clutches  30 L and  30 R due to the continuous rotation of the auxiliary flywheel  76 . 
         [0037]    While for the purpose of simplicity the main description of the operation of the engine deals with the embodiment shown in  FIGS. 1-4  wherein one pair of cylinders are shown, it should be understood that any number of pairs of cylinders can be used and interconnected with the gear and rack assembly. 
         [0038]    Another embodiment of the invention is shown in  FIGS. 6 and 7 , which is similar in most respects to that shown in  FIGS. 1-4  except that it uses two pairs of cylinders instead of one. In this embodiment the engine is identified by the numeral  10 ′. The parts of engine  10 ′ that are identical to engine  10  will bear identical numerals to those in  FIGS. 1-4  except that the parts associated with the second pair of pistons will be identified with numerals bearing a prime (′). 
         [0039]    Cylinders  12 ′ and  14 ′ are mounted adjacent the opposite ends of clutches  30 L and  30 R from the cylinders  12  and  14 . Cylinder  12 ′ contains opposed pistons  18 L′ and  18 R′ respectively connected to piston rods  26 L′ and  26 R′ which in turn are connected to pivot arms  28 L′ and  28 R′ mounted one end of clutches  30 L and  30 R. Cylinder  14 ′ contains a pair of opposed pistons, connected to piston rods and pivot arms similar to those associated with cylinder  12 ′ but are not show for the purpose of simplicity. The interaction between the parts associated with cylinders  12 ′ and  14 ′ are similar to those of cylinders  12  and  14  shown in  FIG. 2 . 
         [0040]    In  FIG. 6  it may be seen that the parts associated with cylinder  12  and  12 ′ are connected to opposite ends of the clutches  30 L and  30 R. The pistons in both cylinders  12  and  12 ′ are both shown as in the same position within their respective cylinders. This is necessary since they are connected to the same clutch and move with the clutch as it oscillates back and forth as described with regard to the embodiment in  FIGS. 1-4 . 
         [0041]    It is also possible that the pistons and piston rods could be connected to two separate clutches instead of a single clutch. In such instance, the pistons need not be moving together in the same respective position within the cylinder. For example one set of pistons could be in the retracted position while the other set of pistons would be in the extended position. 
         [0042]    As shown in  FIGS. 6 and 7 , when both pairs of pistons are connected to the same clutch only one gear and rack assembly  62  is needed. If each pair of pistons is connected to two separate clutches, there will need to be a separate gear and rack assembly for each clutch. The operation of the engine  10 ′ is basically the same as engine  10  and will not be described in further detail. No side elevational view is shown of the embodiment shown in  FIGS. 6 and 7  since it is identical to the view shown in  FIG. 2 . The cross section view in  FIG. 3  showing the gear and rack assembly  62  applies to both the engine  10  and  10 ′. 
         [0043]    It will be appreciated that the embodiments of the invention presented and described above typically employ pivot arms  28 ,  36  respectively connected to piston rods  26 ,  34  for transferring the piston force through a gear chain to an output. While the embodiments presented and described are efficient and effective for their intended purpose, the implementation of pivot arms interconnected with piston rods, which are themselves pivotally connected to the associated pistons, result in a torque arm that changes with translational movement. As a result, the output force varies accordingly. While the losses associated with this pivotal action are somewhat minimal, it is most desirable to provide power transmission from the pistons through a torque arm that is constant. Such an embodiment is shown in  FIGS. 8-10 . 
         [0044]    With reference now to  FIGS. 8-10 , it can be seen that an internal pressure driven engine made in accordance with another embodiment of the invention is designated generally by the numeral  10 ″. For purposes of facilitating an understanding of this embodiment, where elements of the embodiment of  FIGS. 8-10  correspond to elements of the embodiments in  FIGS. 1-7 , the same numeral designation is employed, with the addition of a double prime (″) marker. 
         [0045]    As shown in  FIGS. 8 and 10 , a drive shaft  48 ″ is connected to a flywheel  50 ″, comprising an output for the internal pressure driven engine  10 ″. The drive shaft  48 ″ is mounted through bearings  52 ″ to pinion gears, which will be discussed below. 
         [0046]    Also included as part and parcel of the instant invention is a starting mechanism similar to that presented earlier herein. In that regard, a connecting rod  70 ″ connects to a crankshaft  72 ″ which is rotatable through bearings  74 ″, as shown. The crank shaft  72 ″ is connected to an auxiliary flywheel  76 ″, which in turn is connected to a starting motor, driving gear and ring gear, similar to the starting motor  80 , driving gear  82  and ring gear  78 , not shown here for purposes of simplicity. The connecting rod  70 ″ interconnects with a two-sided gear rack  66 ″ for purposes similar to those presented herein, as will become apparent below. 
         [0047]    As shown in  FIGS. 8-10 , the internal pressure driven engine  10 ″ includes four cylinders  100 ,  102 ,  104 ,  106 , each having a pair of opposed pistons  100   a ,  100   b,    102   a,    102   b,    104   a,    104   b,    106   a,    106   b,  received therein. Serving as piston rods and connected to each of the piston heads  100   a,    100   b,    106   a,    106   b  are respective gear racks  100   c,    100   d,    102   c ,  102   d,    104   c,    104   d,    106   c,    106   d.  These piston rod gear racks are respectively connected to piston pins  100   e,    100   f,    102   e ,  102   f,    104   e,    104   f,    106   e,    106   f,  as illustrated. 
         [0048]    One way clutches  108 ,  110  are positioned on opposite sides of the cylinders  100 - 106 . These one way clutches operate in a manner similar to that presented above, being freewheeling in one direction and in driving engagement with respective clutch shafts  124 ,  126  in the other. Each of the one way clutches  108 ,  110  has a respective center pinion gear  112 ,  114  and outboard pinion gears  116 ,  118  associated with the clutch  108 , and outboard pinion gears  120 ,  122  associated with the clutch  110 . The clutch shafts  124 ,  126 , selectively driven by the associated one way clutch assembly  108 ,  110 , are rotatably mounted in bearings  42 ″ and appropriately splined, keyed or otherwise connected to respective output drive gears  128 ,  130 . These output drive gears  128 ,  130  drive an output driven gear  132  splined or otherwise connected to the drive shaft  48 ″. 
         [0049]    It will be appreciated by those skilled in the art that axial movement of the piston heads  100   a,    100   b - 106   a,    106   b,  within respective cylinders  100 - 106 , cause the gear racks  100   c,    100   d - 106   c,    106   d  to linearly translate, without rotational movement, across respectively associated outboard pinion gears  116 - 122 , transmitting the resultant rotational movement through clutch shafts  124 ,  126  to pinion output drive gears  128 ,  130 , which in turn drive output driven gear  132 , shaft  48 ″ and flywheel  50 ″. 
         [0050]    The starter employed for the internal pressure driven engine  10 ″ includes the flywheel  76 ″, crankshaft  72 ″, and two-sided gear rack  134  connected by an appropriate universal joint or the like to the connecting rod  70 ″. The gear rack  134  is interposed between pinion gear  114  of the one way clutch  110  and pinion gear  112  of the one way clutch  108 . The gear rack  134  is appropriately mounted on bearings  136 ,  138 . The gear rack  134  drives pinion gears  112  and  114  of the one way clutches  108  and  110 . Starting of the engine with an associated starting motor, driving gear and ring gear (not shown) may be achieved in the fashion presented earlier herein. 
         [0051]    It will be readily appreciated by those skilled in the art that the linear translation of the piston rod gear racks  100   c,    100   d - 106   c,    106   d  and their driving interconnection with uniquely associated pinion gears  116 - 122  achieves the maintenance of a constant torque arm for the output power of the piston heads as they reciprocate within the associated cylinders. Accordingly, power losses are minimized and efficiency is maximized. Those skilled in the art will readily appreciate that the implementation of a piston rod serving as a gear rack in engagement with a pinion gear on a one way clutch may be substituted for the piston rod and pivot arm interconnection in the embodiment earlier presented herein. 
         [0052]    Referring now to  FIGS. 11-13 , an appreciation may be obtained of yet another embodiment of the invention designated generally by the numeral  150 . In this embodiment, gear racks serve as piston rods for directly driving pinion gears through associated one way clutches to achieve the desired power output. As shown in an exemplary embodiment, cylinders  152   a - 152   d  respectively receive pistons  154   a - 154   d,  with the pistons  154   a, b  being interconnected by a common piston rod in the form of a gear rack  156 , and the pistons  154   c, d  being similarly interconnected by a gear rack  158 . The gear rack  156  is in driving engagement with pinion gears  160   a,    160   b,  while gear rack  158  is in driving communication with pinion gears  162   a,    162   b.  The pinion gears  160   a,    162   a  are respectively interconnected through a one way clutch  164  to a drive shaft  168 . Similarly, pinion gears  160   b,    162   b  are interconnected through a one way clutch  166  to a drive shaft  170 . Those skilled in the art will appreciate that the one way clutches  164 ,  166  are respectively oppositely directed, being freewheeling in opposite directions, to effect mutually exclusive output drive to the drive shafts  168 ,  170 . 
         [0053]    Pinion gears  172 ,  174  are respectively mounted on drive shafts  168 ,  170 , with the pinion gears  172 ,  174  being operative to mutually exclusively and alternately drive the pinion gear  176  mounted upon output shaft  178 . The output shaft  178  is supported by bearing  180 , and is interconnected with the output flywheel  182 . 
         [0054]    With an understanding of the structure just described, those skilled in the art will appreciate that as the pistons  154   a - d  reciprocate in associated cylinders  152   a - d , the associated gear racks  156 ,  158  cause driving interengagement with pinion gears  160   a, b , and  162   a, b  which, through associated one way clutches  164 ,  166  in mutually exclusive operative engagement, drive the pinion gear  176  through respective pinion gears  172 ,  174  mounted upon drive shafts  168 ,  170 . 
         [0055]    With reference now to  FIG. 13 , in association with  FIGS. 11 and 12 , an appreciation can be obtained of the starter mechanism  184 . Here, a gear rack  186  is in functional engagement with pinion gears  188 ,  190 . As shown, pinion gear  188  is fixed to a spacer or adapter  198   a,  which in turn is fixed to pinion gear  162   a.  Pinion gears  160   a  and  162   a  are fixed to one way clutch  164 . Accordingly, pinion gears  160   a,    162   a,    188  rotate together. Similarly, pinion gear  190  is fixed to a spacer or adapter  198   b,  which in turn is fixed to pinion gear  162   b.  Pinion gears  160   b,    162   b  are fixed to one way clutch  166 . Accordingly, pinion gears  160   b,    162   b,    190  rotate together. A connecting rod  192  interconnects the gear rack  186  with a flywheel  194 , which is in selective operative engagement with a starter motor  196 . Those skilled in the art will appreciate that as with the mechanism of  FIG. 4 , actuation of the starter motor  196  causes rotation of the flywheel  194 , which, through the connecting rod mechanism  192 , causes reciprocation of the gear rack  186  which, through pinion gears  188 ,  190  causes reciprocation of the pistons  154   a - 154   d  within associated cylinders  152   a - 152   d  through the interengagement of gear racks  156 ,  158  with pinion gears  160 ,  162 . Of course, once the engine  150  has started, disengagement of the starter  196  is effected, and operation of the engine continues as it cycles with kinetic energy stored in the flywheel  194 . 
         [0056]    Many variations of the gears and cylinder arrangements can be used without departing from the scope of the invention so long as the combination of two opposed pistons in each cylinder are connected through on/off clutches and through a gear rack assembly to provide continuous rotation of a main output shaft. 
         [0057]    It should also be understood that the overall principle of this engine can be applied to gasoline engines, diesel engines, steam engines or engines using other types of fuel or fluid pressure injected into the cylinders. In cases of steam engines the opposed pistons are caused to move by steam pressure between the pistons rather that combustion of the fuel.