Abstract:
A motor vehicle is provided with a power train having primary and auxiliary internal combustion engines which selectively feed power to a jackshaft. The power accumulated in the jackshaft is conveyed to a speed change transmission. Fuel economy is achieved by utilizing only one engine when lesser power is needed by the vehicle.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to a vehicle having multiple internal combustion engines whose power output can be combined and routed to a transmission for the purpose of improving fuel efficiency and accommodating the power needs of the vehicle. 
         [0003]    2. Description of the Prior Art 
         [0004]    Increasing greenhouse gas emissions to the atmosphere and the increasing cost of fossil fuels have driven the search for means to improve automotive fuel efficiency. One solution has been the hybrid automobile which uses a small fuel-efficient internal combustion engine augmented by a battery-driven electric motor to power the vehicle. Another solution uses two or more internal combustion engines, using their combined power for acceleration, climbing steep grades, etc., and using the power of one engine to cruise economically. 
         [0005]    The present invention relates to the latter solution, using multiple engines for acceleration, and using one engine to cruise. 
         [0006]    Prior vehicles using multiple engines have problems related to the need to design and fabricate new transmission components and even to design entirely new engine blocks and parts thereof to result in a useful product. These requirements entail substantial expenditure of time, technical expertise and financial resources for the design, fabrication, testing and manufacturing of essentially new and untested technology which will then need to be perfected and made reliable to be profitably marketable. 
         [0007]    U.S. Pat. No. 7,270,030 to Belloso describes a speed changing transmission with multiple input ports for multiple-engine vehicles. It calls for a substantial redesign of the transmission, using new parts therefor, so that multiple engines can be bolted onto it. It is not amenable to the use of an unmodified speed change gearbox. 
         [0008]    U.S. Pat. No. 6,637,283 to Belloso describes a control apparatus for a continuously variable transmission capable of receiving power from a plurality of engines. It requires a totally new design of a speed change gearbox which would entail substantial design and development costs and then extensive reliability testing before it can be marketable. 
         [0009]    U.S. Pat. No. 7,080,622 to Belloso describes an internal combustion engine with multiple independently rotating crankshafts and a common output shaft, which functions like a combination of engines in one vehicle. It calls for the design of an entirely new type of engine block and the installation of novel components therein. This would call for substantial design, tooling, fabrication and testing costs before it can be ready for mass manufacture. 
         [0010]    It is, therefore, an object of this invention to provide a vehicle equipped with two or more engines for the purpose of achieving improved fuel efficiency through the use of currently available manual or automatic speed change transmissions without the need to make substantial modifications thereof. 
         [0011]    It is another object of the present invention to provide a vehicle of the aforesaid nature wherein the operational speed of each engine is separately controllable, and the output powers of said engines can be accumulated and fed to a speed change transmission. 
         [0012]    These objects and other objects and advantages of the invention will be apparent from the following description. 
       SUMMARY OF THE INVENTION 
       [0013]    The above and other beneficial objects and advantages are accomplished in accordance with the present invention by a motor vehicle having a chassis elongated upon a center axis between paired front and paired rear wheels, and a power train comprised of:
   a) primary and auxiliary internal combustion engines located one in front of the other adjacent said front wheels, each engine having a power output shaft extending in parallel juxtaposition with said center axis and both having the same direction of rotary motion,   b) releasible coupling and power transfer means associated with each output shaft,   c) a speed change transmission positioned rearwardly of said engines and having an input shaft, and   d) a jackshaft laterally spaced from said engines in parallel relationship to said center axis, and rotatably secured by said chassis to selectively receive and accumulate power from said engine output shafts and convey said accumulated power to the input shaft of said speed change transmission, whereby   e) economy of operation is achieved by deactivating one engine when lesser power is needed for propulsion of the vehicle.   
 
         [0019]    Said releasable coupling and power transfer means may be a movable sheave torque converter unit (CVT) that produces continuously variable output rotational speeds, or may be a fluid torque converter. Still other specific embodiments of the releasible coupling and power transfer means include releasible automatic or manually activated clutches such as a centrifugal clutch, electromagnetic power clutch, cone clutch and friction plate clutch. 
         [0020]    Said jackshaft may be divided into sections, each section being interactive with a separate engine, with each section releasibly coupled to the next contiguous section by way of a suitable coupling means such as a free wheeling clutch such as a sprag clutch. Such construction serves to ensure more complete decoupling of one engine from the other during low power operations such as when traveling at cruising speeds on a highway. 
         [0021]    The primary engine may be made to have about ½ to ⅓ the size and power capacity of the auxiliary engine to maximize fuel economy while cruising with minimum load, and to maximize performance in acceleration and other heavy duty capacity. Furthermore, each engine may be coupled to the jackshaft via a free-wheeling clutch, such as a sprag clutch, so that it becomes possible to choose to power the vehicle with only the primary engine for light duty operation (e.g., for cruising with minimum load), or with only the auxiliary engine for medium duty operation (e.g., for cruising when fully loaded), and with power from both the primary engine and the auxiliary engine for maximal acceleration or heavy duty operation. 
         [0022]    In general, an internal combustion engine is most fuel-efficient when it is operated at about 60% to 90% of its rated capacity. It is generally less fuel-efficient when operated outside this range. Furthermore, an automobile weighing about 3000 lbs may need only about 30 horsepower (HP) to maintain cruising speed on the highway, but may need about 120 HP to accelerate within an acceptably short time to keep up with traffic. In a conventional automobile equipped with only one engine, this vehicle would have to be equipped with an engine having a rated capacity of at least 120 HP, yet when it is operated to produce only 30 HP for cruising it would be operating at only 25% of its rated capacity which is too far below the 60% to 90% range of its rated capacity for it to be fuel-efficient. It would be preferable, from the fuel efficiency standpoint, for the vehicle to be powered by a 40 HP engine for cruising, since this engine would then be operating at 75% of its rated capacity, i.e. at the middle of its most fuel efficient range. 
         [0023]    To permit selective use of either the primary engine or the auxiliary engine, or both, the fuel supply of each engine may be controlled through a separate gas pedal for each engine. Said gas pedals may be most conveniently operated by the operator&#39;s right foot if they are placed next to each other in the usual location of the gas pedal, with their size and position being adjusted so that either pedal may be independently depressed to control the operation of either engine, or both may be depressed together, by the right foot, to operate both engines at the same time. 
         [0024]    Alternatively, load sensors associated with the power train may be used to send input data to a vehicle&#39;s power management computer to regulate selective use of either or both engines, as needed, to suit operating conditions. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0025]    For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing forming a part of this specification and in which similar numerals of reference indicate corresponding parts in all the figures of the drawing: 
           [0026]      FIG. 1  is a schematic top view of an embodiment of the vehicle of the present invention. 
           [0027]      FIG. 2  is a schematic top view of a first alternative embodiment of the vehicle of the present invention. 
           [0028]      FIG. 3  is a schematic top view of a second alternative embodiment of the vehicle of the present invention. 
           [0029]      FIG. 4  is a schematic top view of a third alternative embodiment of the vehicle of the present invention. 
           [0030]      FIG. 5  is a schematic top view of a fourth alternative embodiment of the vehicle of the present invention. 
           [0031]      FIG. 6  is a schematic top view of a fifth alternative embodiment of the vehicle of the present invention. 
       
    
    
       [0032]    For clarity of illustration, details which are not relevant to the invention, such as engine mounts, transmission mounts, undercarriage of the vehicle, and internal parts of the transmission and differential, etc., have been omitted from the aforesaid drawings. Furthermore details of the internal parts of the electric motors, generators, CVT torque converters and sprag clutches, which are well known in the art and readily available in the standard texts on the subjects, are likewise omitted from the aforesaid drawings. 
       DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0033]    Referring now to the drawings wherein one character designates one part of the vehicle,  FIG. 1  shows a vehicle of the present invention having a chassis  11  connected to front bumper  12  and rear bumper  13 , and supported by paired front wheels  14  and paired rear wheels  15 . 
         [0034]    A power train is shown comprised of primary “cruiser” engine  16  mounted on chassis  11 . Primary CVT driver pulley  17  is mounted on output shaft  18  of said primary engine, and is connected to primary CVT driven pulley  19  by drive belt  20 . Driven pulley  19  is fixedly mounted on jackshaft  21  which is rotatably journaled on bearings  22  which are anchored on chassis  11 . Jackshaft  21  is connected to input shaft  23  of speed change transmission  24  via chain  25  and sprockets  26 . Power from speed change transmission  24  is conveyed via front universal joint  27 , propeller shaft  28 , rear universal joint  29 , pinion  30 , and differential  31  to the rear wheels  15  to drive the vehicle. 
         [0035]    The size and power capacity of primary engine  16  is designed to be sufficient to keep the vehicle at cruising speed on a fairly level highway, but small enough so that it can maintain said cruising speed in the most fuel-efficient manner. 
         [0036]    For heavy duty operation, such as for acceleration, towing, carrying heavy load, or climbing a steep grade, the vehicle is equipped with an auxiliary engine  32  whose size and power capacity is designed so that, when it is operated together with primary engine  16 , their combined power will be sufficient to power the vehicle during said heavy duty operations. 
         [0037]    Auxiliary CVT drive pulley  33  is mounted on the output shaft  34  of auxiliary engine  32  and is connected to auxiliary driven pulley  35  by auxiliary drive belt  36 . Auxiliary driven pulley  35  is fixedly mounted on jackshaft  21  so that when both primary engine  16  and auxiliary engine  32  are operated at the same time, their combined power is conveyed by jackshaft  21  to speed change transmission  24  thence to said rear wheels. The two engines  16  and  32  are operated together for acceleration and other heavy duty operations. After the vehicle reaches cruising speed, auxiliary engine  32  is throttled down to idle speed or stopped to conserve fuel, and the vehicle is maintained at cruising speed by power from primary engine  16  alone. 
         [0038]    The CVT torque converter, comprised of drive pulley  33 , drive belt  36  and driven pulley  35 , automatically becomes disengaged when auxiliary engine  32  runs below a minimum “engagement speed” such as when it is stopped or run at idle speed. Accordingly, when the vehicle is traveling at cruising speed, the slowed or stopped auxiliary engine  32  is automatically disengaged from the rest of the power train so that it will not exert a drag on primary engine  16 . If engine  32  runs at idle speed, its power is readily available when needed by simply increasing its fuel supply. If it is stopped, means for it to be quickly restarted to provide auxiliary power may be provided, in a manner similar to current hybrid vehicles. 
         [0039]    Primary engine gas pedal  37  regulates fuel supply to primary engine  16 , and auxiliary engine gas pedal  38  regulates fuel supply to auxiliary engine  32 . The driver, therefore, is able to selectively operate either engine  16  or engine  32  by selectively depressing its corresponding gas pedal,  37  or  38 . To operate both engines  16  and  32  at the same time, he simply depresses both pedals simultaneously. 
         [0040]      FIG. 2  shows a first alternative embodiment of the vehicle  41  having a chassis  42 , front bumper  43 , rear bumper  44 , front wheels  45  and rear wheels  46 . Primary engine  47  is coupled to a fluid torque converter  48  on whose output shaft  49  is mounted drive sprocket  50 . Jackshaft  51  is mounted alongside primary engine  47  rotatably journaled on bearings  52  which are anchored on chassis  42 . Power from primary engine  47  is transmitted to jackshaft  51  via torque converter  48 , drive sprocket  50 , endless chain  53  and driven sprocket  54  which is fixedly mounted on jackshaft  51 . 
         [0041]    The size and power capacity of primary engine  47  is selected to be sufficient to maintain the vehicle  41  at cruising speed, and yet be small enough to perform such function in the most fuel-efficient manner. 
         [0042]    For heavy duty operation, such as acceleration and climbing a steep grade, auxiliary engine  55  is installed in vehicle  41  to provide additional power. Auxiliary engine  55  is coupled to auxiliary fluid torque converter  56  on whose output shaft  57  is mounted auxiliary drive sprocket  58  which is connected by endless chain  59  to driven sprocket  60  which is fixedly attached to the outer race  61  of sprag clutch  62  whose inner race  63  is fixedly mounted on jackshaft  51 . Jackshaft  51  is connected to speed change transmission  64  via jackshaft drive sprocket  65 , endless chain  66  and driven sprocket  67  which is mounted on input shaft  68  of transmission  64 . 
         [0043]    The power capacity and size of auxiliary engine  55  is selected so that its power output, when combined with the power output of primary engine  47  will be sufficient to give the vehicle  41  satisfactory performance in acceleration, climbing a grade and other heavy duty operations in which the vehicle is expected to be used. 
         [0044]    To operate the vehicle, primary engine  47  and auxiliary engine  55  are started and speeded up. Power from primary engine  47  is conveyed via fluid torque converter  48 , thence through chain  53  and sprockets  50  and  54  to jackshaft  51 , thence via chain  66  and sprockets  65  and  67  to speed change transmission  64  which is shifted to “drive” thereby transmitting power to propeller shaft  69  and differential  70  to drive wheels  46 . Additional power from auxiliary engine  55  is conveyed via auxiliary fluid torque converter  56  through chain  59  and sprockets  58  and  60  thence via sprag clutch  62  and jackshaft  51  to chain  66 , sprockets  65  and  67  and transmission  64  to supply additional power to the wheels  46 . 
         [0045]    After the vehicle  41  reaches cruising speed, auxiliary engine  55  is throttled down to idle speed or stopped altogether to conserve fuel. When auxiliary engine  55  is slowed down or stopped, sprag clutch  62  disengages outer race  61  automatically from inner race  63  thereby decoupling the auxiliary engine  55  completely from jackshaft  51  and preventing the auxiliary engine  55  from exerting a drag force on the vehicle. Vehicle  41  then continues to travel, fuel-efficiently, on power from primary engine  47  alone. 
         [0046]    Whenever additional power is again needed, the operator simply feeds more fuel to auxiliary engine  55 , speeding it up, which will cause sprag clutch  62  to be automatically engaged, thereby transmitting the additional power to jackshaft  51  to help power the vehicle. 
         [0047]      FIG. 2  shows auxiliary engine  55  to be substantially larger than primary engine  47 . This is to illustrate that for the purpose of maximizing fuel economy it may be advantageous to downsize the cruiser engine (in this case, primary engine  47 ) to about one-fourth of the total power capacity available to the vehicle. The literature suggests that the average automobile is able to cruise comfortably, on a relatively level highway, using as little as about 25 to 35 horsepower which is approximately one-fourth of the power output of the engine of an average automobile. Conversely, for maximal performance, the power of the auxiliary engine may be selected to be two to four times that of the primary engine. 
         [0048]    Primary engine gas pedal  39  regulates fuel supply to primary engine  47  and auxiliary engine gas pedal  40  regulates fuel supply to auxiliary engine  55 . The operator, therefore, is able to selectively operate either engine  47  or engine  55  by selectively depressing its corresponding gas pedal,  39  or  40 . To operate both engines at the same time he simply depresses both pedals simultaneously with one foot which is easy to do since the two pedals are located side by side. 
         [0049]    A second alternative embodiment, illustrated in  FIG. 3 , shows a vehicle  71  having a chassis  72 , front bumper  73 , rear bumper  74 , front wheels  75 , rear wheels  76 , primary engine  77  and auxiliary engine  78 . A centrifugal clutch  79  is mounted on the output shaft  80  of primary engine  77  and is coupled to jackshaft  81  by endless chain  82  and sprockets  83 . Jackshaft  81  is rotatably mounted on bearings  84 . Auxiliary centrifugal clutch  85  is mounted on the output shaft  86  of auxiliary engine  78 , and is connected to jackshaft  81  by endless chain  87  and sprockets  88 . 
         [0050]    To operate the vehicle  71 , primary engine  77  and auxiliary engine  78  are started and speeded up. Centrifugal clutch  79  has a preset “engagement speed” and when the rotational speed of output shaft  80  exceeds the engagement speed the centrifugal clutch  79  automatically engages and transmits power to jackshaft  81  via endless chain  82  and sprockets  83 . Similarly, auxiliary centrifugal clutch  85  has a preset engagement speed, and when the rotational speed of output shaft  86  exceeds this engagement speed the centrifugal clutch  85  automatically engages and transmits power to jackshaft  81  via endless chain  87  and sprockets  88 . Jackshaft  81  then transmits this combined power of the two engines  77  and  78  to transmission  89  via jackshaft sprocket  90 , endless chain  91  and transmission sprocket  92  which is mounted on transmission input shaft  93 . Power from transmission  89  is then conveyed through propeller shaft  94  and differential  95  to drive wheels  76  to propel the vehicle  71 . 
         [0051]    When vehicle  71  reaches cruising speed auxiliary engine  78  is slowed down to idle speed (or stopped altogether) to conserve fuel. When the rotational speed of output shaft  86  falls below the engagement speed of centrifugal clutch  85 , centrifugal clutch  85  automatically disengages so that auxiliary engine  78  will not exert any drag on the vehicle. Vehicle  71  then continues traveling economically on power from primary engine  77  alone. 
         [0052]    When additional power is needed such as for accelerating to pass another vehicle, or to climb a grade, auxiliary engine  78  is simply speeded up to be re-engaged automatically via centrifugal clutch  85 , or, if it had been stopped, it is then restarted and speeded up to supply additional power as needed. 
         [0053]    Although a centrifugal clutch is shown in this embodiment, other types of clutches can be used, such as an electromagnetic clutch, friction clutch, or toroidal torque converter. 
         [0054]    Primary engine gas pedal  96  regulates fuel supply to primary engine  77 , and auxiliary engine gas pedal  97  regulates fuel supply to auxiliary engine  78 . The operator, therefore, may selectively operate either engine  77  or engine  78  by selectively depressing its corresponding gas pedal,  96  or  97 . To operate both engines at the same time he simply depresses both pedals simultaneously. 
         [0055]    A third alternative embodiment is illustrated in  FIG. 4  which shows a vehicle  101  having a chassis  102 , front bumper  103 , rear bumper  104 , front wheels  105 , rear wheels  106 , primary engine  107  and auxiliary engine  108 . Primary engine  107  is directly coupled to primary generator  109  which is used to charge primary battery  110  and supply electricity to primary electric motor-generator  111 . Auxiliary engine  108  is directly coupled to auxiliary generator  112  which is used to charge auxiliary battery  113  and supply electricity to auxiliary electric motor  114 . Primary motor-generator  111  is directly mounted on primary jackshaft  115  which is integrated into motor-generator  111  by serving as the axial shaft of the armature of said motor-generator  111 . Jackshaft  115  is rotatably journaled to primary jackshaft bearings  116 . 
         [0056]    Auxiliary electric motor  114  is directly mounted on auxiliary jackshaft  117  which is integrated into electric motor  114  by serving as the axial shaft of the armature of said electric motor  114 . The front end of auxiliary jackshaft  117  is rotatably journaled to auxiliary jackshaft bearing  118 , and its rear end is flexibly coupled via universal joint  119  to the outer race  120  of sprag clutch  121  whose inner race  122  is mounted on a forward extension of jackshaft  115 . Sprag clutch  121  is a freewheeling clutch which automatically engages, in this application, when the speed of rotation of the outer, “driver” race  119  exceeds the rate of rotation of the inner (“driven”) race  122 , and then automatically disengages when the speed of rotation of outer race  120  falls below the speed of rotation of the inner race  122 . 
         [0057]    To operate the vehicle  101  primary engine  107  is started up and run to power generator  109  which supplies electricity to battery  110  and motor-generator  111 . Battery  110  also supplies stored current to motor-generator  111  which then transmits mechanical power to jackshaft  115 . Similarly, auxiliary engine  108  is started and speeded up to drive generator  112  which supplies electric power to battery  113  and auxiliary electric motor  114 , which, upon activation, transmits mechanical power to auxiliary jackshaft  117 , thence via universal joint  119 , sprag clutch outer race  120  which then drives inner race  112  which conveys additional mechanical power to jackshaft  115  upon which it is mounted. The combined power of both electric motors  111  and  114  is then conveyed to speed change transmission  123  via endless chain  124  and sprockets  125 , thence to propeller shaft  126  and differential  127  to drive wheels  106 . 
         [0058]    To control the operation of the vehicle a rheostat pedal may be employed in place of the gas pedal in the operator&#39;s seating area so that he can control the flow of power from electric motors  111  and  114  in accordance to the power needed for the proper operation of the vehicle. The primary engine  107  and auxiliary engine  108  may be equipped with preset controls to permit automatic starting and running of each engine to replenish the charge of each&#39;s associated battery whenever said battery is discharged to a predetermined degree, and to automatically stop running when said batteries are fully charged. Said automatic controls may be further designed to run said engines at optimal speeds to supply additional power to the associated electric motors whenever the operator signals a need for more electricity than what the batteries can deliver. 
         [0059]    When the vehicle  101  reaches cruising speed, auxiliary electric motor  114  may be deactivated so that the vehicle can travel economically on power from motor-generator  111  alone. 
         [0060]    The size and power capacity of primary engine  107  and associated generator  109 , battery  110  and motor-generator  111  are selected so that they are sufficient to permit vehicle  101  to travel comfortably and maintain cruising speed on a relatively level highway, with maximal fuel economy, without the need to receive additional power from auxiliary electric motor  114 . Fuel efficiency is further maximized by recharging battery  110  with electricity generated by motor-generator  111  through regenerative braking, a means well known in the art. 
         [0061]    The size and power capacity of auxiliary engine  108  and associated generator  112 , battery  113  and electric motor  114  are selected so that they are capable of supplying sufficient additional power, as needed, to permit said vehicle  101  to have satisfactory performance in acceleration, climbing a grade, carrying loads or towing, as demanded by the operator, to a degree reasonably expected of a regular motor vehicle. 
         [0062]    The interposition of electrical components (generator, battery and electric motor) to transmit power from the engines (primary and auxiliary) to the jackshaft permits operation of said engines at their most fuel efficient speeds as needed, and for them to be shut down to save fuel when additional electricity is not needed. 
         [0063]    Rheostat pedal  98  regulates the flow of current to primary motor-generator  111 , and rheostat pedal  99  regulates the flow of current to auxiliary electric motor  114 . The operator, therefore, is able to selectively operate either primary motor-generator  111  or auxiliary electric motor  114  by selectively depressing corresponding rheostat pedals  98  or  99 . To operate both motors at the same time he simply depresses both rheostat pedals simultaneously. 
         [0064]      FIG. 5  shows how additional alternative embodiments may be made by combining certain features of any of the foregoing embodiments with selected features of another. The fourth alternative embodiment shown in  FIG. 5  comprises a vehicle  131  having a chassis  132 , front bumper  133 , rear bumper  134 , front wheels  135 , rear wheels  136 , primary engine  137  and auxiliary engine  138 . CVT drive pulley  139  is mounted on output shaft  140  of primary engine  137  and is connected to CVT driven pulley  141  by drive belt  142 . CVT driven pulley  141  is mounted on jackshaft  143  which is rotatably mounted on bearings  144 . Jackshaft  143  is connected to input shaft  145  of speed change transmission  146  via endless chain  147  and sprockets  148 . Power from speed change transmission  146  is conveyed to rear wheels  136  via propeller shaft  149  and differential  150 . 
         [0065]    Auxiliary engine  138  is coupled to fluid torque converter  151  via torque converter sprocket  152 , endless chain  153  and sprag clutch sprocket  154  which is fixedly mounted on the outer race  155  of sprag clutch  156  whose inner race  157  is fixedly mounted on jackshaft  143 . Sprag clutch  156  is a freewheeling clutch whose outer race  155  automatically engages (and drives) the inner race  157  whenever the rate of rotation of the outer race  155  exceeds that of inner race  157 , and automatically disengages when the rate of rotation of outer race  155  is less than that of inner race  157 . 
         [0066]    To operate vehicle  131 , primary engine  137  and auxiliary engine  138  are started and speeded up. When the rate of rotation of primary engine output shaft  140  exceeds the engagement speed of CVT drive pulley  139 , drive pulley  139  engages and drives driven pulley  141  via drive belt  142  which turns jackshaft  143 . Power from auxiliary engine  138  is conveyed to said jackshaft via torque converter  151 , sprocket  152 , endless chain  153 , sprag clutch sprocket  154  and sprag clutch outer race  155  which causes sprag clutch  156  to engage and cause inner race  157  to turn jackshaft  143 , thus combining the power of auxiliary engine  138  with that of primary engine  137  to turn said jackshaft. 
         [0067]    Power from jackshaft  143  is then conveyed to speed change transmission  146  via endless chain  147  and sprockets  148 , and the power is in turn transmitted via transmission  146 , propeller shaft  149 , and differential  150  to rear wheels  136  to drive the vehicle  131 . After the vehicle  131  reaches cruising speed, the auxiliary engine may be throttled down to idle speed or stopped altogether to conserve fuel. When the speed of auxiliary engine  138  falls below that of primary engine  137 , sprag clutch  156  automatically disengages so that neither auxiliary engine  138  or associated torque converter  151  can exert drag on jackshaft  143 . The vehicle  131  will then continue to travel fuel-efficiently on power from primary engine  137  alone. 
         [0068]    Fuel supply to primary engine  137  is regulated through primary engine gas pedal  158 , and fuel supply to auxiliary engine  138  is regulated through auxiliary engine gas pedal  159  which is located alongside gas pedal  158  so that the operator may conveniently depress either pedal singly or depress both pedals at the same time with one foot. He may then easily elect to operate both engines for maximal power, or operate only said primary engine for maximal fuel economy. It should be noted that whenever primary engine  137  slows down below the engagement speed of CVT drive pulley  139 , the associated CVT torque converter automatically disengages. 
         [0069]      FIG. 6  shows a particularly fuel efficient embodiment amenable to easy construction. It comprises a vehicle  161  having a chassis  162 , front bumper  163 , rear bumper  164 , front wheels  165 , rear wheels  166 , primary engine  167  and auxiliary engine  168 . Primary engine  167  is directly coupled to generator  169  which charges battery  170  and supplies current to drive motor-generator  171 . Battery  170  also supplies electric current to drive motor-generator  171 , and receives current from motor generator  171  during regenerative braking. The axial shaft of motor-generator  171  serves as primary jackshaft  172  which is journaled to chassis  162  through bearings  173  and is coupled to the input shaft  174  of transmission  175  via sprockets  176  and endless chain  177 . 
         [0070]    Auxiliary engine  168  is coupled to auxiliary jackshaft  178  via CVT torque converter  179  whose drive pulley  180  is mounted on output shaft  181  of auxiliary engine  168 , and whose driven pulley  182  is mounted on auxiliary jackshaft  178 . Drive belt  183  connects drive pulley  180  to driven pulley  182 . The front end of auxiliary jackshaft  178  is journaled to chassis  162  via auxiliary bearing  184  and its rear end is coupled to the outer race  185  of sprag clutch  186  via universal joint  187 . Sprag clutch  186  is a freewheeling clutch which automatically engages when the speed of rotation of the outer, “driver” race  185  exceeds the rate of rotation of the inner (“driven”) race  188 , and then automatically disengages when the speed of rotation of the outer race  185  falls below the speed of rotation of the inner race  188 . 
         [0071]    To operate vehicle  161 , primary engine  167  is started up and run to power generator  169  which supplies electricity to battery  170  and motor-generator  171 . Battery  170  also supplies stored current to motor-generator  171  which then transmits mechanical power to jackshaft  172 . Similarly, auxiliary engine  168  is started and speeded up to a speed in excess of the “engagement speed” of drive pulley  180  of CVT torque converter  179 , causing the drive pulley to transmit power to driven pulley  182  via drive belt  183 , thereby transmitting mechanical power to auxiliary jackshaft  178 , thence via universal joint  187  to sprag clutch outer race  185  which then drives inner race  188  which conveys additional power to jackshaft  172  upon which it is mounted. The combined power of motor-generator  171  and auxiliary engine  168  is then conveyed to speed change transmission  175  via endless chain  177  and sprockets  176 , thence to propeller shaft  189  and differential  190  to drive wheels  166 . 
         [0072]    To control the operation of vehicle  161 , a rheostat pedal  191  is employed alongside the gas pedal  192  in the operator&#39;s seating area so that he can control the flow of power from electric motor-generator  171  in accordance to the power needed for the proper operation of the vehicle. Gas pedal  192  controls the flow of fuel to auxiliary engine  168  so that the operator can control the flow of power from auxiliary engine  168  in accordance to the power needed for the proper operation of the vehicle, particularly for acceleration, climbing a grade, towing and carrying heavy loads. Primary engine  167  may be equipped with preset controls to permit automatic starting and running of said primary engine  167  to replenish the charge of battery  170  whenever said battery is discharged to a predetermined degree, and to automatically stop running when said battery is fully charged. Said automatic controls may be further designed to run said engine at optimal speeds to supply additional power to motor-generator  171  whenever the operator signals a need for more electricity than what battery  170  can deliver, such as by further depressing rheostat pedal  191 . Thus, the need for yet another accelerator pedal to directly control fuel flow to primary engine  169  is eliminated. If the operator finds that he needs yet more power than motor-generator  171  (when powered by both battery  170  and generator  169  simultaneously) can deliver, he can then simply depress both rheostat pedal  191  and gas pedal  192  simultaneously, to avail of maximal supply of power from both motor-generator  171  and auxiliary engine  168 . 
         [0073]    When the vehicle  161  reaches cruising speed, auxiliary engine  168  may be deactivated so that the vehicle can travel economically on power from motor-generator  171  alone. Motor-generator  171  and its controls may be further designed so that it can generate electricity through regenerative braking to assist in recharging battery  170  to further enhance the fuel-efficiency of the vehicle. 
         [0074]    Rheostat pedal  191  and gas pedal  192  are positioned alongside each other in such a manner that enables the operator to selectively operate either motor-generator  171  or auxiliary engine  168  by selectively depressing rheostat pedal  191  or gas pedal  192 . To-operate both motor-generator  171  and auxiliary engine  168  at the same time he simply depresses both pedals simultaneously. 
         [0075]    It may be seen that this particular embodiment employing a coaxial two section jackshaft, has the additional advantages of (1) enhancing fuel efficiency through regenerative braking, and (2) added versatility afforded by the use of a CVT torque converter  179  to connect the auxiliary engine  168  to auxiliary jackshaft section  178 , resulting in continuously variable torque multiplication which may be used either to enhance acceleration performance or to permit reduction of the size and power of auxiliary motor  168 , resulting in reduction of the weight and cost of the vehicle. 
         [0076]    Other additional alternative embodiments of the invention may be made by using other combinations of clutches and torque converters to connect the primary and the auxiliary engines to the jackshaft, such as by using an electromagnetic power clutch or a centrifugal clutch to connect either engine to the jackshaft in combination with a CVT torque converter or a fluid torque converter for the other engine, or even the combination of an electric generator with associated battery and electric motor. 
         [0077]    Although the preferred embodiments are described in great detail, it is to be understood that various changes and modifications may be made therein without departing from the scope of the invention as described in the appended claims.