Abstract:
Method for transferring rotation energy from an input shaft to an output shaft at a continuously variable transmission ratio, whereby direct or indirect energy transfer between the shafts by means of at least one elastic collision involving at least one switch unit capable of controlling energy transfer satisfying the conditions of operating whithout absorbing much energy, operating very fast, operating with minimal internal friction or wear and operating without using friction as a major part in how energy is transferred, combined with the use of at least one elastic unit and optionally the use of energy store units, whereby all three unit categories and units may independently be implemented using mechanical, hydraulic, pneumatic, magnetic or electronic means.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention is related to a method and a transmission for continuously variable transmission.  
         [0003]     2. Description of the Related Art  
         [0004]     Known transmission of the above type compromise gearboxes and transmissions which roughly can be grouped into ordinary gearboxes using a combination of cogwheels or toothed wheels, transmissions based on hydraulic torque converters and cogwheels or is toothed wheels, continuously variable transmissions using conic shafts, often in combination with different kind of belts and finally transmissions using energy transfer through variable momentum of inertia.  
         [0005]     Known gearboxes and transmissions based on the above mentioned principles have limitations in respect to one ore more of the following. In some cases only a relatively poor efficiency can be achieved. Furthermore are available transmission ratios often limited. In many cases is the response time relatively and unacceptable long. Other known transmission provide restricted operational pattern. Again other transmission has high complexity, high weight, large size and high production cost.  
       SUMMARY OF THE INVENTION  
       [0006]     The continuously variable transmission according to the present invention avoids the shortages of existing gearboxes and transmission, as defined by the features stated in the claims.  
         [0007]     Additionally the transmission according to the present invention provides a high theoretically efficiency, the number of available transmission ratios are ideally unlimited. Due to simplicity of its operational principle it is possible to implement the transmission according to the invention for practical use in applications resulting in higher functionality, radically lower complexity, weight, size and production-cost than comparable existing solutions. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in connection with the accompanying drawings in which:  
         [0009]      FIG. 1  shows the principle solution of the continuously variable transmission.  
         [0010]      FIG. 2  shows implementation 1, a typical car transmission, in a longitudal view.  
         [0011]      FIG. 3  shows implementation 1 in at cut-trough the middle longitudal view.  
         [0012]      FIG. 4  shows implementation 1 in a perspective and partly cut through view.  
         [0013]      FIG. 5  shows implementation 1.1, a typical car transmission with reverse/backward capability, in a perspective and partly cut-through view.  
         [0014]      FIG. 6  shows implementation 2, a typical bicycle transmission, in a look through along the longitudinal axis.  
         [0015]      FIG. 7  shows implementation 2 in a perspective and cut through the middle view.  
         [0016]      FIG. 8  shows implementation 2 in a view along the longitudal axis in a look through as seen from the left hand side in  FIG. 6 .  
         [0017]      FIG. 9  shows implementation 3, a typical car transmission, in a perspective view.  
         [0018]      FIG. 10  shows details of implementation 3 in a longitudal view.  
         [0019]      FIG. 11  shows implementation 3 in a view along the longitudal axis. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]     In general the operational pattern can easily be controlled by low cost computers contributing to highest overall functionality. In other implementations operational pattern can be part of the construction it self.  
         [0021]     The operational principle of the transmission is based on the use of elastic collisions, however, in order to implement the principle in a transmission one have to overcome several practical challenges.  
         [0022]      FIG. 1  identifies the three main component categories in the present innovation. Not all units in  FIG. 1  may be necessary, neither is the connection to reference point  15  necessary for all units. The categories are as follows: 
        1. Switch unit. A unit that can control energy transfer, which can be implemented in a number of ways using such as mechanical, hydraulic, pneumatic, magnetic or electric means. In order to be practical useful in the present invention switches  3 ,  5 ,  6 ,  8 ,  9 ,  11  and  12  has to satisfy the following four criterias: 
            A. Energy associated by the operation of switches themselves is in general not contributing to useful energy transfer between unit  1  and unit  14  in  FIG. 1 . This calls for switches that operate without absorbing much energy in order to keep the overall efficiency high.     B. The need for fast response time—quick adoption to ideally energy transfer between unit  1  and unit  14  in  FIG. 1 —makes it necessary for the switches to be able to operate fast.     C. In order to obtain a long life cycle it is necessary for switches to operate with minimal internal friction or wear.     D. To avoid low overall efficiency in energy transfer between unit  1  and unit  14 , and to enhance long life cycle, friction is not to play a major part in how the switches transfers energy.    
            2. Elastic unit. Stores energy due to elastic properties. Can be implemented in a number of ways using such as steel springs, elastic fluid, elastic gas, elastomer, rubber, magnetic field, electric field etc.     3. Energy store unit. Stores energy without having elastic properties. Can be implemented in a number of ways using such as mechanical, hydraulic, pneumatic, magnetic or electronic means.          
         [0030]     Units above can be combined into combined-units having characteristic of more than one component category. Not all units in  FIG. 1  have to be implemented in order to use the principle of the present innovation. The minimum configuration of the transmission itself consists of at least one elastic unit and at least one switch unit.  
         [0031]     Referring to  FIG. 1  showing the principle operational process of the present innovation. A driving unit  1  supplies rotational energy through the present innovation to a driven rotational unit  14  that absorbs rotational energy. An energy store  2  may be associated with the momentum of inertia of the driving unit  1  while an energy store  13  may be associated with the momentum of inertia of the driven unit  14 . The energy stores  2  and  13  will not be referenced any further in the following principle explanation.  
         [0032]     Energy is taken from driving unit  1  in an elastic collision with at least one of the following: 
        1 Through elastic unit  4  with reference point  15  in  FIG. 1 .     2 Through elastic unit  4  with energy store  7  in  FIG. 1 .     3 Not using energy store  7  or elastic unit  10 , through elastic unit  4  with driven unit  14  in  FIG. 1 . 
 
 The energy stored in the elastic unit  4  can be given to at least one of the following: 
    1 Driving unit  1 .     2 Energy store  7 .     3 Not using energy store  7  or elastic unit  10 , to driven unit  14 . 
 
 Energy stored in energy store  7  can be given to at least one of the following: 
    1 Driving unit  1  through elastic unit  4 .     2 Driven unit  14  through elastic unit  10 .     3 Through elastic unit  4  with reference point  15 .     4 Through elastic unit  10  with reference point  15 . 
 
 Energy stored in the elastic unit  10  can be given to at least one of the following: 
    1 Driven unit  14 .     2 Energy store  7 .     3 Not using energy store  7  or elastic unit  4 , to driving unit  1 .        
 
         [0049]     The process described above is possible through the use of switch units. Depending upon practical implementation it may be possible for the present innovation to transfer rotational energy both ways, not only from unit  1  to unit  14  in  FIG. 1 , but also the opposite way. This as well as implementations of switches will be demonstrated in the later description of practical implementations.  
         [0050]     A controlling mechanism is typical operating switch units, it may also operate elastic units—controlling the elasticity, or the energy store units—controlling the energy store capability. Input to the controlling mechanism may be taken from different units. The controlling mechanism may also control elements outside the transmission or receive input from alike in order to achieve the highest degree of functionality.  
         [0051]     In order to achieve continuously energy transfer between unit  1  and unit  14  the is controlling mechanism have to initiate elastic collisions at such a frequency, pattern and quantity that a desired energy transfer is achieve between the units.  
         [0052]     Additional series and/or parallel connection of the three category units is possible.  
         [0053]     The transmission ratio is given by the rotational speed of unit  1  and unit  14 , which is ruled by the controlled energy transfer. The major challenge facing a transmission based on the principle of elastic collision is to design practical useful switches.  
       Implementation 1  
       [0054]     A continuously variable transmission will be described hereinafter as installed in a car in place of an ordinary automatic transmission between engine and a driving shaft, both rotating around the x-axis.  
         [0055]     Referring to  FIG. 2  showing the transmission in a longitudal view. An engine&#39;s rotating shaft is connected to a disc  101  and the driving shaft is connected to a disc  102 . A freely rotating ring  103  with a high momentum of inertia obtain rotational energy through an elastic collision with disc  101 , storing this energy and then hands rotational energy to disc  102  through an elastic collision with this disc. Discs  101  and  102  and the ring  103  are rotating around the x-axis. In this description of the innovation it is supposed that disc  101  rotates faster than disc  102 , if this is not the case, energy can be transferred the opposite way, typical using the car&#39;s engine as an engine break.  
         [0056]     Referring to  FIG. 3  showing the transmission in a longitudal view as in  FIG. 2 , but this time in a cut-trough the middle view. This view discloses a concentric to x-axis circular hollow space  104  filled with elastic fluid  105 .  
         [0057]     Referring to  FIG. 4  showing a low pressure valve  102   c  that may be useful in order to assure that the fluid pressure in the hollow space  104  does not get to low if the combined bearings and seals  106   a,    106   b  and  106   c  should show unwanted fluid leakage.  
         [0058]     A bearing  106   a  is provided between the disc  101  and the ring  103 , a bearing  106   b  between the disc  102  and the ring  103 , a bearing  106   c  between the disc  101  and the disc  102 , all assuring that disc  101 , disc  102  and the ring  103  all can rotate independent of each other. A bearing  106   d  together with a shim  102   b  and a snap ring to fit into a groove  102   a  (snap ring not shown) keeps the disc  101 , the disc  102  and the ring  103  tight together and still rotating freely and independently of each other. Screw threads  101   a  are used for connecting the disc  101  to the engine.  
         [0059]     A switch element  107   a  can be driven by an electromagnet  108   a  to stabilize in two positions parallel to the x-axis, one position being inside the hollow space  104  effectively closing for any passage of fluid  105 , the other position being just outside the hollow space  104  opening for free passage of fluid  105 . The switch element  107   a  can is switch between its two positions very fast assuming low weight of the element itself due to small size and the parallel to x-axis operation leaving operation virtually independent of fluid pressure in hollow space  104 .  
         [0060]     The combined unit of switch element  107   a  and the electromagnet  108   a  is fixed to the disc  101  and thus rotating at the same speed.  
         [0061]     The combined unit of switch element  107   b  and the electromagnet  108   b  is similarly fixed to the disc  102  and thus rotating at the same speed as disc  102 .  
         [0062]     The rotating ring  103  has a partition wall  103 b connected with the ring  103 , which effectively will close for any passage of fluid  105  in the hollow space  104 .  
         [0063]     Assuming that the disc  101  is rotating, the disc  102  and the ring  103  are at rest. In order to establish an elastic collision between the disc  101  and the ring  103 , the switch element  107   b  has to be out of the hollow space  104 , while the switch element  107   a  has to be out of the hollow space  104  until it is approximately 180° away from the partition wall  103   b.  The switch element  107   a  is then driven by an electromagnet  108   a  into the hollow space  104 , effectively establishing a fluid cushion on each side of the switch element  107   a  and the partition wall  103   b.  Because of the elasticity of the fluid  105 , the ring  103  will experience an elastic collision with the disc  101  and in such a way aquire rotational energy and be accelerated to approximately the same rotational speed as disc  101 .  
         [0064]     In order to establish an elastic collision between the ring  103  and the disc  102 , the switch element  107   a  has to be out of the hollow space  104 , while the switch element  107   b  has to be out of the hollow space  104  until it is approximately 180° away from the partition wall  103   b.  The switch element  107   b  is then driven by an electromagnet  108   b  into the hollow space  104 , effectively establishing a fluid cushion on each side of the switch element  107   b  and the partition wall  103   b.  Because of the elasticity of the fluid  105 , the disc  102  will experience an elastic collision with the ring  103  and acquire rotational energy. In this process the speed of the ring  103  will be retarded from its current rotational speed to approximately the same rotational speed as the now accelerated disc  102 .  
         [0065]     The process above passes energy from the engine to the driving shaft via the ring  103 . This process is repeated under supervision of the controlling mechanism which operates switch elements  107   a  and  107   b  alternately, and so often that wanted energy transfer is achieved between the engine and the driving shaft. The transmission ratio between the discs  101  and  102  is given by the ratio of the rotation speeds of the discs and is controlled by the energy transfer described above.  
         [0066]     In a normal operational situation the ring  103  will alternate between approximately the rotational speed of discs  101  and  102 . Engine power can only be transferred to the driving shaft if disc  101  rotates faster than the disc  102 . High difference in rotational speed between discs  101  and  102  allows higher energy transfer between the engine and the driving shaft, the overall transmission ratio between engine and car wheels must take this fact into account.  
         [0067]     The controlling mechanism has sensors connected to discs  101  and  102  and the ring  103  assuring that the switch elements  107   a  and  107   b  operate as described, and do not collide with each other or the fixed partition wall  103   b.  A high momentum of inertia in both engine and driving shaft/wheels assures a steady and smooth rotation of discs  101  and  102 .  
       Implementation 1.1  
       [0068]     Description of implementation 1.1 is basically the same as implementation 1, but with two main differences.  
         [0069]     The first difference is that it also offers a reverse capability—switch direction of rotation. The second difference is that it uses an elastic liquid  205   b  instead of elastic fluid, and because of the relatively higher specific weight of liquid compared to gas, this implementation do not need a freely rotating ring with a high momentum of inertia.  
         [0070]     A continuously variable transmission will be described hereinafter as installed in a car in place of an ordinary automatic transmission between the engine and a driving shaft, both rotating around the x-axis.  
         [0071]     Referring to  FIG. 5 . The engine&#39;s rotating shaft is connected to disc  201  and the driving shaft is connected to a disc  202 . A freely rotating ring with the fixed partition wall is not part of this implementation. Instead the concentric to x-axis circular hollow space  204  is filled with the elastic liquid  205   b  achieving a high momentum of inertia due to high specific weight.  
         [0072]     A teethed rotational ring  209  is connected through teethed wheels  210  to a teethed wheel  201   b  and is thus rotating in the opposite direction of disc  201 . For practical reasons it is assumed that the ring  209  is rotating at a lower speed than disc  201  because the car does not need to drive very fast in reverse/backward, but this is not a necessity. Discs  201  and  202  and the ring  209  are rotating around the x-axis.  
         [0073]     The combined bearings and seals  206   a,    206   b  and  206   d  assure that the hollow space  204  is kept free from leakage of the elastic liquid  205   b.  A bearing  106   c  is not a part of this implementation. The bearing  206   a  is between disc  201  and ring  209 , bearing  206   b  between disc  202  and ring  209 , bearing  206   d  between disc  201  and disc  202  all assuring that disc  201 , disc  202  and ring  209  all can rotate without friction. Disc  202  rotates freely and independently of the disc  201  and the ring  209 .  
         [0074]     In this description of the innovation it is supposed that the disc  201  rotates faster than the disc  202  or that the ring  209  rotates faster than disc  202  in case of ‘reverse’ operation. If this is not the case energy can be transferred the opposite way, typical using the car&#39;s engine as an engine break.  
         [0075]     The switch element  207   a  can be driven by an electromagnet  208   a  to stabilize in two positions parallel to the x-axis, one position being inside the hollow space  204  effectively closing for any passage of the liquid  205   b,  the other position being just outside the hollow space  204 , opening for free passage of the liquid  205   b.  The switch element  207   a  can switch between its two positions very fast assuming low weight of the element itself due to small size and the parallel to x-axis operation leaving operation virtually independent of the liquid pressure in the hollow space  204 . The combined unit of switch element  207   a  and the electromagnet  208   a  is fixed to the disc  201  and thus rotating at the same speed.  
         [0076]     The combined unit of switch element  207   b  and electromagnet  208   b  is similar to the switch element  207   a  and the electromagnet  208   a,  but is fixed to the disc  202  and thus rotating at the same speed as disc  202 .  
         [0077]     The combined unit of switch element  207   c  and electromagnet  208   c  is similar to the switch element  207   a  and the electromagnet  208   a,  but is fixed to the ring  209  and thus rotating at the same speed as the ring  209 .  
         [0078]     Assuming that the disc  201  is rotating, the disc  202  and the liquid  205   b  are at rest. In order to establish an elastic collision between the disc  201  and the liquid  205   b,  switch elements  207   b  and  207   c  have to be out of the hollow space  204 . The switch element  207   a  is then driven by the electromagnet  208   a  into the hollow space  204 , colliding elastically with the liquid  205   b  that aquires rotational energy. The liquid  205   b  will be accelerated to approximately the same rotational speed as the disc  201 .  
         [0079]     In order to establish an elastic collision between the liquid  205   b  and the disc  202 , the switch elements  207   a  and  207   c  have to be out of the hollow space  204 . The switch element  207   b  is then driven by the electromagnet  208   b  into the hollow space  204 , colliding elastically with the liquid  205   b.  The disc  202  will experience an elastic collision with the liquid  205   b  and acquire rotational energy. In this process the speed of the liquid  205   b  will be retarded from its current rotational speed to approximately the same rotational speed as the now accelerated disc  202 .  
         [0080]     To enable reverse operation, assuming that the ring  209  is rotating, the disc  202  and the liquid  205   b  are at rest. In order to establish an elastic collision between the ring  209  and the liquid  205   b,  the switch elements  207   a  and  207   b  have to be out of the hollow space  204 . The switch element  207   c  is then driven by the electromagnet  208   c  into the hollow space  204 , colliding elastically with the liquid  205   b.  In this way the liquid  205   b  will acquire rotational energy with an opposite rotational direction of disc  201 .  
         [0081]     In order to establish an elastic collision between the now rotating liquid  205   b  and the disc  202 , the switch elements  207   a  and  207   c  have to be out of the hollow space  204 . The switch element  207   b  is then driven by the electromagnet  208   b  into the hollow space  204 , colliding elastically with the liquid  205   b.  The disc  202  will experience an elastic collision with the liquid  205   b  and acquire rotational energy. In this process the speed of the liquid  205   b  will be retarded from its current rotational speed to approximately the same rotational speed as the now accelerated disc  202 .  
         [0082]     The process above passes energy from the engine to the driving shaft via the elastic liquid  205   b.  This processes is repeated under supervision of the controlling mechanism which operates the switch elements  207   a  and  207   b  alternately, and so often that wanted energy transfer is achieved between engine and driving shaft.  
         [0083]     For reverse operation the process above passes energy from the engine to the driving shaft via the liquid  205   b.  This processes is repeated under supervision of the controlling mechanism which operates the switch elements  207   c  and  207   b  alternately, and so often that wanted energy transfer is achieved between engine and driving shaft.  
         [0084]     The transmission ratio between the disc  201  and the disc  202  is give by the ratio of the rotation speeds of the discs and is controlled by the energy transfer described above.  
         [0085]     In a normal operational situation the liquid  205   b  will alternate between approximately the rotational speed of discs  201  and  202 , in reverse operation between approximately the rotational speed of the ring  209  and the disc  202 . The engine power can only be transferred to the driving shaft if the disc  201  or the ring  209  rotates faster than the disc  202 . High difference in rotational speed between the disc  201  or the ring  209  and the disc  202  allows higher energy transfer between engine and driving shaft, the overall transmission ratio between engine and car wheels must take this fact into account.  
         [0086]     A controlling mechanism with sensors connected to the discs  201  and  202  and the ring  209  assures that the switch elements  207   a,    207   b  and  207   c  operate as described and do not collide with each other.  
         [0087]     A high momentum of inertia in both engine and driving shaft/wheels assures a steady and smooth rotation of the discs  201  and  202 .  
       Implementation 2  
       [0088]     A continuously variable transmission will be described hereinafter as installed in a bicycle in place of an ordinary bicycle transmission.  
         [0089]     Referring to  FIG. 6  showing the transmission in a longitudal view. The pedals are connected to a disc  302  and the driving shaft is connected to a shaft  301 . A disc  301   a  is connected to the shaft  301  through a spring  301   b  thus allowing temporarily small differences in rotational speed between the shaft  301  and the disc  301   a.    
         [0090]     Referring to  FIG. 8  showing a frame or a chassis  303  and a rotational ring  304 . Hollow spaces  308  are filled with hydraulic oil. Bearing and seal  306   a  allows rotational ring  304  to rotate independently of frame  303  while keeping hydraulic oil inside a hollow space  308  between the frame  303  and the ring  304 . Bearing and seal  306   b  allows the rotational ring  304  to rotate independently of disc  301   a  while keeping hydraulic oil inside the hollow space  308  between the disc  301   a  and the ring  304 . A piston pump  305  is filled with elastic fluid and is connected with the disc  302  through a bearing  306   c,  and connected with the ring  304  through a bearing  306   d.  When disc  302  is rotating clockwise, the pump  305  will act as an elastic spring between the disc  302  and the ring  304 . The ring  304  will begin rotating clockwise, and assuming that the disc  301   a  is opposing to rotational movement, so will the ring  304  due to operation of one way valves  309   b  operating hydraulic liquid in hollow space  308 . As the disc  302  rotates even more, the pump  305  compresses elastic fluid inside the piston pump more, making the force on the ring  304  rise. Assuming the force exercised by the pump  305  is making the disc  301   a  starting to rotate, rotational energy may be given to the driving shaft  301  through the spring  301   b  in  FIG. 6  in an elastic push. Assuming disc  302  rotates faster than ring  304 , the bearing  306   c  will pass the bearing  306   d  and thereby activate one way valves  309   a  operating hydraulic liquid in hollow space  308  as pump  305  decompresses between frame  303  and disc  302 , giving rotational energy back to the disc  302  through an elastic push.  
         [0091]     Energy given back to the disc  302  in this way is dependent upon the rotational speed of the disc  301   a  and the shaft  301 .  
         [0092]     A controlling mechanism may adjust the spring constant of the piston pump  305  through valves  305   a  and thereby energy transfer between the disc  302  and the shaft  301 . A controlling mechanism may be omitted choosing the right spring constant of the piston pump  305  for a given situation. The transmission ratio between the disc  302  and the shaft  301  is given by the ratio of the rotation speeds and is controlled by the energy transfer described above.  
       Implementation 3  
       [0093]     A continuously variable transmission will be described hereinafter as installed in a car in place of an ordinary manual gearbox using a combination of cogwheels or toothed wheels. Referring to  FIG. 9 , the engine&#39;s rotating shaft is connected to a shaft  401  and the driving shaft is connected to a shaft  402 .  
         [0094]     A teethed wheel  404  can connect teethed wheels  403  with ratio 2:1 and ratio 1:2 by choosing either of the outmost circumferences on the wheels  403 . The middle circumference on the wheels  403  is so shaped that it is possible for the wheel  404  to move in a longitudal way along the x-axis from one outmost position on the wheels  403  to the other. This is achieved when the wheels  403  are rotating and an pneumatic servo  405  through a rod  405   a  with guides  406  and a spring  405   b  exercises longitudal force on a symmetrical leg  404   a  and thereby the wheel  404 . Springs  405   b  and the soft cut edges of the wheel  404  assure that this process is achieved without excess force or friction between the wheel  404  and the wheels  403 , but still sufficient fast.  
         [0095]     If the wheel  404  is all the time at one outmost circumference the ratio is say 2:1. If the wheel  404  is spending 50% of the time at each outmost circumference the ratio between the shaft  401  and the shaft  402  is in time average 1:1. If the wheel  404  is all the time at the other outmost circumference the ratio between the shaft  401  and the shaft  402  is 1:2. By devoting major time spent by the wheel  404  to one or the other outmost circumference it is possible to achieve different transmission ratios in the interval between 2:1 and 1:2 on a time average. This is controlled by a controlling mechanism. The shaft  401  is connected to the associated wheel  403  through a spring  401   a,  the shaft  402  is connected to the associated wheel  403  through a spring  402   a.  This principle is shown in  FIG. 10 . In this way the variable transmission ratios will express elastic collision between the shafts  401  and  402 , allowing the transmission ratio to be given by its average over time.  
         [0096]      FIG. 11  shows the teethed wheels used in this implementation. Each wheel  403  consist of three teethed wheels, the outmost having the radius r 1  respectively r 3 =2·r 1 . The teethed unsymmetrical wheel in the middle has a radius r 2  given by approximately: 
 0&lt;=v&lt;90°: r 2 =r 1   90&lt;= v&lt; 180 °: r   2 = r   1 (1+( v− 90)/90)  180 &lt;=v&lt; 270 °: r   2 =2 ·r   1 =r 3   270 &lt;=v&lt; 360 °: r   2 = r   1 (2−( v− 270)/90)  
         [0097]     In  FIGS. 9 and 11  the radius r 1  is associated with 12 teeth, the radius r 3  with 24 teeth, but other combinations may be found. Different tooth shapes may be found useful.  
         [0098]     The wheels  403  and  404 , the symmetrical leg  404   a,  the pneumatic servo  405 , the rod  405   a  wirh guides  406  and the spring  405   b  may be looked upon as one switch unit.  
         [0099]     A controlling mechanism may adjust the time constants wheel  404  spend at the two outmost circumferences on wheels  403  and thereby the average transmission ratio.  
         [heading-0100]     Practical Applications  
         [0101]     The transmission according to the present invention is in general a substitute for existing gears and transmissions and may find practical applications for example in cars, motor cycles, commercial vehicles or locomotives, for instance between the engine and the drive shaft. Furthermore in bicycles for instance between pedal and drive shaft, in boats for instance between engine and propeller, in power plants for instance between turbines and generator, in power tools for instance between engine and driving shaft and in toys for instance between engine and driving shaft.