Abstract:
An infinitely variable transmission mechanism that transmits produced torque to a wheel or output shaft without gears and is capable of an expansive range of active gear ratios in a relatively small envelope

Description:
[0001]    This application claims the benefit of U.S. provisional application No. 61/390,393 filed Oct. 6, 2010 and entitled Infinitely Variable Transmission Mechanism (Attorney Docket No. COETHO P04AUSPR), which is hereby incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to an infinitely variable transmission mechanism that transmits produced torque to a wheel or output shaft without gears and is capable of an expansive range of active gear ratios in a relatively small envelope. 
       BACKGROUND OF THE INVENTION 
       [0003]    Mechanical gearing is used in almost any device having rotating parts, for example, bicycle gearing allows for a selection of an appropriate gear ratio for the speed and efficiency in varied physical terrains. An adjustment to the gear ratio adjusts the amount the bicycle moves forward on each pedal stroke. Based on the number of teeth on each sprocket gear of the bicycle, the smaller wheel gear rotates faster than the larger pedal gear with the ratio of the number of teeth determining the revolutions per minute (rpm) of each gear and thereby the overall speed of the bicycle. 
         [0004]    Adjustments to gear ratio on a bicycle or a car transmission require multiple gears of varying diameters stacked and aligned within a gearing system. Motors, belts, and other adjustment mechanisms are used to move and change the alignment of the gears within the gearing system to adjust the rotational speeds. For slower speeds, sets of larger gears are required and for faster speeds sets of smaller gears are required with limiting factors being the cost, space and rate required to achieve appropriate gear ratio ranges for functional operation of the vehicle or other equipment. 
         [0005]    What is needed is a transmission system that uses fewer numbers of gear sets and adjustment mechanisms while achieving acceptable gear ranges to operate machinery safely and efficiently. 
       OBJECTS AND SUMMARY OF THE INVENTION 
       [0006]    The present invention relates to an infinitely variable transmission mechanism which is mechanically engaged to a power system. 
         [0007]    An object of the present invention is to reduce the gears required within a variable transmission system while maintaining an appropriate range of active gear ratios. 
         [0008]    Another object of the invention is to reduce the space and weight requirements of a variable transmission drive system. 
         [0009]    Another object of the present invention is to provide automatic shifting of drive components within the transmission system to accommodate variable loading cycles. 
         [0010]    Another object of the invention is to communicate power between misaligned shafts with multiple degrees of freedom in a variable power transmission system. 
         [0011]    A further object of the invention is to stack the transmission system and gears in a compact series arrangement to achieve multiple and infinitely variable ranges of active gear ratios. 
         [0012]    The present invention is related to a variable power transmission mechanism for producing a desired torque comprising at least one hub having a slot aligned along a shaft; at least one drive ring having at least one pin assembly positioned adjacent the at least one hub along the shaft; at least one array plate positioned adjacent the at least one drive ring; and wherein adjustment of the hub and slot relative to the shaft forces the at least one pin assembly to engage the at least one array plate and change the torque produced by the variable power transmission mechanism. 
         [0013]    The present invention is further related to a method for producing a desired torque from a variable power transmission mechanism comprising the steps of aligning at least one array plate along a stationary axle; aligning at least one drive ring having at least one pin assembly adjacent the array plate; affixing at least one adjustable hub to the axle adjacent the drive ring; and moving the adjustable hub to force the at least one pin assembly to engage the array plate and alter the torque produced by the variable power transmission mechanism. 
         [0014]    These and other features, advantages and improvements according to this invention will be better understood by reference to the following detailed description and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    Several embodiments of the present invention will now be described by way of example only, with reference to the accompanying drawings in which: 
           [0016]      FIG. 1  is an exploded view of a first embodiment of the present invention; 
           [0017]      FIG. 1A  in an exploded view of a first embodiment of a pin assembly of the first embodiment of the present invention; 
           [0018]      FIG. 2  is a perspective view of a first embodiment of the present invention with the position hub aligned along the center line of the stationary axis; 
           [0019]      FIG. 3  is a perspective view of the first embodiment of the present invention with the position hub at a maximum torque position relative to the center line of the stationary axis; 
           [0020]      FIG. 3A  is a detailed view of the pin assembly supported on a ledge of the position hub of a first embodiment of the present invention; 
           [0021]      FIG. 4  is a perspective view of pins engaging the arrays and being overrun by the arrays of the array plate of a first embodiment of the present invention; 
           [0022]      FIGS. 5A and 5B  are elevation views of the first embodiment of the present invention showing maximum and minimum torque positions; 
           [0023]      FIG. 6  is an elevation view of an engagement of a pin assembly with the array plate of a further embodiment of the present invention; 
           [0024]      FIG. 7  is an elevation view of an engagement of a second pin assembly with the array plate of a further embodiment of the present invention; 
           [0025]      FIG. 8  is an elevation view of an engagement of a third pin assembly with the array plate of a further embodiment of the present invention; 
           [0026]      FIG. 9  is an elevation view of an engagement of a fourth pin assembly with the array plate of a further embodiment of the present invention; 
           [0027]      FIG. 10  is a still further embodiment of the present invention in a fixed shaft application using a cross drive system; 
           [0028]      FIG. 11  is a still further embodiment of the present invention in a fishing reel application; and 
           [0029]      FIG. 12  is a still further embodiment of the present invention in a series configuration. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0030]    In its simplest form the infinitely variable transmission mechanism is made up of four major components; an array or channel plate  10 , a drive ring  12 , one or more pin-assemblies  14  and a movable position hub  16 . All the components are in a compact sandwich arrangement. By simply moving the position hub  16  above or below the center line C of the array plate  10  the active gear ratio is changed with the output ratio being directly proportional to the distance moved. While positioned at dead center a 1:1 ratio is realized. When the position hub  16  is moved in a first direction, a speed reduction is induced, and when moved in an opposing direction, a speed increase occurs. This compact and simple arrangement can be applied to many types of equipment for example fishing reels, winches, bicycles, wheel chairs, generators, transport vehicles, and other machinery having rotating mechanisms. 
         [0031]    As illustrated in  FIG. 1 , the four major components are mounted about a stationary axle  18  with the drive ring  12  shown with a bicycle type chain sprocket  20  on its perimeter. The array plate  10  and the drive ring  12  are placed in close proximity perpendicular to the axis A of the stationary axle  18 . The array plate  10  has a number of pitch arrays, channels grooves or slots  38  that extend out from the center of the plate  10 . These arrays may extend radially or be substantially curved as shown in  FIG. 1 . A number of pin assemblies  14 , as an example approximately twenty-four (24) are nested in openings  17  around an outer rim  15  of the drive ring  12 . The position hub  16  in an initial position affixed along the center line C has an outer diameter OD slightly smaller than the inner diameter ID of the drive ring  12  so that the hub  16  fits through the center of the drive ring  12  as seen in  FIG. 2 . The center shaft  23  of the axle  18  may extend through a position hub slot  24 . Flats  22  of the axle  18  are of a slightly smaller width d than the width w of the slot  24  so that the flats  22  fully enter and engage the edges of the slot  24 . 
         [0032]    The pin assembly  14  as shown in the exploded view of  FIG. 1A  has substantially four components, a plunger pin  30 , a nested spring  32 , a tooth body  33  and a support rim  35 . The plunger pin  30  has a rounded top  31  that slides along the surface  42  of the position hub  16 . The spring  32  and plunger  30  bias the tooth body  33  towards and into the array, groove, slot or channel  38  of the array plate  10  to provide system torque. The tooth body  33  has a jutted face profile  34  with a ramp feature  36 , this feature allows for the pin assembly  14  to compress and adjust when overrun by an array of the array plate  10 . The support rim  35  holds the plunger pin  30  away from the array plate  10  during a segment of the rotation as will be described in greater detail below. The support rim  35  may have a scalloped radius matching the profile of the position hub perimeter to assist in preventing rotation. In a further embodiment, the pin assembly may be jeweled incorporating a rounded or roller element in place of the tooth face profile. 
         [0033]    When an ample tangential force is applied to the sprocket  20  of the drive ring  12  the drive ring will rotate around the stationary axle  18  within the position hub  16  while carrying a quantity of pin assemblies  14 . As shown in  FIG. 3 , the drive ring  12  with the pin assemblies  14  is aligned adjacent the array plate  10  with the position hub  16  aligned adjacent the drive ring  12 . The under surface of the position hub  42  has a shoulder  40  that transitions to a cam lobe  26 . As the drive ring  12  rotates around the stationary axle  18  the rounded top  31  of the pin assembly  14  rides along the under surface  42  of the position hub  16 , transitions through the shoulder  40  and is moved towards the cam lobe  26 . The cam lobe  26  extends around a segment of the position hub  16  to a range of between 80 degrees and 130 degrees, and more preferably to a range of 100 degrees and during this segment, this movement biases the jutted face profile  34  of the pin assembly  14  through the drive ring  12  to engage the array plate  10 . One or more pins  14  are brought into contact with the array  38  or are held up by the tops of the arrays  38  to the cam lobe  26  as the drive ring  12  and array plate rotate  10 . As the pin assemblies  14  enter or engage the pitch arrays  38  torque is communicated causing the speed of rotation to slow. During this cam lobe  26  segment not every pin will engage an array  38  but may instead be held up by or be overrun by the array  38  with the nested spring  32  of the pin compressing and lifting the pins  33  and  37  as shown in  FIG. 4 . 
         [0034]    Turning back to  FIG. 3A , at the end of the cam lobe 100 degree segment of rotation the support rim  35  of the pin assembly  14  rides up and onto the hub support shelf or ledge  41  that extends approximately 260 degrees around the position hub  16  in parallel to the under surface  42  and shoulder  40  to the point where the cam lobe  26  begins. At this point the pin assembly  14  transitions from the support shelf  41  to the surface  13  of the drive ring where one or more pins are compressed by the cam lobe  26  and forced through the drive ring  12  to engage the arrays  38  of the array plate  10 . 
         [0035]    The amount of force and resultant torque applied to the drive ring  12  is dependent upon the position of the position hub slot  24  in relation to the stationary axle  18 . As the position hub  16  moves in one direction using an external force along the slot  24  to a first position or in the opposite direction to an opposing position the radial distance  2   r  of the pin assembly of the drive ring will be increased or decreased as measured from the center line C of the output shaft  18  modifying the active ratio. This change in radial distance is shown in  FIGS. 5A and 5B . The ratio induced is a function of the distance of the array plate center axis A to the contact point of the actively loaded pin multiplied by two and divided by the pitch diameter of the drive ring pin opening  17 .  FIG. 5A  shows the variable transmission mechanism in low gear for maximum torque and  FIG. 5B  show the system in high gear for maximum speed. 
         [0036]    The position hub  16  has three significant functions and features, the first function is to hold the drive ring  12  in the desired position within the slot  24  with regards to the center axis A of the stationary shaft  18  using an external adjustment force mechanism (not shown) to position the hub  16 ; second it provides a journal for the drive ring  12  to rotate upon; and third it controls the pin engagement by either forcing the pin assemblies  14  out towards the arrays  38  of the array plate  10  via the axial cam lobe  26 , or preventing engagement by holding the support rim  35  of the pin along the hub support shelf  41  pulling the pin assembly  14  away from the array plate  10  as shown in  FIG. 3A . The drive ring  12  has two major functions, first to carry the pin assemblies  14  around the position hub  16  and second to transmit the incoming torque to the pin assemblies  14  once they have engaged the arrays  38  of the array plate  10 . 
         [0037]    The pin assembly  14  has one main function, the transmission of torque; this requires having several features of importance, first the tooth face profile  34  which engages an array of the array plate  10 . Extending from the tooth profile  34 , the tooth body  33  has a ramp feature  36  that provides for the tooth assembly  14  to compress its internal spring  32  and move away from the array plate as the tooth body  33  is over run by the arrays  38  of the array plate  10 . The pin spring  32  readily compresses if a tooth body  33  is misaligned with an array  38  and therefore the compressed pin  14  does not inhibit the rotation of the drive ring  12  or the array plate  10 . There is also enough clearance within the cam lobe segment  26  so that the pin may be pushed towards the cam lobe  26  when the spring  38  is fully compressed, as seen in  FIG. 4 . In this figure as described above pin  33  and  37  have misaligned with an array  38  of the array plate and compressed against the cam lobe  26  as the tooth body  33  does not enter the array  38  or provide torque to the system. When properly aligned as shown by pin assembly  19 , the nested spring  32  and plunger  30  bias the pin body  33  to enter the arrays  38  of the array plate  10 . 
         [0038]    The array plate  10  has two main functions, first is to allow and maintain contact with the pin assemblies  14  allowing them to raise and lower unimpeded by the arrays; second is to transmit the produced torque and speed to the wheel or output shaft (not shown). With respect to the array plate geometry a relationship with the drive ring  12  has significant engagement importance. Attempts at making Huntington Ratios or odd-to-even engagement relationships have resulted in poor performance or failure of the pin assemblies to engage or unload prior to reaching the extraction point. However, as shown in the current embodiment direct proportional relationships have been successful, where there are twice as many pin assemblies  14  as arrays  38  on the array plate  10 . 
         [0039]    In determining the geometry of the array plate  10  the number of pin assemblies  14  of the drive ring are divided by two and this number of primary arrays or slots  44  are extended radially from the center X of the array plate  10  as shown in  FIG. 6  towards the outer edge O of the plate  10 . Extending the arrays  44  radially in straight lines causes the distance between each primary array  44  to expand. Parallel constant pitch arrays  45  of varying lengths are then added between the primary arrays  44 . The constant pitch of the parallel arrays is substantially equivalent to the circular pitch of the pin openings  17  of the drive ring providing better frequency of engagement and loading and unloading of the pins  14 . These parallel constant pitch arrays  45  are repeated as many times as practical based on the surface area of the array plate  10 . Each array  44 ,  45  has a steep side and a gradual side that allows the pin assemblies  14  to be overrun by the array  44 ,  45 , but not to jump an array once a pin has entered. The parallel or circular pitch edges may have jagged edges or ridges  46  that are decreasing in length as they run along one or both of each wall of the array to assist in engaging the pin  14  within the arrays  44 ,  45 . This curved geometry of the arrays  44 ,  45  assists in the loading and unloading of the pin assemblies  14  through each cycle of rotation, however more exaggerated profiles may have the effect of decreased performance. It is clear that with the right geometry and curve an automatic response to an external load can be induced. For example, if a high load is placed on the spool of a fishing reel, the loading could force the pin assemblies  14  to travel within and up the arrays  44 ,  45  of the array plate  10 ; and in effect automatically shift into a lower gear ratio. When the gear ratio is at a setting of 1:1, the apex X of the 100 degree window as shown in  FIG. 6  is at the center of the stationary axle  18 , with the center line of the 100 degree window aligned along the center of the position slot  24 . 
         [0040]      FIGS. 6-9  show several illustrations of a typical pin engagements and the unique properties that an embodiment of this design possesses. In the first illustration of  FIG. 6  the system is in a reduction mode, pin  1  is in contact with the slot edge  48  in the 100 degree engagement window. In  FIG. 7 , as the drive ring sprocket  20  rotates counter clockwise pin  5  is accelerated and enters the 100° window and contacts the array edge  48  of the array plate  10 . In  FIG. 8 , pin  7  is now in contact with pin  9  accelerating up into the contact window. The contact occurs within 30 to 45 degrees. Most notably pin  1  has now been unloaded as it decelerates and will stay unloaded all the way to the point where it will be retracted from the arrays  44 ,  45  of the array plate  10  at the end of the 100 degree window. And finally in  FIG. 9  we see pin  9  in contact with the array edge  48  of the array plate  10  and picking up the load from pin  7 . This process of loading, unloading and overrunning is accommodated by the ramp feature  36  on the back side of the pin body  33  in cooperation with the plunger  30  and plunger spring  32  arrangements as previously described. 
         [0041]    With each revolution of the drive ring  12 , the position hub  16  adjusted to a first position at a distance above the center line C and will force an engagement of one or more of the pins  14  to the arrays  44 ,  45  increasing torque and lowering the speed of rotation of the drive ring  12  and array plate  10 . The cam lobe  26  forces the pin assemblies  14  to protrude out of the drive ring  12  and engage the array plate  10 . During this time, one, two, or more pin assemblies  14  will engage the arrays  44 ,  45  of the array plate  10 . At the end of the cam lobe segment the pin assemblies  14  are pulled away from the plate  10  by the support rim  35  riding up and onto the support shelf  41  as described above. The support rim  35  of the pin assembly  14  holds the pin away from the array plate until the pin assembly  14  returns to within the 100 degree segment of the cam lobe  26 . 
         [0042]    The illustration in  FIG. 10  shows a fixed shaft application using a cross drive power delivery system. In this embodiment the transmission system within a housing  49  is similar to that previously described however the input  50  and output shaft  51  are concentric, so the input power using an external force or adjustment mechanism  47  must now be communicated to the center hub  53  that can travel to a first position and an opposing position from the center axis C of the input and output shafts  50 ,  51 . 
         [0043]    The cross-drive system is made up of two major components, the drive slot plate  52  and cross side plate  54 . The drive slot plate  52  transmits the power from the input shaft  50  and communicates the energy through the slot  55  to the cross slide plate  54  via the slot  57  and pins  58 . The energy is then in communication via the slot  56  in the cross-drive plate  52  to the pins  59  protruding out of the center hub  53 . The array plate  60  is similar to the array plate previously described. This mechanism can anticipate two degrees of freedom but in this case one only is allowed. This mechanism has capabilities well beyond the capabilities of typical shaft alignment devices. 
         [0044]    In a further embodiment the variable transmission system may be implemented on a fishing reel or winch application as shown in  FIG. 11 . In this configuration the shaft  62  (not shown) drive ring  63  and array plate  64  are within a housing  66  with the center hub  68  being actuated by a geared lever  70 . The reel crank  72  with handle  74  travels up and down with the center hub  68  and by biasing the center hub  68  against a hub spring  76  (not shown) the variable transmission system under heavy loads would automatically shift into a lower gear and then as the load decreases the hub spring  76  would bias the center hub  68  back into a higher ratios for faster retrieval. 
         [0045]    In a further embodiment shown in  FIGS. 12A and 12B , an external force or adjustment mechanism  80  is positioned between a first and second position hub  82  and  84  with a first and second drive ring  86  and  88  and a first and second array plate  90  and  92  aligned along a shaft  94  within a series configuration. In this application very high gear ratios are attainable in a compact arrangement. For example, by placing a transmission system assembly having an active gear ratio range of 5:1 within a series of two systems having similar active gear ratios, the combined transmission system will result in an infinitely variable transmission system having a range of active gear ratios to 25:1. Alignment of the 100 degree window of each position hub must be oriented in an opposing manner to provide a maximum active gear ratio within the system. 
         [0046]    The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.