Patent Publication Number: US-11028909-B2

Title: Simplified gearbox mechanism

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation application of U.S. patent application Ser. No. 16/111,344 filed Aug. 24, 2018, which is a continuation-in-part application of U.S. patent application Ser. No. 14/995,094 filed Jan. 13, 2016, which is a continuation application of U.S. patent application Ser. No. 13/795,488 filed Mar. 12, 2013 (now U.S. Pat. No. 9,261,176), the technical disclosures of which are hereby incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Technical Field of the Invention 
     The present invention relates to a universal gearbox mechanism featuring cam-actuated gear block assemblies that periodically engage the output gear causing power transfer. It has particular, but not exclusive, application for use in servomotor assemblies. 
     Description of the Related Art 
     Conventional machines typically consist of a power source and a power transmission system, which provides controlled application of the power. A variety of proposals have previously been made in the art of power transmission systems. The simplest transmissions, often called gearboxes to reflect their simplicity (although complex systems are also called gearboxes in the vernacular), provide gear reduction (or, more rarely, an increase in speed), sometimes in conjunction with a change in direction of the powered shaft. A transmission system may be defined as an assembly of parts including a speed-changing gear mechanism and an output shaft by which power is transmitted from the power source (e.g., electric motor) to an output shaft. Often transmission refers simply to the gearbox that uses gears and gear trains to provide speed and torque conversions from a power source to another device. 
     Gearboxes have been used for many years and they have many different applications. In general, conventional gearboxes comprise four main elements: power source; drive train; housing and output means. The power source places force and motion into the drive train. The power source may be a motor connected to the drive train through suitable gearing, such as a spur, bevel, helical or worm gear. 
     The drive train enables the manipulation of output motion and force with respect to the input motion and force provided by the power source. The drive train typically comprises a plurality of gears of varying parameters such as different sizes, number of teeth, tooth type and usage, for example spur gears, helical gears, worm gears and/or internal or externally toothed gears. 
     The gearbox housing is the means which retains the internal workings of the gearbox in the correct manner. For example it allows the power source, drive train and output means to be held in the correct relationship for the desired operation of the gearbox. The output means is associated with the drive train and allows the force and motion from the drive train to be applied for an application. Usually, the output means exits the gearbox housing. 
     The output means typically can be connected to a body whereby the resultant output motion and force from the drive train is transmitted via the output means (e.g., an output shaft) to the body to impart the output mean&#39;s motion and force upon the body. Alternatively, the output means can impart the motion and force output from the drive train to the gearbox housing whereby the output means is held sufficiently as to allow the gearbox housing to rotate. 
     Rotating power sources typically operate at higher rotational speeds than the devices that will use that power. Consequently, gearboxes not only transmit power but also convert speed into torque. The torque ratio of a gear train, also known as its mechanical advantage, is determined by the gear ratio. The energy generated from any power source has to go through the internal components of the gearbox in the form of stresses or mechanical pressure on the gear elements. Therefore, a critical aspect in any gearbox design comprises engineering the proper contact between the intermeshing gear elements. These contacts are typically points or lines on the gear teeth where the force concentrates. Because the area of contact points or lines in conventional gear trains is typically very low and the amount of power transmitted is considerable, the resultant stress along the points or lines of contact is in all cases very high. For this reason, designers of gearbox devices typically concentrate a substantial portion of their engineering efforts in creating as large a line of contact as possible or create as many simultaneous points of contacts between the two intermeshed gears in order to reduce the resultant stress experienced by the respective teeth of each gear. 
     Another important consideration in gearbox design is minimizing the amount of backlash between intermeshing gears. Backlash is the striking back of connected wheels in a piece of mechanism when pressure is applied. In the context of gears, backlash (sometimes called lash or play) is clearance between mating components, or the amount of lost motion due to clearance or slackness when movement is reversed and contact is re-established. For example, in a pair of gears backlash is the amount of clearance between mated gear teeth. 
     Theoretically, backlash should be zero, but in actual practice some backlash is typically allowed to prevent jamming. It is unavoidable for nearly all reversing mechanical couplings, although its effects can be negated. Depending on the application it may or may not be desirable. Typical reasons for requiring backlash include allowing for lubrication, manufacturing errors, deflection under load and thermal expansion. Nonetheless, low backlash or even zero backlash is required in many applications to increase precision and to avoid shocks or vibrations. Consequently, zero backlash gear train devices are in many cases expensive, short lived and relatively heavy. 
     Weight and size are yet another consideration in the design of gearboxes. The concentration of the aforementioned stresses on points or lines of contact in the intermeshed gear trains necessitates the selection of materials that are able to resist those forces and stresses. However, those materials are oftentimes relatively heavy, hard and difficult to manufacture. 
     Thus, a need exists for an improved and more lightweight gearbox mechanism, which is capable of handling high stress loads in points or lines of contact between its intermeshed gears. Further, a need exists for an improved and more lightweight gearbox mechanism having low or zero backlash that is less expensive to manufacture and more reliable and durable. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes many of the disadvantages of prior art gearbox mechanisms by utilizing a plurality of cam-actuated gear block assemblies to transfer power from a power shaft to a secondary or output gear element. In a first embodiment, each gear block assembly includes a gear block having a surface that periodically interfaces with a secondary or output gear element. In a preferred embodiment the interface surface comprises a plurality of projections or teeth which correspond to complementary projections or gear teeth on the output gear element. Each gear block assembly further includes a plurality of linkage assemblies, which connect or link the gear block to a cam assembly, which in turn is connected to a power source. The cam assembly includes about its circumference a unique pathway or groove for each linkage assembly of a particular gear block assembly so that the movement of the gear block may be controlled in two dimensions in accordance with a certain design parameter. 
     Each linkage assembly comprises a linkage mechanism, which at its proximal end is pivotally attached end to its respective gear block and at its distal end maintains contact with its respective pathway or groove formed in the cam assembly. In a preferred embodiment, each linkage mechanism includes two pivotally coupled connector arms. An upper connector arm includes a first pivot point that is pivotally coupled to its respective gear block element and a second pivot point pivotally coupled to a lower connector arm. The lower connector arm includes a cam follower element at its distal end that maintains contact with its respective pathway or groove formed in the cam assembly. The lower connector arm further includes a pivot point having a fixed axis of rotation relative to the central axis of rotation of the cam assembly. 
     In a preferred embodiment, each gear block assembly includes three linkage assemblies pivotally coupled to the gear block and in constant contact with the cam assembly. The gear block includes pivot bars configured on opposing ends that serve to pivotally couple the linkage assemblies to the gear block. Two linkage assemblies are coupled to a pivot bar on one end while a single linkage assembly is coupled to the pivot bar on the opposing end. Each of the linkage assemblies includes a pivot point that is rotatively coupled to a fixed axis of rotation relative to the central axis of rotation of the cam assembly. In one embodiment, this fixed pivot point comprises a pivot bar fixably contained between two stationary plates. Each of the linkage assemblies is biased so that its respective cam follower element maintains contact with the surface of its respective pathway or groove formed in the cam assembly throughout the rotation cycle of the cam assembly. 
     The gear block assembly is designed to drive its respective gear block through a two-dimensional circuit in response to rotation of the cam assembly. Broadly speaking, the two-dimensional circuit includes urging the gear block to engage a secondary or output gear element and move or rotate a specified quantum distance prior to disengaging from the output gear element, and returning back the specified quantum distance to again reengage the secondary or output gear element once again and repeat the process. The travel path or circuit of each gear block is controlled by adjusting the length and configuration of the various linkage assemblies and altering the pathways or grooves formed in the cam assembly. 
     When adapted to a gearbox mechanism a plurality of gear block assemblies are configured about a central axis of the cam assembly. The cam assembly is rotatively coupled with a power source. As the cam assembly rotates, the cam follower elements of the respective linkage assemblies of each gear block assembly maintain contact with a particular pathway or groove formed in the circumferential surface of the cam assembly. The variance of distance from the center of rotation of the different pathways or grooves of the cam assembly causes the respective linkage assemblies to work in concert to move their respective gear block through a predetermined circuit of movement. This predetermined circuit of movement of the gear block can be precisely calibrated to meet specific engineering requirements. For example, the torque ratio and speed reduction may be regulated and controlled by adjusting the circuit of movement of each gear block assembly. 
     A second embodiment of a gearbox mechanism of the present invention may include a main body, an output element, and a plurality of simplified gear block assemblies. Additionally, the gearbox mechanism may have a retainer that interfaces with the main body and the output element. Each simplified gear block assembly includes a gear block, a torque lever, cam follower(s), and/or socket (or a portion of a socket). The cam actuated gear block assemblies are configured about a central axis. The rotational force on the cam element allows for a driving or rotative force on the cam actuated gear block assemblies. 
     In a preferred embodiment, the torque lever also has a set of cam followers allowing for the following of a specified path formed along a planer surface of the cam element. The cam element includes at least one unique pathway or groove that interfaces with the cam follower of gear block or torque lever so that as the cam element rotates, the movement of the gear block or torque lever is controlled in two dimensions in accordance with at least one certain design parameter. 
     By varying the radius of the pathway or grooves on the cam element, the cam actuated gear block assemblies drive respective gear block(s) through a two-dimensional circuit in response to rotation of the cam element. Broadly speaking, the two-dimensional circuit includes urging the gear block to engage the output element and move and/or rotate the output element a specified distance prior to disengaging from the output element, and returning back the specified distance to again reengage the output element once again, and repeat the process. The travel path or circuit of each gear block is controlled by adjusting the length, width, height, and/or size of the respective gear block and/or torque lever and/or altering the pathways or grooves formed in the cam element. In a preferred embodiment, there is at least one pivot point for both the gear block and the torque lever that allows each to pivot separately from each other. 
     A third embodiment of the gearbox mechanism of the present invention may include a cam element, a main body and output element and a plurality of simplified gear block assemblies. In at least one example, the output element is retained within the main body by a retainer. The gear block assemblies are placed within the main body and interface with the output element and cam element. The gear block assemblies can include a torque lever, a gear block, a first cam follower, and a second cam follower. The cam followers follow pathways in the cam element to generate forces on the torque lever, and/or the gear block(s) generating a pivoting motion for the both the torque lever and the gear block(s). In at least one version, the pivoting motion can be generally square pivot path for the gear block(s). While in other versions, the pivot path of the gear block(s) will generally be oval or circular. 
     In at least one version, a central aperture aligned with a central axis may be a part of the gearbox mechanism. Each gear block assembly includes a gear block, a torque lever, and at least one cam follower, which connect the gear block to the planer surface of the cam element. The torque lever, and/or gear block can interact to be pivotally attached, and correspond to the interaction and/or engagement of the cam follower(s) with the cam element. The rotation of the output element may also be controlled through a reverse or tension engagement (i.e., negative bias) of gear block(s) that are not in a driving or positive bias rotational engagement in order to reduce and/or element backlash. 
     In at least one version, the main body provides a housing for the gear assemblies. The gear block assemblies rest and/or are supported by the main body retaining surface. The gear block(s) may also be retained and/or supported by the main body gear block interface surface. The torque lever(s) may also be supported and/or retained by the main body torque lever interface surface, and/or the main body torque lever void as defined by the main body. The pivoting motion of the torque lever can also coincide with a pivoting motion of the gear block that allows for the interfacing, engaging, and/or rotating of an output element. 
     Numerous embodiments of gearbox mechanisms are possible using the gear block assembly of the present invention. The plurality of gear block assemblies configured about the central axis of the cam assembly can comprise either an odd or even number of gear block assemblies. At least two, and preferably three gear block assemblies are required for a gearbox mechanism of the present invention. The movement of the gear block assemblies typically move in a rotational series to one another. At least one gear block assembly is always engaged with the output gear element at any particular instance in time. Preferably, only one gear block assembly is disengaged with the output gear element at any particular instance in time. However, in another preferred embodiment wherein the plurality of gear block assemblies comprises four or more even-numbered gear block assemblies, the gear block assemblies configured on opposing sides of the cam assembly engage and disengage in unison from the secondary or output gear element. 
     The design of the gear block assemblies of the present invention enable a greater number of gear teeth to engage the output gear at any given time, thereby spreading the stresses associated therein across a greater area. By dramatically increasing the contact area between the gear block and the output gear at any given time the mechanical stress level is significantly decreased. In addition, the gear block assemblies of the present invention reduce backlash to zero and even preloaded conditions to create a tight connection between the power source and the powered device. This is an extremely desirable feature especially for high vibration applications. By reducing backlash to zero or preloaded condition, the mechanical impedance may also be reduced at a broad range of high vibration frequencies. Moreover, because the stresses associated with engagement of the gear block against the output gear are distributed across a greater area, the gear block mechanism may be manufactured of lighter weight, more flexible materials, which are less expensive and easier to manufacture, with no degradation in reliability. Indeed, using flexible materials further reduces the mechanical impedance at low frequencies. By reducing its weight and size, the gearbox mechanism of the present invention is adaptable to a broad range of applications that were previously impractical because of weight and space limitations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the method and apparatus of the present invention may be had by reference to the following detailed description when taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1A  is a perspective view of a first embodiment of the gearbox mechanism of the present invention attached to a power source; 
         FIG. 1B  is a side elevation view thereof; 
         FIG. 2  is an exploded perspective view thereof; 
         FIG. 3  is an end view thereof with the outer stationary plate removed; 
         FIG. 4A  is a close-up side elevation view of a gear block assembly shown in  FIG. 3A ; 
         FIG. 4B  is a perspective view of a gear block assembly shown in  FIG. 3A ; 
         FIG. 4C  is an exploded perspective view thereof; 
         FIG. 4D  is close-up cross-sectional view of a gear block assembly shown in  FIG. 4A  engaged with an output gear. 
         FIG. 5  is a perspective view of the embodiment of the gearbox mechanism shown in  FIG. 3A ; 
         FIG. 6  is a close-up perspective view of a gear block assembly shown in  FIG. 5 ; 
         FIGS. 7A-7C  are end views with the outer stationary plate removed of different variant embodiments of the gearbox mechanism of the present invention shown in  FIG. 1 ; 
         FIG. 8  is an exploded view of a second embodiment of a gearbox mechanism of the present invention; 
         FIG. 9A  is a perspective view of a cam element along with the torque lever, socket, and gear block of the gearbox mechanism shown in  FIG. 8 ; 
         FIG. 9B  is a partial-cutaway, perspective view of a cam element, torque lever, and cam followers of the gearbox mechanism shown in  FIG. 8 ; 
         FIG. 10A  is a close-up side view of a gear block and the output element of the gearbox mechanism shown in  FIG. 8 ; 
         FIG. 10B  is a close-up side view of a gear block and the output element of the gearbox mechanism shown in  FIG. 8 ; 
         FIG. 10C  is a side view of a gear block and the output element of the gearbox mechanism shown in  FIG. 8 ; 
         FIG. 11  is an exploded view of a third embodiment of a gearbox mechanism of the present invention; 
         FIG. 12A  is an exploded view of a main body, output element and retainer of the gearbox mechanism shown in  FIG. 11 . 
         FIG. 12B  is a perspective view of a main body of the gearbox mechanism shown in  FIG. 11 . 
         FIG. 12C  is an exploded perspective view of a main body, and gear block assemblies of the gearbox mechanism shown in  FIG. 11 . 
         FIG. 13  is a perspective view of a cam element of the gearbox mechanism shown in  FIG. 11 ; and 
         FIG. 14  is a perspective view of the gear block assemblies of the gearbox mechanism shown in  FIG. 11 . 
     
    
    
     Where used in the various figures of the drawing, the same numerals designate the same or similar parts. Furthermore, when the terms “top,” “bottom,” “first,” “second,” “upper,” “lower,” “height,” “width,” “length,” “end,” “side,” “horizontal,” “vertical,” and similar terms are used herein, it should be understood that these terms have reference only to the structure shown in the drawing and are utilized only to facilitate describing the invention. 
     All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiment will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following teachings of the present invention have been read and understood. 
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to the Figures, and in particular  FIGS. 1A, 1B and 2 , an embodiment of a machine  10  utilizing the gearbox mechanism  20  of the present invention is depicted. The machine  10  includes a power source or actuator  2 , which includes an output device  4  that transmits the power generated by the power source  2 . While the embodiment shown in the Figure generally depicts the power source  2  as an electric motor and the output device  4  as an output shaft of the electric motor, it is understood that there are numerous possible embodiments. For example, output device  4  need not be directly connected to the power source  2  but may be rotatively coupled by means of gears, chains, belts or magnetic fields. Likewise, the power source  2  may comprise an electric motor, an internal combustion engine, or any conventional power source that can be adapted to generate rotative power in an output device  4 . Moreover, the power source  2  may also comprise the output gear of a preceding gear train mechanism. 
     The output device  4  comprises a central shaft that connected to the gearbox mechanism  20  through a central aperture  32  in the cam assembly  30  of the gearbox mechanism  20 . The gearbox mechanism  20  is configured about the central axis  6  of the central shaft of the output device and comprises two stationary plates  40  between which are configured an output or power gear  50 , a cam assembly  30  and a plurality of cam-actuated gear block assemblies  60 , which transfer power from the cam assembly  30  to an output or power gear element  50 . Two bearing assemblies  22  isolate the cam assembly  30  from the stationary plates  40  so that the cam assembly  30  can rotate freely between the two stationary plates  40 . Likewise, spacer elements  46  configured between the two stationary plates  40  ensure that movement of the power gear element  50  is not impeded by the stationary plates  40 . The gear block assemblies  60  are evenly spaced about the circumference of the cam assembly  30 . Each gear block assembly  60  includes a gear block  62  and a plurality of linkage assemblies, which connect the gear block  62  to the outer circumferential surface of the cam assembly  30 . Each linkage assembly comprises a linkage mechanism, which at its proximal end is pivotally attached to its respective gear block  62  and at its distal end includes a cam follower element, which maintains contact with its respective pathway or groove formed in the circumferential surface  34  of the cam assembly  30 . Each linkage assembly includes a fixed axis pivot point that is connected to the two stationary plates  40 . While each linkage assembly can pivot about its respective fixed axis pivot point  48  the alignment and configuration of the pivot point remains fixed in relation to the two stationary plates  40 . 
     As shown in the embodiment depicted in the Figures, the plurality of cam-actuated gear block assemblies  60  transfer power from the power shaft  4  to an annular secondary or output gear element  50 . In a preferred embodiment, each gear block assembly  60  includes a gear block  62  having an interface surface  63  (e.g., a plurality of projections or teeth  66 ) which correspond to a complementary interface surface  54  (e.g., projections or gear teeth) configured on an inner circumferential surface  53  of the annular secondary or output gear element  50 . It is understood that the interface between the gear block  62  and the inner circumferential surface  53  of the output gear element  50  of the present invention comprises not only the preferred gear teeth as depicted, but also any complementary arrangement such as pins and holes or even friction fit surfaces. 
     While the annular output or power gear element  50  is depicted as two circular rings held apart by spacer elements  55 , it is understood that the output or power gear element  50  may comprise a single circular ring. The output or power gear element  50  includes apertures or holes  58  for attaching to an output shaft or power takeoff (not shown). In addition, it is understood that the outer circumference  51  of the output or power gear element  50  may also comprise a surface to interface with some other gear train mechanism. 
     In addition, it is understood that the gear block  62  may include a divider/alignment block  68  dividing the interface surface  63  into two separate sections. The variant of the gear block  62  featuring the alignment block  68  is particularly suitable to embodiments which feature output or power gear elements  50  comprised of two circular rings. 
     The gear blocks  62  of the present invention are specifically designed to enable a greater surface area (e.g., greater number of gear teeth) to engage the output gear  50  at any given time, thereby spreading the stresses associated therein across a greater area. By dramatically increasing the contact area between the gear block  62  and the output gear  50  at any given time the mechanical stress level is significantly decreased. In addition, the gear block  62  assemblies of the present invention reduce backlash to zero and even preloaded conditions to create a tight connection between the power source  2  and the powered device. This is an extremely desirable feature especially for high vibration applications. Moreover, because the stresses associated with engagement of the gear block  62  against the output gear  50  are distributed across a greater area, the gear block  62  may be manufactured of lighter weight materials, which are typically less expensive and easier to manufacture, with no degradation in reliability. For example, per Hertz Contact Theory a typical stress result for spur gears are in the range from 450 MPa to 600 MPa. High grade steels are the best fitted materials for handling such high stress levels. Other materials like low grade steel or aluminum will deform under the similar conditions. However, by distributing the stresses across a large areas of contact in accordance with the gearbox mechanism of the present invention, the levels of stress under the similar conditions can be reduced to about 20 MPa. These low stress levels allow the gearbox mechanism of the present invention to be manufactured using low grade steels, aluminums or even plastics for the same application. By reducing its weight and size, the gearbox mechanism of the present invention is adaptable to a broad range of applications that were previously impractical because of weight and space limitations. 
     The cam assembly  30  is coupled to the power source  2  by means of the output device or power shaft  4 . Thus, power generated by the power source  2  is transferred to the power shaft  4 , which causes the cam assembly  30  to rotate about the central axis  6 . The cam assembly  30  includes about its circumferential surface  34  a plurality of unique pathways or grooves which each interface with the cam follower element of a single linkage assembly of each gear block assembly  60  so that as the cam assembly  30  rotates, the movement of the gear block  62  is controlled in two dimensions in accordance with a certain design parameter. By varying the radius of the pathway or grooves on the cam assembly  30  the linkage assemblies of the gear block assembly  60  drive respective gear block  62  through a two-dimensional circuit in response to rotation of the cam assembly  30 . Broadly speaking, the two-dimensional circuit includes urging the gear block to engage the output gear element  50  and move or rotate the output gear element  50  a specified quantum distance prior to disengaging from the output gear element  50 , and returning back the specified quantum distance to again reengage the output gear element  50  once again and repeat the process. The travel path or circuit of each gear block  62  is controlled by adjusting the length and configuration of the various linkage assemblies and altering the pathways or grooves formed in the cam assembly  30 . 
     In a preferred embodiment, each linkage mechanism includes two pivotally coupled connector arms. An upper connector arm includes a first pivot point that is pivotally coupled to its respective gear block  62  and a second pivot point pivotally coupled to a lower connector arm. The lower connector arm includes a cam follower element at its distal end that maintains contact with its respective pathway or groove formed in the cam assembly  30 . The lower connector arm further includes a pivot point having a fixed axis of rotation relative to the central axis  6  of rotation of the cam assembly  30 . 
     With reference now to  FIGS. 4A-4D , a preferred embodiment of the gear block assembly  60  is shown. In the depicted preferred embodiment, each gear block assembly  60  includes three linkage assemblies  70 ,  80 ,  90 , which are each pivotally coupled to the gear block  62  and include a cam follower element  74 ,  84 ,  94 , respectively, which maintain constant contact with the cam assembly  30 . The gear block  62  includes pivot bars configured on opposing ends that serve to pivotally couple the linkage assemblies  70 ,  80 ,  90  to the gear block  62 . For example, two linkage assemblies  70 ,  80  are pivotally coupled to a pivot bar  64   a  on one end while a single linkage assembly  90  is pivotally coupled to the pivot bar  64   b  on the opposing end. Each of the linkage assemblies  70 ,  80 ,  90  includes a pivot point  78 ,  88 ,  98 , respectively, that is rotatively coupled to a fixed axis of rotation relative to the central axis  6  of rotation of the cam assembly  30 . As depicted, each fixed axis of rotation comprises a pivot pin  48  that is secured in matching alignment holes  44  configured in the two stationary plates  40 . While each of the linkage assemblies  70 ,  80 ,  90  can pivot about its respective fixed axis pivot point  78 ,  88 ,  98 , respectively, the alignment and configuration of the pivot points remains fixed in relation to the two stationary plates  40 . Each of the linkage assemblies  70 ,  80 ,  90  is biased so that its respective cam follower element  74 ,  84 ,  94 , respectively, maintains contact with the surface of its respective pathway or groove formed in the cam assembly  30  throughout the rotation cycle of the cam assembly  30 . 
     In the depicted preferred embodiment, each of the linkage assemblies may further comprise at least two connector arms. For example, the first linkage assembly  70  may include a lower connector arm  72  that is pivotally connected to an upper connector arm  74 , which is also pivotally connected to the gear block  62 . A pivot pin  71  serves to pivotally connect the lower connector arm  72  to the upper connector arm  74 . The lower connector arm  72  includes a cam follower element  74  at its distal end. In a preferred embodiment the cam follower element  74  comprises a bearing wheel  75  rotatively coupled at the distal end of the lower connector arm by means of an axle  76 . The lower connector arm  72  further includes a pivot point  78  that is rotatively coupled to a fixed axis of rotation relative to the central axis  6  of rotation of the cam assembly  30 . For example, a pivot pin  48   a  secured in matching alignment holes  44  configured in the two stationary plates  40  serves as a fixed axis of rotation relative to the central axis  6  of rotation of the cam assembly  30 . While the lower connector arm  72  may pivot about its fixed axis pivot point  78 , the alignment and configuration of the pivot point  78  remains fixed in relation to the two stationary plates  40 . Each of the pivotal connections in the first linkage assembly  70  is biased so that the cam follower element  74  maintains contact with the surface of its respective pathway or groove  36  formed in the circumferential surface  34  of the cam assembly  30  throughout the rotation cycle of the cam assembly  30 . For example, the pivotal connections may further include torsional spring elements (not shown) which bias the first linkage assembly  70  so that the cam follower element  74  maintains contact with the surface of its respective pathway or groove  36  formed in the circumferential surface  34  of the cam assembly  30  throughout the rotation cycle of the cam assembly  30 . Alternatively, the cam follower element of each linkage assembly may include conjugate cams to bias the pivotal connections in the linkage assembly. Alternatively or in addition, a ring spring connecting all of the gear blocks  62  in a gear train may be used as a biasing mechanism in accordance with the present invention. 
     Similarly, the second linkage assembly  80  may include a lower connector arm  82  that is pivotally connected to an upper connector arm  84 , which is also pivotally connected to the gear block  62 . The upper connector arm  84  is pivotally connected to the gear block  62  by means of the same pivot bar  64   a  used to pivotally connect the upper connector arm  74  of the first linkage assembly  70 . A pivot pin  81  serves to pivotally connect the lower connector arm  82  to the upper connector arm  84 . The lower connector arm  82  includes a cam follower element  84  at its distal end. In a preferred embodiment the cam follower element  84  comprises a bearing wheel  85  rotatively coupled at the distal end of the lower connector arm by means of an axle  86 . The lower connector arm  82  further includes a pivot point  88  that is rotatively coupled to a fixed axis of rotation relative to the central axis  6  of rotation of the cam assembly  30 . For example, a pivot pin  48   b  secured in matching alignment holes  44  configured in the two stationary plates  40  serves as a fixed axis of rotation relative to the central axis  6  of rotation of the cam assembly  30 . While the lower connector arm  82  may pivot about its fixed axis pivot point  88 , the alignment and configuration of the pivot point  88  remains fixed in relation to the two stationary plates  40 . Each of the pivotal connections in the second linkage assembly  80  is biased so that the cam follower element  84  maintains contact with the surface of its respective pathway or groove  37  formed in the circumferential surface  34  of the cam assembly  30  throughout the rotation cycle of the cam assembly  30 . For example, the pivotal connections may further include torsional spring elements (not shown) which bias the second linkage assembly  80  so that the cam follower element  84  maintains contact with the surface of its respective pathway or groove  37  formed in the circumferential surface  34  of the cam assembly  30  throughout the rotation cycle of the cam assembly  30 . Alternatively or in addition, a ring spring connecting all of the gear blocks  62  in a gear train may be used as a biasing mechanism in accordance with the present invention. 
     Likewise, the third linkage assembly  90  may include a lower connector arm  92  that is pivotally connected to an upper connector arm  94 , which is also pivotally connected to the gear block  62 . The upper connector arm  94  of the third linkage assembly  90  is pivotally coupled to a pivot bar  64   b  configured on the opposing end of the gear block  62  as the pivot bar  64   a  to which the upper connector arms  74 ,  84  of the first and second linkage assemblies  70 ,  80  are rotatively coupled. A pivot pin  91  serves to pivotally connect the lower connector arm  92  to the upper connector arm  94 . The lower connector arm  92  includes a cam follower element  94  at its distal end. In a preferred embodiment the cam follower element  94  comprises a bearing wheel  95  rotatively coupled at the distal end of the lower connector arm by means of an axle  96 . The lower connector arm  92  further includes a pivot point  98  that is rotatively coupled to a fixed axis of rotation relative to the central axis  6  of rotation of the cam assembly  30 . For example, a pivot pin  48   c  secured in matching alignment holes  44  configured in the two stationary plates  40  serves as a fixed axis of rotation relative to the central axis  6  of rotation of the cam assembly  30 . While the lower connector arm  92  may pivot about its fixed axis pivot point  98 , the alignment and configuration of the pivot point  98  remains fixed in relation to the two stationary plates  40 . Each of the pivotal connections in the second linkage assembly  90  is biased so that the cam follower element  94  maintains contact with the surface of its respective pathway or groove  38  formed in the circumferential surface  34  of the cam assembly  30  throughout the rotation cycle of the cam assembly  30 . For example, the pivotal connections may further include torsional spring elements (not shown) which bias the second linkage assembly  90  so that the cam follower element  94  maintains contact with the surface of its respective pathway or groove  38  formed in the circumferential surface  34  of the cam assembly  30  throughout the rotation cycle of the cam assembly  30 . Alternatively or in addition, a ring spring connecting all of the gear blocks  62  in a gear train may be used as a biasing mechanism in accordance with the present invention. 
     Each of the linkage assemblies  70 ,  80 ,  90  is biased so that its respective cam follower element  74 ,  84 ,  94  maintains contact with the surface of its respective pathway or groove formed in the cam assembly  30  throughout the rotation cycle of the cam assembly  30 . For example, cam follower element  74  maintains contact with the surface of a first pathway  36 , cam follower element  84  maintains contact with the surface of a second pathway  37 , and cam follower element  94  maintains contact with the surface of a third pathway  38 . Each pathway has a unique circumference, the radius of which varies over the course of the pathway. Thus, for example as shown in  FIGS. 5 and 6 , the first pathway  36  has a first radius r 1  at one part of its circumference that is greater than a second radius r 2  at another part of its circumference. This creates a unique, undulating path for each pathway as the cam assembly  30  rotates. While the cam assembly  30  depicted in the Figures, appears to be a single disc or unit having a plurality of pathways or grooves formed in the circumferential surface  34  of the cam assembly  30 , it is understood that the cam assembly  30  may also comprise a plurality of separate discs, each having a unique pathway formed in its circumferential surface, which are mechanically coupled to one another to assemble a single cam assembly  30 . 
     As the cam assembly  30  rotates, the cam follower element follows its respective pathway maintaining contact with the circumferential surface of the respective pathway. As the radius of the pathway changes, the respective linkage assembly pivots about its fixed axis pivot point to compensate. This pivoting of the linkage assembly about its fixed axis pivot point induces similar movement in the pivotal connection with the gear block  62 , which results in movement of the gear block  62 . Thus, as the cam assembly  30  rotates, the movement of the gear block  62  is controlled by the induced pivoting of the plurality linkage assemblies. For example, by varying the radius of the first pathway or groove  36  on the cam assembly  30 , the first linkage assembly  70  pivots about its fixed axis pivot point  78  to compensate and maintain contact between the first cam follower  74  and the surface of the first pathway or groove  36 . This pivoting of the first linkage assembly  70  about its fixed axis pivot point  78  induces movement in the pivotal connection with the gear block  62 . Each linkage assembly acts independently of the other linkage assemblies due to the cam follower element of each linkage assembly following a distinct pathway formed in the circumferential surface of the cam assembly. 
     By varying the radius of each pathways or grooves  36 ,  37 ,  38  on the cam assembly  30 , linkage assemblies  70 ,  80 ,  90  drive their respective gear block  62  through a two-dimensional circuit in response to rotation of the cam assembly  30 . As shown in  FIG. 4A , in general, the two-dimensional circuit  65  includes urging the gear block to engage the output gear element  50  and move or rotate the output gear element  50  a specified quantum distance prior to disengaging from the output gear element  50 , and returning back the specified quantum distance to again reengage the output gear element  50  once again and repeat the process. It is understood that the two-dimensional circuit  65  depicted in the drawings is not to scale and is somewhat exaggerated to illustrate the general principal of the invention. For example, the distance A-B would typically be much smaller than depicted. The travel path or circuit  65  of each gear block  62  is controlled by adjusting the length and configuration of the various linkage assemblies and altering the pathways or grooves formed in the cam assembly  30 . 
     When adapted to a gearbox mechanism  20 , a plurality of gear block assemblies  60  are configured about the central axis  6  of the cam assembly  30 . The cam assembly  30  is coupled with a power source  2  by means of output device  6 . As the cam assembly  30  rotates, the cam follower elements (e.g.,  74 ,  84 ,  94 ) of the respective linkage assemblies (e.g.,  70 ,  80 ,  90 ) of each gear block assembly  60  maintain contact with a particular pathway or groove (e.g.,  36 ,  37 ,  38 ) formed in the circumferential surface  34  of the cam assembly  30 . The variance of distance from the center of rotation of the different pathways or grooves (e.g.,  36 ,  37 ,  38 ) of the cam assembly  30  causes the linkage assemblies pivotally attached to its respective gear block  60  to work in concert to move their respective gear block through a predetermined circuit of movement  65 . This predetermined circuit of movement  65  of the gear block  60  can be precisely calibrated to meet specific engineering requirements. For example, the torque ratio and speed reduction may be regulated and controlled by adjusting the circuit of movement  65  of each gear block assembly  60 . 
     Numerous embodiments of gearbox mechanisms are possible using the gear block assembly  60  of the present invention. All embodiments of gearbox mechanisms constructed in accordance with the present invention feature a plurality of gear block assemblies  60  configured about the central axis  6  of the cam assembly  30  and may comprise either an odd or even number of gear block assemblies  60 . At least two, and preferably three gear block assemblies are required for a gearbox mechanism of the present invention. For example, as shown in  FIG. 7A , a variant embodiment of the gearbox mechanism  100  featuring three gear block assemblies  60  is depicted.  FIG. 7B  depicts a variant embodiment of the gearbox mechanism  110  featuring five gear block assemblies  60 . The movement of the gear block assemblies  60  typically moves in a rotational series to one another. 
     However, in a preferred embodiment of the present invention wherein the plurality of gear block assemblies comprises four or more even-number gear block assemblies  60 , the gear block assemblies  60  configured on opposing sides of the cam assembly  30  engage and disengage in unison from the secondary or output gear element  50 . For example as shown in  FIG. 3 , an embodiment of the gearbox mechanism  20  featuring four gear block assemblies  60  is depicted. Similarly,  FIG. 7C  depicts a variant embodiment of the gearbox mechanism  120  featuring six gear block assemblies  60 . This is accomplished by ensuring that the individual pathways or grooves formed in the circumferential surface of the cam assembly are in phase with one another on opposing sides of the cam assembly circumference. 
     With reference now to  FIG. 8 , a second embodiment of a gearbox mechanism  120  of the present invention is shown. The gearbox mechanism  120  can include a main body  140 , an output element  150  and a plurality of simplified gear block assemblies  160 . Additionally, the gearbox mechanism  120  may have a retainer  112  that interfaces with the main body  140  and the output element  150 . This interface allows for the output element  150  to be connected to an output device and/or a rotatable device as part of the gearbox mechanism. The output device and/or the rotatable device can be an electric motor, an internal combustion engine, or any conventional power source, that can be adapted to generate or receive rotative power. Additionally, the output device and/or rotatable device may be rotatively coupled by means of gears, chains, belts, or magnetic fields. The output element  150  interfaces with the gear blocks  162  via an interfacing surface, where an output element  150  can have an internal interface surface or external interface surface. An internal or external interface surface can include gear teeth, friction based geometric engagement, friction wedges, or any other forms of mating surfaces, including but not limited to, pole and hole. 
     With reference now to  FIGS. 8 and 9 , the cam actuated gear block assembly  160  can include a gear block  162 , a torque lever  199 , cam follower(s)  194 , and/or socket  189  (or a portion of a socket  189 ). The cam actuated gear block assemblies  160  are configured about a central axis  106 . A shaft, gears, belts, or magnetic fields (not illustrated) may be utilized along the central axis  106  to couple an input device and/or rotating device with a cam element  130  to generate a force or rotative force on the cam element  130 . The rotational force on the cam element  130  allows for a driving or rotative force on the cam actuated gear block assemblies  160 . In a preferred embodiment, the main body  140  is stationary or is a stationary plate with respect to the cam actuated gear block assemblies  160  and/or the output element  150 . 
     While the output element  150  is depicted as a single circular ring, it is understood that the output element or power gear element  150  may comprise two circular rings held apart by spacer elements (not illustrated). The output element  150  includes apertures or holes  158  defined along an outer surfaces and/or within the output element  150  for attaching to an output shaft or power takeoff (not illustrated). In addition, it is understood that the outer circumference  151  of the output element  150  may also comprise a surface to interface with some other gear train mechanism, or other output devices through belts, or gears. 
     The gear blocks  162  of the present invention are specifically designed to enable a greater surface area (e.g., greater number of gear teeth) to engage the output element  150  at any given time, thereby spreading the stresses associated therein across a greater area. By dramatically increasing the contact area between the gear block  162  and the output element  150  at any given time the mechanical stress level is significantly decreased. In addition, the gear block  162  assemblies of the present invention reduce backlash to zero and even preloaded conditions to create a tight connection between the power source and/or the powered device (not illustrated). This is an extremely desirable feature especially for high vibration applications. Moreover, because the stresses associated with engagement of the gear block  162  against the output element  150  are distributed across a greater area, the gear block  162  may be manufactured of lighter-weight materials, which are typically less expensive and easier to manufacture, with no degradation in reliability. 
     For example, per Hertz Contact Theory a typical stress result for spur gears are in the range from 450 MPa to 600 MPa. High grade steels are the best fitted materials for handling such high stress levels. Other materials like low grade steel or aluminum will deform under the similar conditions. However, by distributing the stresses across a large areas of contact in accordance with the gearbox mechanism of the present invention, the levels of stress under the similar conditions can be reduced to about 20 MPa. These low stress levels allow the gearbox mechanism of the present invention to be manufactured using low grade steels, aluminums or even plastics for the same application. By reducing its weight and size, the gearbox mechanism  120  of the present invention is adaptable to a broad range of applications that were previously impractical because of weight and space limitations. 
     In at least one embodiment of the present disclosure, the gear blocks  162  may also rest inside or be surrounded by a socket  189 . The socket  189  may also be associated or coupled with the torque lever  199 . In some embodiments, the torque lever  199  can also have a set of cam followers  194  allowing for the following of a specified pathway(s) formed in or along a planer surface of the cam element  130 . The cam element  130  can also have an input hub  114  or a ball bearing assembly  116  that allows the cam element  130  to rotate freely based upon an input device such as a shaft or rotatable elements such as a set of other gearing, belts, levers, magnetic or electrical fields, etc. The socket  189  can also have a central guide  124  that rests in the center that allows a shaft and/or rotatable element to be passed through of the output element, main body, retainer, gear blocks, torque levers, and/or cam element along a central axis  106 . The gear blocks  162 , cam followers  194 , central guide  124 , socket  189 , torque levers  199 , and cam element  130  can comprise a gear block assembly  160 . The gear block assembly  160  allows for the gear block  162  to be rotated in a manner that engages with the output element  150  by an intersection of the cam followers  194 , and cam element  130 . The interface surfaces of the gear block  162  can engage with the output element interface surface (not illustrated) of the output element  150 . In some embodiments, the gear blocks are rotated by the socket and an associated movement of the torque lever  199 . 
     The cam element  130  includes at least one unique pathway or groove that interfaces with the cam follower  194  of gear block  162  or torque lever  199  so that as the cam element  130  rotates, the movement of the gear block  162  or torque lever  199  is controlled in two dimensions in accordance with at least one certain design parameter. By varying the radius of the pathway or grooves on the cam element  130 , the cam actuated gear block assemblies  160  drive respective gear block(s)  162  through a two-dimensional circuit in response to rotation of the cam element  130 . Broadly speaking, the two-dimensional circuit includes urging the gear block(s)  162  to engage the output element  150  and move and/or rotate the output element  150  a specified distance prior to disengaging from the output element  150 , and returning back the specified distance to again reengage the output element  150  once again, and repeat the process. The travel path or circuit of each gear block  160  is controlled by adjusting the length, width, height, and/or size of the respective gear block and/or torque lever and/or altering the pathways or grooves formed in the cam element  130 . 
     The torque lever is pivoted around a specific pivot point by the cam follower  199 , which traverses the path in the cam element  130 . Additionally, the socket and/or the gear blocks may also have a cam follower  199  that follows the same or a separate path along the cam element  130  that also triggers a pivot point for the socket or gear block(s). In at least one embodiment, there is at least one pivot point for both the gear block and the torque lever that allows each to pivot separately from each other and while also being in a moving conjunction to create a specific pattern of movement for the gear blocks. The movement of a gear block, in at least one example, is a cyclical, annular or closed loop movement that may have a generally rectangular, elliptical, circular, square, conical, oval, ovoid, truncated circular pattern, or any combination thereof, design specified pattern of movement. 
     With reference now to  FIG. 9A , a perspective view is depicted of the cam element  130  along with the torque lever  199 , socket  189 , and gear block  162 . Central axis  106  can pass through the central guide  124  at the center of the socket  189 , cam element  130 , and/or output element  150 . The socket  189  can include individual pieces that also correspond to each individual gear block  162 . In at least one embodiment of the present disclosure, the socket  189  interacts with the toque lever  199  along with the gear block  162  to rotate and cause a movement of the gear block  162  to have a cyclical, annular or closed loop movement having a generally rectangular, elliptical, circular, square, conical, oval, ovoid, truncated circular pattern, or any combination thereof, design specified pattern of movement based upon the pathways in the cam element  150  that may allow a cam follower (not illustrated) attached to the torque lever  199  to traverse along the pathway to generate movement of the gear block(s). 
     The cam follower (not illustrated) can also be attached to a gear block and/or socket allowing a force to be generated against them as well. Each of the cam followers can have a separate path or, in some embodiments, may have a single path. The gear block(s)  162  can be pivotally connected to the torque lever  199 , and/or the socket  199 . Alternatively or in addition, a ring spring connecting all of the gear blocks  162  in a gear train may be used as a biasing mechanism in accordance with the present invention. In at least one embodiment of the present disclosure, the paths in the cam element  130  can be in the same plane where they are parallel paths, or paths of different distances from the central axis  106 , or the paths can be in separate planes stacked in the direction of the central axis  106 . 
     With reference now to  FIG. 9B , a perspective view of the cam element  130 , torque lever  199 , cam followers  194  coupled to the torque lever  199  as well as the cam follower  194  coupled with the gear block  162 . In at least one embodiment, the first pathway  136  along cam element  130  as well as a second pathway  137  along the cam element  130  allow for movement and rotation of the gear blocks allowing for the interface surfaces of the gear blocks  162  to engage, interface and/or interact with the output element (not illustrated). Cam follower(s)  194  maintain contact with the surface of their respective pathways or grooves formed in the cam element  130 . The first pathway  136  has a first radius r 1  at one part of its plane that is greater than a second radius r 2  at another part of its plane. This creates a unique, undulating path for each pathway as the cam element  130  rotates. While the cam element  130  depicted in the Figures, appears to be a single disc or unit having a plurality of pathways or grooves formed in the planer surface  134  of the cam element  130 , it is understood that the cam element  130  may also comprise a plurality of separate discs, each having a unique pathway formed in its circumferential surface, which are mechanically coupled to one another to assemble a single cam assembly  130 . 
     As the cam element  130  rotates, the cam follower(s)  194  follow their respective pathways maintaining contact with the planar surface of the respective pathway or groove  136 / 137 . As the radius of the pathway changes, the respective gear block  162 , and/or torque lever  199  pivots or moves about its pivot point to compensate for the change in the pathway or groove. In at least one version, the torque lever  199  may pivot about its pivot point inducing a movement or pivoting of the socket (not illustrated) and/or a gear block  162  to which is it pivotally coupled to, and results in a movement of the gear block  162 . Thus, as the cam element  130  rotates, the movement of the gear block  162  is controlled by the induced pivoting of the torque lever  199 , and/or socket (not illustrated). For example, by varying the radius of the first pathway or groove  136  on the cam element  130 , the torque lever  199  pivots about its pivot point to compensate and maintain contact between torque lever  199  and the socket (not illustrated). This pivoting or moving of the torque lever  199  about its pivot point induces movement in the pivotal connection with the socket (not illustrated) and/or gear block  162 . Each torque lever  199  acts independently of the other torque lever(s)  199  due to the cam follower(s)  194  of each torque lever  199  following and/or traversing first pathway  136  formed in the planar surface of the cam element  130  at their respective distinct points. 
     With regards to the cam element  130 , the first pathway  136  and the second pathway  137  can be in the same plane and at times be parallel and/or nonparallel with each other, wherein the first pathway is on an outer radius of the cam element  130 . In the second pathway  137  along an inner radius and is closer to the central axis of the cam element  130 . It is understood, that in some embodiments the pathways can be stacked in separate planes such that the first plane and second plane are stacked one on top of the other in a Z direction or central axis  106 . As the cam followers for the gear block and the torque lever follow their respective pathways, the torque lever can pivot at specific point causing a socket and/or the gear block itself to rotate around a specific point. Cam follower(s) for the gear block also allow for the gear block to transition in certain present and/or predetermined directions. For example, the pivot point of the torque element will trigger a left, right, or a linear motion, or a latitudinal motion while the cam follower following the second pathway coupled to the gear block  162  can allow for a longitudinal movement of the gear block. Associated together they allow for a cyclical, annular or closed-loop movement of the gear block and the interfacing surface that has a generally rectangular, elliptical, circular, square, conical, oval, ovoid, truncated circular pattern, or any combination thereof, design specified pattern of movement. 
     With reference now to  FIG. 10A , an illustration of a gear block  162  interacting with the output element  150  is depicted illustrating the variable bias which may be programmed or designed into the interaction between the gear block  162  and the output element  150 . The interaction of the gear block  162  with the output element  150  may be biased either positively (i.e., in the direction of rotation), negatively (i.e., in the opposite direction of rotation) or neutrally. While applicable to all interface surfaces, variable biasing is especially important when the interface surfaces are gear teeth. Gear block  162  is illustrated in  FIG. 10A  as having a positive bias so that the advancing face  164   a  of each interface element (e.g., gear tooth) is biased to positively engage a respective advancing face  150   a  of the interface element (e.g., gear tooth) of the output element  150  so as to transfer rotational movement from the gear block  162  to the output element  150 . In  FIG. 10B  the gear block  162  is illustrated as having a negative bias so that the following face  164   b  of each interface element (e.g., gear tooth) is biased to engage a respective following face  150   b  of the interface element (e.g., gear tooth) of the output element  150 . The negative bias induced by the gear block  162  can impart a slight tension on the output element  150  to reduce and/or eliminate backlash along the output element as the gear block  162  rotates the output element  150 . For example, a gear block on one side of an output element can be in a positively biased configuration  126  while a gear block interfacing on the opposite side or offset from the positively biased gear block, can be in a negatively biased configuration  127 . 
     A gear block may also be configured in a neutral or balanced configuration  125  ( FIG. 10C ) wherein the gear block interface element (e.g., gear tooth) is neither positively nor negatively biased towards the interface element or surface of the output element  150 . For example, when the gear block  162  is moving from a positively biased configuration  126  ( FIG. 10A ) to a negatively biased configuration  127  ( FIG. 10B ), the gear block  162  can be in a balanced and/or neutral configuration which decreases the rotational tension or engagement of the gear block interface surface with the output element interface surface. Additionally, when the gear block transitions, repositions and/or returns from a negative bias configuration  127  to a positive bias configuration  126 , or vice versa, the gear block  162  can be unloaded and/or disengaged from the output element interface surface so that the gear block  162  can smoothly disengage (i.e., pull and/or drop away) from the output element  150 . 
     Gear blocks  162  can be arranged so that they extend outwardly, for example, the interface surface  163  (e.g., a plurality of projections or teeth  166 ), which correspond to a complementary interface surface  154  (e.g., projections or gear teeth) configured on an interface surface  153  of the output element  150 , extending outwardly from a center guide or central axis  106  or, the interface surface  163  can extend inwardly towards a central axis  106 . Gear blocks  162  can also include a set of cam followers  194  that may allow for a traversing of a pathway of the cam element  130 . The cam follower(s)  194  can maintain contact with a pathway or groove formed in the planar surface of the cam element  130 . It is understood that the interface between the gear block  162  and the output element interface surface  153  of the output element  150  of the present invention comprises not only the preferred gear teeth as depicted, but also any complementary arrangement such as pins and holes or even friction fit surfaces. 
     With reference now to  FIG. 10C , a side elevation view of the output element  150 , gear blocks  162 , torque levers  199  in the central aperture  132  is shown. A shaft and/or other rotatable device can be passed through the central aperture  132  attached to the output element and/or cam element (not illustrated). The cam followers  194  can be coupled to the gear blocks  162 , as well as the torque levers  199 . The cam followers  194  can follow specific paths for both the torque levers and the gear blocks generating forces to move them through their various positions going from a path along the outer path of the cam element or an inner path for the gear blocks. 
     The gear block(s) illustrated  162  are shown in various positions starting with the top most gear block  162 A is shown in a transitioning/repositioning position  128  where it is fully disengaged from the interface surface of the output element  150  and the interface surface of the gear block  162 A is fully disengaged. (Please note that the illustrated spacing of the gear block teeth is exaggerated to better illustrate the different bias configurations at issue). Moving to gear block  162 B is shown in a reversed tension or negative bias configuration  127 . There can also be a position such as one that gear block  162 C and/or  162 D when they are in a neutral bias configuration. Gear block  162 E is illustrated in a positively biased or engaged configuration  126 , which can result in a rotation of the output element  150 . Gear block  162 F is illustrated also in a positively biased or engaged configuration  126 . Gear block  162 G is also illustrated as one in a neutral bias configuration. There can be three engagement positions for a gear block to be in: an engaged or positive bias position  126 , a reversed tension or negative bias position  127 , and/or a neutral bias or balanced position  125 . Additionally, a gear block can be in a transitioning/repositioning position  128 , which allows for the gear block  162  to disengage and/or move away from the output element  150  to return to one of the engagement positions. 
     Moreover, it should be understood that the, annular or closed loop cyclical movement of each gear block and cam element may be specifically programmed or designed to vary the bias configurations during a single cycle to enhance the effectiveness of the gear block assembly. Additionally, the amount or strength of bias, whether positive, negative, or balanced can be calibrated and varied throughout the cycle. For example, in one embodiment, when a gear block first engages the interface surface of the output element, the gear block is designed to engage with a neutral bias to maximize the efficiency of the engagement process, then quickly transition to a positive bias to maximize power transfer, then slightly before disengagement a return to a neutral bias to assist with an efficient disengagement prior to the transitioning/repositioning. The negative bias configuration could be programmed into the cycle to minimize backlash. 
     As the cam followers coupled to the gear block follow the first or second pathway of the cam element, they enable the gear block to move in a radial direction or what can be referred to as an up or down motion. An associated pivoting of the torque lever allows for the rotation or angular movement of the gear block in what can be referred to as a left or right movement. These movements can be corresponded or calculated together to generate a cyclical, annular or closed loop path for the gear block that may have a generally rectangular, elliptical, circular, square, conical, oval, ovoid, truncated circular pattern, or any combination thereof, design specified pattern of movement. In at least one embodiment of the present disclosure, torque lever and/or gear block are coupled together in a way that allows for a pivot point of the gear block and torque lever as caused by the traversing of the path by the cam followers to create the movement of the gear block. In at least one example, the angular movement of the gear block places a torque upon the output element  150 . 
     With reference to  FIGS. 9A, 9B, 10A, 10B, and 10C , by varying the radius of each pathway or groove  136 ,  137  on the cam element  130 , torque lever(s)  199  drive their respective gear block(s)  162  through a two-dimensional circuit in response to rotation of the cam element  130 . In general, the two-dimensional circuit  139  includes urging the gear block  162  to engage the output element  150  and move or rotate the output element  150  a specified distance prior to disengaging from the output element  150 , and returning back the same specified distance to again reengage the output element  150  once again and repeat the process. It is understood that the two-dimensional circuit  139  depicted in the drawings is not to scale and is somewhat exaggerated to illustrate the general principal of the invention. For example, the distance A-B would typically be much smaller than depicted. The travel path or circuit  139  of each gear block  162  is controlled by adjusting the size and configuration of the torque lever(s)  199 , socket  189 , gear block(s)  162 , and/or altering the pathways or grooves  136 ,  137  formed in the cam element  130 . 
     When adapted to a gearbox mechanism  120 , a plurality of gear block assemblies  160  are configured about the central axis  106  of the cam element  130 . The cam element  130 , in at least one version, may be coupled to a power source (not illustrated) by an output device (not illustrated). As the cam element  130  rotates, the cam follower(s)  194  of the respective torque lever(s)  199  and/or gear block(s)  162  of each gear block assembly  160  maintain contact with a particular pathway or groove  136 ,  137  formed in the planar surface  135  of the cam element  130 . The variance of distance from the center of rotation of the different pathways or grooves  136 ,  137  of the cam element  130  causes the torque lever(s)  199 , and/or socket  189  pivotally attached to a gear block(s)  162  to work in concert to move their respective gear block(s)  162  through a predetermined circuit of movement  139 . This predetermined circuit of movement  139  of the gear block  160  can be precisely calibrated to meet specific engineering requirements. For example, the torque ratio and speed reduction may be regulated and controlled by adjusting the circuit of movement  139  of each gear block assembly  160 . 
     Numerous embodiments of gearbox mechanisms are possible using the gear block assembly  160  of the present invention. All embodiments of gearbox mechanisms constructed in accordance with the present invention feature a plurality of gear block assemblies  160  configured about the central axis  106  of the cam element  130  and may comprise either an odd or even number of gear block assemblies  160 . At least two, and preferably three or more, gear block assemblies are required for a gearbox mechanism of the present invention. The movement of the gear block assemblies  160  typically moves in a rotational series to one another. 
     However, in a preferred embodiment of the present invention wherein the plurality of gear block assemblies comprises four or more even-number gear block assemblies  160 , the gear block assemblies  160  configured on opposing sides of the cam element  130  engage and disengage in unison from the secondary or output element  150 . For example, an embodiment of the gearbox mechanism  120  may feature four gear block assemblies  160 . Similarly, another embodiment of the gearbox mechanism  120  may feature six gear block assemblies  160 . This is accomplished by ensuring that the individual pathways or grooves formed in the planar surface of the cam element are in phase with one another along the planer surface of the cam element. 
     With reference now to  FIG. 11 , an illustration of a third embodiment of a gearbox mechanism  220  of the present invention is depicted. The gearbox mechanism  220 , in at least one version, can include a cam element  230 , a main body  240 , and output element  250 , and a plurality of simplified gear block assemblies  260 . In at least one example, the output element  250  is retained within the main body  240  by a retainer  212  (or retainer ring) via fasteners and/or couplers. The gear block assemblies  260  can be placed within the main body  240 , and interfacing with the output element  250  and cam element  230 . In some examples, the cam element  230  interfaces with an input hub and/or ball bearing assembly  216  (can also include a set of ball bearings, roller bearings, or ball bearing ring) through a friction or geometrical fit. A central axis  206  can traverse the retainer  212 , output element  250 , the main body  240 , the gear block assemblies  260 , the cam element  230 , the input hub  214 , and/or the ball bearing assembly  216 . 
     The simplified gear block assemblies  260  can include a torque lever  299 , a gear block  262 , a first cam follower  294 A, and a second cam follower  294 B. The cam followers  294 A/ 294 B follow pathways (not illustrated) in the cam element  230  to generate forces on the torque lever  299 , and/or the gear block(s)  262  generating a pivoting motion for both the torque lever  299  and the gear block(s)  262 . In at least one version, the pivoting motion can be generally square pivot path for the gear block(s)  262 . While in other versions, the pivot path of the gear block(s)  262  will generally be oval or circular. 
     The gearbox mechanism  220  can be coupled to an input or rotating device (not illustrated) such as an electric motor, internal combustion engine, or any conventional power source that can be adapted to generate rotative power. The input or rotating device (not illustrated) may be rotatively coupled through means of gears, chains, belts, or magnetic fields. An output device (not illustrated) may be coupled to the output element  250 . 
     In at least one version, a central aperture  232  that has a central axis  206  traversing through it may be a part of the gearbox mechanism  220 . The gearbox mechanism  220  is configured about the central axis  206  and can include a main body  240  that is stationary with respect to the cam element  230 , output element  250 , and/or cam-actuated gear block assemblies  260 . In at least one example, spacer element(s) (not illustrated) may also be used to ensure that movement of the output element  250 , cam element  230 , and/or cam-actuated gear block assemblies  260  are not impeded by the main body  240  and/or retainer(s)  212 ,  214 . The cam-actuated gear block assemblies  260  can be evenly spaced about the circumference of the output element  250 . Each gear block assembly  260  includes a gear block  262 , a torque lever  299 , and at least one cam follower  294 , which connect the gear block  262  to the planer surface of the cam element  230 . The torque lever  299 , and/or gear block  262  can interact to be pivotally attached, and correspond to the interaction and/or engagement of the cam follower(s)  294  with the cam element  230 . 
     With reference now to  FIG. 12A , an exploded view of the main body  240 , output element  250 , and retainer  212  is shown. In a preferred embodiment, the main body  240  serves as a housing for the gear block assemblies (not illustrated), and the cam element (not illustrated). The main body  240  can be coupled on the cam side  241  to an input hub, rotating device, a retainer, a plate, or other protective or securing devices via a fastener or coupling aperture  245 . On the output side  243 , the main body  240  can be coupled to a retainer  212  via retainer fastener or coupling aperture  245 . 
     The retainer  212  can also interface with the output element  250  and/or the output element outer circumferential surface  251 , through a retainer inner circumferential surface  257 . In at least one version, the output element  250  can have an output element lip  259  that may support and/or engage, the retainer  212  and/or retainer inner circumferential surface  257 . A portion of the retainer  212  can interface with the output element  250 , while the remaining amount of the retainer can interface with the main body  240 . A fastener (not illustrated) can couple, fasten, and/or pass through a retainer fastener aperture  259  for fastening and/or coupling of the retainer  212  and the main body  240 . 
     The output element  250 , in at least one version, can include a roller track  261  (or ball bearing track) to allow and/or assist the output element  250  in rotation. The rotation of the output element  250  can result with the gear block(s)  262  engage with the output element interface surface  253 . In at least one example, the rotation of the output element  250  may also be controlled through a reverse or tension engagement (i.e., negative bias configuration) of gear block(s)  262  that are not in a driving or positive bias rotational engagement in order to reduce and/or eliminate backlash. 
     With reference now to  FIG. 12B , a perspective view of a main body  240  is shown. The main body  240 , in at least one version, can provide a housing for the gear assemblies (not illustrated). The gear block assemblies (not illustrated) can rest and/or be supported by the main body retaining surface  267 . The gear block(s) (not illustrated) may also be retained and/or supported by the main body gear block interface surface  269 . The torque lever(s) (not illustrated) may be supported and/or retained by the main body torque lever interface surface, and/or the main body torque lever void  277  as defined by the main body  240 . A torque lever post (not illustrated) can be configured to be retained and/or supported by the main body torque lever void  277  to allow for a pivoting motion of the torque lever (not illustrated) to occur. The pivoting motion of the torque lever (not illustrated) can also coincide with a pivoting motion of the gear block (not illustrated) that allows for the interfacing, engaging, and/or rotating of an output element (not illustrated). 
     In at least one version, the main body  240  can also have a spacer (not illustrated) for the gear assemblies that can be secured to the main body  240  through a spacer aperture  279  defined by the main body  240 . The spacer aperture  279  may be surrounded by the main body spacer interface surface  287 . A cam interface surface  289  can support a cam element (not illustrated) as it engages with the gear assemblies (not illustrated), a rotatable or rotating device, and/or an input device. The main body  240  can be coupled on the cam side  241  to an input hub, rotating device, a retainer, a plate, or other protective or securing devices via a fastener or coupling aperture  244 . The input hub, rotating device, a retainer, a plate, or other protective or securing devices, in at least one example, can be utilized to secure and/or support a cam element (not illustrated). 
     With reference now to  FIG. 12C , an exploded perspective view of a main body  240 , and gear block assemblies  260 . The output element  250  may rest and/or be supported by the main body  240 , and have a ball bearing assembly  207  (could also include a set of ball bearings, roller bearings, or ball bearing ring) that can be coaxial with the guide of a cam element (not illustrated) to allow the cam element freedom of movement. The gear block  262  can have a gear block post  264  that may interact with a torque lever aperture  297  to provide a pivot point for the gear block  262  and/or torque lever  299 . The torque lever  299  may also have a torque lever post  288  that interacts and/or engages with a main body torque lever void  277  and/or a gear block opening  211  to provide a pivot point for the torque lever  299  and/or gear block  262 . A cam follower  294  can also be rotatively coupled to the gear block post  264 , and a cam follower  294 B can be rotatively coupled to a cam follower post  286  of the torque lever  299 . The torque lever  299 , the gear block  262 , and cam follower(s)  294 A,  294 B can be in at least one version, a cam actuated gear block assembly  260 . In at least one example, a spacer  246  may also be added to provide support and/or secure the torque lever  299  and/or gear block  262 . 
     With reference now to  FIG. 13 , a perspective view of a cam element  230  is depicted. The cam element  230  can have at least one plane  215 A along the central axis  206 . In at least one version, the cam element  230  can have two planes  215 A/ 215 B. While in other versions, the cam element  230  may have three planes  215 A/ 215 B/ 215 C. The cam element  230  can have a cam element guide  216  that allows for an interaction of the cam element  230  with an output element guide and/or ball bearing assembly (or set of ball bearings) (not illustrated). The cam element guide  216  can be coaxial with the output element guide and/or ball bearing assembly (or set of ball bearings) (not illustrated) allowing for a centering along the central axis  206  via the cam element central aperture  232 . The output element guide and/or ball bearing assembly (or set of ball bearings) (not illustrated) can interface with a cam element guide circumferential surface  217  along the outside of the cam element guide  216 . 
     In at least one example, the first plane  215 A may correspond and/or include a first pathway  236 . The first pathway  236  can allow for the transversal of a cam follower (not illustrated) to generate a pivot or pivoting force on a torque lever and/or gear block (not illustrated). As the cam follower (not illustrated) traverses the first pathway  236  the pathway can change in direction to move a torque lever and/or gear block (not illustrated) coupled to the cam follower. Similarly, the second plane  215 B may correspond and/or include a second pathway  237 . The second pathway  237  can allow for the transversal of a cam follower (not illustrated) to generate a pivot or pivoting force on a torque lever and/or gear block (not illustrated). As the cam follower (not illustrated) traverses the second pathway  237 , the pathway can change in direction to move a torque lever and/or gear block (not illustrated) coupled to the cam follower. 
     The gear block assemblies (not illustrated) can rest and/or be supported by a cam element support surface  218 . A vertical or depth surface  219  of the cam element support surface  218  may also, in at least one example, provide a surface for the gear block assemblies to interface with and/or engage with. A cam element spacer  221  may also be included and/or coupled to the cam element guide  216 . The cam element spacer  221  may, in some examples, be in a third plane  215 C of the cam element  230 . 
     With reference now to  FIG. 14 , a perspective view of gear block assemblies  260  interfacing with an output element  250 . The gear block assemblies  260  can include a gear block  262 , a torque lever  299 , a first cam follower  294 A, and/or a second cam follower  294 B. In at least one version the first cam follower  294 A is coupled to the gear block  262 , and the second cam follower  294 B is coupled to the torque lever  299 . As the cam followers  294 A/ 294 B traverse the first and second pathways  236 / 237  they generate radial and angular movements of the torque lever  299  and/or the gear block  262 . These longitudinal and latitudinal movements of the torque lever  299  and/or gear block  262  allow for and/or generate the pivot movements of the torque lever  299 , and/or gear block  262 . In at least one example, a spacer  246  can be utilized to support and/or engage the torque lever  299 . 
     The torque lever pivot post  288  and the gear block pivot void  297  interact to generate forces that cause the gear block  262  to engage and/or disengage from the output element  250 . The movement of a gear block  262 , in at least one example, is a cyclical, annular or closed loop movement that may have a generally rectangular, elliptical, circular, square, conical, oval, ovoid, truncated circular pattern, or any combination thereof, design specified pattern of movement. 
     For example, a gear block interface surface  263  can engage and/or disengage from an output element interface surface. The gear block  262  will move in a cyclical manner as a result of the pivot movements of the torque lever  299  and cam followers  294 A/ 294 B. In at least one version, the gear block can have four positions. A first position  228  (or transitioning position) allows for the gear block to traverse or move to a new position to begin a new rotation of the output element  250 . The second position  226  (or engaged or positive bias movement position) allows for the gear block to generate a rotational or pulling force  228  on the output element  250 . The third position  225  (or neutral or balanced position) may allow the gear block  262  to be in a position to engage, rotate, or disengage from the output element interface surface with no forces generated on the output element. The fourth position  227  (i.e., reverse tension or negative bias configuration) allows for a tension to be placed on the output element  250  to assist in the prevention and/or elimination of backlash of the output element  250 . 
     The cam element guide  216  can be interfaced with the output element  250  through a rotational support, ball bearing assembly, and/or set of ball bearings (not illustrated) that can be placed between the cam element guide circumferential surface  217  and the output element circumferential surface  251 . 
     As shown in the embodiment depicted in the Figures, the plurality of cam-actuated gear block assemblies  260  transfer power from an input or rotating device (not illustrated) to an output element  250 . In a preferred embodiment, each gear block assembly  260  includes a gear block  262  having an interface surface  263  (e.g., a plurality of projections or teeth  266 ) which correspond to a complementary output element interface surface  254  (e.g., projections or gear teeth) configured on an outer circumferential surface  251  of the output element  250 . The present invention comprises not only the preferred gear teeth as depicted, but also any complementary arrangement such as pins and holes or even friction fit surfaces. 
     While the output element  250  is depicted as a single circular ring, it is understood that the output element  250  may comprise two circular rings held apart by spacer elements (not illustrated). The output element  250  includes apertures or holes  258  for attaching to an output shaft or power takeoff (not illustrated). In addition, it is understood that the inner circumference  251  of the output element  250  may also comprise a surface to interface with some other gear train mechanism. 
     In addition, it is understood that the gear block  262  may include a divider/alignment block (not illustrated) dividing the interface surface  263  into two separate sections. The variant of the gear block  262  featuring the alignment block (not illustrated) is particularly suitable to embodiments which feature output elements  250  comprised of circular rings. 
     The gear blocks  262  of the present invention are specifically designed to enable a greater surface area (e.g., greater number of gear teeth) to engage the output element  250  at any given time, thereby spreading the stresses associated therein across a greater area. By dramatically increasing the contact area between the gear block  262  and the output element  250  at any given time the mechanical stress level is significantly decreased. In addition, the gear block  262  assemblies  260  of the present invention reduce backlash to zero and even preloaded conditions to create a tight connection between the power source and/or the powered device (not illustrated). This is an extremely desirable feature especially for high vibration applications. Moreover, because the stresses associated with engagement of the gear block  262  against the output element  250  are distributed across a greater area, the gear block  262  may be manufactured of lighter-weight materials, which are typically less expensive and easier to manufacture, with no degradation in reliability. 
     For example, per Hertz Contact Theory a typical stress result for spur gears are in the range from 450 MPa to 600 MPa. High grade steels are the best fitted materials for handling such high stress levels. Other materials like low grade steel or aluminum will deform under the similar conditions. However, by distributing the stresses across a large areas of contact in accordance with the gearbox mechanism of the present invention, the levels of stress under the similar conditions can be reduced to about 20 MPa. These low stress levels allow the gearbox mechanism of the present invention to be manufactured using low grade steels, aluminums or even plastics for the same application. By reducing its weight and size, the gearbox mechanism of the present invention is adaptable to a broad range of applications that were previously impractical because of weight and space limitations. 
     The cam element  230  can be coupled to an input device, power source, or other rotating device (not illustrated) by means of an shaft, gears, belts, magnetic fields, friction fit, or other means of coupling. Power generated by an input device, power source, or other rotating device (not illustrated) can be transferred to a shaft, gears, belts, magnetic fields, friction fit, or other means of coupling, which causes the cam element  230  to rotate about the central axis  206 . The cam assembly  230  includes along its planar surface a plurality of unique pathways or grooves which each interface with the cam follower(s)  294  of a gear block assembly  260  so that as the cam element  230  rotates, the movement of the gear block  262  is controlled in two dimensions in accordance with a certain design parameter. By varying the radius of the pathway or grooves on the cam element  230  the gear block assemblies  260  drive respective gear block(s)  262  through a two-dimensional circuit in response to rotation of the cam element  230 . Broadly speaking, the two-dimensional circuit includes urging the gear block  262  to engage the output element  250  and move or rotate the output element  250  a specified distance prior to disengaging from the output element  250 , and returning back the specified distance to again reengage the output element  250  once again and repeat the process. The travel path or circuit of each gear block  262  is controlled by adjusting the size, height, length and configuration of the torque lever(s)  299 , gear block(s)  262 , and/or cam follower(s)  294  and altering the pathways or grooves formed in the cam element  230 . 
     For example, the pivotal connections may further include torsional spring elements (not shown) which bias the torque lever  299 , and/or gear block  262  so that the cam follower  294  maintains contact with the surface of its respective pathway or groove  236 ,  237  formed in the planar surface  235  of the cam element  230  throughout the rotation cycle of the cam element  230 . Alternatively or in addition, a ring spring connecting all of the gear blocks  262  in a gear train may be used as a biasing mechanism in accordance with the present invention. 
     The gear block assemblies  260  are biased and/or secured so that each cam follower  294  maintains contact with the surface of its respective pathway or groove formed in the cam element  230  throughout the rotation cycle of the cam element  230 . For example, cam follower  294 A maintains contact with the surface of a first pathway  236 , and cam follow  294 B maintains contact with the surface of a second pathway  237 . Each pathway has a unique circumference, the radius of which varies over the course of the pathway. 
     The first pathway  236  has a first radius r 1  at one part of its circuit that is greater than a second radius r 2  at another part of its circuit. This creates a unique, undulating path for each pathway as the cam element  230  rotates. While the cam element  230  depicted in the Figures, appears to be a single disc or unit having a plurality of pathways or grooves formed in the planar surface  235  of the cam element  230 , it is understood that the cam element  230  may also comprise a plurality of separate discs, each having a unique pathway formed in its planar or circumferential surface, which are mechanically coupled to one another to assemble a single cam assembly  230 . 
     With reference to  FIGS. 12A, 12B, 12C, 13, and 14 , by varying the radius of each pathway or groove  236 ,  237  on the cam element  230 , torque lever(s)  299  drive their respective gear block(s)  262  through a two-dimensional circuit in response to rotation of the cam element  230 . In general, the two-dimensional circuit  239  includes urging the gear block  262  to engage the output element  250  and move or rotate the output element  250  a specified distance prior to disengaging form the output element  250 , and returning back the same specified distance to again reengage the output element  250  once again and repeat the process. It is understood that the two-dimensional circuit  239  depicted in the drawings is not to scale and is somewhat exaggerated to illustrate the general principal of the invention. For example, the distance A-B would typically be much smaller than depicted. The travel path or circuit  239  of each gear block  262  is controlled by adjusting the size and configuration of the torque lever(s)  299 , gear block(s)  262 , and/or altering the pathways or grooves  236 ,  237  formed in the cam element  230 . 
     When adapted to a gearbox mechanism  220 , a plurality of gear block assemblies  260  are configured about the central axis  206  of the cam element  230 . The cam element  230 , in at least one version, may be coupled to a power source (not illustrated) by an output device (not illustrated). As the cam element  230  rotates, the cam follower(s)  294  of the respective torque lever(s)  299  and/or gear block(s)  262  of each gear block assembly  260  maintain contact with a particular pathway or groove  236 ,  237  formed in the planar surface  235  of the cam element  230 . The variance of distance from the center of rotation of the different pathways or grooves  236 ,  237  of the cam element  230  causes the torque lever(s)  299  pivotally attached to a cam follower(s)  194  to work in concert to move their respective gear block(s)  262  through a predetermined circuit of movement  239 . This predetermined circuit of movement  239  of the gear block  260  can be precisely calibrated to meet specific engineering requirements. For example, the torque ratio and speed reduction may be regulated and controlled by adjusting the circuit of movement  239  of each gear block assembly  260 . 
     Numerous embodiments of gearbox mechanisms are possible using the gear block assembly  260  of the present invention. All embodiments of gearbox mechanisms constructed in accordance with the present invention feature a plurality of gear block assemblies  260  configured about the central axis  206  of the cam element  230  and may comprise either an odd or even number of gear block assemblies  260 . At least two, and preferably three gear block assemblies are required for a gearbox mechanism of the present invention. The movement of the gear block assemblies  260  typically moves in a rotational series to one another. 
     However, in a preferred embodiment of the present invention wherein the plurality of gear block assemblies comprises four or more even-number gear block assemblies  260 , the gear block assemblies  260  configured on opposing sides of the cam element  230  engage and disengage in unison from the secondary or output element  250 . For example, an embodiment of the gearbox mechanism  220  may feature four gear block assemblies  260 . Similarly, another embodiment of the gearbox mechanism  220  may feature six gear block assemblies  260 . This is accomplished by ensuring that the individual pathways or grooves formed in the planar surface of the cam element are in phase with one another along the planer surface of the cam element. 
     It will now be evident to those skilled in the art that there has been described herein an improved gearbox mechanism. Although the invention hereof has been described by way of a preferred embodiment, it will be evident that other adaptations and modifications can be employed without departing from the spirit and scope thereof. The terms and expressions employed herein have been used as terms of description and not of limitation; and thus, there is no intent of excluding equivalents, but on the contrary it is intended to cover any and all equivalents that may be employed without departing from the spirit and scope of the invention.