Patent Publication Number: US-11028910-B2

Title: Spiral cam gearbox mechanism

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 16/194,053, filed Nov. 16, 2018, which is a continuation-in-part application of U.S. patent application Ser. No. 14/995,094, filed on 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 disclosure of which is 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. 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 distance prior to disengaging from the output gear element, and returning back the specified 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 set of stationary plates, an output element, a plurality of pivot assemblies, torque block assemblies, and a cam assembly comprising a set of unique, corresponding cam elements arranged in a tandem configuration. Additionally, the gearbox mechanism may include a cam follower as part of the pivot assembly that follows the circuitous pathway formed in opposing interior surfaces of the tandem-configured cam elements. In a preferred embodiment, a portion of the pathway is generally spiral in shape. Each pivot assembly includes a pivot pin, a pivot lever, and a cam follower. The torque block assemblies are removably coupled to the pivot assemblies and are configured about a central axis. The rotation of the cam assembly (i.e., set of cam elements) drives the pivot assemblies and torque block assemblies. 
     By varying the radius of the pathway or groove in the cam elements, the cam actuated gear block assemblies drive respective torque block(s) through a three-dimensional circuit in response to rotation of the cam assembly. Broadly speaking, the three-dimensional circuit includes urging the torque 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 torque 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 elements. In a preferred embodiment, there is at least one pivot point for both the torque block and the pivot lever that allows each to pivot separately from each other. 
     In at least one version, a central aperture aligned with a central axis may be a part of the gearbox mechanism. Each torque block assembly includes a torque block, a pivot lever, and at least one cam follower, which connect the torque block to the planer surface of the cam element. The pivot lever, and/or torque 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 eliminate backlash. 
     In at least one version, the stationary plates provide a housing for the pivot assemblies. The torque block assemblies may pass through the main body stationary plate. The torque block(s) may also be retained and/or supported by the main body apertures. The pivot lever(s) may also be supported and/or retained by the stationary plates, and/or the void as defined by the stationary plates. The pivoting motion of the pivot lever can also coincide with a pivoting motion of the torque 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 an 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 embodiments of the gearbox mechanism of the present inventions; 
         FIG. 8  is a perspective view of the gearbox mechanism of the present invention; 
         FIG. 9  is an exploded view of the gearbox mechanism of the present invention; 
         FIG. 10A  is a front view of an outer stationary plate; 
         FIG. 10B  is a cross-sectional view of a spiral gearbox mechanism shown in  FIG. 10A ; 
         FIG. 10C  is a front view of a main body stationary plate; 
         FIG. 11  is a front view of a spiral gearbox mechanism and stationary plate; 
         FIG. 12A  is a perspective view of one half of a cam assembly of the spiral gearbox mechanism; 
         FIG. 12B  is a perspective view of one half of a cam assembly coupled with torque block assemblies of the spiral gear block mechanism; and 
         FIG. 12C  is a perspective view of one half of a cam assembly of the spiral gear block mechanism; 
         FIG. 12D  is a perspective view of a cam assembly coupled with torque block assemblies of the spiral gearbox mechanism; 
         FIG. 12E  is a perspective view of a cam assembly coupled with torque block assemblies of the spiral gearbox mechanism; 
         FIG. 12F  is a perspective silhouetted view of a cam assembly coupled with torque block assemblies of the spiral gearbox mechanism; 
         FIG. 12G  is a cutaway view of a channel of a one half of a cam assembly of the spiral gearbox mechanism; 
         FIG. 12H  is a cutaway view of a channel of a one half of a cam assembly of the spiral gearbox mechanism; 
         FIG. 13A  is a front perspective view of a pivot assembly and gear block assembly of the spiral gearbox mechanism; and 
         FIG. 13B  is a rear perspective view of a pivot assembly and gear block assembly of the spiral gearbox mechanism. 
     
    
    
     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 distance prior to disengaging from the output gear element  50 , and returning back the specified 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 distance prior to disengaging from the output gear element  50 , and returning back the specified 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 , an embodiment of the gearbox mechanism  100  featuring three gear block assemblies  60  is depicted.  FIG. 7B  depicts an 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 an 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 to the Figures, and in particular  FIGS. 8 and 9 , an embodiment of a spiral gearbox mechanism  220  of the present invention is depicted. In an exemplary embodiment, the spiral gearbox mechanism  220  works with a power source or actuator, which includes a coupling device that transmits the power generated by the power source. While the embodiment shown in the Figures generally depicts an input shaft  204  coupled with the spiral gearbox mechanism  220 , it is understood that there are numerous possible embodiments. For example, the input shaft  204  may be directly connected to a power source. Alternatively, the input shaft  204  may also be coupled to gears, belts, or coupling devices or systems that allow for a transfer of energy and/or power. In some embodiments, the input shaft  204  may be formed with a cam assembly  230 . 
     The output of the spiral gearbox mechanism  220  may comprise an output element  250  that is positioned along the central axis  206  passing through the input shaft  204  of the spiral gearbox mechanism  220 . The spiral gearbox mechanism  220  can be configured about the central axis  206  passing through the input shaft  204  and may comprise two stationary plates—the main body stationary plate  241  and the outer stationary plate  242 —a void may be defined within and/or between the main body stationary plate  241 , and the outer stationary plate  242 . A cam assembly  230  (that may include a first spiral cam body or element  230 A, and a second spiral cam body or element  230 B) and a plurality of cam-actuated pivot assemblies  270  ( FIG. 12D ), may be housed within the void, between, and/or within the main body stationary plate  241 , and the outer stationary plate  242 . The cam assembly  230  and a plurality of cam-actuated pivot assemblies  270  and/or torque block assemblies  260  ( FIG. 12D ), can transfer power from the cam assembly  230  to the spiral output element  250 . 
     The main body stationary plate  241  can be an interface or separator between the cam assembly  230  and the output element  250 . The main body stationary plate  241  may have apertures defined through its planar surface (may also be referred to as the front or rear surface) which allow for the plurality of cam-actuated torque block assemblies  260  pass and engage with the output element  250 . The pivot assemblies  270  may be positioned between each body  230 A/ 230 B of the cam assembly  230  such that one end of the pivot assemblies  270  including the torque block assembly  260  is positioned along and/or outside the circumference of the cam assembly  230 . In at least one embodiment, the torque block assemblies  260  are evenly spaced about the circumference of the cam assembly  230  or outside the circumference of the cam assembly  230 . In other embodiments, the torque block assemblies  260  may be unevenly spaced about the circumference of the cam assembly  230  or outside the circumference of the cam assembly  230 . 
     Each torque block assembly  260  includes a torque block  262  coupled with torque pins  266 . The torque block assemblies  260  can be coupled to a pivot assembly  270  via the torque block  262 . Each pivot assembly  270  comprises a pivot lever  272 ; a spiral cam follower  274  pivotably coupled to a first or distal end of the pivot lever  272  closer to the central axis  206  of the gearbox mechanism; a linkage pin  271  coupled to the pivot lever  272  and a torque block  262  at a second or proximal end of the pivot lever  272 ; and a fixed axis pivot point  278  on the second or proximal end of the pivot lever  272  opposite of the spiral cam follower  274 . The fixed axis pivot point  278  connects the pivot assembly  270  with the main body stationary plate  241  and/or outer stationary plate  242  by a pivot pin  279 . For example, the pivot pin  279  may extend from one or both sides of the spiral fixed axis pivot point  278  to allow for the pivot pin  279  to couple with one or both of the main body stationary plate  241  and/or outer stationary plate  242 . While each torque block assembly  260  can slidably couple and rotate with its respective linkage pin  271 , the block assembly  260  can be moved in a three-dimensional (3D) circuit based on the movement and pivoting of the pivot assembly  270 . The pivot assembly  270 , is configured and aligned in a manner that allows for rotation, or angular motion about the fixed pivot point  278  and/or pivot pin  279 . 
     As shown in the embodiment depicted in the Figures, the plurality of torque block assemblies  260  transfer power from the input shaft  204  and/or cam assembly  230  to the output element  250 . In a preferred embodiment, each torque block assembly  260  includes a torque block  262  coupled with torque pins  266  which correspond to a complementary interface surface  254  (e.g., a plurality of torque pin holes) configured on a planar surface of the output element  250  perpendicular to the central axis  206 . In other embodiments, the torque pins  266  may be gear teeth that can allow for an engagement with an interface surface of the output element  250 , along the inner or outer circumferential surface, or planar surface. It is understood that the interface between the torque block  262  with torque pins  266  and any surface of the output element  250  of the present invention comprises not only the preferred pins and holes as depicted, but also any complementary arrangement such as gear teeth or even friction fit surfaces. However, in the depicted preferred embodiment, the output interface surface  254  (e.g., a plurality of torque pin holes) are arranged in a ring coaxial to the central axis  206 , and are positioned so that torque pins  266  can engage or disengage the output interface surface  254 . 
     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. The output element  250  includes a central aperture or hole for coaxial arrangement of the output element  250  surrounding and/or adjacent to the main body stationary plate  241 . In addition, it is understood that the inner or outer circumference of the output element  250  or a planar surface of the output element  250  opposite the planar surface adjacent to the main body stationary plate  241  may also comprise a surface to interface with some other gear train mechanism or pin and holes mechanism. 
     With reference to  FIGS. 10A, 10B, 10C and 11 , a preferred embodiment of the gearbox mechanism is shown in unexploded views, one of which is a cross-sectional view of the gearbox mechanism. In the depicted preferred embodiment, the cam assembly  230  is positioned between the outer stationary plate  242  and the main body stationary plate  241 , with the first cam body or element  230 A facing the second cam body  230 B. The pivot lever  272  and the cam follower  274  are positioned between the first cam body  230 A and the second cam body  230 B, with the pivot lever  272  extending beyond the circumference of the cam assembly  230 . The torque pin  266  and the fixed axis pivot point  278  are located on the opposite end of the pivot lever  272  from the cam follower  274 . The fixed axis pivot point  278  comprises an aperture configured and sized to receive a pivot pin  279  that pivotably couples the pivot lever  272  to the main body stationary plate  241  and/or outer stationary plate  242 , and the linkage pin  271  slidably and rotatably couples the pivot lever  272  to the torque block  262 . The torque block  262  is coupled to torque pins  266  and extend through apertures of the main body stationary plate  241  so that the torque pins  266  can engage with the output interface surface  254  (e.g., a plurality of torque pin holes). The torque pin holes can be configured and sized to receive at least a portion of the torque pins  266 . As mentioned previously, the torque block  262  and torque pins  266  move along the three-dimensional circuit created by the two pathways  236 ,  237  of the cam assembly  230 . In  FIG. 10B , the two torque block assemblies  260  illustrated show that the cam follower  274  are engaged with the first spiral pathway  236  (not illustrated in  FIG. 10B ) of the first cam body  230 A, and disengaged from the second spiral pathway  237  (not illustrated in  FIG. 10B ) of the second cam body  230 B. 
     With reference to  FIG. 10A , a perspective view of the outer stationary plate  242  is illustrated. The outer stationary plate  242  can have a first level  243 A that is depressed from, and/or surrounded by a second level  243 B. The second level  243 B can also create a lip or circumferential surface of the outer stationary plate  242 , that defines a void or a first half of a void that allows for the housing of the cam assembly (not illustrated), torque block assembly (not illustrated), and/or pivot assembly (not illustrated). In at least one embodiment, the second level  243 B is a circular ring, and in alternative embodiments may be other shapes, or have additional opening or voids around the inner circumference to allow for the housing of the cam assembly (not illustrated), torque block assembly (not illustrated), and/or pivot assembly (not illustrated). 
     The outer stationary plate  242  may also include one or more securing apertures  245 . The securing apertures  245 , allow for the outer stationary plate  242  to be fastened with a fastener (not illustrated) to the main body stationary plate  241 . Additionally, the securing fastener (not illustrated) can also allow for the outer stationary plate  242  to be secured to a power source, device, or holder. The outer stationary plate  242 , can also have at least one spacer aperture  246  that allows for the spacing of the outer stationary plate  242  and main body stationary plate  241  to be modified by a spacing fastener (not illustrated). For example, the spacing between the stationary plates  241 / 242  may require adjustment to give the cam assembly  230  more freedom of movement and/or rotation within the void created between the plates. The spacing fastener (not illustrated) can provide an anchor for a spacer device, such as a plastic or metal washer. The spacing fastener (not illustrated) may be a set screw or other fastener. The outer stationary plate  242  may also have a bearing, set of bearings, or rollers  247 . 
     With reference to  FIG. 10B , a cross-sectional view of the gearbox mechanism  220  is provided. The gearbox mechanism  220  can have an input shaft  204  aligned along a central axis  206 . The input shaft  204  may pass through a central aperture of an outer stationary plate  242 . The outer stationary plate  242  can house and/or support one or more cam bodies or elements  230 A/ 230 B of a cam assembly  230 . The cam bodies or elements can have pathways  236 / 237  that are unique to each cam body or element  230 A/ 230 B. The unique pathways  236 / 237  allow for a cam follower  274  to travel along the pathways  236 / 237  and generate movements of a pivot lever  272 . The pivot lever  272  may be coupled to the outer stationary plate  242 , and/or the main body stationary plate  241  via a pivot point  278  and pivot pin  279 . The pivot lever  272  can move in a three-dimensional (3D) circuit of motion based on the position of the cam follower  274  along one of the unique pathways  236 / 237 , the pivot point  278 , and pivot pin  279 . For example, as a cam follower  274  transitions from a first pathway  236  to a second pathway  237 , the pivot lever  272  may also transition in a liner manner along the pivot pin  279 . The linear movement of the pivot lever  272  can also generate a linear movement of the torque block  262  via the linkage pin  271 . As illustrated the linear movement would be a left or right movement. 
     The void that houses and/or supports the cam assembly  230  can have on one side the main body stationary plate  241 . The main body stationary plate  241 , can have a central aperture for allowing the input shaft  204  to pass through, and at least one main body aperture to allow the torque block(s)  262 , and torque pins  266  to pass through. The main body aperture(s) allow the torque block(s)  262 , and their interface surface (illustrated here as pins  266 ) to engage with a corresponding interface surface on an output element. The output element  250  can have an interface surface  254  (illustrated here as a pin and hole configuration) that allows for the transfer of power from the input shaft  204 , through the cam assembly  230 , pivot assembly  270 , and gear block assembly  260 , to the output element  250 . The output element  250  can also have a bearing, set of bearings, or rollers  255  to ease the movement of the output element  250 . The bearing, set of bearings, or rollers  255  can be coupled to the output element  250  via a retainer  256 , and/or fastener(s)  257 . The retainer  256  can be coupled and/or fastened to the output element  250 . In at least one embodiment, the output element  250  can have a central aperture that allows the output element  250  to interface with the main body stationary plate  241 . The interfacing may be direct, or indirect through the bearing, set of bearings, or rollers  255 . A cap  224  can also be coupled to the main body stationary plate  241  via fasteners  258 . The cap  224  can also interface with the output element  250 , and/or bearing, set of bearings, or rollers  255 . 
     With reference now to  FIG. 10C , an illustration of the main body stationary plate  241  in a perspective view is depicted. The main body stationary plate  241 , does not move with respect to the output ring (not illustrated), nor the outer stationary plate (not illustrated). The main body stationary plate  241  can be coupled to the outer stationary plate (not illustrated) by one or more securing apertures  245 . The securing apertures  245 , allow for the main body stationary plate  241  to be fastened with a fastener (not illustrated) to the outer stationary plate  242 . The main body stationary plate  241 , can have main body aperture(s)  241 A that are sized and configured to allow a torque block assembly (not illustrated) to pass through. The torque block assembly (not illustrated) can be moveably coupled to a pivot assembly (not illustrated). The pivot assembly (not illustrated) may be pivotably coupled to the main body stationary plate  241  by a pivot pin (not illustrated) that is removably coupled to the main body stationary plate  241  and/or outer stationary plate (not illustrated). The pivot pin (not illustrated), can be received by a pivot point  278  that is defined by the main body stationary plate, outer stationary plate, or pivot lever. 
     The main body stationary plate  241  can also have a pivot receiver  280  that is sized and configured to allow for a pivot lever  272  to pivot about a pivot pin (not illustrated). The pivot receiver  280  can have at least one blocking point  281 A,  281 B (collectively  281 ) that prevents a pivot assembly (not illustrated) from exceeding its desired pivoting movements. In at least one embodiment, the blocking point(s)  281  prevent a pivot lever (not illustrated) from rotating beyond the bounds of it pivot rotation. The pivot lever (not illustrated) may also be prevented from exceeding a defined linear motion up and down along a pivot pin (not illustrated) by the pivot receiver  280 . The pivot receiver  280  can also have a rotation indention  282 . In some embodiments, the rotation indention  282  can be comprised of two indention(s). 
     The main body stationary plate  241  may also include a bearing, set of bearings, or rollers  283  surrounding the main body stationary plate central aperture  241 B. The bearing, set of bearings, or rollers  283  can support an input shaft (not illustrated) that passes through the cam assembly (not illustrated). For example, the bearing, set of bearings, or rollers  283  can provide a rotatable support for the input shaft (not illustrated), and/or the cam assembly (not illustrated) that can be coupled to the input shaft. A support surface  284  can also be a surface of the main body stationary plate  241 . The support surface  284  can provide support for the outer stationary plate (not illustrated), and/or a stand-off or stanchion of a depth similar to the depth of the torque blocks (not illustrated). The stand-off would allow for the proper spacing of the cam assembly (not illustrated) within the main body stationary plate  241 , and/or outer stationary plate (not illustrated). 
     With reference now to  FIG. 11 , a top view of an outer stationary plate  242 , pivot assembly  270 , and torque block assembly  260  is depicted. The pivot assembly  270  can be pivotally coupled to the outer stationary plate  242  and/or main body stationary plate (not illustrated). The pivoting connection can be through the pivot point  278  and/or pivot pin  279 . As the pivot assembly  270  pivots around the pivot point  278  the pivot lever  272  can be guided by paths, channels, and/or grooves of a cam assembly (not illustrated). The paths, channels, and/or grooves of a cam assembly (not illustrated) can also engage the pivot lever  272  through a cam follower  274  generating a movement that would cause a pivoting motion of the pivot assembly  270  and/or torque block assembly  260  about a pivot point  278 , and/or pivot pin  279 . The torque block assembly  260  can be slidably connected to the pivot assembly  270  via a linkage pin  271 . The linkage pin  271  can accept a torque block  262 , through a sliding connection. However, the connection can also be performed through other methods such as a fastener or other connection means. The torque block(s)  262  can have an interface surface, such as, but not limited to torque pin(s)  266 . The interface surface can engage with an output interface surface through pin and hole, gears, belts, and/or other interfacing methods or systems that allow for a transfer of energy and/or power. The torque block assembly  260  can move in combination with the pivot assembly  270 , in an angular, and linear motion. In at least one embodiment, as the pivot assembly is rotatably moved and/or pivoted about the pivot point  278  and/or pivot point  279  in an angular rotation, the torque block assembly can also have a corresponding angular rotation. The corresponding angular rotation of the torque block assembly  260  can be in direct relation to the movement of the pivot assembly  270  or can be a ratioed angular movement based that moves in relation to the angular movement of the pivot assembly. The pivot assembly  270  may also move linear (as illustrated in and out of the page) with respective to the position of the cam follower  274  along one or more paths, channels, and/or grooves of a cam assembly (not illustrated). The torque block assemblies  260  can also relative to the linear movements of the pivot assembly  270 . As the pivot assembly  270  moves linearly the torque block assembly  260  can also move linearly and engage or disengage from an output interface surface. For example, the angular rotation of the pivot assembly  270  and/or torque block assembly  260  can be cyclical, and at specific points along the cyclical movement a linear motion can occur. 
     With reference now to  FIGS. 12A, 12B, 12C, 12D, 12E, 12F, 1211, and 12G  a preferred embodiment of the torque block assemblies  260  and the cam assembly  230  is shown.  FIG. 12A  shows a perspective view of the first cam body or element  230 A with the first spiral pathway  236 , and  FIG. 12C  shows a perspective view of the second cam body or element  230 B with the second spiral pathway  237 . In the depicted preferred embodiment, each torque block assembly  260  may be positioned along the outer edges of the cam assembly  230 . The pivot assembly  270  can be positioned between the first cam body or element  230 A and the second cam body or element  230 B.  FIG. 12B  illustrates the torque block assembly  260  and pivot assembly  270  with the first cam body or element  230 A, and  FIG. 12D  illustrates the torque block assembly  260  and pivot assembly  270  with the second cam body or element  230 B. As mentioned previously, the torque block assembly  260  comprises a torque block  262  and torque pins  266 . The pivot assembly  270  includes a pivot lever  272  pivotably coupled to the torque block  262  with a linkage pin  271 , and includes a cam follower  274  engaged with either the first spiral pathway  236  or the second return spiral pathway  237  and pivotably coupled to the distal end of the pivot lever  272 . The first spiral pathway  236  and the second return spiral pathway  237  may be combined to create a circuitous pathway. The pivot assembly  270  also includes fixed axis pivot point  278  that is rotatively coupled to a fixed axis of rotation relative to the central axis  206  of rotation of the cam assembly  230 . For example, a fixed axis pivot point pin  279  secured in corresponding fixed axis alignment holes  278  configured in the main body stationary plate  241  and/or outer stationary plate  242  and at the proximal end of the pivot lever  272  serves as a fixed axis of rotation relative to the rotation of the cam assembly  230  about the central axis  206 . While the pivot lever  272  may pivot about its fixed axis pivot point  278 , the alignment and configuration of the fixed axis pivot point  278  remains fixed in relation to the pivot lever  272  and the main body stationary plate  241  and/or outer stationary plate  242 . Each of the pivot assemblies  270  is biased so that the cam follower  274  of each pivot assembly  270  maintains contact with the either of the two spiral pathways  236 ,  237  throughout the rotation cycle of the cam assembly  230 . For example, in the depicted preferred embodiment, the gearbox mechanism comprises four torque block assemblies  260 , and pivot assemblies  270  and they are positioned and biased so that the cam follower  274  of each pivot assembly  270  and the rotation of the cam assembly  230  does not cause the collision of the cam follower  274 . The torque block assemblies  260  can be evenly spaced along a circumference surrounding the central axis  206 . In at least one embodiment, the torque block assemblies  260  are arranged and evenly spaced outside the circumference of the cam assembly  230 . 
     The torque blocks  262  of the torque block assemblies  260  are specifically designed to enable a greater surface area (e.g., greater number of pins) to engage the output element  250  at any given time, thereby spreading the stresses associated therein across a greater area. By increasing the contact area and number of pins coupled to the corresponding output interface surface  254  at any given time, the mechanical stress level is significantly decreased. In addition, torque block assemblies  260  of the present invention reduce backlash to zero and even preloaded conditions to create a tight connection between any power source and any powered device. Moreover, because the stresses associated with engagement of the torque blocks  262  and torque pins  266  with the output interface surface  254  are distributed across a greater area and a greater number pins and holes, the torque block assemblies  260  may be manufactured with lighter weight materials, which are typically less expensive and easier to manufacture, with no degradation in reliability. 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. 
     As shown in the embodiment depicted in the Figures, especially  FIGS. 12A and 12C , the cam assembly  230  is coupled to a power source by means of the input shaft  204 . Thus the power generated by a power source is transferred to the input shaft  204 , which causes the cam assembly  230  to rotate about the central axis  206 . The cam assembly  230  comprises a first cam body or element  230 A with a first spiral pathway  236  and a second cam body or element  230 B with a second spiral pathway  237  which interface with the cam follower  274  of each pivot assembly  270 . As the cam assembly  230  rotates, the movements of the torque blocks  262  and torque pins  266  is controlled in three dimensions in accordance with a certain design parameter. Because of the circuitous pathway the cam follower  274  may follow a spiral pathway on both the first cam body or element  230 A and the second cam body or element  230 B. The rate of change of the radius of the pathway curves may vary and therefore, the pivot assemblies  270  drives each torque block assembly  260  including torque block  262  and torque pins  266  through a three-dimensional circuit in response to rotation of the cam assembly  230 . Broadly speaking, the three-dimensional circuit includes urging the torque block assembly  260  to engage the output element  250  and move or rotate the output element  250  a specified distance prior to disengaging the output element  250 , and returning back the specified distance to again reengage the output element  250  once again and repeat the process. It is understood that the three-dimensional circuit or circuitous pathway formed by the first spiral pathway  236  and the second return spiral pathway  237  is not to scale and may be exaggerated to illustrate the general principal of the invention. The travel path or circuit of each torque block  262  and corresponding torque pins  266  is controlled by the angling and configuration of the various pivot assemblies  270  and/or spiral pathways  236 ,  237  of the cam assembly  230 . 
     It is understood that the spiral curve of the spiral pathways  236 ,  237  of the present invention can be defined as a curve that closes or opens upon itself, or a first point along the pathway. While in some embodiments portions of the spiral pathways may have a constant rate of change (e.g., a constantly increasing distance from the first point). In other embodiments, the rate of change may be variable, to create a spiral curve with one or more curve profiles. For example, a spiral pathway may include a first section with a constant rate of change, and a second section with a variable rate of change. 
     In a preferred embodiment, each pivot assembly  270  includes a pivot lever  272  that is coupled to other components. A cam follower  274  is pivotably coupled to a distal end of the pivot lever  272 , and maintains contact with either the first spiral pathway  236  formed in the first cam body or element  230 A or the second spiral pathway  237  formed in the second cam body or element  230 B. The distal end of the pivot lever  272  is positioned closer to the central axis  206  as compared to the proximal end of the pivot lever  272 . At the proximal end of the pivot lever  272  is the fixed axis pivot point  278 . The fixed axis pivot point  278  includes a pin that pivotably couples the pivot assembly  270  to the main body stationary plate  241 . Also near the proximal end of the pivot lever  272  is a linkage pin  271  that pivotably couples the pivot lever  272  to the torque block  262 . 
     Each of the pivot assemblies  270  are biased so that its respective cam follower  274  maintains engagement with either the first spiral pathway  236  formed in the first cam body  230 A or the second spiral pathway  237  formed in the second cam body  230 B throughout the rotation cycle of the cam assembly  230 . For example, one of the pivot assemblies  270  maintains engagement with the second spiral pathway  237  of the second cam element or body  230 B, and the other pivot assemblies  270  maintains engagement with the first spiral pathway  236  of the first cam element or body  230 A. In a preferred embodiment, the pivot assemblies  270  will include at least four pivot assemblies  270  that can be configured to allow three of the pivot assemblies  270  to be engaged with the first cam element or body  230 A, and one of the pivot assemblies  270  to be engaged with the second cam element or body  230 B. 
     The first spiral pathway  236  comprises a curved path emanating from a first end  236 A of the first spiral pathway  236 . The first spiral pathway  236  revolves around the center of the first cam element  230 A at a continuously increasing distance from the center until the first spiral pathway  236  ends at a second spiral end  236 B of the first spiral pathway  236 . The continuously increasing distance from the center of the first cam element  230 A creates a unique effect on the torque block assemblies  260  as the cam assembly  230  rotates. It would be understood that in some embodiments, the distance may not increase continuously or at all for at least one section of the spiral pathway  236 ,  237 . Each end  236 A,  236 B of the first spiral pathway  236  is angled in elevation, which allows for engagement and disengagement with the first spiral pathway  236 . For example, when the cam follower  274  is engaged with the first spiral pathway  236 , the cam follower  274  eventually reaches the second end  236 B of the first spiral pathway  236 . Upon reaching the second end  236 B of the first spiral pathway  236 , the cam follower  274  gradually disengages from the first spiral pathway  236  because the gradual incline or elevation of the second end  236 B of the first spiral pathway  236  urges the cam follower  274  to elevate out of the first spiral pathway. Accordingly, when the cam follower  274  is disengaged from the first spiral pathway  236 , the cam follower  274  eventually reaches the first end  237 A of the second spiral pathway  237 . Upon reaching the first end  236 A of the first spiral pathway  236 , the cam follower  274  gradually engages with the first spiral pathway  236  because the gradual decline or elevation of the first end  236 A of the first spiral pathway  236  urges the spiral cam follower  274  to descend into the first spiral pathway  236 . The first spiral pathway  236 , in at least one embodiment, can be a groove for a cam follower (not illustrated) to travel or traverse. The first spiral pathway  236  can have a first side  290 A, a second side  290 B, and a bottom  291  defined by the first cam body  230 A. In other embodiments, the first spiral pathway  236  may be comprised of other grooves and/or channels that would engage a cam follower. 
     Similarly, the second spiral pathway  237  comprises a curved path emanating from a first end  237 A of the second spiral pathway  237 , and the second spiral pathway  237  revolves around the center of the second cam body  230 B at a continuously increasing distance from the center of the second cam element  230 B until the second spiral pathway  237  ends at the second end  237 B of the second spiral pathway  237 . While the first spiral pathway  236  comprises multiple revolutions around the center of the first cam element or body  230 A, the second spiral pathway  237  comprises a single revolution around the center of the second cam element or body  230 B to facilitate the return of the cam follower  274  from the second end  236 B of the first spiral pathway  236  to the first end  236 A of the first spiral pathway  236 . Like the first spiral pathway  236 , each end  237 A,  237 B of the second spiral pathway  237  is angled in elevation, which allows for engagement and disengagement with the second spiral pathway  237 . For example, when the cam follower  274  is engaged with the second spiral pathway  237 , the cam follower  274  eventually reaches the second end  237 B of the second spiral pathway  237 . Upon reaching the second end  237 B of the second spiral pathway  237 , the cam follower  274  gradually disengages from the second spiral pathway  237  because the gradual incline or elevation of the second end  237 B of the second spiral pathway  237  urges the cam follower  274  to elevate out of the second spiral pathway  237 . Accordingly, when the cam follower  274  is disengaged from the second spiral pathway  237 , the cam follower  274  eventually reaches the first end  236 A of the first spiral pathway  236 . Upon reaching the first end  237 A of the second spiral pathway  237 , the cam follower  274  gradually engages with the second spiral pathway  237  because the gradual incline or elevation of the first end  237 A of the second spiral pathway  237  urges the cam follower  274  to descend into the second spiral pathway  237 . The second spiral pathway  237 , in at least one embodiment, can have a channel  292  that allows for the engagement of a cam follower (not illustrated). The channel  292  can have a shaft gap  293  and a receiving section  294  sized and configured to receive a portion of a cam follower (not illustrated) that corresponds to the size and shape of the receiving section  294 , defined by the second cam body  230 B. In other embodiments, the receiving section may be sized and configured to receive any number of shapes or configurations of a cam follower. 
     As the cam assembly  230  rotates, the cam follower  274  shifts according to the first spiral pathway  236  and the second spiral pathway  237 , and causes the shifting and pivoting of the pivot lever  272 . For the pivot assemblies  270  with cam follower  274  engaged with the first spiral pathway  236 , the shifting and pivoting of the pivot lever  272  causes the torque blocks  262  to shift and pivot accordingly, and thereby urge the movement and rotation of the output element  250  using the torque pins  266  engaged with the output interface surface  254 . For the pivot assemblies  270  with the cam follower  274  engaged with the second spiral pathway  237 , the shifting and pivoting of the pivot lever  272  causes the torque block  262  to move in a direction opposite of the direction of rotation of the output element  250 . By moving in a direction opposite of the direction of rotation of the output element  250 , the torque block assembly  260  returns back the specified distance to again reengage the output element  250 . This predetermined circuit of movement of the torque block assembly  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 revolutions of the first spiral pathway  236  and or second spiral pathway  237 . 
     Once a cam follower  274  reaches the second end  237 B of the second spiral pathway  237 , the cam follower  274  gradually disengages from the second spiral pathway  237  through the gradual elevation of the cam follower  274  using the gradual incline of the second end  237 B of the second spiral pathway  237 . As the cam follower  274  gradually disengages from the second spiral pathway  237 , the cam follower  274  gradually engages with the first spiral pathway  236  through the gradual descent of the cam follower  274  into the first spiral pathway  236  using the gradual incline of the first end  236 A of the first spiral pathway  236 . Similarly, once the cam follower  274  reaches the second end of the first spiral pathway  236 , the cam follower  274  gradually disengages from the first spiral pathway  236  through the gradual elevation of the cam follower  274  using the gradual incline of the second end of the first spiral pathway  236 . As the cam follower  274  gradually disengages from the first spiral pathway  236 , the cam follower  274  gradually engages with the second spiral pathway through the gradual descent of the cam follower  274  into the second spiral pathway using the gradual incline of the first end of the second spiral pathway  237 . Accordingly, the travel path of each cam follower  274  is three-dimensional because the transitions between the first spiral pathway  236  and the second spiral pathway  237  move the cam follower  274  in a direction parallel to the central axis  206 . An example of the path taken by each of the cam follower  274  is shown in  FIG. 12F . It is understood that the three-dimensional path made by the first spiral pathway  236  and the second spiral pathway  237  is not to scale and may be exaggerated to illustrate the general principal of the invention. In at least one embodiment, the pathways  236 ,  237  are formed as corresponding pathways on opposing interior surfaces of the cam elements  230 A,  230 B which create a circuitous pathway. These surfaces in one example would be opposing each other as interior surfaces when placed together as cam assembly  230 . Alternatively, in other examples, the corresponding surfaces would be configured opposite of each other as exterior surfaces when formed as cam assembly  230 . 
     With reference to  FIGS. 12D and 12E , that are illustrations of gear blocks and general movements of the torque block assemblies  260  relative to the movement of an output element  229 . The gear block(s) illustrated  262  are shown in various positions starting with the right most gear block  262 A is shown in a transitioning/repositioning position  228  where it is fully disengaged from the interface surface  254  of the output element (not illustrated) and the interface surface  266  (illustrated as a set of pins) of the gear block  262 A is fully disengaged. Moving to gear block  262 B, that is shown in a reversed tension or negative bias configuration  227 . There can also be a position such as one that gear block  262 C is in, a neutral bias configuration  225 . Gear block  162 D is illustrated in a positively biased or engaged configuration  226 , which can result in a rotation of the output element (not illustrated). There can be three engagement positions for a gear block to be in: an engaged or positive bias position  226 , a reversed tension or negative bias position  227 , and/or a neutral bias or balanced position  225 . Additionally, a gear block can be in a transitioning/repositioning position  228 , which allows for the gear block  262  to disengage and/or move away from the output element (not illustrated) 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. 
     With reference now to  FIGS. 13A and 13B , a front perspective view, and a rear perspective view of a pivot assembly  270  and torque block assembly  260  are illustrated. The pivot assembly  270  in at least one embodiment includes a pivot lever  272 , a cam follower  274 , and a linkage pin  271 . The pivot lever  272  may have a cam follower aperture  275  configured to accept a cam follower  274 , and/or a bearing, set of bearings, or roller(s)  276 . The cam follower aperture  275  may be at a distal end of the pivot lever  272 , and be sized and defining a passage for a portion of a cam follower  274  to pass through and coupled. At a proximal end of the pivot lever  272 , a pivot column  277  can define a pivot point  278  that can allow for a pivot pin  279  to be passed through and/or coupled to the pivot lever  272 . The pivot column  277  can also define a linage pin aperture  285  to allow for a linkage pin  271  to pass through and/or couple to the pivot lever  272 . 
     The linkage pin  271  can have a link head  286  coupled with a link shaft  287 , coupled to the linkage pin body  288 . In at least one embodiment, the link head  286  is equal to or greater in diameter than the linkage pin body  288 . The link shaft  287  can sized with a width and length that allow for a torque block  262  to be slidably coupled to the linkage pin  271 . The torque block  262  can have a block opening  289 . The block opening  289  can have a block shelf  295 , and block gap  296 . The block shelf  295  can allow the link head  286  to be even and/or not extend above a top surface of the torque block  262 . In other examples, the link head  286  can extend above the top surface of the torque block  262  to allow for a buffering or setoff from a surface of the output element  250 . The torque block  262  can include at least on interface surface illustrated as torque pins  266 A,  266 B (collectively  266 ) or gear teeth  267 . The gear teeth  267 , can have a valley  268 A, and ridges  268 B, or other forms of interface surfaces for engagement and/or disengagement with an output element or device. In some embodiments, the torque pins  266  can have a standoff section  269 A,  269 B (collectively  269 ) that prevents the torque pins from engaging with an output element or device in a manner that would prevent the torque block  262  from disengaging from the output element or device. For example, if the torque pins  262  engage too deep with an output element or device, it may prevent the torque block  262  from being able to disengage from the output element or device. 
     To allow for a coupling and/or engagement of the cam follower  274  with the respective pathways (not illustrated), a first tracking end  297 A and a second tracking end  297 B can be utilized to prevent the cam follower  274  from following the wrong pathway. The first tracking end  297 A that can have a pin or point that is smaller than the second tracking end  297 B. The second tracking end  297 B may have a groove  298  with a flanges  299 A,  299 B (collectively  299 ) that allow for an engagement with a pathway (not illustrated). The second tracking end  297 B may have other shapes such as a following head or band larger than the main body of the cam follower  274 . 
     Numerous embodiments of gearbox mechanisms are possible using the torque block assembly  260  of the present invention. All embodiments of gearbox mechanisms constructed in accordance with the present invention feature a plurality of torque block assemblies  260  configured about the central axis  206  of the cam assembly  230  and may comprise either an odd or even number of torque block assemblies  260 . At least two, preferably four gear block assemblies are required for a gearbox mechanism of the present invention. 
     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.