Patent Publication Number: US-2016238115-A1

Title: Human-powered drive train

Description:
BACKGROUND INFORMATION 
     1. Field of the Disclosure 
     Examples of the present disclosure are related to systems and methods for a human-powered drivetrain. Specifically, embodiments are related to human-powered drivetrain that converts force into rotational force. 
     2. Background 
     A conventional bicycle is a human-powered, pedal-driven, single-track vehicle. A conventional bicycle has two wheels attached to a frame, where one wheel is positioned behind a second wheel. A conventional bicycle is positioned upright, where a user of the conventional bicycle may apply rotational force to the pedals to move the bicycle. Further, when a pedal of a conventional bicycle is rotated, the second pedal is also automatically rotated. Thus, the pedals are dependent upon each other, therefore the pedals are rotated at the same frequency and amplitude. 
     Over time, different types of bicycles have been created, such as a rowing bicycle. To use a rowing bicycle a user may use their upper body to pull on a handle. Responsive to the user pulling the handle, the handle may apply force to a gear shaft to move the bicycle. Rowing bicycles only include a single handle that is configured to be pulled by the user&#39;s entire upper body. 
     Accordingly, needs exist for more effective and efficient methods and systems that allow a user to perform independent left and right strokes, while also allowing the user to vary the stroke frequency, displacement and/or amplitude of pedals. 
     SUMMARY 
     Human appendages, such as arms and legs, are relatively strong parts of a user&#39;s body. The term appendage used herein may refer to a user&#39;s legs, arms, or other appendages. A user&#39;s legs are typically the strongest appendages and are able to move heavier loads than arms, such as the entire weight of the user&#39;s body. Using their legs, the user may be able to walk, run, and lift heavy objects. Utilizing the user&#39;s legs, the user may be able to generate force, mechanical power, etc. 
     Embodiments described herein are configured to receive force generated by a user moving their appendages, and converting the movement into mechanical force and/or energy. More specifically, embodiments may convert axial and/or tangential force into rotational force. The rotational force may be utilized to power devices, drivetrains, vehicles, such as bicycles, tricycles, kayaks, boats, etc. The rotational force may be stored as potential energy, electrical energy, kinetic energy, and used with various devices. Embodiments are configured to receive force generated by a user retracting their appendages by moving their hips back and bending their knees and hips, such that the user&#39;s knees are closer to the user&#39;s torso and extending their appendages by extending their appendages to be in a linear position. 
     Embodiments include a human-powered drivetrain coupled to a vehicle that is configured to convert force into rotational force. The human-powered drivetrain may include two independent pedals that are configured to interface with a user&#39;s appendages. The independent pedals may be configured to receive force from the user&#39;s appendages, wherein the independent pedals may receive force at different frequencies, amplitudes, and/or timing. Therefore, the user may vary the displacement of each pedal via independent strokes, wherein a first appendage may move the vehicle independent to the movement of a second appendage. 
     In embodiments, a power stroke may refer to the motion of moving a user&#39;s appendages in a first direction, and a reset stroke may refer to the motion of moving the user&#39;s appendages in a second direction. In embodiments, the first direction may be a motion extending the user&#39;s appendages, or the first direction may be a motion retracting the user&#39;s appendages. Further, the second direction may be a motion extending the user&#39;s appendages, or the second direction may be a motion retracting the user&#39;s appendages. Accordingly, the power stroke and reset stroke may refer to the user moving their appendages in opposite directions. In embodiments, a reset stroke and/or a power stroke may be assisted using various mechanical devices, such as hydraulics, springs, etc. For example, upon completing a power stroke, hydraulics and/or springs may apply force in the second direction to assist the user to complete a reset stroke. If only a reset stroke and/or a power stroke is assisted using mechanical devices, then the reset stroke and the power stroke may require different amounts of energy or force. 
     In embodiments, the user may apply a first power stroke and/or reset stroke to a first pedal, independent to the movement of the second pedal, and vice versa. The user may apply power strokes to both pedals in unison to create more force at a given time, or may apply the power strokes independently to create continuous force. To this end, the movement of the first and second pedals may be independent of each other, and may be made at any desired frequency, amplitude, etc. (e.g. random pedal movements). For example, the first pedal may be at rest while the second pedal performs multiple power strokes. 
     In embodiments, each pedal may be displaced at varying positions along a drivetrain, wherein each stroke may displace the pedals at various distances. The ability of the pedals to be displaced at various distances may allow users having varied appendage lengths to utilize the human-powered drivetrain without adjustment. 
     These, and other, aspects of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. The following description, while indicating various embodiments of the invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many substitutions, modifications, additions or rearrangements may be made within the scope of the invention, and the invention includes all such substitutions, modifications, additions, or rearrangements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. 
         FIG. 1  depicts a human-powered drivetrain, according to an embodiment. 
         FIG. 2  depicts a human-powered drivetrain, according to an embodiment. 
         FIG. 3  depicts a human-powered drivetrain, according to an embodiment. 
         FIG. 4  depicts a human-powered drivetrain, according to an embodiment. 
         FIG. 5  depicts a human-powered drivetrain, according to an embodiment. 
         FIG. 6  depicts a human-powered drivetrain, according to an embodiment. 
         FIG. 7  depicts a side view of a human-powered drivetrain, according to an embodiment. 
         FIG. 8  depicts a method for a human-powered drivetrain. 
         FIGS. 9-12  depict embodiments of a user creating power strokes and reset strokes associated with a first rigid projection and a second rigid projection. 
     
    
    
     Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present disclosure. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present disclosure. Embodiments and elements are not necessarily represented to scale in the FIGURES, and are presented as is for simplicity. 
     DETAILED DESCRIPTION 
     In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present embodiments. It will be apparent to one having ordinary skill in the art, that the specific detail need not be employed to practice the present embodiments. In other instances, well-known materials or methods have not been described in detail in order to avoid obscuring the present embodiments. 
     Embodiments described herein disclose a human-powered drivetrain configured to receive forces generated by a user&#39;s appendages, and to convert the forces into mechanical rotational force and/or energy. 
       FIG. 1  depicts a human-powered drivetrain  100 , according to an embodiment. Human power drivetrain  100  may include frame  102 , first rigid projection  105 ( a ), second rigid projection  105 ( b ), first pedal  110 ( a ), second pedal  110 ( b ), axle  115 , first gear  120 ( a ), second gear  120 ( b ), fixed hub  125 , chain  130 , support axle  135 , secondary gear  140 , and wheel  150 . 
     Frame  102  may be a frame of human-powered drivetrain  100  onto which other components of human-power drivetrain  100  may be fitted or coupled, such as rigid projections  105 ( a ) and  105 ( b ), pedals  110 ( a ) and  110 ( b ), axle  115 , gears  120 ( a ) and  120 ( b ), fixed hub  125 , chain  130 , support axle  135 , secondary gear  140 , and/or wheel  150 . Frame  102  may be comprised of various materials, such as metal and/or plastics, and frame  102  may be configured to be made in various shapes and/or sizes. Frame  102  and may be configured to be strong, rigid, and light in weight. 
     First rigid projection  105 ( a ) and second rigid projection  105 ( b ) may be coupled to frame  102 , and be configured to move along a linear axis, wherein the linear axis may be tangential to axle  115  and parallel to chain  130 . First rigid projection  105 ( a ) and second rigid projection  105 ( b ) may include a plurality of ridges, projections, teeth, cogs, etc. (referred to hereinafter collectively and individually as projections). The projections disposed on a first surface of first rigid projection  105 ( a ) may be configured to interface with teeth position on first gear  120 ( a ), and projections disposed on a first surface of second rigid projection  105 ( b ) may be configured to interface with teeth positioned on second gear  120 ( b ). In embodiments, first rigid projection  105 ( a ) and second rigid projection  105 ( b ) may have projections positioned on multiple sides of first rigid projection  105 ( a ) and second rigid projection  105 ( b ). 
     First pedal  110 ( a ) may be a pedal, stirrup, strap, loop, etc. configured to receive a user&#39;s first appendage. First pedal  110 ( a ) may be configured to be coupled to first rigid projection  105 ( a ). First pedal  110 ( a ) may be coupled to first rigid projection  105 ( a ) at a position proximate to a first end of first rigid projection  105 ( a ), and may be positioned on a side of first rigid projection  105 ( a ) opposite wheel  150  with respect to frame  102 . First pedal  110 ( a ) may be configured to receive force from the user&#39;s appendage to move first rigid projection  110 ( a ) in both directions along a linear axis. In embodiments, a reset stroke may be completed by the user moving first pedal  110 ( a )in a first direction, wherein the first direction may be a movement of first pedal  110 ( a ) from a position proximate to wheel  150  towards the torso of the user. In embodiments, a power stroke may be completed by the user moving first pedal  110 ( a ) in a second direction, wherein the first direction may be a movement of second pedal  110 ( b ) from a position proximate to the user&#39;s torso towards wheel  150 . Movement of first pedal  110 ( a ) and first rigid projection  105 ( a ) may be made independent of movement of second pedal  110 ( b ) and second rigid projection  105 ( b ). 
     Second pedal  110 ( b ) may be a pedal, stirrup, strap, loop, etc. configured to receive a user&#39;s second appendage. Second pedal  110 ( b ) may be configured to be coupled to second rigid projection  105 ( b ). Second pedal  110 ( b ) may be coupled to second rigid projection  105 ( b ) at a position proximate to a first end of second rigid projection  105 ( b ), and may be positioned on a side of second rigid projection  105 ( b ) opposite wheel  150  with respect to frame  102 . Second pedal  110 ( b ) may be configured to receive force from the user&#39;s appendage to move second rigid projection  105 ( b ) in both directions along a linear axis. In embodiments, a reset stroke may be completed by the user moving second pedal  110 ( b ) from in a first direction. In embodiments, a power stroke may be completed by the user moving second pedal  110 ( b ) in a second direction. Movement of second pedal  110 ( b ) and second rigid projection  105 ( b ) may be made independent of movement of first pedal  110 ( a ) and first rigid projection  105 ( a ). 
     Axle  115  may be a central shaft coupled to fixed hub  125 , first gear  120 ( a ), second gear  120 ( b ), and chain  130 . Axle  115  may be configured to be fixed at a stationary location within frame  102 , and axle  115  may rotate responsive to first gear  120 ( a ) or second gear  120 ( b ) being rotated. In embodiments, axle  115  may be coupled to both first gear  120 ( a ) and/or second gear  120 ( b ), such that axle  115  includes a single, central axle that rotates responsive to a power stroke applied to first rigid projection  105 ( a ) or second rigid projection  105 ( b ), wherein axle  115  controls the rotation of wheel  150 . 
     First gear  120 ( a ) may be positioned on a first end of axle  115 . First gear  120 ( a ) may have a plurality of mating teeth configured to interface with the projections disposed on first rigid projection  105 ( a ). First gear  120 ( a ) may be a cogwheel that is a rotating machine that interfaces with the projections disposed on first rigid projection in order to generate torque responsive to first rigid projection  105 ( a ) moving along the linear axis. Responsive to first gear  120 ( a ) receiving torque, first gear  120 ( a ) may rotate axle  115  in a first direction. In embodiments, first gear  120 ( a ) may be a freewheeling gear, such that first gear  120 ( a ) may only be rotated in a first direction corresponding to a power stroke, wherein the first direction may be an opposite rotational force to the direction of the power stroke. Therefore, as a user completes a power stroke first gear  120 ( a ) may be rotated in the first direction, and as the user completes a reset stroke first gear  120 ( a ) may not be rotated. 
     Second gear  120 ( b ) may be positioned on a second end of axle  115 . Second gear  120 ( b ) may have a plurality of mating teeth configured to interface with the projections disposed on second rigid projection  105 ( b ). Second gear  120 ( b ) may be a cogwheel that is a rotating machine that interfaces with the projections disposed on first rigid projection in order to generate torque responsive to second rigid projection  105 ( b ) moving along the linear axis. Responsive to second gear  120 ( b ) receiving torque, second gear  120 ( b ) may rotate axle  115  in the first direction. In embodiments, second gear  120 ( b ) may be a freewheeling gear, such that second gear  120 ( b ) may only be rotated in the first direction corresponding to a power stroke, wherein the first direction may be an opposite rotational force to the direction of the power stroke. Therefore, as a user completes a power stroke second gear  120 ( b ) may be rotated in the first direction, and as the user completes a reset stroke second gear  120 ( b ) may not be rotated. 
     In embodiments, a ratio of the number projections and mating teeth along first rigid projection  105 ( a ) and first gear  120 ( a ) and second rigid projection  105 ( b ) or  120 ( b ) may vary to produce different mechanical advantages. The ratio of the number of projections may be configured to be a ratio suitable for a length of an average user&#39;s appendages and strength. Furthermore, additional gears and/or drivetrains may be used to increase or decrease the mechanical advantages, such as a multi-speed bicycle. 
     In embodiments, first rigid projection  105 ( a ) or second rigid projection  105 ( b ) may be performing a power stroke, reset stroke, or be at rest, while the other projection may be performing a power stroke, reset stroke or be at rest. Furthermore, first rigid projection  105 ( a ) or secondary rigid projection  105 ( b ) may perform multiple iterations of a power stroke, reset stroke, or be at rest, without moving the other rigid projection. Therefore, human-powered drivetrain  100  allows a user to apply force with both appendages simultaneously, wherein the force generated by each appendage may be added during a power stroke, potentially doubling the force generated by a power stroke. Furthermore, each power stroke or reset stroke may have displaced first rigid projection  105 ( a ) or second rigid projection  105 ( b ), wherein the displacement of first rigid projection  105 ( a ) may be different than the displacement of second rigid projection  105 ( b ) and the displacements may vary at different times based on the frequency of strokes, amplitude of strokes, etc. 
     Fixed hub  125  may be a gear coupled to axle  115  and chain  130 . Responsive to axle  115  being rotated, fixed hub  125  may also be rotated. Fixed hub  125  may be configured to be rotated responsive to a user performing a power stroke to move first rigid projection  105 ( a ) and/or second rigid projection  105 ( b ). Accordingly, two independent rigid projections  105 ( a ) and  105 ( b ) may be configured to rotate fixed hub  125  at different speeds, frequencies, intervals, and/or amplitudes, wherein fixed hub  125  may be a single central hub, and in other embodiments fixed hub  125  may include multiple hubs. 
     Chain  150  may be a bicycle chain, such as a roller chain that is configured to transfer power from fixed hub  125  to secondary gear  140 . Chain  150  may be comprised of plastic, plain carbon, alloys, metals, or other materials. Chain  150  may include a plurality of orifices configured to receive projections positioned on fixed hub  125  and secondary gear  140 . Responsive to fixed hub  125  being rotated, chain  130  may be pulled, and chain  150  may subsequently rotate secondary gear  140 . 
     Secondary axle  135  may be a fixed axle within frame  102  configured to support secondary gear  140  and wheel  150 . In embodiments, responsive to secondary gear  140  being moved by chain  130 , secondary gear  140  may be rotated about secondary axle  135  and wheel  150  may be rotated. 
       FIG. 2  depicts a human-powered drivetrain  100 , according to an embodiment. In the embodiment as depicted in  FIG. 2 , wheel  150  has been replaced with a boat paddle  200 . To this end, human-powered drivetrain  100  may be configured to provide power to move a number of different vehicles, such as bicycles, boats, or any other device where force may move the vehicle. 
       FIG. 3  depicts a human-powered drivetrain  300 , according to an embodiment. Human-powered drivetrain  300  may include first rigid projection  105 ( a ), second rigid projection  105 ( b ), first gear  310 ( a ), second gear  310 ( b ), axle  320 , and wheel  330 . 
     First gear  310 ( a ) may be positioned on a first end of axle  320 . First gear  310 ( a ) may have a plurality of teeth configured to interface with the projections disposed on first rigid projection  105 ( a ). Second gear  310 ( b ) may be positioned on a second end of axle  320 . Second gear  310 ( b ) may have a plurality of teeth configured to interface with the projections disposed on second rigid projection  050 ( b ). 
     Axle  320  may be central shaft for coupled to first gear  310 ( a ), second gear  310 ( b ), frame  102 , and wheel  330 . Axle  320  may be directly coupled to first gear  310 ( a ) and  310 ( b ), such that as gears  310 ( a ) and  310 ( b ) are rotated via rigid projections  105 ( a ) and  05   b ), axle  320  may rotate wheel  330 . 
       FIG. 4  depicts a human-powered drivetrain  400 , according to an embodiment. As depicted in  FIG. 4 , rigid projections  420 ( a ) and  420 ( b ) may be curved projections that move along a track. A user may apply force to rigid projections  420 ( a ) and  420 ( b ) to generate power strokes and reset strokes. Accordingly, rigid projections  420 ( a ) and  420 ( b ) may be comprised of various shapes and/or sizes, and rigid projections  420 ( a ) and  420 ( b ) are configured to receive force from a user&#39;s appendages to move along tracks, wherein the force applied to one of the rigid projections  420 ( a ) and  420 ( b ) may independently move human-powered drivetrain  400 . 
       FIG. 5  depicts a human-powered drivetrain  500 , according to an embodiment. As depicted in  FIG. 5 , rigid projections  420 ( a ) and  420 ( b ) may be positioned on opposite sides of gears  310 ( a ) and  310 ( b ), respectively. Accordingly, human-powered drivetrain  500  may be configured to move in an opposite direction as human-powered drivetrain  400 . To this end, a user may switch the direction of the rotational output by changing the orientation of rigid projections  420 ( a ) and  420 ( b ) with respect to gears  310 ( a ) and  310 ( b ). Therefore, human-powered drivetrain  500  may be positioned on a vehicle&#39;s front wheel or back wheel at any given point in time. 
       FIG. 6  depicts a human-powered drivetrain  600 , according to an embodiment. As depicted in in  FIG. 6 , fixed hub  125  may include a plurality of projections configured to be interfaced with hypoid gear  610 . Hypoid gear  610  may be configured to be positioned perpendicular to axle  115 , such that as axle  115  is rotated in a first direction, hypoid gear  610  may be rotated in a second direction, wherein the first direction is perpendicular to the second direction. Specifically, hypoid gear  610  may be configured to be offset at a ninety degree angle with respect to fixed hub  125 . In embodiments, as fixed hub  125  is rotated, projections positioned on fixed hub  125  may interface with mating teeth faces positioned on hypoid gear  610  to rotate hypoid gear  610 . 
     Drive shaft  620  may be a shaft that is coupled to hypoid gear  610 , wherein hypoid gear  610  is coupled to a first end of drive shaft  620 . Responsive to hypoid gear  610  being rotated, drive shaft  620  may be rotated in the same direction as hypoid gear  610 . Disposed on a second end of drive shaft  620  may be a propeller, fan, etc. The propeller may be configured to interact with another substance such as air or water to move the vehicle coupled to human-powered drivetrain  600 . 
       FIG. 7  depicts a side view of human-powered drivetrain  100 , according to an embodiment.  FIG. 7  includes embodiments of first rigid projection  105 ( a ), first pedal  110 ( a ), and first gear  120 ( a ). As depicted in  FIG. 7 , first pedal  110 ( a ) may be coupled at any point along first rigid projection  105 ( a ); however, first pedal  110 ( a ) may be coupled to first rigid projection  105 ( a ) at a location proximate to one end of first rigid projection  105 ( a ). 
     First rigid projection  105 ( a ) may include projections  710 . Projections  710  may be evenly, offset, and/or varied spaced projections, teeth, etc. that are configured to interface with mating teeth  720  positioned on first gear  105 ( a ). 
     Gear  120 ( a ) may include mating teeth  720 , free wheel hub  730 , and axle  125 . Mating teeth  720  may be shaped, spaced, and/or sized to interface with projections  710 , such that as first rigid projection  105 ( a ) moves in a linear direction, mating teeth  720  may rotate gear  120 ( a ) responsive to the force applied by projections  710 . 
     Free wheel hub  730  may be a device configured to allow gear  120 ( a ) to transfer torque to final drive axle  740  in only a single direction. As first rigid projection  105 ( a ) receives force to generate a power stroke, free wheel hub  730  may interface with gear  120 ( a ) to rotate axle  125 . However, as first rigid projection  105 ( a ) receives force to generate a reset stroke, free wheel hub  730  may not interface with gear  120 ( a ), and thus axle  125  may not be rotated. 
       FIG. 8  depicts a method  800  for a human-powered drivetrain, according to an embodiment. The operations of method  800  presented below are intended to be illustrative. In some embodiments, method  800  may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of method  800  are illustrated in  FIG. 8  and described below is not intended to be limiting. 
     At operation  810 , a user may insert a first appendage into a first pedal positioned on a first rigid projection, and the user may insert a second appendage into a second pedal on a second rigid projection. The user may then extend their appendages, such that the pedals are displaced at a position furthest away from the user&#39;s torso. Operation  810  may be completed by pedals that are the same as or similar to pedals  110 ( a ) and  110 ( b ), in accordance with one or more implementations. 
     At operation  820 , the user may move their first appendage towards the user&#39;s torso. Responsive to the user moving the first appendage towards the user&#39;s torso, the first rigid projection may be displaced a first distance, wherein the first distance may be associated with how far the user extends the first appendage. Operation  820  may be completed by a first rigid projection which is the same as or similar to first rigid projection  105 ( a ), in accordance with one or more implementations. 
     At operation  830 , the user may move their second appendage towards the user&#39;s torso. Responsive to the user moving the second appendage towards the user&#39;s torso, the second rigid projection may be displaced a second distance, wherein the second distance may be associated with how far the user extended the first appendage, and the second distance may be a different distance than the first distance. Operation  830  may be completed by a second rigid projection which is the same as or similar to second rigid projection  105 ( b ), in accordance with one or more implementations. 
     At operation  840 , the user may move their second appendage away from the user&#39;s torso to create a power stroke. Responsive to the user extending their second appendage, a second gear may interface with the second rigid projection to move a vehicle. Furthermore, the second appendage may be displaced at a third distance, wherein the third distance may be based on the second distance and how far the user moved their second appendage away from their torso. Operation  840  may be completed by a second rigid projection which is the same as or similar to second rigid projection  105 ( b ), in accordance with one or more implementations. 
     At operation  850 , the user may move their first appendage away from the user&#39;s torso to create a power stroke. Responsive to the user extending their first appendage, a first gear may interface with the first rigid projection to move the vehicle. Furthermore, the first appendage may be displaced at a fourth distance, wherein the fourth distance may be based on the first distance and how far the user moved their first appendage away from their torso. Operation  850  may be completed by a first rigid projection which is the same as or similar to first rigid projection  105 ( a ), in accordance with one or more implementations. 
     One skilled in the art will appreciate that operations  830  and  840  may be made independent to operations  820  and  850 , or operations  820  and  830  may be made simultaneously, and operations  840  and  850  may be made simultaneously. As such, the user may chose a desired rate to create reset strokes and/or power strokes for each appendage, wherein the power strokes for the first rigid projection and second rigid projection may be used to rotate the same hub or gear. 
       FIGS. 9-12  depict embodiments of a user creating power strokes and reset strokes associated with first rigid projection  105 ( a ) and second rigid projection  105 ( b ). 
       FIG. 9  depicts an embodiment where first rigid projection  105 ( a ) and second rigid projection  105 ( b ) are moved simultaneously, and have the same displacements. Accordingly, when first rigid projection  105 ( a ) is completing a power stroke second rigid projection  105 ( b ) is completing a power stroke, and when first rigid projection  105 ( a ) is completing a reset stroke second rigid projection  105 ( b ) is completing a reset stroke. 
       FIG. 10  depicts an embodiment where first rigid projection  105 ( a ) and second rigid projection  105 ( b ) are being moved simultaneously but being phase shifted one hundred eighty degrees. Accordingly, when first rigid projection  105 ( a ) is completing a power stroke second rigid projection  105 ( b ) is completing a reset stroke, and when first rigid projection  105 ( a ) is completing a reset stroke second rigid projection  105 ( b ) is completing a power stroke. 
       FIG. 11  depicts an embodiment where first rigid projection  105 ( a ) and second rigid projection  105 ( b ) are being moved independently of one another. During a first time period, first rigid projection  105 ( a ) and second rigid projection  105 ( b ) are phase shifted one hundred eighty degrees. During a second time period, second rigid projection  105 ( b ) may complete a power stroke and a reset stroke while first rigid projection  105 ( a ) is at rest. During a third time period, first rigid projection  105 ( a ) and second rigid projection  105 ( b ) may be complete a power stroke and a reset stroke at the same time. 
       FIG. 12  depicts an embodiment where first rigid projection  105 ( a ) and second rigid projection  105 ( b ) are being moved independent of one another. As depicted in  FIG. 12 , the movement of first rigid projection  105 ( a ) is not based on the movement of second rigid projection  105 ( b ), and vice versa. Furthermore, the amplitude and/or frequency of power strokes and/or reset strokes may vary. 
     Although the present technology has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred implementations, it is to be understood that such detail is solely for that purpose and that the technology is not limited to the disclosed implementations, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present technology contemplates that, to the extent possible, one or more features of any implementation can be combined with one or more features of any other implementation. 
     Reference throughout this specification to “one embodiment”, “an embodiment”, “one example” or “an example” means that a particular feature, structure or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment”, “in an embodiment”, “one example” or “an example” in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures or characteristics may be combined in any suitable combinations and/or sub-combinations in one or more embodiments or examples. In addition, it is appreciated that the figures provided herewith are for explanation purposes to persons ordinarily skilled in the art and that the drawings are not necessarily drawn to scale. 
     The flowcharts and block diagrams in the flow diagrams illustrate the architecture, functionality, and operation of possible implementations of systems, and methods.