WO2020172302A1

WO2020172302A1 - Quick release crank arm mechanism

Info

Publication number: WO2020172302A1
Application number: PCT/US2020/018857
Authority: WO
Inventors: David W. Kraus; Miklos HUZAR
Original assignee: Hpn Holdings, Inc.
Priority date: 2019-02-19
Filing date: 2020-02-19
Publication date: 2020-08-27

Abstract

A quick-release crank arm for a crank-powered machine that includes an elongate crank arm having a first end and a second end; means for connecting the crank arm to a first spindle near the first end; means for reversibly locking the connecting means into the crank arm by reorienting a lever; and means for connecting the crank arm to a second spindle near the second end.

Description

QUICK RELEASE CRANK ARM MECHANISM

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application cites the priority of U.S. Pat. App. No. 62/807,669, filed on 19 February 2019 (pending), and which is incorporated by reference herein in its entirety.

SUMMARY

[0002] The present disclosure describes a quick-release crank arm assembly that allows a crank arm to be removed and reattached at a 180° offset without the use of specialized tools or mechanical expertise.

[0003] In a first aspect a releasable crank arm assembly for a crank-powered machine is provided, the crank arm assembly comprising: an elongate crank arm having a proximal end for connection to a bracket spindle, a distal end for connection of a pedal spindle, a stem aperture, and a cavity proximate to the proximal end; a bracket block in the cavity, comprising a bracket spindle connector; a stem positioned in the stem aperture to compress the bracket block against the cavity; a lever on a terminal end of the stem configured to lock the stem in place or release the stem, allowing the stem to be removed or repositioned, wherein when said stem is removed or repositioned the crank arm may be easily removed or replaced on the bracket spindle.

[0004] In a second aspect a releasable crank arm assembly for a crank-powered machine is provided, the crank arm assembly comprising: an elongate crank arm having a first end and a second end; means for connecting the crank arm to a first spindle near the first end; means for reversibly locking the connecting means into the crank arm by reorienting a lever; and means for connecting the crank arm to a second spindle near the second end.

[0005] In a third aspect a method of removing a crank arm from a crank-powered vehicle without tools is provided, wherein said crank-powered vehicle comprises a releasable crank- arm assembly of the first or second aspect, and wherein the bracket block is semi permanently connected to a bracket spindle, the method comprising: manually reorienting the lever to release tension on the stem; and removing the crank arm from the bracket block.

[0006] In a fourth aspect a human powered vehicle driven by elliptical motion of a rider's legs is provided, comprising: a pair of opposing crank arms, each crank arm having a proximal end and a distal end, the proximal end of each crank arm fixedly attached to a bracket spindle, wherein at least one of the pair of crank arms is the crank-arm assembly of any one of the first or second aspects; and a pair of elongate striding members, adapted to receive the feet of said user and support said user while ambulating, having a pivot end and a drive end, the drive end of each striding member rotationally coupled to the distal end of one of said cranks.

[0007] The above presents a simplified summary to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview. It is not intended to identify key or critical elements or to delineate the scope of the claimed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is an exploded view of an embodiment of the crank arm assembly.

[0009] FIG. 2 is a perspective view of the embodiment of the crank arm assembly shown in FIG. 1, in the locked position.

[0010] FIG. 3 is a front view (3A) and a bottom view (3B) of an alternative embodiment of the crank arm assembly.

[0011] FIG. 4 is a front view of a further alternative embodiment of the crank arm assembly in a closed (4A) and an open (4B) configuration.

[0012] FIG. 5 is a distal end view (5A) and a top view (5B) of a further embodiment of the crank arm assembly.

[0013] FIG. 6 is a front view of a further alternative embodiment of the crank arm assembly in an open position (6A) and a disconnected position (6B).

[0014] FIG. 7 is an embodiment of an elliptically-driven human powered vehicle comprising an embodiment of the crank arm assembly in a folded position.

[0015] FIG. 8 is a perspective view of one embodiment of an elliptically-driven human powered vehicle.

[0016] FIG. 9 is a side view of the embodiment of FIG. 8.

[0017] FIG. 10 is a top view of the embodiment of FIG. 8.

[0018] FIG. 11 is a side view of an adjustable footbed, which may optionally be utilized in the embodiment of FIG. 8.

[0019] FIG. 12 (A and B) are front views of an embodiment of an elliptical traveler utilizing a steering mechanism to turn the front wheels. [0020] FIG. 13 is a top sectional view of the steering mechanism utilized in the embodiment of FIG. 12.

[0021] FIG. 14 (A and B) are front views of an embodiment of the elliptical traveler that utilizes a wheel camber mechanism to steer.

[0022] FIG. 15 (A and B) are front sectional views of the camber mechanism utilized in the embodiment of FIG. 14.

[0023] FIG. 16 is a top sectional view of an exemplary drive assembly of the embodiment of FIG. 8.

[0024] FIG. 17 is a schematic view of an exemplary internal gear system of the drive assembly of FIG. 16.

[0025] FIG. 18 is a perspective view of an embodiment of the elliptical traveler that does not use reciprocal arm motion.

DETAILED DESCRIPTION

[0026] DEFINITIONS

[0027] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art of this disclosure. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well known functions or constructions may not be described in detail for brevity or clarity.

[0028] The terms "about" and "approximately" shall generally mean an acceptable degree of error or variation for the quantity measured given the nature or precision of the measurements. Typical, exemplary degrees of error or variation are within 20 percent (%), preferably within 10%, more preferably within 5%, and still more preferably within 1% of a given value or range of values. Numerical quantities given in this description are approximate unless stated otherwise, meaning that the term "about" or "approximately" can be inferred when not expressly stated.

[0029] It will be understood that when a feature or element is referred to as being "on" another feature or element, it can be directly on the other feature or element or intervening features and/or elements may also be present. In contrast, when a feature or element is referred to as being "directly on" another feature or element, there are no intervening features or elements present. It will also be understood that, when a feature or element is referred to as being "connected", "attached" or "coupled" to another feature or element, it can be directly connected, attached or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being "directly connected", "directly attached" or "directly coupled" to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements so described or shown can apply to other embodiments.

[0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0031] Spatially relative terms, such as "under", "below", "lower", "over", "upper" and the like, may be used herein for ease of description to describe one element or feature's relationship to another when the apparatus is right side up.

[0032] The terms "first", "second", and the like are used herein to describe various features or elements, but these features or elements should not be limited by these terms. These terms are only used to distinguish one feature or element from another feature or element. Thus, a first feature or element discussed below could be termed a second feature or element, and similarly, a second feature or element discussed below could be termed a first feature or element without departing from the teachings of the present disclosure.

[0033] Terms such as "at least one of A and B" should be understood to mean "only A, only B, or both A and B." The same construction should be applied to longer list (e.g., "at least one of A, B, and C").

[0034] The term "consisting essentially of" means that, in addition to the recited elements, what is claimed may also contain other elements (steps, structures, ingredients, components, etc.) that do not adversely affect the operability of what is claimed for its intended purpose as stated in this disclosure. This term excludes such other elements that adversely affect the operability of what is claimed for its intended purpose as stated in this disclosure, even if such other elements might enhance the operability of what is claimed for some other purpose. [0035] It is to be understood that any given elements of the disclosed embodiments of the invention may be embodied in a single structure, a single step, a single substance, or the like. Similarly, a given element of the disclosed embodiment may be embodied in multiple structures, steps, substances, or the like.

[0036] CRANK ARM ASSEMBLY

[0037] An easily releasable crank arm assembly for a crank-powered machine is provided. The crank arm assembly finds various uses for crank-powered machines in which the crank arm must be removed and re-attached frequently, especially by an end-user who may lack specialized tools or expertise that is normally required to remove and replace a crank arm. Although in conventional bicycles the crank arms for the pedals rarely need to be removed by a user, in more advanced human-powered vehicles, such as elliptical striders, removal and reorientation of the crank arms facilitates easy folding.

[0038] A general embodiment of the crank arm assembly comprises an elongate crank arm having a first end and a second end; means for connecting the crank arm to a first spindle near the first end; means for reversibly locking the connecting means into the crank arm by reorienting a lever; and means for connecting the crank arm to a second spindle near the second end.

[0039] In a preferred embodiment the crank arm has a "proximal" end for connection to a first spindle, and a "distal" end for connection of a pedal spindle. In this context "proximal" and "distal" have no special meaning except that one end is normally connected to a bracket spindle and the other is normally connected to a pedal spindle in a preferred embodiment. In the broader context of this description the proximal and distal ends of the crank arm are simply opposite ends of the crank arm along the longitudinal axis.

[0040] In the embodiments of the assembly shown in the accompanying drawings, the crank arm has a stem aperture. The stem aperture accommodates the insertion of the stem, described in more detail below. The illustrated embodiments include a cavity proximate to the proximal end, for insertion of a spindle block or other structure to which the crank arm is secured on the proximal end.

[0041] The crank arm can optionally be designed with different lengths and/or with different offset profiles, sometimes referred to as the "Q factor," to accommodate the design of the vehicle to which it is attached. A Q factor of zero indicates that the crank arm is not curved away from the midline of the vehicle, from the proximal to the distal end of the crank arm. A Q. factor greater than zero indicates that the distal end of the crank arm is further from the frame midline than the proximal end of the crank arm. Embodiments of the quick release crank arm can be designed to a length and a Q factor as necessary for the crank-powered machine to which it will be secured.

[0042] The distal end of crank arm 1 may have a threaded hole, into which a pedal spindle may be screwed. The pedal spindle can be designed to support a rotating pedal or the rear end of a rotating foot platform, which may be attached to other structures located at the forward end of a crank-powered machine.

[0043] The means for connecting the crank arm to the first spindle may take the form of a bracket block in the cavity. The bracket block has a bracket spindle connector, such as an aperture for a screw or other fastener, one specific example of which is a bicycle-style crank screw. The bracket block may be semi-permanently secured to the bracket spindle with the fastener. In a preferred embodiment, block 2 has a centered square tapered hole that extends from the front face to the rear face and is dimensioned to fit onto the male end of a bottom bracket spindle with a square tapered end. Block 2 may have a recessed circular opening on the front face to accept a standard flanged crank bolt, which can semi permanently secure block 2 to a bottom bracket spindle.

[0044] The bracket block may be approximately the same shape as the cavity, with smaller external dimensions than the internal dimensions of the cavity. In specific embodiments the bracket block may be shaped approximately like a rectangular prism, and the cavity at the proximal end of the crank arm may be approximately rectangular with slightly (about 0.05 mm) larger internal dimensions than the external dimensions of the bracket block, so that it can be slid onto or out of the bracket block. The use of a rectangular prism has the advantage of allowing the crank arm to be reoriented 180° while preventing the crank arm from being accidentally reoriented by 90° (or some other angle) as would be possible using a prism or a square (or other equilateral polygon). In further embodiments the cavity and spindle block are both prisms having bilateral symmetry, but not multilateral symmetry.

[0045] The bracket block may comprise a lateral key groove to accommodate the stem, such that the stem is positioned in the lateral key groove during use. The key groove may be positioned such that the stem compresses the bracket block when the stem is in the lateral key groove, but does not compress the bracket block when the stem is not in the lateral key groove. Some embodiments of the bracket block comprise two key grooves, as in the illustrated embodiments showing a key groove on two opposite sides of the block. Preferably, the block 2 includes at least two opposite faces that have a hemi-cylindrical groove that is preferably located between the front and rear faces of block 2. In a preferred embodiment having a block in the shape of a rectangular prism, the grooves are located on the outer faces of block 2 having the shorter dimensions than are normal to the long axis of crank arm 1. The groove is located on the face of block 2 so that it fits adjacent to the bisected hole in the inner face of the rectangular opening of crank arm 1. When assembled, the groove serves to become the other half of the bisected hole through which stem 5 is inserted.

[0046] A back plate 3 may be optionally secured to the rear face of block 2. For instance, the back plate may be secured with two screws positioned diagonally across the rectangle shape and near the comers. An exemplary embodiment of the back plate 3 is approximately 2 mm thick, has a central hole with a diameter large enough to pass the bottom bracket spindle, and is approximately rectangular in shape with dimensions that are approximately 5 mm larger than the outer dimensions of block 2. The optional back plate 3 serves to ensure that when crank arm 1 is slid onto block 2, crank arm 1 will not slide past the rear face of block 2, so that the front face and the rear face of block 2 and those of crank arm 1 opening are each within approximately the same plane.

[0047] The cavity is shaped to allow the bracket block to be removed and/or replaced when not locked in place, and to allow the bracket block to be well secured when in place. For example, embodiments of the cavity shown in FIGS. 1-3 have a cavity shaped to allow the bracket block to be removed in a direction parallel to the axis of the bracket spindle. The embodiments of the cavity shown in FIG. 4-5 have a cavity shaped to allow the bracket block to be removed in a direction orthogonal to the axis of the bracket spindle. For example, the cavity may be open on the proximal end of the crank arm as shown in FIGS. 4-5, allowing the bracket block to be removed in a direction orthogonal to the axis of the bracket spindle. Alternatively, the cavity may form a lateral opening in the crank arm as shown in FIGS. 1-3, allowing the bracket block to be removed in a direction parallel to the axis of the bracket spindle.

[0048] In the illustrated embodiments of the crank arm assembly, the longer dimension of the rectangular cavity is parallel to the longitudinal axis of crank arm 1. [0049] Some embodiments of the crank arm assembly include a compression slot to impart flexibility to the crank arm to compress the cavity against the bracket block. In some embodiments, the longitudinal compression slot in the crank arm may be contiguous with the cavity. The embodiment of the crank arm shown in FIGS. 1, 2, 4, and 5 has a longitudinal compression slot in the crank arm that is contiguous with the cavity and extends toward the distal end of the crank arm. An alternative embodiment of the crank arm shown in FIG. 3 has a longitudinal compression slot in the crank arm that is contiguous with the cavity and extends toward the proximal end of the crank arm (reaching the proximal end). The compression slot may be preferably centered in the front face of crank arm 1 and penetrate through to the rear face, and it preferably extends parallel to the long axis of crank arm 1 from the rectangular opening to an approximate midway location of the crank arm. In such embodiments the compression slot allows the walls of the rectangular opening to be compressed against the sides of block 2.

[0050] In a specific embodiment, a cylindrical aperture passes through crank arm 1 from the top surface to the bottom surface and is dimensioned so that lever stem 5 (stem) can be inserted. Preferably, the aperture is located to bisect the compression slot and, more preferably, is aligned with the same inner face of the rectangular cavity from which the compression slot extends. In a specific preferred embodiment, the aperture is approximately 0.1 mm larger in diameter than stem 5, is oriented normal to the long axis of crank arm 1, and is approximately centered between the front and rear faces of crank arm 1.

[0051] In a specific embodiment with a rectangular cavity in crank arm 1, crank arm 1 can be slid onto block 2 in two positions, either at about 0° or at about 180° relative to the other crank arm. In both positions, the groove in the shorter face of block 2 may allow stem 5 to lock crank arm 1 onto block 2, and closing lever 4 compresses the crank arm 1 onto block 2.

[0052] The crank arm assembly comprises means for reversibly locking the connecting means into the crank arm by reorienting a lever, such as a stem (with a lever) positioned in the stem aperture to compress the bracket block against the cavity. A lever may be present on a terminal end of the stem configured to lock the stem in place or release the stem, allowing the stem to be removed or repositioned, wherein when said stem is removed or repositioned the crank arm may be easily removed or replaced on the bracket spindle (i.e., the bracket block may be removed from the cavity). Some embodiments have a stem lever and locking stem, allowing the stem to be lifted and rotated by hand.

[0053] A preferred embodiment of the stem has a cylindrical portion. The cylindrical portion has the advantage of allowing the stem to be at least partially rotated in the stem aperture of the groove, and also allowing the stem to be axially translated in the stem aperture of the groove. It also can impart compression to the spindle block, as described in more detail below.

[0054] Further embodiments of the stem have a cylindrical portion with a flat side, such that the stem does not compress the bracket block when the flat side faces the bracket block. In a preferred embodiment, a cylindrical stem is connected to a quick release lever, passes through the crank arm, and fits into the grooves on the bottom bracket block, which locks the crank arm onto the bracket block. In some embodiments, the quick release lever may be lifted away from the crank arm, or opened, to allow the stem to be rotated into or out of the key groove. In reassembly, the quick-release lever can then be closed to fit the stem into the key groove, thus locking the crank arm onto the bracket block and also compressing the crank arm onto the bracket block, making a secure connection between bottom bracket block and crank arm.

[0055] In some embodiments of the crank arm assembly, releasing the stem with the lever allows the stem to be rotated about its longitudinal axis, wherein the stem has a cylindrical portion with a flat side, and wherein the stem does not compress the bracket block when the flat side faces the bracket block.

[0056] In various embodiments of the crank arm assembly the stem may be positioned differently. For example, in some embodiments the stem is positioned between the bracket block and the distal end of the crank arm (as shown in FIGS. 1-2); in other embodiments the stem is positioned between the bracket block and the proximal end of the crank arm (as shown in FIGS. 3-5). In either case the stem compresses the spindle block against the interior surface of the cavity.

[0057] In the illustrated embodiment, the stem 5 is inserted into the aperture in crank arm 1. In some preferred embodiments, the stem 5 is fitted with a fine threaded stem nut 8 on the bottom end, and it is screwed into a threaded hole in lever pivot 6 at the top end. The pivot 6 may be inserted through a hole in the proximal end of a lever 4. The proximal end of lever 4 may have a radius that approximately matches the radius of a concave lever cup 7, into which it rests. In use in a preferred embodiment, the lever 4 is movable so that the long axis of lever 4 can be parallel to the long axis of crank arm 1, which may be a closed position, and the distal end of lever 4 can be lifted away from crank arm 1 so that the long axis of lever 4 is normal to the long axis of crank arm 1, which may be an open position. In this embodiment of the iever 4, the hole in the proximal end of lever 4 wherein the position of the pivot is eccentric with the radius of the proximal end of the Iever 4 that rests in cup 7. When Iever 4 is closed, the distance between the long axis of pivot 6 and the concave surface of cup 7 is increased. When Iever 4 is open, the distance between pivot 6 and cup 7 is decreased. By closing Iever 4, tension is applied to stem 5, which compresses crank arm 1 aperture against block 2, and preferably forms a secure connection between crank arm 1 and block 2. The amount of tension applied to stem 5 when Iever 4 is closed may be optionally adjusted by screwing nut 8 further onto the lower end of stem 5.

[0058] In some preferred embodiments (such as those shown in FIGS. 1-3), a section of stem 5 is hemi-cylindrical, such that if that section of the cylinder is viewed in cross-section, solid material only occupies one portion of the cylinder, and the other portion is vacant. The hemi-cylindrical section is preferably located so that, when the stem 5 is assembled on the crank arm 1, it is positioned between the upper and lower inner faces of the aperture in crank arm 1. During use when the long axis of Iever 4 is closed, the stem 5 is oriented so that the solid hemi-cylindrical stem section fits into the groove on the face of block 2, thus locking block 2 into the aperture of the crank arm 1. When Iever 4 is open, Iever 4 and stem 5 can be rotated about the long axis of stem 5, which rotates the solid hemi-cylindrical section out of the groove in the block 2 so that the flat face of the hemi-cylindrical solid section is approximately co-planar with the inner face of crank arm 1 rectangular opening. With minimal tension on stem 5, no compression of crank arm 1 onto block 2, and stem 5 not fitted into the groove of block 2, crank arm 1 can be slid off block 2 in a direction parallel to the long axis of the bottom bracket spindle.

[0059] VEHICLE

[0060] In a preferred embodiment, the crank arm assembly is attached to a bracket spindle of a pedaled human-powered vehicle, one such vehicle being a mobile elliptically-driven vehicle. Such vehicles commonly have two opposing crank arms, one on the left and one on the right. Either or both of the crank arms may be any embodiment of the crank arm assembly described above. In some embodiments of the vehicle comprising a chain drive, the quick release crank arm assembly is located on the opposite side of the drive side of the vehicle (the drive side being the side that includes a chain, belt, drive-shaft, etc. to power the vehicle). For example, if the drive side crank arm was on the left, the right-side crank arm may be fitted with the quick release crank arm assembly. Such a configuration has the advantage of allowing easy folding (or other reconfigurations) of the vehicle, particularly in the case of an elliptically-driven tricycle.

[0061] In a general embodiment, the human powered vehicle driven by elliptical motion of a rider's legs, and comprises a pair of crank arms each fixedly attached to a bracket spindle at the proximal end, wherein at least one of the pair of cranks is an embodiment of the quick-release crank-arm assembly described above. A pair of elongate striding members may be present, adapted to receive the feet of said user and support said user while ambulating. The striding members may have a pivot end and a drive end, the drive end of each striding member rotationally coupled to the distal end of one of the cranks. Some elliptically-driven vehicles are hindered from easy folding, due to the 180° orientation of the crank arms. Some embodiments of the vehicle are configured to fold when the crank arm assembly is removed from the bracket spindle. For example, the crank arm assembly may be rotated to be about 0° offset from the other opposing crank arm, and replaced on the bracket spindle.

[0062] A specific embodiment of the vehicle is shown in FIG. 7, comprising a longitudinal frame member having a front end, a transverse substantially horizontal frame member joined to the front end of the longitudinal frame member, and an upright frame member. The frame members are jointed together in such a way as to allow the upright frame member to fold down when the crank arm assembly is removed from the bracket spindle. In the illustrated embodiment, the left quick release crank arm is at a position of about 180° relative to the right crank arm when the mobile elliptical tricycle is being ridden. The left quick release crank arm is at a position of about 0° relative to the right crank arm, a mirror image, when the tricycle is to be folded. The face of the bottom bracket block, over which the crank arm opening slides, is preferably shaped so that the crank arm can be fitted onto the part in two positions, each about 180° apart from the other.

[0063] In greater detail, in the illustrated embodiment in FIG. 7, the right and left pedals (one of which is secured by a quick release side crank arm) are positioned 180° apart when the vehicle is ridden so that each leg can provide alternating force to propel the vehicle. To fold the vehicle, it may be advantageous to position the crank arms 0° apart so the right and left sides are in the same mirrored configuration. To transition from the riding position to the folding position in this first exemplary embodiment, lever 4 on a quick release side crank arm can be opened and rotated about 180° so crank arm 1 can be slid off block 2. With crank arm 1 off block 2, the opposite crank arm can be rotated about 180° and the quick release side crank arm 1 can be slid back onto the block 2, after which the two crank arms will be approximately co-aligned.

[0064] In a typical embodiment, the male ends of bottom bracket spindles are designed to securely attach crank arms and may be shaped as a tapered square or as a splined cylinder with shallow or deep splines, and the splines can be more or less numerous. The bottom bracket block of the quick release crank arm can be made to fit most male bottom bracket spindle ends. The outer shape of the bottom bracket block may be approximately rectangular, as shown in this embodiment, but it may also be other geometric shapes. Preferably, the block has an outer shape that includes two parallel sides to facilitate two positions: one wherein the left and right crank arms are about 180° apart for riding the vehicle, and another wherein both crank arms are about 0° apart to facilitate folding.

[0065] One embodiment of the vehicle is a mobile device comprising a frame including a longitudinal frame member oriented substantially horizontally, a transverse frame member oriented substantially horizontally, joined in a substantially normal orientation to the longitudinal member, and an upright frame member joined to the longitudinal member at a position rearward of said transverse member. On either end of the transverse frame member is a front wheel, and a rear wheel comprising a drive assembly is rotationally coupled to the rear end of said longitudinal frame member. The inner end of each of a pair of opposing cranks, oriented 180° apart, is attached to the drive assembly, such that the outer end of said cranks, when rotated, defines a path concentric with the axis of rotation of the rear wheel. A pair of elongate striding members is positioned substantially horizontally along either side of the longitudinal frame members, with the rearward end of each striding member rotationally coupled to the outer end of one of the cranks. A pair of upright arm levers, each with an upper grip end and a lower pivot end, is pivotally coupled to the upright frame member so that the upper and lower ends of the arm levers may reciprocate back and forth about the pivot point. The lower pivot end of each arm lever is pivotally coupled to the front end of one of the striding members. The drive assembly includes a hub body, a rotating axle (to which the inner ends of the crank arms are affixed), and an internal gear system translating the rotation of said axle to the hub body. The device also may include a mechanism for steering, including a wheel turning mechanism or a camber mechanism, as well as brakes and multiple gearing. An embodiment that does not utilize reciprocal arm motion to drive the device also is possible.

[0066] As shown in FIG. 1, one embodiment of the mobile elliptically driven device 10 (hereinafter referred to as the elliptical traveler) comprises a frame 20, front wheels 40, a rear wheel 50, a pair of striding members 80, and arm members 90.

[0067] The frame 20 comprises a longitudinal, substantially horizontal frame member 25, a transverse, substantially horizontal frame member 30, and an upright frame member 35. The transverse frame member 30 is joined to the front end of longitudinal frame member 25. These components may be fixedly joined, or they may be joined together in such a way as to allow the longitudinal frame member 25 to rotate axially a fixed amount within transverse frame member 30 to effect wheel camber for steering, as hereinafter described.

[0068] The upright frame member 35 is mounted to the longitudinal frame member 25 such that it extends in a substantially upright manner from the longitudinal frame member 25. The upright frame member 35 is shown mounted in FIG. 8 in a substantially normal orientation, although it could be angled forwards or rearwards as might suit a particular design or application. Moreover, the upright frame member 35 may be mounted to the longitudinal member 25 via an adjustable joint 36, which may be tightened to fix upright frame member 35 in a desired position, and which also allows upright frame member to fold down, or collapse, to flatten the entire device for storage as shown in FIG. 9.

[0069] The longitudinal frame member may include a rear fork 27, in which the rear wheel 50 is mounted. Alternatively, the rear of longitudinal frame member 25 may comprise a single arm to which the rear wheel 50 is mounted. This single arm may be offset axially from the primary portion of the longitudinal frame member to allow the rear wheel to be centered under the rider (which is not necessary because this embodiment is self-standing, independent of whether the radial plane of the rear wheel is coplanar with the longitudinal axis of frame member 25). The front wheels are mounted on either end of the transverse frame member 30 via appropriate rotary couplings.

[0070] Along either side of longitudinal frame member 25 is a striding member 80. The rear or drive ends of the striding members are rotationally coupled to a drive assembly 100 of the rear wheel (described in detail below), such as by one of a pair of opposing cranks 70. Each striding member may include a footbed 84 to provide a stable platform for the rider's feet. The front or pivot end of each striding member is pivotally connected to the bottom end of one of a pair of reciprocating arm members 90, each of which extends upwards generally alongside the upright frame member 35 and terminates in a grip end 92. The upright frame member includes a crossbar 37, which includes a rotational coupling 38 on either end. Each arm member 90 is fixed to one of the rotational couplings 38.

[0071] When the rider applies force to the striding members to put them in motion, the rear end of each striding member 80, rotationally attached to crank 70, follows a circular path concentric with the rear wheel 50, while the front end of striding member 80 (defined by pivot joint 82) reciprocates in a substantially horizontal arcuate path. This action results in the footbed 84 tracing an elliptical path, and, more particularly, an asymmetrical ellipse with the arc of the front of the ellipse being smaller than that of the back (i.e., egg-shaped). The lower end of each arm member 90, attached to pivot joint 82, moves in conjunction therewith, while the grip end 92 also reciprocates through an arcuate path. Thus, as may be seen from FIG. 8 in conjunction with the foregoing description, a rider may propel the elliptical traveler 10 forward by applying alternating force to the grip end 92 of each arm member 90 while striding with the legs and feet in a natural elliptical path on footbeds 84.

[0072] FIG. 11 shows an optional and exemplary means to make the position of each footbed 84 adjustable. In this embodiment, striding member 80 includes a notched cam cut 85. Footbed 84 includes a cam follower 86 with a tightening means (e.g., a nut and bolt, or screw) such that the rider may select the desired position of footbed 84 by sliding it along the cam cut 85 and tightening cam follower 86 in the desired notch. By altering the position of footbed 84, the rider alters, in the vertical dimension, the shape of the elliptical path traced by his feet as he rides traveler 10, and thus the rider may adjust the amount of leg lift utilized in each stride.

[0073] As noted, each arm member 90 terminates at its upper end in a grip end 92. The upper ends of arm members 90 may be adjustable in length to alter the length of travel of the grip ends 92.

[0074] Each grip end 92 may include a brake lever 94. One brake lever 94 operates the front brakes 42 via a cable routed between the brake lever and front brakes. The other brake lever 94 operates the rear brake 52, as shown in FIG. 10, via a cable routed between the brake lever and rear brake. The cables may be routed internal the arm members and frame components, or externally, or a combination thereof as desired, utilizing cable housing where necessary as known in the art. Disc brakes are shown, although other conventional braking mechanisms known in the art (such as a Y or caliper brake for the rear wheel) may be utilized.

[0075] One embodiment of elliptical traveler 10 is a direct-drive, straight-line device. A preferred embodiment of the traveler comprises a gearing mechanism and a steering mechanism. Two embodiments of steering mechanisms for the elliptical traveler 10 are described below. An embodiment of elliptical traveler 10 could utilize either one of the steering mechanisms individually, or both steering mechanisms could be incorporated in an elliptical traveler 10, as desired or required by the application. The particular embodiments of steering mechanisms described below are in all respects exemplary, and any other suitable mechanism known in the art to steer a pair of transversely opposed wheels also could be used.

[0076] The first steering mechanism turns the wheels left or right, as one does when steering a car. As shown in FIGS. 12A-B and 13, each grip end 92 may pivot (e.g., transversely, left or right). A cable 93 connects each grip end 92 to a turning mechanism 150 contained within transverse frame member 30. As shown, when either of cable 93 is pulled by pivoting grip end 92, the longitudinal force exerted by cable 93 is translated to a transverse force on the turning mechanism 150 by control arm 152, which in turn is coupled to each axle of the front wheels 40 via the linkage arms 153, and linkage members 154 and

155, to the rotary coupling 160 shown in FIG. 13, thus causing the front wheels 40 to pivot or turn. The rider controls which direction the wheels 40 turn by exerting force on the corresponding grip end 92. The steering mechanism 150 also may include a bias member

156, shown as a spring, to center bias the steering mechanism and thus keep the wheels directed in a straight line in the absence of an applied force on one of the grip ends 92. As noted, the steering mechanism 150 shown in FIG. 13 is exemplary only, and any steering linkage known in the art could be used. Further, hydraulic, pneumatic, or electrical (e.g., servo motors) actuators could be used in lieu of the cable-driven system shown.

[0077] A second mechanism for steering is shown in FIGS. 14A-B and 15A-B, which effects steering by wheel camber. The camber mechanism 170 is contained within the transverse frame member 30. The camber mechanism 170 comprises two parallel linkage members 172 coupled to C-shaped members 174, which in turn are coupled through the rotary coupling 160 to the axles of the front wheels 40. Many designs for a rotary coupling 160, such as an axle mounted to a gimbal-type joint, capable of permitting rotation of the front wheel about the axle while translating force for the turning and camber of the wheels to the axle as described above are known in the mechanical arts. Each parallel linkage member 172 is fixed, such as via rods 176, to points at or near the circumference approximate the front end of longitudinal frame member 25. The coupling that joins the front end of longitudinal frame member 25 with the transverse frame member 30 permits partial rotation of longitudinal frame member 25, which is effected by the rider shifting his weight or leaning towards one side. The camber mechanism 170 translates the arcuate partial rotation of longitudinal frame member 25 into wheel camber as shown, thus causing the elliptical traveler 10 to curve in the direction desired by the rider. The camber mechanism 170 may also comprise a center bias means 178, shown as a spring, to keep the wheels in a vertical orientation in the absence of applied force by the rider and also to limit the degree of camber. Note that any biasing means may be used for this purpose, such as a bushing (made of a rubber, polymeric, or other dampening material), or a combination of bushings and springs. As noted, the camber mechanism shown is illustrative only. Any conventional mechanical or electromechanical assembly to effect wheel camber could be used without departing from the scope and spirit of this embodiment of the present invention.

[0078] One embodiment of the drive assembly 100 is shown in FIG. 16. The drive assembly 100 comprises a hub body 105, an axle 110, and an internal gear system 120. The hub body 105 is connected mechanically to the rim of the rear wheel 50, via spokes or other traditional mechanical means (e.g., a metallic wheel body, a composite disc, etc.). Also, the disc of rear brake 52 is shown as attached to the hub body 105.

[0079] One of the pair of opposing cranks 70 is attached to either end of the axle 110 via any conventional mechanical attachment means. (Note that one or both of the attachment means between the crank 70 and the axle 110 could be releasable, such that with the attachment released one crank 70 could be rotated into alignment with the other crank 70 to allow the traveler 10 to be folded into the smallest possible size when the upright frame member 35 is collapsed, as described above.)

[0080] The axle 110 extends through the rear end of each arm of the fork 27, through the axis of the hub body 105, and through the sun gear arm 122 described below. Free rotation of the crank within the fork 27, hub body 105, and sun gear arm 122 is permitted by fork bearings 112, hub bearings 114, and sun gear arm bearings (not shown). The internal gear system 120 is located inside the hub body 105. Note that the internal gear system 120 shown in FIGS. 16-17 is illustrative only; any internal gearing system utilizing a rotating axle known in the art, or hereinafter developed, could be used and employed. The internal gear system 120 is shown for illustration purposes to be a planetary gear system. A central or sun gear 121 is held in a fixed (non-rotating) position by sun gear arm 122, which connects the sun gear 121 to the frame. Planetary gears 123 rotate about sun gear 121. The planetary gears in turn contact a complementary ring gear 125 on the inside surface of hub body 105. The planetary gears are mounted to planetary gear carrier 124, which is fixedly attached to the axle 110. As the rider applies force to the striding members 80 and arm members 90, thereby rotating the cranks 70 and axle 110, rotary motion is imparted to the hub body 105 via internal gear system 120. The ratio between the rotation of the axle and rotation of the rear wheel can be altered by altering the gear ratio between the planetary and sun gears, as is known in the art.

[0081] Internal gear system 120 is shown as a single-gear system for simplicity. Those skilled in the art will recognize that multiple gear ratios can be achieved by providing additional planetary gear combinations that may be switched in and out between the sun gear 121 and the ring gear 125 on the inside surface of hub body 105. Such gearing systems, called compound planetary gear systems, typically utilize the variable tension of a cable in combination with a spring to switch the active gear. For this reason, as shown in FIGS. 8-9, one grip end 92 additionally includes a shift lever 96, from which a cable (not shown) is routed either internally within the frame or externally alongside it to the internal gear system, as is known in the art. Likewise, manufacturers of internal gear hubs are beginning to use electrically driven shift systems. Any such shifting system known in the art or hereinafter developed could be used in this embodiment of the traveler.

[0082] An alternative embodiment of the device comprises a chain drive to transfer power from the cranks to a drive wheel.

[0083] An alternative embodiment that does not utilize reciprocal arm motion to propel the elliptical traveler is shown in FIG. 18. Instead, the striding members 80 are pivotally coupled to the lower end of a pair of supports 190, the upper ends of which are fixed to rotational couplings 38 at either end of crossbar 37. The striding members 80 (and the footbeds 84) therefore follow the essentially same path in this embodiment as described above. A handlebar 193 is connected to crossbar 37 by a stem 192. The handlebar 193 is fitted with brake levers 194 and shift lever 196, which operate in a manner similar to that described above. Further, either of the steering mechanisms described herein may be utilized with this embodiment. With respect to the wheel turning mechanism, force is translated by any conventional means to the turning mechanism by the turning of the handlebar. The height of stem 192 may be made adjustable to suit the needs of the rider, and the shape of the handlebar 193 is exemplary. Any shape of handlebar could be utilized as desired by a particular rider.

[0084] METHOD

[0085] The releasable crank-arm assembly may be manually removed and replaced, preferably without tools when the bracket block is semi-permanently connected to a bracket spindle. Removal may be accomplished by manually reorienting the lever to release tension on the stem and removing the crank arm from the bracket block. In embodiments in which the stem has a cylindrical portion with a flat side the tension on the stem may be released by rotating the stem so that the flat side faces the bracket block; in that position the stem does not exert pressure on the bracket block against the crank arm. In some embodiments of this approach, prior to release the stem compresses the cavity against the bracket block, and releasing tension on the stem releases the compression of the cavity by the stem.

[0086] PROPHETIC EXAMPLES

[0087] FIGS. 1 and 2 provide a view of an assembled quick release crank arm according to a first exemplary embodiment, where the lever 4 is in the closed position so that the block 2 is compressed and locked within the opening of crank arm 1.

[0088] FIG. 3 provides an exploded view of a second exemplary embodiment of the quick release crank arm. Except where noted otherwise, the parts in this second exemplary embodiment are similar to the parts in the embodiment illustrated in FIGS. 1 and 2. The rectangular cavity on the proximal end of crank arm 1 is dimensioned to fit onto block 2, which may be secured to a bracket spindle with a standard crank arm screw. The stem 5 is shown to include a hemi-cylindrical section that fits into the hemi-cylindrical grooves on the short face of block 2, which may lock crank arm 1 onto block 2 when the lever 4 is closed to compress the rectangular cavity onto block 2. As shown, the compression slot in crank arm 1 extends from the inner face of the rectangular opening that is closest to the proximal end of crank arm 1 and extends to the proximal end face of crank arm 1. The hole through which stem 5 is inserted is aligned with the inner face of the rectangular opening closest to the proximal end of crank arm 1. When lever 4 is opened and rotated so that the flat face of the hemi-cylindrical section is approximately coplanar with the inner face of the rectangular cavity, the block 2 is unlocked and crank arm 1 can be slid off or onto block 2 in a direction parallel to the long axis of bracket spindle.

[0089] FIG. 4 provides two front views of a third exemplary embodiment of the quick release crank arm, where the arm is in the closed position in FIG. 4A and in the open position in FIG. 4B. In this embodiment, the crank arm 1 has an oblong cavity at the proximal end that is open at the rear face of crank arm 1, and block 2 has a matching oblong shape that fits into the oblong cavity of crank arm 1. Block 2 may be secured onto a bracket spindle end with a standard crank arm screw 10. Crank arm 1 can be slid onto or off of block 2 though the opening at the proximal end of the rear face of crank arm 1 in a direction that is normal to the long axis of the bracket spindle, which is indicated by the arrows in FIG. 4B. When crank arm 1 is slid onto block 2, crank arm 1 may be locked onto block 2 by closing lever 4. Lever 4 preferably has an eccentric hole at the proximal end which accommodates a pivot 6 at the upper end of stem 5. When lever 4 is closed with stem 5 in the vertical position, tension is applied to stem 5 thereby compressing the upper and lower inner faces of the cavity onto block 2 and also pressing the midsection of stem 5 against block 2. These forces help to prevent any movement of the block within the opening of crank arm 1. In this embodiment, to remove crank arm 1 from block 2, lever 4 may be opened, stem 5 may then be rotated on lower pivot 9 to a horizontal position so that the rear opening is unobstructed, as shown in FIG. 4B. For the folding position, once crank arm 1 is slid off of block 2, the opposite crank arm can be rotated to a position of approximately 0° relative to crank arm 1, and then the crank arm 1 can be reattached to block 2. A similar procedure can also be used to rotate the opposite crank arm to a position of approximately 180° relative to crank arm 1.

[0090] FIG. 5A provides a distal end view of the embodiment of the quick release crank arm shown in FIG. 4 in the closed position, and FIG. 5B provides a top view in the closed position. The square tapered bottom bracket spindle end 11 may be secured to block 2 with crank arm screw 10 to create a semi-permanent connection between these two parts. The outer face of block 2 onto which the opening of crank arm 1 slides may have outer lips around the oblong circumference that extend beyond the inner edge of the oblong opening in crank arm 1, and the rear face of the block may include a hemi-circular groove into which stem 5 fits. The multi-level profile of block 2 is preferably matched by the opposite profile found in the opening of crank arm 1. The matched faces of crank arm 1 and block 2 preferably serves to interlock these two parts when lever 4 is closed to create a secure connection between these two parts.

[0091] CONCLUSION

[0092] The foregoing description illustrates and describes the processes, machines, manufactures, compositions of matter, and other teachings of the present disclosure. Additionally, the disclosure shows and describes only certain embodiments of the processes, machines, manufactures, compositions of matter, and other teachings disclosed, but, as mentioned above, it is to be understood that the teachings of the present disclosure are capable of use in various other combinations, modifications, and environments and is capable of changes or modifications within the scope of the teachings as expressed herein, commensurate with the skill and/or knowledge of a person having ordinary skill in the relevant art. The embodiments described hereinabove are further intended to explain certain best modes known of practicing the processes, machines, manufactures, compositions of matter, and other teachings of the present disclosure and to enable others skilled in the art to utilize the teachings of the present disclosure in such, or other, embodiments and with the various modifications required by the particular applications or uses. Accordingly, the processes, machines, manufactures, compositions of matter, and other teachings of the present disclosure are not intended to limit the exact embodiments and examples disclosed herein. Any section headings herein are provided only for consistency with the suggestions of 37 C.F.R. § 1.77 or otherwise to provide organizational queues. These headings shall not limit or characterize the invention(s) set forth herein.

Claims

CLAIMS The following is claimed:

1. A releasable crank arm assembly for a crank-powered machine, the crank arm assembly comprising:

(a) an elongate crank arm having: a proximal end for connection to a bracket spindle; a distal end for connection of a pedal spindle; a stem aperture; and a cavity proximate to the proximal end;

(b) a bracket block in the cavity, comprising a bracket spindle connector;

(c) a stem positioned in the stem aperture to compress the bracket block against the cavity;

(d) a lever on a terminal end of the stem configured to lock the stem in place or release the stem, allowing the stem to be removed or repositioned, wherein when said stem is removed or repositioned the crank arm may be easily removed or replaced on the bracket spindle.

2. The releasable crank arm assembly of claim 1, wherein the stem has a cylindrical portion.

3. The releasable crank arm assembly of claim 1, wherein the stem has a cylindrical portion with a flat side, and wherein the stem does not compress the bracket block when the flat side faces the bracket block.

4. The releasable crank arm assembly of claim 1, wherein releasing the stem with the lever allows the stem to be rotated about its longitudinal axis, wherein the stem has a cylindrical portion with a flat side, and wherein the stem does not compress the bracket block when the flat side faces the bracket block.

5. The releasable crank arm assembly of claim 1, wherein the bracket block comprises a lateral key groove, and wherein the stem is positioned in the lateral key groove.

6. The releasable crank arm assembly of claim 1, wherein the bracket block comprises a lateral key groove, wherein the stem compresses the bracket block when the stem is in the lateral key groove, but does not compress the bracket block when the stem is not in the lateral key groove.

7. The releasable crank arm assembly of claim 1, wherein the stem may be removed from the stem aperture to allow the bracket block to be removed from the cavity.

8. The releasable crank arm assembly of claim 1, comprising a longitudinal compression slot in the crank arm that is contiguous with the cavity, wherein said longitudinal compression slot imparts flexibility to the crank arm to compress the cavity against the bracket block.

9. The releasable crank arm assembly of claim 1, comprising a longitudinal compression slot in the crank arm that is contiguous with the cavity and extends toward the distal end of the crank arm, wherein said longitudinal compression slot imparts flexibility to the crank arm to compress the cavity against the bracket block.

10. The releasable crank arm assembly of claim 1, comprising a longitudinal compression slot in the crank arm that is contiguous with the cavity and extends to the proximal end of the crank arm, wherein said longitudinal compression slot imparts flexibility to the crank arm to compress the cavity against the bracket block.

11. The releasable crank arm assembly of claim 1, wherein the stem is positioned between the bracket block and the proximal end of the crank arm.

12. The releasable crank arm assembly of claim 1, wherein the stem is positioned between the bracket block and the distal end of the crank arm.

13. The releasable crank arm assembly of claim 1, wherein the cavity allows the bracket block to be removed in a direction parallel to the axis of the bracket spindle.

14. The releasable crank arm assembly of claim 1, wherein the bracket block is approximately the same shape as the cavity and wherein the block has smaller external dimensions than the internal dimensions of the cavity.

15. The releasable crank arm assembly of claim 1, wherein the cavity is open on the proximal end of the crank arm, allowing the bracket block to be removed in a direction orthogonal to the axis of the bracket spindle.

16. The releasable crank arm assembly of claim 1, wherein the cavity forms a lateral opening in the crank arm.

17. A releasable crank arm assembly for a crank-powered machine, the crank arm assembly comprising:

(a) an elongate crank arm having a first end and a second end;

(b) means for connecting the crank arm to a first spindle near the first end;

(c) means for reversibly locking the connecting means into the crank arm by reorienting a lever; and (d) means for connecting the crank arm to a second spindle near the second end.

18. A method of removing a crank arm from a crank-powered vehicle without tools, wherein said crank-powered vehicle comprises the releasable crank-arm assembly of any one of claims 1 -17, and wherein the bracket block is semi-permanently connected to a bracket spindle, the method comprising:

(a) manually reorienting the lever to release tension on the stem; and

(b) removing the crank arm from the bracket block.

19. The method of claim 18, wherein the stem has a cylindrical portion with a flat side, and wherein the tension on the stem is released by rotating the stem so that the flat side faces the bracket block, such that the stem does not exert pressure on the bracket block against the crank arm.

20. The method of claim 18, wherein prior to step (a) the stem compresses the cavity against the bracket block, and wherein releasing tension on the stem releases the compression of the cavity by the stem.

21. A human powered vehicle driven by elliptical motion of a rider's legs, comprising:

(a) a pair of opposing crank arms, each crank arm having a proximal end and a distal end, the proximal end of each crank arm fixedly attached to a bracket spindle, wherein at least one of the pair of cranks is the crank-arm assembly of any one of claims 1-17; and

(b) a pair of elongate striding members, adapted to receive the feet of said user and support said user while ambulating, having a pivot end and a drive end, the drive end of each striding member rotationally coupled to the distal end of one of said cranks.

22. The vehicle of claim 21, wherein the vehicle is configured to fold when the crank arm assembly is removed from the bracket spindle.

23. The vehicle of claim 21, wherein the opposing crank arms are 180° offset when the vehicle is configured for operation, and wherein the vehicle is configured to fold when the crank arm assembly is rotated to be about 0° offset from the other opposing crank, and replaced on the bracket spindle.

24. The vehicle of claim 21, comprising a longitudinal frame member having a front end, a transverse substantially horizontal frame member joined to the front end of the longitudinal frame member, and an upright frame member, wherein said frame members are jointed together in such a way as to allow the upright frame member to fold down when the crank arm assembly is removed from the bracket spindle.