Abstract
A novel cycle device including a transmission assembly (or assemblies) that significantly reduces torque interference with steering operations is provided. Such an assembly is provided in one or more of a modular, fixed or movable configuration according reduced complexity of implementation, improved efficiency of operation, and useful assembly modularity for manufacture and repair. Such a device may further include an improved means for selecting between direct and overdrive functions of a fixed transmission assembly. Additionally, a removable front transmission assembly comprising a steering fork with handlebars is also encompassed herein.
Claims
1. A wheel support component of a vehicle, comprising a movable transmission assembly, a driven wheel, a first axis, and a shock-absorbing element, wherein said movable transmission assembly supports said driven wheel while said driven wheel is steered about said first axis, wherein said movable transmission assembly further exhibits a second substantially transverse axis of rotation in relation to said first axis of rotation, and wherein said second substantially transverse axis of rotation generates a transfer of collision energy to said shock-absorbing element during operation of said driven wheel.
2. The wheel support component of claim 1 further comprising a plurality of meshing gears between said driven wheel and said movable transmission assembly, and an indexing cam affixed to said movable transmission assembly, and arranged to effect a separation distance of said plurality of meshing gears, wherein said indexing cam permits setting and maintaining the spacing between said meshing gears on demand.
3. The wheel support component of claim 1 wherein said movable transmission assembly provides torque multiplication.
4. A manual vehicle comprising said wheel support component of claim 1.
5. A vehicle transmission component comprising a modular transmission assembly, a manual pedal assembly, an intermediate shaft, and a movable transmission assembly, wherein said modular transmission assembly exhibits torque reduction, receives torque from said manual pedal assembly, and provides torque to said movable transmission assembly through said intermediate shaft.
6. The vehicle transmission component of claim 5 further comprising an epicyclic swing gear mechanism configured to select between alternate, parallel gear train paths of different torque ratios, both driving a common torque output shaft, such that a reversed direction of rotation applied to said epicyclic swing gear mechanism effects a selection of an alternate, parallel gear train path resulting in an alternate ratio of torque reduction between said manual pedal assembly and said intermediate shaft.
7. The vehicle transmission component of claim 6 wherein said epicyclic swing gear mechanism further comprises a central sun gear, a planet gear exhibiting a sweep path having opposing ends, a planet carrier, and two pinion gears, wherein said planet carrier is configured to arrest motion of said swing gear mechanism at a position of optimal engagement of said planet gear to one of said two pinion gears arranged at each of said opposing ends of said sweep path of said planet gear about said central sun gear.
8. A manual vehicle comprising said vehicle transmission component of claim 5.
9. A manual vehicle comprising said vehicle transmission component of claim 6.
10. A torque limiting device comprising a hub exhibiting an axis of rotation, a magnetic indexing body, a magnet located within said hub, and a contacting element disposed between said hub and said magnetic indexing body, wherein rotation of said hub relative to said magnetic indexing body tends to force a separation between said hub and said magnetic indexing body due to interference of said contacting element with opposing features of said hub and said magnetic indexing body, wherein said magnetic indexing body is in close proximity to or in contact with a pole of said magnet exhibiting a tendency to resist said separation by a magnetic attractive force and thus enabling a transfer of torque between said indexing body and said hub about said axis until such time as a force generated by said interference exceeds a magnetic attractive force exerted between said magnetic indexing body and said hub containing said magnet, whereupon said interference forces a separation of said magnetic indexing body and said hub and thus enables passage of said contacting element therebetween, generating a relative rotation between said hub and said magnetic indexing body, thereby breaking said transfer of torque and limiting a torque transmitted therebetween.
11. The torque limiting device of claim 10 wherein said hub further comprises a gear employed to transmit torque from a coaxial shaft to a remote mesh gear.
12. The torque limiting device of claim 10 wherein a second magnetic body is arranged in continuous contact with an opposing pole of said magnet.
13. A transmission employing the torque limiting device of claim 10.
14. A vehicle employing the transmission of claim 13.
15. A torque limiting device comprising an axis of rotation, a coaxial hub, a coaxial indexing body, a magnetic body, a magnet located within said hub and between said indexing body and said magnetic body, an annular body constrained to rotate about said hub, and a contacting element constrained to rotate within said annular body and disposed between, and in contact with, said indexing body and said magnetic body, such that rotation of said annular body relative to said indexing body tends to force a separation between said indexing body and said magnetic body due to interference of said contacting element with interfering features of said indexing body, wherein said magnetic body is in close proximity to or in contact with a pole of said magnet, thereby creating a magnetic attractive force therebetween, exhibiting a tendency to resist said separation, and thus enabling a transfer of torque between said indexing body and said annular body about said axis until such time as a reaction force generated by said indexing body and said magnetic body by said interference exceeds a magnetic attractive force exerted between said magnetic body and said magnet, whereupon such interference forces separation of said indexing body and said magnetic body and thus enables passage of said contacting element therebetween, further allowing a relative rotation between said indexing body and said annular body, thereby breaking a synchronous rotation of said indexing body and said annular body, and thereby limiting a torque transmitted therebetween.
16. The torque limiting device of claim 15 wherein said annular body further comprises a gear employed to transmit torque from a coaxial shaft to a remote mesh gear.
17. The torque limiting device of claim 15 further comprising a modular transmission assembly, a manual pedal assembly, and an intermediate shaft in contact with said modular transmission assembly, wherein said modular transmission assembly receives torque input from said manual pedal assembly, exhibits torque reduction, and transmits output torque to said intermediate shaft.
18. A manual vehicle comprising said torque limiting device of claim 15.
19. The torque limiting device of claim 15 wherein said indexing body and said hub comprise a single body.
20. A single modular wheel, steering column, pedal drive, and transmission unit for a manual vehicle, said unit comprising i) a single wheel engaged with at least one gear, ii) a transmission component providing a fixed assembly structure and a power unit exhibiting at least two different drive torque capabilities, iii) a steering column aligned with said single wheel, iv) two opposing pedals extended outwardly from said transmission and engaged therewith through at least one gear; wherein said at least one gear engaged with said single wheel is engaged with said transmission.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1a shows a side view of a potentially preferred embodiment of an inventive manually operated cycle device.
[0033] FIG. 1b shows the same cycle device of FIG. 1a with a modular unit disengaged therefrom.
[0034] FIG. 2 shows a separated view of the components of a modular unit of the inventive cycle device.
[0035] FIG. 3a depicts a rear perspective view of one potential embodiment of a disclosed transmission assembly.
[0036] FIG. 3b depicts an interior side view of the transmission assembly of FIG. 3a.
[0037] FIG. 3c shows the same interior side view of FIG. 3b, but an alternate transmission drive path.
[0038] FIG. 4a shows a separated view of the components of an inventive torque limiting device.
[0039] FIG. 4b shows a section view of the assembled torque limiting device in an engaged condition.
[0040] FIG. 4c shows a section view of the assembled torque limiting device in a disengaged condition.
[0041] FIG. 4d shows a separated view of the components of an alternate embodiment of an inventive torque limiting device.
[0042] FIG. 4e shows a section view of the alternate embodiment of the torque limiting device in an engaged condition.
[0043] FIG. 4f shows a section view of the alternate embodiment of the torque limiting device in a disengaged condition.
[0044] FIG. 5a depicts a side view of the movable transmission with a front wheel attached.
[0045] FIG. 5b shows a side view of the movable transmission with housing components removed.
[0046] FIG. 5c shows an indexing cam assembled to the movable transmission housing.
[0047] FIG. 5d shows an indexing cam assembled to the movable transmission housing in an alternate position of gear lash adjustment.
[0048] FIG. 6a shows a side view of the movable transmission and wheel with typical force vectors of collision loading.
[0049] FIG. 6b shows a rear perspective view of the head frame assembly, revealing movable transmission suspension components.
DETAILED DESCRIPTION OF THE DRAWINGS AND PREFERRED EMBODIMENTS
[0050] The invention is herein described in greater detail through the utilization of the accompanying drawings. By no means are these drawings and accompanying descriptions intended to limit the scope of the invention as the ordinarily skilled artisan within this area would fully understand the breadth of the inventive device(s) herein discussed.
[0051] The inventive transmission accords surprising and beneficial characteristics to a recumbent cycle device, namely the ability to provide high mechanical efficiency so the operator does not expend too much energy during actual operation, while permitting nearly unrestricted steering function and a sizeable steering motion range, and little to no steering control effect through pedal-created torque.
[0052] With all of this provided by the inventive transmission and thus the inventive manually operated recumbent cycle device, potentially preferred, though not necessarily required, embodiments are further provided within the drawings.
[0053] FIG. 1 shows a right-hand side view of a head frame assembly (1) both attached (FIG. 1a) and detached (FIG. 1b) from a main frame assembly (2), for a pedal-powered (manual) vehicle (that may also include an electrical component for automated maneuvering and driving, as well).
[0054] FIG. 2 shows a head frame assembly further separated into sub-modules: a power unit (fixed transmission assembly) (3), a movable transmission unit (4) mounted to a head frame housing (5); and a steering column with handlebars (6), mounted to the movable transmission unit and the head frame housing, with a wheel assembly (7) further separated from the movable transmission unit. These units comprise major, separable modules of a modular head frame assembly for the vehicle. An intermediate shaft (8) connects an output shaft of a power unit with an input shaft of the movable transmission unit, as well. Steerable portions of the movable transmission unit, steering column, and wheel assembly are shown slightly rotated as in a left turn.
[0055] FIG. 3 shows operation of a swing gear mechanism to select a torque reduction path within a modular power unit. FIGS. 3a-3c show interior views illustrating a swing gear function, with certain components omitted for clarity purposes. A housing (301) (right-hand and rear sides omitted from view) encloses a gear train. A ring gear (302) is mounted to, and rotates with, a pedal crankshaft and cranks (omitted from view) in a conventional manner. This ring gear drives a spur gear (303) affixed to a drive shaft (304) extending into, and supported by the housing. The drive shaft supports a coaxial sun gear (305), itself in permanent engagement with a planetary idler gear (306) mounted within a carrier (307) rotatable about a drive shaft axis. The carrier is designed to balance a rotating mass about the drive shaft axis so that operation is not adversely affected by gravity, and is constrained to an arc of rotation by an opening therein, through which passes a carrier stop shaft (308). The said carrier opening is designed to permit engagement of the planetary idler gear with one of two remote gears, each at opposite limits of carrier rotation in contact with the carrier stop shaft. At the counter-clockwise limit of carrier rotation (FIG. 3b), the planetary idler gear meshes with a first gear (309) mounted to a first transfer shaft (310) to which is further affixed a second gear (311). The second gear engages a third gear (312) mounted to a second transfer shaft (313), to which is further affixed a first bevel gear (314). The first bevel gear engages a second bevel gear (315) affixed to an output shaft (316) at right angles to the second transfer shaft, and terminating at a rearward end with a conventional universal-type joint interface. At an opposite, clockwise limit of the carrier rotation against said stop shaft (FIG. 3c), the planetary idler gear engages a fourth gear (317) affixed to a third transfer shaft (318), to which is further affixed a larger fifth gear (319), thus comprising a compound-gear, torque reduction stage of a power transmission. The fifth gear engages a sixth gear (320) affixed to a fourth transfer shaft (321), to which is further affixed a larger seventh gear (322), comprising an additional, compound-gear, torque reduction stage. The seventh gear engages the third gear on the second transfer shaft. Accordingly, a single path of power transmission from the sun gear to the bevel gears can be selected between a substantially direct path and an alternate path of substantial, further torque reduction, according to a direction of input rotation at a pedal crankshaft. Due to a particular arrangement of gearing employed in each power transmission path, output rotation from each path occurs in a common direction (i.e., clockwise), regardless of input rotation direction.
[0056] FIGS. 4a-4f show a torque limiting device of two particular embodiments incorporated within a gear. A first embodiment is depicted in FIG. 4a-4c. An alternate embodiment is depicted in FIG. 4d-4f. The gear (305) of FIG. 4a, coaxially located on a shaft (304), includes three permanent magnets (401) and three bearing balls (402) mounted within openings of the gear. A magnetic body (403) is mounted about a protruding hub of the gear, contacting the magnets and the balls simultaneously. An indexing body (404), also magnetic, is mounted coaxial to said shaft, in contact with said magnets, and additionally comprises a slot feature engaging a cross pin (405) of the shaft, such that the pin will drive the indexing body in synchronous rotation with the shaft. FIG. 4b shows a torque limiting device in a normally engaged configuration with the balls protruding partially through openings of the indexing body. In this configuration, a torque is conventionally transferred from a shaft (304) and pin (405) to an indexing body (404). Reaction forces occur at contacting points of indexing body edges with balls (402), and consequently between contacting surfaces of balls against openings in gear (305). By this means, a driving torque may be transmitted from a shaft to a gear. At a position on a ball surface whereby contact occurs with an edge of an indexing body opening, a reaction force may be divided into two orthogonal components: a tangential force which acts to create a torque about a shaft axis, and an axial force acting normal to an indexing body, acting to separate an indexing body from a magnet exerting an attractive force in opposition thereto. A geometric relationship determined by ball diameter and contact position enables precise calculation of force vector components in a manner well known to those ordinarily skilled in the art. Therefore, a known separation force of a magnet and a magnetic body in a particular configuration may allow accurate prediction of a maximum torque transmitted through such a device before a magnet holding force is exceeded. FIG. 4c shows a condition wherein an indexing body (404) has separated to a gap from said magnets, and where said magnets continue to exert a net attractive force sufficient to maintain contact of the balls and the indexing body surface between openings, during an interval of relative rotation between the indexing body and the gear, caused by continuing application of (reduced) shaft torque. At a point where rotation of the indexing body nears the angular spacing of openings therein, edges of said openings will slide along contacting ball surfaces until an indexing body will again be pulled into contact with the magnets, completing a cycle of operation. FIG. 4d depicts an alternate embodiment of a torque limiting device of similar operation, but with a hub (305a) containing the magnets (401) separated from the annular ring gear (305b) containing the balls (402). In this alternate embodiment, the indexing body is preferably (but not necessarily) magnetic, in order to further concentrate the magnetic fields and increase attractive force of the magnets with the magnetic body. The outer diameter of the hub functions as the inner race of a ball bearing supporting the ring gear, and the ring gear functions as both the outer bearing race and the ball cage. FIG. 4e shows the engaged condition of the alternate embodiment in section view, with a function similar to that described previously in reference to FIG. 4b. FIG. 4f shows a disengaged condition of the alternate torque limiter embodiment, wherein interferences of the protruding balls (402) with contacting edges of slot openings in the indexing body (404) create a net axial force exceeding a magnetic attractive force of the magnets (401) with the magnetic body (403). In this case, the indexing body, magnets, and inner hub remain together with the ring gear in an unchanged axial position relative to the shaft (304), as the ring gear and balls rotate together about the shaft axis. The balls and magnetic body are together dislocated parallel to the shaft axis by the relative rotation of the indexing body, such that the balls are temporarily enforcing an increased separation of the indexing body and magnetic body, creating a separation gap between the magnets and magnetic body during an interval of reduced-torque rotation of the ring gear relative to the shaft. At a point where rotation of the indexing body nears the angular spacing of the openings therein, contacting ball surfaces will slide along edges of said openings until a magnetic body will again be pulled into contact with the magnets, completing a cycle of operation. One of ordinary skill in the art will note the configuration of FIG. 4d is advantaged over the configuration of 4a by the elimination of enforced relative rotation between the magnets and a magnetic body in the path of torque transmission, thereby eliminating the variable effect of significant sliding friction caused by the high magnetic attractive forces occurring at the interfaces therebetween. It will also be apparent to the ordinarily skilled artisan that the functions of an inner hub (305a), indexing body (404), and magnets (401) may be variously combined into fewer parts, though optimum performance of some functions may present mutually exclusive demands on available materials.
[0057] FIGS. 5a and 5b show a modular movable transmission assembly (4), housing a gear train (501) comprising an input shaft (511) driving through miter gears (512) a sun gear shaft (513), itself coaxial with a steering axis, to which is mounted a sun gear (514). An epicyclic spur gear (515) mounted to an offset shaft (516) drives a pinion gear (518) through miter gears (517), in turn driving a compound gear torque multiplication stage, comprising a pinion gear (502), meshing with a ring gear (503) of a wheel assembly (7). An indexing cam (504), mounted by a center screw to a movable transmission structure (505), progressively changes a separation distance between an axis of the indexing cam and a bearing surface of a wheel axle (506) when rotationally indexed among twelve positions marked from A to L. A change of said separation distance likewise changes a radial separation of the pinion and the ring gears, thereby effectively controlling gear lash. When an axle nut (507) is tightened to a said movable transmission structure in a conventional manner, an established spacing may be maintained permanently in service, including occasional removal and reinstallation of a wheel assembly from a movable transmission assembly. An identical indexing cam may be similarly used on an opposing side for the purpose of further setting and maintaining correct alignment of a wheel within the movable transmission assembly, and may be applied at other modular gear mesh interfaces, as well, such as that occurring between a pedal crank ring gear (302 of FIG. 3a) and a pinion gear of a modular power unit (303 of FIG. 3a). FIG. 5c shows closer detail of the indexing cam at position F as it sets a center distance between the ring gear (503), mounted coaxially with axle (506), and pinion gear (502) to the dimension X1. Dimension Y represents a fixed distance between the center of rotation of the indexing cam (504) and the pinion gear shaft axis. Dimension Z1 represents a variable distance between the cam center of rotation and the wheel axle as controlled by the indexing cam position. FIG. 5d shows the indexing cam rotated three steps CCW to position I, incrementally increasing dimension Z1 to Z2, and thus increasing a gear center distance X1 to X2, effectively increasing the backlash between the pinion and ring gears by a prescribed amount, as will be understood by one of ordinary skill in the art. By this means, a tedious though functionally critical task of setting and maintaining correct backlash of this gear mesh may be accomplished upon removal and reinstallation of a wheel, without requiring extreme dimensional accuracy of the assembled parts or assembly process. Although this particular example of indexing cam function pertains to gear mesh at a driven wheel, the mechanism clearly applies generally to meshing gears of adjustable positioning within a transmission assembly.
[0058] FIG. 6a shows as simplified body force diagram of service loads borne by the movable transmission structure. Vectors (F.sub.H) and (F.sub.V) represent the respective horizontal and vertical components of a contact force (F) acting upon a front wheel (7) of a moving cycle colliding with a fixed object, such as a curbing (603). FIG. 6b shows a rear interior view of a head frame assembly with identification of movable transmission suspension components. Said contact force (F) transfers at a wheel hub to a supporting movable transmission structure (505), as shown. Functionally, an attachment of a movable transmission to a frame may support a moment (M) generated by a force vector (F) on a line of action at a distance (d) from a point of said attachment. A pivot shaft (508), itself rigidly affixed at each end to a head frame housing (5), and thus to a vehicle frame by a bolt (601), may be acted upon by said force (F) transferred through the movable transmission structure from the wheel. The horizontal component of said force (F.sub.H) is opposed equally by a force (m.Math.a.sub.c) created by the deceleration (a.sub.c) of the cycle mass (m). Said pivot shaft supports rotation of said movable transmission structure on suitable bearings about an axis thereof, according to a moment (M) applied to the movable transmission structure. A second shaft (509) is likewise rigidly affixed at each end with a bolt (602) to the head frame housing and thusly to the vehicle frame. One or more shock absorbing elements (510) are positioned between the movable transmission structure, and said second shaft, so as to resist rotation of the movable transmission structure under the moment (M), by a net force (F.sub.S) exerted by the movable transmission structure on the shock absorbing elements. Therefore, as a result of a moment created about a movable transmission structure pivot axis, a net body force (F.sub.V+F.sub.S) acting upon the vehicle frame acts to lift said vehicle frame against a portion of vehicle weight (W) supported thereupon. For simplicity, a desirable damping function is commonly derived by use of a stiffness element, such as rubber, which exhibits a damping effect due to energy dissipation within the material. In this case, rubber bumpers may act as both a spring and a damper in one shock absorbing element. Simply stated, during a time interval when a movable transmission structure is rotating backwards against a force of collision exerted by a rolling wheel striking an obstacle, a moment generated about a movable transmission pivot acts to accelerate a vehicle frame in an upward direction. This action, in turn, augments a vertical contact force component also acting to lift the weight of a vehicle frame. Such action may improve a tendency of a wheel to continue rolling upwards and over a low obstacle, further lessening a potential for damage in some cases.
[0059] The resultant inventive device thus accords great versatility and capability for an operator to maneuver under high drive torque conditions with great steering stability. Additionally, the potential for transport facilitation and overall accessibility for a variety of short travel purposes, all with not only the ability to utilize both a manual and electrical motion protocol, but also for exercise activity, all show the unexpectedly effective results such a novel device accords a suitable user.
[0060] The preceding examples are set forth to illustrate the principles of the invention, and specific embodiments of operation of the invention. The examples are not intended to limit the scope of the matter. Additional embodiments and advantages within the scope of the claimed invention will be apparent to one of ordinary skill in the art.
