CROSS-REFERENCES TO RELATED APPLICATIONS [0001] This application claims the benefit of priority to a U.S. Provisional Application No. 61/811,780, filed April 14, 2013, titled "Original personal trailer using a single spherical wheel", naming inventor Eric Hjertberg. The above-cited application is incorporated by reference. BACKGROUND OF THE INVENTION

[0002] Since the beginning of human time, people have needed to transport goods, belongings, children, etc. from place to place. Domestic animals considerably aided the task that otherwise requires carrying weight on the back, in the arms, or on the head.

[0003] Many nomadic people dragged goods behind them using what are today called travois. Two long poles are held in the hands. The other ends of the poles reach behind the individual and rest on the ground. Between the poles are tied the goods to be carried. The job is much easier than without the poles because a significant percentage of the vertical load weight rests upon the pole ends that rest on the ground.

[0004] The later invention of the wheel led to 2, 3 and 4 wheeled carts. Two wheel carts were either pulled like travois (but with less effort) or by domestic animals. [0005] A category of useful carts uses only one wheel. Primary among these is the wheel barrow. The hands of a person can grab handles that extend from a bucket. Under the bucket is one small wheel. The barrow is unstable while moving except for the control of the person exerted through the handles. However, this makes emptying the barrow's bucket quite easy and makes possible travel along narrow paths.

[0006] One wheeled vehicle trailers are not common but have been used behind bicycles, in particular, and hikers, but not commonly. Compared to multiple wheeled trailers, the one wheel hiking or cycling trailer has some advantages and some problems. [0007] The advantages are that the trailer can be lighter, less expensive, have lower rolling friction, and be narrower for greater maneuverability and safety around other vehicles.

[0008] The problems relate to stability. The trailer depends upon the pulling mechanism for its upright stability. In the case of a bicycle, this requires a hitch that cannot tip side to side or, in the case of a hiker, constant correction via handles in each hand is needed to prevent tipping. Secondly, a narrow bicycle-type wheel will sink quickly on soft ground such as loose sand or mud, with a large increase in rolling friction, even immobility.

[0009] In practice, the instability of the hiking trailer has limited its popularity especially off of paved surfaces. Once substantial weight is in it, the person using it must work hard to keep it upright. On bicycles, this is less of an impediment but, nonetheless, detracts from ease of riding. BRIEF SUMMARY OF THE INVENTION

[0010] An apparatus for pulling loads while hiking, walking or cycling with improved load stability over a variety of surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Fig. 1 is a drawing of the wheel portion and lower end of the apparatus

[0012] Fig. 2 is a drawing of one embodiment for being pulled by a person

[0013] Fig. 3 is a drawing of one embodiment for being pulled by a bicycle

[0014] Fig. 4 is a drawing of one embodiment of a fork yoke wheel attachment

DETAILED DESCRIPTION OF INVENTION

[0015] The trailer incorporates a wheel that is a sphere rather than a doughnut shaped tire on a disk shaped wheel. The spherical tire could simply be a ball, like a soccer ball or basketball. What this spherical ball would need to be effective is consistent rotation to function as a trailer wheel.

[0016] Ball or spherical wheels have been seen on wheel barrows and vacuum cleaners and on beach toy vehicles (tricycles for sand). Their popularity for beaches is owed to an important feature. A spherical tire does not sink as fast in mud, sand, or other loose soil. It can float over unstable surfaces rather than sinking and becoming difficult to move. A small sinking of a spherical wheel causes a large increase in contact area. Consequently, the downward pressure per square area unit is quickly decreased making further sinking less likely.

[0017] The most important feature of a spherical wheel trailer is not its versatility for unstable surfaces but added stability for tipping left and right. When the spherical wheel trailer is leaned to the side, the center of gravity drops less because the spherical wheel rolls rather than leans.

[0018] This means, as the spherical wheel trailer tips left and right while walking, hiking, or riding, the consequent center of gravity changes are less. It takes, therefore, less effort to keep the trailer level during this tipping. The trailer would seem to the person using it to be more stable and carefree.

[0019] One embodiment uses as a wheel either a basketball or soccer ball which are made by the millions with great economy and toughness. By bonding two axle stub cups to such a ball, precisely on a diameter, the ball can be made to roll like a wheel. One embodiment of a framework accepts these stubs, forces them to remain parallel, offers ball bearings, and can be connected to a load platform and handles for hands or bicycle hitch.

[0020] The loading platform of the trailer can take many forms and the load can be placed balanced and draped over each side of the load bearing structure, as side mounted panniers, as a top situated box, as a bucket like a wheel barrow, etc.

[0021] The drawings provided are intended to represent the basic features of one embodiment of the invention. The best mode may be described textually in the specification and claims, but not visually in the drawings. A spherical object viewed from any angle would appear when projected in two dimensions to be a circle whereas many other circular objects would appear as ovals unless viewed perpendicular to their face. If any of the spherical objects appear as ovals, they should be viewed as if they appeared as circles when reduced to two dimensions in the drawings. [0022] In some embodiments, an inflated spherical wheel 101 is attached to a fork yoke 102. A person of ordinary skill in the art would recognize the fork yoke can be any structure capable of holding the wheel so that it may rotate in the direction of travel when it rotates. [0023] The fork yoke 102 is attached to the lower end of a load bearing structure 103. Some embodiments of this connection is to attach an axle stud with a spheric section end to the spherical wheel. In order for this to perform well, the axle studs on opposite sides must be aligned exactly diametrically. Because in many embodiments the spherical wheel 101 is attached to the fork yoke 102 without an axle passing through the wheel, it opens up the possibility of using many easy to find inflated spherical wheels, such as soccer balls and basketballs.

[0024] To bind the spheric section ends to the axle studs a strong bonding agent should be used. It would probably be too difficult in most embodiments to rely on merely a friction fit between the wheel and the axle stud because the spherical wheel would come out too easily under heavy loads. An example of a bonding agent would be a strong adhesive.

[0025] In some embodiments, the protruding end of an axle stud 104 would be connected to a bearing 105 housed in a bearing carrier 106. The end of each fork yoke leg 107 would be drilled so that the bearing carrier 106 and the axle stud 104 could be attached with the fork yoke leg 107 with an axle screw 108, permitting the axle stud 104 to spin freely.

[0026] There are also some embodiments that have an axle which passes through the center of the inflatable sphere. In these embodiments, the spherical wheel must be specially sealed around a cylindrically shaped axle instead of axle stud that do not penetrate the inflated interior.

[0027] In some embodiments, the load bearing structure 103 is attached to handgrip clamps 201 which are attached to a handgrip bar 202 to permit a person using the trailer to balance it with their hands. The handgrip bar 202 shape is probably best to open wide enough to go around the back of the average person, and the handles would be best to angle up away from the ground rather than remain parallel to the ground in order to be more ergonomic.

Embodiments like this could also have adjustable handles so the user could set them to the angle and position of their preference. Further embodiments could also include articulating handles so the user could move arms and hands in a walking rhythm while maintaining control of the trailer.

[0028] In other embodiments, the load bearing structure 103 is attached to bicycle clamp 301 which may then be attached to a bicycle or other vehicle. It is best for the bicycle clamp used to connect on both left and right sides of the bicycle to permit the bicycle rider to balance the load by shifting their weight left or right on the bicycle.

[0029] Although the load bearing structure 103 is represented in the drawings as a single tube, it is not necessary for this to be one single tube. It would be best if the material used for the load bearing structure was resistant to bending and compression and as light in weight as possible to reduce the added weight the user needs to move. Various other embodiments that distribute the load left and right of the user's center of gravity are possible. Also, the load bearing structure 103 does not need to be merely one or more tubes. It is likely in many embodiments that the load bearing structure 103 will have a load platform or some other means of securing a load to minimize the jostling that will occur during transport. It is also possible, as is the case with panniers, that the load will be distributed underneath the load bearing structure 103 and be hanging or suspended from it, or from a hook or stud. [0030] Nothing in this specification requires the wheel to be a perfect sphere, and both soccer balls and basketballs could themselves have textures or other imperfections which renders them sphere-like instead of perfect spheres.

[0031] Also, the benefits of a sphere-like wheel with respect to better control of the side to side center of gravity would work (but not as well) if instead of a full sphere-like shape, spherical caps of equal size, centered on the axle entry points, are removed from the sides of the sphere. A visual representation of this kind of shape is what the shape of the planet Earth would be if equal sections of polar caps were removed from the North and South poles, or if spherical caps the size of all the non-tropical areas of Earth were removed from the North and South poles. This is not to imply that these are the only angles at which such a sphere could be trimmed into such a portion of a sphere. This specification defines the term "sphere tropic" for the shape of the portion of a sphere that has had opposite spherical caps of the same size removed. [0032] When the wheel shape is a sphere tropic, inflating the entire sphere tropic shape is not possible because such parallel sides in the shape of a circle would bulge. Such a wheel shape would need a separate air sealed tire that conforms to the wheel's sphere tropic shape were it to offer inflation. The sphere tropic exterior can be supported internally with well- known technologies for internal support like spokes, and some embodiments would not even require the parallel side walls shaped like circles. In at least one embodiment, spherical caps could be put into place to permit the wheel to still have the appearance of a sphere, provide protection from dirt and debris, and reclaim some of the advantages of the sphere shape when tipping.

[0033] A wheel shaped like a sphere tropic would also require some kind of interior axle because there is not enough support of air pressure throughout the shape to support axle studs bonded to the outside of the sphere tropic. [0034] With a sphere tropic and the structure of the wheel requiring an axle, it becomes possible to put well known compact motorized systems inside the wheel to drive the axle. Such a motorized system could be controlled by the operator of the personal trailer resulting in a powered-assist or even power-drive mode. [0035] There are many means of connecting a wheel to respective fork yoke legs. One of the embodiments possible involves an axle stud, bearing, bearing carrier, and axle screw. However, a person of ordinary skill in the art would recognize many other ways to attach a rotating wheel to a relatively motionless frame. [0036] There are many means of connecting the load bearing structure to the fork yoke.

One of the embodiments possible involves welding the load bearing structure to the fork yoke to create a connection that allows the two parts to move as one. It is also possible that the load bearing structure and fork yoke could be extruded as one part. A person of ordinary skill the art would recognize many other ways of connecting these two to serve the purpose of a strong and resilient frame.

[0037] There are many means of connecting the load bearing structure to a means of balance and motion. The invention does not claim the means of balance and motion because the invention does not need to comprise this. The language "means of balance and motion" is only used to indicate some aspects of the connection that would be understood by a person of ordinary skill in the art. For instance, a multi-wheeled trailer that is pulled by a bicycle normally needs a fairly low and off-center connector because it is only necessary for the trailer to be pulled with a means of motion, but the balance is effectively provided by its own wheels. In the case of a trailer with one wheel, the connector has to be located higher and must be strong enough to handle the torque as the carried load shifts during motion. The means of balance and motion for a personal trailer of this sort would normally be a person, or a bicycle balanced by a person. However, it could also be a motorcycle balanced by a person, or a golf cart, or a car, or a truck, or some other vehicle. A person of ordinary skill in the art would recognize that the connection between the load bearing structure to the means of balance and motion would need to have more strength as any greater speeds were

contemplated, or as the center of gravity of the load became higher off the ground.

[0038] There are many means of connecting a motor to an axle, and many means of controlling such a motor. One of the embodiments possible involves existing bicycle-assist motors and their controls. A person of ordinary skill in the art recognizes that these controls could be placed on the handle bars of the present invention similar to the handle bars of a bicycle, and could use wire controls or even wireless controls. The power of such an motor, if it were electric, would likely be provided by rechargeable batteries or battery packs, and the person of ordinary skill in the art would recognize that these could be placed within the sphere tropic or elsewhere on the trailer.

[0039] In this specification, when "axle" is used as a noun, it means an actual physical axle. However, some of the embodiments that use an "axle stud" and "axle screw" do not require an actual physical axle, but instead have a virtual axle, or axis of rotation. A person of ordinary skill in the art would recognize that this is necessary for some of the embodiments that involve using an inflatable wheel to permit rotation without puncturing the wheel.

[0040] The person of ordinary skill in the art would be a person with at least 10 years of experience in bicycle design, particularly bicycle wheel design, as well as a thorough understanding of axles, spokes, couplings and handle bars.

[0041] Preferred embodiments of the invention are described herein, including the best mode known by the inventor for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described here. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims as permitted by applicable law. Also, any combination of the described elements in all possible variations is encompassed by the invention unless otherwise indicated.

[0042] Additionally, some embodiments of the present invention may be described in the form of claims as:

[0043] 1. An apparatus for a personal trailer comprising: a spherical shaped wheel; a fork yoke with a left fork yoke leg and a right fork yoke leg; a means of connecting the wheel to the left fork yoke leg and the right fork yoke leg; a load bearing structure with a low-rear end opposite a high- front end; a means of connecting the low-rear end of the load bearing structure to the fork yoke; a means of connecting the high-front end of the load bearing structure to a means of balance and motion.

[0044] 2. The apparatus of claim 1 where the means of connecting the high- front end of the load bearing structure to a means of balance and motion comprises a means of attaching to a bicycle.

[0045] 3. The apparatus of claim 1 where the means of connecting the high- front end of the load bearing structure to a means of balance and motion comprises a means of providing two handles to be held by the hands of a person.

[0046] 4. The apparatus of claim 3 where the means of providing two handles to be held by the hands of a person comprises: a handgrip bar; a means of attaching the handgrip bar to the high-front end of the load bearing structure.

[0047] 5. The apparatus of claim 1 where the means of connecting the wheel to the left fork yoke leg and the right fork yoke leg comprises: a right axle stud with a protruding stud end opposite a spheric section end; a left axle stud with a protruding stud end opposite a spheric section end; a means of bonding the spheric section end of the right axle stud to the wheel; a means of bonding the spheric section end of the left axle stud to the wheel diametrically opposite the spheric section end of the right axle stud; a bearing around the protruding stud end of each axle stud; a bearing carrier around each bearing; a hole drilled near the end of each fork yoke leg; an axle screw with a means of connecting each fork yoke leg to the respective bearing carrier.

[0048] 6. The apparatus of claim 1 where the wheel comprises a wheel with an inflatable inside portion.

[0049] 7. The apparatus of claim 6 where the wheel comprises a wheel with a cylindrical axle tunnel that is sealed from the inflatable inside portion of the wheel and intersects both the center of the wheel and two points on the surface of the wheel that are diametrically opposed.

[0050] 8. The apparatus of claim 7 wheel the means of connecting the wheel to each fork yoke leg comprises an axle of sufficient length to pass through the axle tunnel and attach to each fork yoke leg.

[0051] 9. An apparatus for a personal trailer comprising: a spheric tropic shaped wheel; a fork yoke with a left fork yoke leg and a right fork yoke leg; a means of connecting the wheel to the left fork yoke leg and the right fork yoke leg with an axle; a load bearing structure with a low-rear end opposite a high-front end; a means of connecting the low-rear end of the load bearing structure to the fork yoke; a means of connecting the high-front end of the load bearing structure to a means of balance and motion.

[0052] 10. The apparatus of claim 9 further comprising: a means of connecting a motor to the axle; a means of controlling the motor.

BACKGROUND ART

[0052] US 5,005,844 (Douglas), "Travois with roller assembly"

[0053] US 4,838,565 (Douglas), "Rolling travios"

[0054] US 6,139,033 (Western), "Stable monowheel travios with counterweight feature"

[0055] US 5,385,355 (Hoffman), "Monowheel travois"

[0056] US 3,827,369 (Mueller), "Wheelbarrow having spherical wheel" [0057] US

[0058] US

trailer"

[0059] US

[0060] US

[0061] US

[0062] US

[0063] US

TECHNICAL FIELD

[0064] The present invention is an apparatus that relates generally to a personal trailer or travois used for hauling supplies, more particularly but not by way of limitation, hauling behind an individual walking or riding a bicycle, and would most likely be in the technical field of "LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS (B62)"

BEST MODE FOR CARRYING OUT THE INVENTION

[0065] Preferred embodiments of the present invention are described herein, including the best mode known the inventor for carrying out the invention.

INDUSTRIAL APPLICABILITY

[0066] In addition to other aspects of industrial applicability present in other sections of this description, the present invention has industrial applicability in that it fosters commerce by improving upon prior inventions with industrial applicability.