HK1258887B - Personal mobility device - Google Patents

Description

Personal mobile devices

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No. 62/351,097, filed June 16, 2016, which is incorporated by reference in its entirety as if fully set forth herein.

Background Art

The present invention relates to a personal mobility device, and more particularly to a personal mobility device that can be folded into a compact size for storage.

Many individuals require mobility assistance, whether due to aging, illness, short-term injury, or other medical conditions. Known mobility assistance devices include various crutches, walkers, transport chairs, wheelchairs, rollators, and the like.

However, current mobility devices have many drawbacks. For example, current walkers and rollators are bulky and can only fold in one plane (e.g., sideways like many wheelchairs, or forward like many rollators). This makes them difficult to transport.

Another drawback of current mobility devices is their appearance. This can lead to individuals who might benefit from using such devices being reluctant to do so. Such individuals often cite the appearance of the device and the attendant fear of stigma and/or embarrassment as reasons for forgoing the use of mobility assistive devices that could potentially improve their quality of life.

Even when individuals choose to use mobility-assistance devices, there are drawbacks. For example, existing mobility devices are heavy and complex. In many cases, individuals using such devices may lack sufficient sensory perception, strength, and/or dexterity to effectively operate the device (e.g., lifting, folding, and/or deploying the device and/or operating caliper brakes). These difficulties may be exacerbated for individuals who lack adequate symmetrical use of their upper limbs, such as stroke victims.

Summary of the Invention

Disclosed herein is a personal mobility device comprising: a first rear leg; a second rear leg; a first front leg pivotally connected to the first rear leg via a first hub; a second front leg pivotally connected to the second rear leg via a second hub; and an annular handle including a grip portion, the handle slidably mounted within the first and second hubs to allow the grip portion to be adjusted in height. The first hub has a first state, a second state, and a third state. In the first state, the first rear leg and the first front leg are locked in an open configuration; in the second state, the first rear leg and the first front leg are locked in a closed configuration; and in the third state, the first rear leg and the first front leg are unlocked and can pivot between the open and closed configurations. Similarly, the second hub has a first state, a second state, and a third state. In the first state, the second rear leg and the second front leg are locked in an open configuration; in the second state, the second rear leg and the second front leg are locked in a closed configuration; and in the third state, the second rear leg and the second front leg are unlocked and can pivot between the open and closed configurations.

According to aspects of the present invention, sliding the handle downward across the first hub switches the first hub between the first hub's first state and the first hub's third state, and sliding the handle downward across the second hub switches the second hub between the second hub's first state and the second hub's third state. Conversely, sliding the handle upward across the first hub switches the first hub between the first hub's second state and the first hub's third state, and sliding the handle upward across the second hub switches the second hub between the second hub's second state and the second hub's third state.

The first hub includes a first follower that, when pressed, switches the first hub to the second state. Similarly, the second hub includes a second follower that, when pressed, switches the second hub to the second state. The handle includes a first cam that presses the first follower and a second cam that presses the second follower. The first and second cams, in turn, include wedges that respectively press the first and second followers as the handle slides downward and upward past the first and second hubs.

The personal mobility device also includes: a first rotating wheel assembly having a first wheel attached to the first front leg; and a second rotating wheel assembly having a second wheel attached to the rear leg, wherein the handle has such a curvature that when the handle slides downward over the first hub and the second hub, the handle engages with the first and second rotating wheel assemblies in the following manner, so that the first wheel is positioned parallel to the second wheel and the first and second rotating wheel assemblies are prevented from rotating.

In other aspects of the present invention, the personal mobility device includes: a first wheel attached to a first rear leg; a second wheel attached to a second rear leg; a first brake shoe disposed adjacent to the first wheel and movable between a retracted configuration and an extended configuration, the first brake shoe not contacting the first wheel in the retracted configuration and the first brake shoe contacting the first wheel in the extended configuration; a second brake shoe disposed adjacent to the second wheel and movable between a retracted configuration and an extended configuration, the second brake shoe not contacting the second wheel in the retracted configuration and the second brake shoe contacting the second wheel in the extended configuration; a first actuator located within the first hub operable to switch the first brake shoe between the retracted configuration and the extended configuration; and a second actuator located within the second hub operable to switch the second brake shoe between the retracted configuration and the extended configuration. The first and second actuators may be coupled to a plurality of the first and second brake shoes via a corresponding plurality of first and second pulleys.

It is also contemplated that the personal mobility device further includes a seat movable between a stowed position and a use position, wherein moving the seat from the stowed position to the use position actuates the first actuator to switch the first brake shoe to the extended configuration and actuates the second actuator to switch the second brake shoe to the extended configuration. For example, the seat may be pivotally coupled to the first and second hubs. Additionally, according to aspects of the present invention, the first and second actuators are biased to switch the first and second brake shoes to the retracted configuration.

In other aspects of the present invention: the first hub includes a first grip height locking pin; the second hub includes a second grip height locking pin; and the handle includes a plurality of stops to engage with the first grip height locking pin and the second grip height locking pin when the handle slides past the first hub and the second hub to fix the grip portion of the handle at a preset height. The handle may include: a plurality of pins located within the handle and positioned adjacent to the plurality of stops, respectively; an actuator operable to move the plurality of pins so that they extend outward from the plurality of stops, thereby preventing the first grip height locking pin and the second grip height locking pin from engaging with the plurality of stops when the handle slides past the first hub and the second hub, so that the height of the grip portion of the handle is adjustable. At least some of the plurality of pins are interconnected.

In other embodiments, the personal mobility device further comprises: a first wheel attached to the first rear leg; a second wheel attached to the second rear leg; a first brake shoe biased to engage the first wheel; and a second brake shoe biased to engage the second wheel. The first and second brake shoes engage inner upper surfaces of the first and second wheels such that a downward force applied to the grip portion of the handle disengages the first brake shoe from the first wheel and the second brake shoe from the second wheel. The handle comprises a closed loop. The grip portion of the handle comprises a flat area in the middle (e.g., to enhance comfort when used as a backrest).

The foregoing and other aspects, features, details, utilities, and advantages of the present invention will be apparent from a reading of the detailed description and claims, and from a reading of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a perspective view of a personal mobility device in an open or deployed configuration with a seat stowed, in accordance with aspects of the present invention.

2 is a side view of the personal mobility device shown in FIG. 1 in a closed or collapsed configuration.

3 is a close-up cross-sectional view of a hub that may be used in conjunction with the personal mobility device shown in FIG. 1 .

FIG. 4 shows a pair of plates rotating within the hub shown in FIG. 3 .

5 illustrates the engagement between the handle and the front wheel assembly of the personal mobility device shown in FIG. 1 .

6 is a perspective view of the personal mobility device shown in FIG. 1 in an open or deployed configuration with the seat in a use position.

7 is a close-up view of the mechanism that moves the seat of the personal mobility device of FIG. 1 between its stowed position and its use position.

FIG. 8 illustrates a parking brake, such as disclosed herein, in connection with the personal mobility device of FIG. 1 .

FIG. 9 illustrates a mechanism for adjusting the height of the grip portion of the handle of the personal mobility device shown in FIG. 1 .

FIG. 10 illustrates a passive brake, such as disclosed herein, in connection with the personal mobility device of FIG. 1 .

Figures 11A-11G, 12A-12G, and 13A-13G are further views of an embodiment of a personal mobility device according to the present invention, illustrating its aesthetic configuration from various angles. Specifically, Figures 11A-11G illustrate an open or extended configuration with the seat stowed, Figures 12A-12G illustrate an open or extended configuration with the seat in a use position, and Figures 13A-13G illustrate a closed or collapsed configuration. In each example, A is a front view, B is a rear view, C is a left side view, D is a right side view, E is a top view, F is a bottom view, and G is a perspective view.

DETAILED DESCRIPTION

FIG1 illustrates an embodiment of a personal mobility device 10 according to the present invention. As shown in FIG1 , the personal mobility device 10 generally includes a first rear leg 12, a second rear leg 14 (which in an embodiment may be parallel to the first rear leg 12), a first front leg 16, a second front leg 18 (which in an embodiment may be parallel to the first front leg 16), and a handle 20.

The first rear leg 12 includes a first rear wheel 13 attached thereto. The second rear leg 14 includes a second rear wheel 15 attached thereto. Further aspects of the first and second rear wheels 13, 15 will be described below.

A first wheel assembly 17 including a first front wheel 17a is attached to the first front leg 16. A second wheel assembly 19 including a second front wheel 19a is attached to the second front leg 18. Further aspects of the first and second wheel assemblies 17, 19 will be described below.

The first rear leg 12 and the first front leg 16 are pivotally connected via a first hub 22. Similarly, the second rear leg 14 and the second front leg 18 are pivotally connected via a second hub 24.

The handle 20 is annular and includes a grip portion 26, two generally vertical members 28, 30, and a lower member 32. In some embodiments, the grip portion 26, the vertical members 28, 30, and the lower member 32 form a closed ring. In other embodiments, the grip portion 26, the vertical members 28, 30, and the lower member 32 can form an open ring, such as by forming an opening in the grip portion 26 to form two distinct hand grips (as opposed to the single, continuous hand grip shown in FIG1 ). The grip portion 26 can be coated with a material such as neoprene to improve grip, comfort, and durability.

The vertical members 28, 30 of the handle 20 are slidably mounted within the first hub 22 and the second hub 24, respectively. This allows the height of the grip 26 to be adjusted upward or downward to accommodate users of different heights and as part of the unfolding and folding operation of the personal mobility device 10, as described in further detail below.

The first hub 22 has a first state in which the first rear leg 12 and the second front leg 16 are locked in an open configuration. Similarly, the second hub 24 has a first state in which the second rear leg 14 and the second front leg 18 are locked in an open configuration. This open configuration (also referred to as the deployed configuration) is shown in FIG. 1 .

The first hub 22 also has a second state in which the first rear leg 12 and the first front leg 16 are locked in a closed configuration. Similarly, the second hub 24 has a second state in which the second rear leg 14 and the second front leg 18 are locked in a closed configuration. This closed configuration (also referred to as a folded configuration or collapsed configuration) is shown in FIG.

The first hub 22 also has a third state in which the first rear leg 12 and the first front leg 16 are unlocked, which allows them to pivot relative to each other to transition between the open and closed configurations, and vice versa, when folding and/or unfolding the personal mobility device 10. Similarly, the second hub 24 has a third state in which the second rear leg 14 and the second front leg 18 are unlocked, which allows them to pivot relative to each other to transition between the open and closed configurations when folding and/or unfolding the personal mobility device 10.

According to aspects of the present invention, sliding the handle 20 across the first and second hubs 22, 24 switches the first and second hubs 22, 24 between the aforementioned states. Specifically, sliding the handle 20 downward across the first and second hubs 22, 24 switches the first and second hubs 22, 24 between the first state (locked in the open configuration) and the third state (unlocked), while sliding the handle 20 upward across the first and second hubs 22, 24 switches the first and second hubs 22, 24 between the second state (locked in the closed configuration) and the third state (unlocked). These aspects will be further described with reference to the second hub 24 shown in Figures 3 and 4.

As shown in FIG3 , the second hub 24 includes a follower 34 that is biased by a spring 36 into contact with the vertical portion 30 of the handle 20. The vertical portion 30 of the handle 20 includes a cam 38. The cam 38 includes a first wedge 40 that, in turn, engages the follower 34 when the handle 20 slides downwardly through the second hub 24. The cam 38 may also include a second wedge 42 that engages the follower 34 when the handle 20 slides upwardly through the second hub 24. Alternatively, the first wedge 40 may also engage the follower 34 when the handle 20 slides upwardly through the second hub 24.

The second hub 24 also includes a switching mechanism 44, which includes a switching arm 46 and a pair of pins 48, 50. The pins 48, 50 engage holes in plates 52, 54, shown in FIG4 , that are attached to the second rear leg 14 and the second front leg 18. When either the pin 48 or the pin 50 is engaged with the plates 52, 54, the plates 52, 54 cannot rotate relative to each other, thereby locking the second rear leg 14 and the second front leg 18 in position. Conversely, when neither the pin 48 or the pin 50 is engaged with the plates 52, 54, the plates 52, 54 can rotate relative to each other, thereby allowing the second rear leg 14 to pivot relative to the second front leg 18 to transition between the open and closed configurations of the personal mobility device 10.

FIG3 shows the second hub 24 in the first (locked in the open configuration) state. As the handle 20 slides downward through the second hub 24, the first wedge 40 engages and depresses the follower 34. This, in turn, triggers the switching arm 48 to pivot about the hinge 56 (shown in FIG3 ), pulling the pin 48 out of engagement with the plates 52, 54, thereby unlocking the second rear leg 14 and the second front leg 18 to pivot relative to each other (e.g., placing the second hub 24 in the third state).

Simultaneously, the switching arm 48 compresses the spring 58 on the pin 50, which engages against the surface of the plate 52. Once the plates 52 and 54 are properly rotated (e.g., the second rear leg 14 and the second front leg 18 are in the closed configuration of FIG. 2 ), the compression of the spring 58 causes the pin 50 to engage with the plates 52, 54, thereby placing the second hub 24 in the second (locked in the closed configuration) state.

As the handle 20 continues to slide downward through the second hub 24, the spring 36 returns the follower 34 to its initial position, reconfiguring the follower 34 to switch the second hub 24 from the second (locked in the closed configuration) state to the third (unlocked) state.

As the handle 20 slides upward through the second hub 24, the second wedge 42 engages and presses the follower 34, and the reverse process occurs to release the second hub 24 from the second state into the third state and relock the second hub 24 into the first state once the plates 52, 54 are properly rotated (e.g., the second rear leg 14 and the second front leg 18 are in the open configuration of FIG. 1).

As can be seen in FIG1 , the vertical portions 28 and 30 of the handle 20 are curved. This curvature allows the handle 20 to engage the first and second wheel assemblies 17, 19 when the handle 20 slides downward through the first and second hubs 22, 24, preventing the wheel assemblies 17, 19 from sliding and positioning the first and second front wheels 17a, 19a parallel to each other. Additionally, a curved tubular member 59 located at the joint between the vertical portion 28 and the lower portion 32 of the handle 20 is wedged against the first front wheel 17a to prevent it from rotating (i.e., the curved tubular member 59 acts as a brake for the first front wheel 17a). For illustration purposes, it is shown relative to the first wheel assembly 17 in FIG5 . This configuration facilitates the folding of the personal mobility device 10 by allowing the first and second front wheels 17a, 19a to be positioned within the first and second rear wheels 13, 15 shown in FIG2 .

[0026] Returning now to Figure 1, an embodiment of the personal mobility device 10 may include a seat 60. Figure 1 shows the seat 60 in a stowed position. Figure 6 shows the seat 60 in a use position.

To switch the seat 60 between the stowed position of FIG1 and the use position of FIG6 , the seat is pivotally coupled to the first hub 22 and the second hub 24. In an embodiment of the present invention, this connection is achieved by a four-bar linkage 62 located at the first and second hubs 22, 24, as shown in FIG7 relative to the first hub 22.

As will be understood by those skilled in the art, two of the four rods 62a, 62b of the four-bar linkage 62 are solid rods, while the third rod 62c, shown in phantom in FIG7 , is a phantom rod defined between a pivot joint 64 between the first rod 62a and the first hub 22 and a pivot joint 66 between the second rod 62b and the member 68. The frame 70 of the seat 60 forms the fourth rod of the four-bar linkage 62.

Advantageously, the use of a four-bar linkage 62, as opposed to simple hinges in existing mobility devices, allows the seat 60 to move further forward relative to the first and second rear legs 12, 14 when in the stowed position. This, in turn, allows the user to move further forward within the footprint of the personal mobility device 10 during use, which increases stability and reduces the force the user must exert to move the personal mobility device 10. It also improves the user's posture by allowing the user to stand more upright, thereby enhancing and extending the duration the user can remain active.

Another advantage of using the four-bar linkage 62 is that the size of the personal mobility device 10 is minimized both when folded and when unfolded. This facilitates the use of the personal mobility device in more confined or densely populated spaces (e.g., social gatherings) or in spaces that require the user to reach in front of themselves (e.g., opening a cabinet). The reduced size may also encourage greater adoption of the personal mobility device 10 relative to existing devices by minimizing the shame and/or embarrassment that many users may feel. Additionally, the reduced size when folded allows the personal mobility device 10 to be more easily stored in confined spaces such as a closet or vehicle trunk and/or parked in crowded areas such as the hallway of a restaurant, theater, or other public venue. In embodiments, the space required to store multiple personal mobility devices 10 may be reduced by nesting identical devices (e.g., in the manner of a shopping cart) or stacking them (e.g., in the manner of a folding chair).

Yet another advantage of using the four-bar linkage 62 is that it allows the user to have more leverage on the seat 60 , which facilitates engaging the parking brake 72 using the seat 60 , as described with reference to FIG. 8 .

8 , the parking brake 72 includes a plurality of brake shoes 74 disposed adjacent the first rear wheel 13. Although FIG8 shows two brake shoes 74, this description should not be considered limiting, as the parking brake 72 may be implemented with more or fewer brake shoes 74 without departing from the scope of the present invention.

The brake shoe 74 is movable between a retracted configuration in which the brake shoe is not in contact with the first rear wheel 13 and an extended configuration in which the brake shoe is in contact with the first rear wheel 13. The extended configuration of the brake shoe 74 is shown in FIG8; in the retracted configuration, the brake shoe 74 can be screwed into the brake housing 76.

Advantageously, the brake shoes 74 extend in such a manner that a force moving the first rear wheel 13 in either direction increases the force applied by the brake shoes 74 by further wedging the corresponding brake shoes 74 between the first rear wheel 13 and the brake housing 76 .

The brake shoe 74 can be switched between an extended configuration and a retracted configuration by an actuator 78 located within the first hub 22, as shown in Figure 7. To provide increased mechanical advantage, the actuator 78 can be coupled to the brake shoe 74 via a plurality of pulleys 80 (e.g., a pulley mechanism), which are desirably included in the first rear leg 12 as shown in Figure 8.

7 , when the seat 60 is moved to the use position, the rod 62 a of the four-bar linkage 62 engages the actuator 78 and extends the brake shoe 74 against the first rear wheel 13. This configuration ensures that a user cannot sit on the seat 60 without engaging the parking brake 72.

The actuator 78 may also be biased (e.g., by a torsion spring within the first hub 22) toward the position shown in FIG7 , which is associated with the parking brake 72 being in a disengaged state (e.g., with the brake shoes 74 in a retracted configuration). Thus, moving the seat 60 to the stowed position disengages the rod 62 a of the four-bar linkage 62 from the actuator 78 and retracts the brake shoes 74, thereby disengaging the brake shoes 72 without further user intervention.

It is also contemplated that the actuator 78 can be moved to a third position after passing the position to which it is driven by the seat 60 in the use position, in association with manually engaging the park actuator 72. This allows the personal mobility device 10 to be parked when the seat is in the stowed position. Additionally, by allowing the actuator 78 to move past the position to which it was actuated by the seat 60 being deployed and into the third position, the likelihood of a user's fingers being pinched between the actuator 78 and the seat 60 is minimized.

When the seat 60 is in the use position and the brake shoes 72 are engaged, the handle 20 can be used as a backrest. For user comfort, the grip 26 of the handle 20 can include a central flat area as shown in Figures 1 and 6.

For user comfort, the height of the grip portion 26 can also be adjusted (e.g., raised when walking, lowered when sitting). As shown in FIG9 , the handle 20 includes a plurality of stop holes 84 located within the vertical members 28 and 30. When the handle 20 slides upward and downward over the first and second hubs 22 and 24, each stop hole 84 corresponds to a corresponding height of the grip portion 26 ( FIG9 only shows the second hub 24 and vertical member 30). To lock the grip portion 26 at a predetermined height, the second hub 24 includes a grip height locking pin 86 that is biased by a spring 88 to engage the stop hole 84.

To adjust the height of the grip portion 26, the grip-height locking pins 86 must first be ejected from the detent holes 84. In an embodiment, the handle 20 includes a spine 90 comprised of a plurality of interconnected pins 92 positioned adjacent the detent holes 84. A cable 94 extends along the spine 90 and is connected at one end to a trigger handle 96, shown in Figures 1 and 6, adjacent to the grip portion 26. Depressing the trigger handle 96 tensions the cable 94, which, due to the curved shape of the vertical member 30, pushes the spine 90 outward and causes the pins 92 to protrude from their corresponding adjacent detent holes 84. This also forces the grip-height locking pins 86 out of engagement with the detent holes 84, allowing the handle 20 to slide freely past the second hub 24 in either direction. Advantageously, the grip-height locking pins 86 will not reengage the detent holes 84 as long as the trigger handle 96 remains depressed.

In another embodiment of the present invention, the personal mobility device 10 includes a passive braking system in place of or in addition to the parking brake 72 described above. For illustration, FIG.

10 , the passive brake 98 includes a brake shoe 100 that is biased (e.g., by a coil spring) into engagement with the first rear wheel 13. According to aspects of the present invention, the brake shoe 100 is engaged to the inner, upper surface of the first rear wheel 13. In particular, a tire 102 on the first wheel 13 may be overmolded around the edge of the first rear wheel 13 such that the brake shoe 100 is engaged to the material of the tire 102.

When the user applies a downward force to the personal mobility device 10, for example by leaning on the grip 26, the brake shoe 100 will disengage from the first rear wheel 13 to allow the personal mobility device 10 to be moved. When the downward force is removed, the brake shoe 100 will engage the center of the first rear wheel 13, preventing the personal mobility device 10 from moving. This passive braking is advantageous when the user must remove their hands from the personal mobility device 10 to perform a task (such as opening a door) because it prevents the personal mobility device 10 from sliding away when not being grasped. In addition, it provides better stability on downwardly sloping surfaces. The passive brake 98 can be deactivated, for example, by sliding the brake shoe 100 along the groove 104.

The passive brake 98 also acts as a suspension for the personal mobility device 10. In other words, the same coil spring that biases the brake shoe 100 into contact with the first rear wheel 13 also allows the first rear wheel 13 to "float" relative to the front fork 106. This helps ensure that the first rear wheel 13 maintains contact with the ground, compensates for uneven undersides, and has the ability to absorb vibrations.

Another advantage of the passive brake 98 is that it does not require cables as in many existing braking systems of mobile devices. This reduces the maintenance burden and provides greater safety compared to existing mobile devices.

Although several embodiments have been described above with a certain degree of particularity, those skilled in the art could make numerous modifications to the disclosed embodiments without departing from the spirit or scope of this invention.

For example, the seat 60 may be modular and removable from the frame 70 .

As another example, a storage pocket may be provided beneath the seat 60 .

Unlike existing mobility devices, the storage pocket preferably remains full when the personal mobility device 10 is collapsed because the contents will not interfere with the folding of the handle 20 and legs 12 , 14 , 16 , and 18 .

As yet another example, wheels 13, 15 and/or wheel assemblies 17, 19 may be removed. Indeed, if all four of the above components are removed, the personal mobility device 10 may be used as a four-point walker and/or a stationary chair. Similarly, if the rear wheels 13, 15 are locked (e.g., by extending the parking actuator 72 and/or engaging the passive brake 98), the personal mobility device 10 may be used as a two-point rolling walker. As the patient regains function, the physical therapist may gradually reduce the friction applied to the rear wheels 13, 15 until they are able to rotate freely.

As yet another example, while many features of the present invention have been described in conjunction with only one aspect or the other of the personal mobility device 10, it should be understood that the disclosed principles can be applied both ways without departing from the scope of the present invention.

Similarly, although many features of the present invention have been described in conjunction with the front or rear wheels of the personal mobility device 10, it should be understood that the disclosed principles can be applied to both the front and rear wheels of the personal mobility device 10 without departing from the scope of the present invention.

Another advantage of the personal mobility device 10 is that it is more aesthetically pleasing than existing mobile devices, which may encourage more use by those in need.

11A-13G are additional views of an embodiment of a personal mobility device 10 according to the teachings herein, illustrating the aesthetic configuration thereof in various orientations.

Yet another advantage of personal mobility device 10 is that all (or nearly all) of the required hardware (eg, springs, cables, and the like) is located internally to the components (eg, disposed within hubs 22, 24 and/or legs 12, 14).

All directional references (e.g., up, down, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are used for illustrative purposes only to assist the reader in understanding the present invention, and in particular, the position, orientation, or use of the present invention are not intended to be limiting. References to coupling (e.g., attaching, coupling, connecting, etc.) are broadly defined and may include intermediate members between the connection of elements and the relative movement between elements. Thus, a reference to coupling does not necessarily mean that two elements are directly connected and in a fixed connection with each other.

It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims.

Claims (19)

1. A personal mobile device, comprising: First hind leg; Second hind leg; A first front leg is pivotally connected to a first rear leg via a first hub, wherein the first hub has a first state, a second state, and a third state, in which the first rear leg and the first front leg are locked in an open state, in the second state, the first rear leg and the first front leg are locked in a closed state, and in the third state, the first rear leg and the first front leg are not locked to pivot between the open and closed states. A second front leg, pivotally connected to a second rear leg via a second hub, wherein the second hub has a first state, a second state, and a third state, in which the second rear leg and the second front leg are locked in an open position; in the second state, the second rear leg and the second front leg are locked in a closed position; and in the third state, the second rear leg and the second front leg are not locked to pivot between the open and closed positions. The grip includes a ring-shaped handle that is slidably mounted within the first and second hubs, such that the height of the grip is adjustable. Wherein: sliding the handle over the first hub causes the first hub to switch between the first state or the second state and the third state, and sliding the handle over the second hub causes the second hub to switch between the first state or the second state and the third state. 2. The personal mobile device according to claim 1, wherein: Sliding the handle downwards past the first hub switches the first hub between a first state and a third state. Sliding the handle downwards through the second hub switches the second hub between a first state and a third state. 3. The personal mobile device according to claim 1, wherein: Sliding the handle upwards past the first hub switches the first hub between a second state and a third state. Sliding the handle upwards through the second hub switches the second hub between a second state and a third state. 4. The personal mobile device according to claim 1, wherein: The first hub includes a first follower, which switches the first hub to the second state when it is pressed; The second hub includes a second follower, which, when pressed, switches the second hub to the second state; and The handle includes a first cam for pressing the first follower and a second cam for pressing the second follower. 5. The personal mobile device according to claim 4, wherein: The first cam includes a wedge that presses against the first follower as the handle slides downward and upward past the first hub; and The second cam includes a wedge that presses the second follower as the handle slides down and up through the second hub. 6. The personal mobile device according to claim 1, further comprising: The first wheel assembly includes a first wheel attached to the first foreleg; and The second wheel assembly includes a second wheel attached to the first hind leg. The handle has such a curvature that, when the handle slides downward past the first hub and the second hub, it engages with the first wheel assembly and the second wheel assembly in such a way that the first wheel is positioned parallel to the second wheel and prevents the first wheel assembly and the second wheel assembly from rotating. 7. The personal mobile device according to claim 1, further comprising: In the first round, it is attached to the first hind leg; In the second round, it is attached to the second hind leg; A first brake shoe is arranged adjacent to the first wheel and is movable between a retracted state and an extended state. In the retracted state, the first brake shoe does not contact the first wheel, and in the extended state, the first brake shoe contacts the first wheel. The second brake shoe is arranged adjacent to the second wheel and can move between a retracted state and an extended state. The second brake shoe does not contact the second wheel in the retracted state and contacts the second wheel in the extended state. A first actuator located within the first hub is operable to switch the first brake shoe between the retracted and extended states; and A second actuator located within the second hub is operable to switch the second brake shoe between the retracted and extended states. 8. The personal mobile device according to claim 1, wherein: The first hub includes a first gripping height locking pin; The second hub includes a second gripping height locking pin; and The handle includes a plurality of stops that engage with the first grip height locking pin and the second grip height locking pin as the handle slides past the first hub and the second hub to fix the grip portion of the handle at a preset height. 9. The personal mobile device according to claim 8, wherein the handle further comprises: Multiple pins, located inside the handle and respectively arranged adjacent to the multiple stops; and An actuator operable to move the plurality of pins such that these pins protrude outward from the plurality of stops, thereby preventing the first grip height locking pin and the second grip height locking pin from engaging with the plurality of stops as the handle slides past the first hub and the second hub to adjust the height of the grip portion of the handle. 10. The personal mobile device of claim 9, wherein at least some of the plurality of pins are interconnected with each other. 11. The personal mobile device according to claim 1, further comprising: In the first round, it is attached to the first hind leg; In the second round, it is attached to the second hind leg; The first brake shoe is biased to engage with the first wheel; and The second brake shoe is biased to engage with the second wheel. 12. The personal mobility device according to claim 11, wherein the first brake shoe engages the inner upper surface of the first wheel, and the second brake shoe engages the inner upper surface of the second wheel. 13. The personal mobility device of claim 11, wherein the downward force applied to the grip portion of the handle disengages the first brake shoe from the first wheel and disengages the second brake shoe from the second wheel. 14. The personal mobile device of claim 1, wherein the handle comprises a closed ring. 15. The personal mobile device of claim 1, wherein the grip portion of the handle includes a centrally located flat area. 16. The personal mobile device according to claim 7, wherein: The first actuator is connected to the first brake shoe via a plurality of first pulleys; and The second actuator is connected to the second brake shoe via a plurality of second pulleys. 17. The personal mobility device of claim 7, further comprising a seat movable between a storage position and a use position, wherein moving the seat from the storage position to the use position actuates the first actuator to switch the first brake shoe to the extended position and actuates the second actuator to switch the second brake shoe to the extended position. 18. The personal mobility device of claim 17, wherein the seat is pivotally connected to the first hub and the second hub. 19. The personal mobile device according to claim 7, wherein: The first actuator is biased to switch the first brake shoe to the retracted position, and The second actuator is biased to switch the second brake shoe to the retracted position.