Abstract:
The wheeled personal transportation device includes a frame member having opposed front and rear ends having front and rear wheels rotatably mounted thereto. An air cushion has upper and lower ends, the lower end being supported by the frame member. A foot platform is mounted on the upper end of the air cushion, the foot platform being adapted for supporting a foot of a user. A pneumatic motor is mounted on the front end of the frame member and is in communication with the front wheel for selectively driving rotation thereof. The pneumatic motor is in fluid communication with the air cushion such that compression of the air cushion by the user&#39;s foot drives the pneumatic motor to drive rotation of the front wheel. A pneumatic brake is further in communication with the rear wheel for selective braking thereof. Alternatively, the front wheel may be powered mechanically by spring-biased gears.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of U.S. patent application Ser. No. 12/253,260, filed Oct. 17, 2008, which claimed the benefit of U.S. Provisional Patent Application Ser. No. 60/981,512, filed Oct. 21, 2007. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to personal transportation, and particularly to a wheeled personal transportation device powered by weight of the user in the form of an in-line skate. 
     2. Description of the Related Art 
     Transportation is a necessity of modern life. Most activities require personal movement from one place to another for work, pleasure or the like. Most transportation devices have their own limitations and drawbacks with regard to health and the environment. Therefore, an efficient, cost effective, healthy, and environmentally friendly personal transportation system is needed. 
     Vehicles may be relatively fast and comfortable. However, they are costly, not friendly to the environment, and are inefficient on congested roadways. Moreover, vehicles are responsible for limiting exercise of the users, thus encouraging unhealthy sedentary lifestyles. 
     Walking is healthy and environmentally friendly, but it is limited to short distance trips. Walking long distances may not be suitable for many people, since it takes much effort and time, especially for daily trips. In-line skates are compact and can be used as personal transportation devices. However, the oscillating movement of the body required to push skates forward is inefficient and consumes much power over long distances. Skates are, therefore, more suitable for sport than for daily movements. 
     Electrically powered skates can be used as personal transportation devices. However, the need to recharge them limits their range, the use of batteries increases their cost, and their use does not encourage people to move. Bicycles are efficient as a means of transportation for short to medium distances. They are relatively fast, healthy and environmentally friendly. However, they are quite bulky and cannot be easily integrated with public transportation. For example, if the trip is relatively long, one may ride his or her bicycle to the nearest bus or train station, but they must park it somewhere in order to be able to use public transportation. Moreover, if the rider&#39;s destination is not near a station, then he or she must walk a long distance or use other means of transportation. 
     Therefore, there is a need for a personal transportation device that can cover short to medium distances, and which can be easily integrated with other modes of transportation. It would be further desirable to provide such a personal transportation device that is compact, has a low cost, is healthy to use, and is environmentally friendly. 
     Thus, a wheeled personal transportation device powered by the weight of the user solving the aforementioned problems is desired. 
     SUMMARY OF THE INVENTION 
     The wheeled personal transportation device powered by weight of the user relates to personal transportation, and particularly to an in-line skate that is powered by the user&#39;s weight. The wheeled personal transportation device includes a frame member having opposed front and rear ends, a front wheel rotatably mounted to the front end, and a rear wheel rotatably mounted to the rear end. The device has an air cushion (or bellows-type air pump) having upper and lower ends, the lower end being supported by the frame member. A foot platform is mounted on the upper end of the air cushion. The foot platform is adapted for supporting a foot of a user. 
     A pneumatic motor is mounted on the front end of the frame member. The front wheels are mounted on the shaft of the pneumatic motor. The pneumatic motor is in fluid communication with the air cushion. Compression of the air cushion by the user&#39;s foot drives the pneumatic motor, which drives rotation of the front wheel. A pneumatic brake is in communication with the rear wheel for selective braking thereof. 
     In an alternative embodiment, the front wheels are driven mechanically. The foot platform is connected to the inline wheel frame member by a pair of scissor arms. The rear of the scissor arms are pivotally attached to the foot platform and the frame member, respectively, while the front of the scissor arms are both pivotally and slidably attached to the foot platform and the frame member. The user raises the boots up and down, and sliding movement of one of the scissor arms pulls a crank member, causing a gear to rotate and compress a torsion spring connected to the gear by a one-way clutch. The torsion spring acts like a mainspring, and expansion of the torsion spring rotates an axle, on which the drive wheel of a chain and sprocket mechanism is mounted. The driven wheel of the chain and sprocket mechanism is coaxial with a bevel gear or the like, which engages a gear on the axle of the front wheel of the inline skate, thereby driving the front wheel. 
     These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an environmental perspective view of a first embodiment of a wheeled personal transportation device powered by the weight of the user according to the present invention. 
         FIG. 2  is a perspective view of the wheeled personal transportation device of  FIG. 1 , shown with the boot raised. 
         FIG. 3  is a side view of the wheeled personal transportation device of  FIG. 2 , shown with the boot lowered. 
         FIG. 4  is a side view of the wheeled personal transportation device of  FIG. 3 , shown in a braking configuration. 
         FIG. 5  is a partial perspective view the wheeled personal transportation device of  FIG. 2 , shown with the frame removed in order to show the mechanical drive mechanism. 
         FIG. 6  is a diagrammatic side view of an alternative embodiment of a wheeled personal transportation device powered by the weight of the user according to the present invention. 
         FIG. 7  is a diagrammatic side view of another alternative embodiment of a wheeled personal transportation device powered by the weight of the user according to the present invention. 
         FIG. 8  is a side view of still another alternative embodiment of a wheeled personal transportation device powered by the weight of the user according to the present invention. 
         FIG. 9  is a diagrammatic side view of yet another alternative embodiment of a wheeled personal transportation device powered by the weight of the user according to the present invention, which uses a bellows-type air pump and pneumatic motor. 
         FIG. 10  is a diagrammatic side view of another alternative embodiment of a wheeled personal transportation device powered by the weight of the user according to the present invention, shown in a braking configuration. 
         FIG. 11  is a partial perspective view of a linkage of the wheeled personal transportation device of  FIG. 10  as viewed from the front. 
         FIG. 12  is a partial perspective view of the linkage of  FIG. 11  as seen from the rear. 
     
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , a user is shown standing atop a pair of personal transportation devices  10 ,  10 ′. The first device  10  supports the left foot, while the second device  10 ′ supports the right foot of the user. Both devices are almost identical and work in the same way, independently of each other. The following description will focus on device  10 , bearing in mind that similar description applies to device  10 ′. More detailed illustrations of the device  10  are presented in  FIGS. 2-5 . 
     The transportation device  10 , as shown in  FIG. 2 , includes foot platform  15  attached securely to a specially designed boot or hard shoe  14  to support and to protect the user&#39;s foot. The foot platform  15  is connected to the transportation attachment  11  of inline wheels by linkage mechanisms  16  and  17 , which include a first pair of parallel scissor arms  16  and a second pair of parallel scissor arms  17 , which are joined at their center by a pivot pin The rear ends of scissor arms  16  are pivotally attached to a pin  50  fixed in the frame member of the transportation attachment  11 , and the rear ends of scissor arms  17  are pivotally attached to a pin  52  fixed in the foot platform  15 , so that the rear ends of the scissor arms  16  and  17  are free to pivot, but cannot slide forward and rearward. The front ends of the scissor arms  16  are pivotally attached to a pivot pin  16 ′ that is slidable in parallel slots  54  defined in the front end of the foot platform  15 , and the front ends of the scissor arms  17  are pivotally attached to a pivot pin  17 ′ that is slidable in parallel slots  60  defined in the frame member of the transportation attachment  11 . Thus, the front ends of the scissor arms  16  and  17  are free to both pivot and to slidably translate forward and rearward. The foot platform  15  is located above the transportation attachment  11  in relation to the support surface, and it supports the user&#39;s foot so that the longitudinal axis of the user&#39;s foot can be positioned in the direction of the intended motive direction supplied by the transportation attachment  11 . 
       FIG. 2  shows the transportation device  10  with the foot platform  15  in a high position at the beginning of a pressing stage.  FIG. 3  shows the transportation device  10  with foot platform  15  in a low position at the end of the pressing stage, and also in the configuration used during normal cruising.  FIG. 4  shows the transportation device during a braking stage, which is actuated by the user&#39;s foot tilting the foot platform  15  backward. 
     The transportation attachment  11  includes inline ground-engaging wheels  12 ,  13  and  19 , which rotate about their axles to allow the transportation attachment  11  to move forward. As shown, wheel  12  is positioned in front (with respect to the orientation of the user&#39;s foot; i.e., nearest the user&#39;s toes), wheel  13  is positioned in the rear, and wheel  19  is positioned centrally and between wheels  12 ,  13 . The frame of the transportation attachment  11  supports most of the components of the transportation device  10 . 
     Returning to  FIG. 2 , the foot platform  15  holds the weight of the user and transfers it to the linkage  17 . Linkage  16  is used to keep the platform  15  in a parallel position with respect to transportation attachment  11 . The two linkages are interconnected in the middle by a common axle, with an X-shape or scissors configuration. As best seen in  FIGS. 3 and 4 , the two linkages  16 ,  17  are free to rotate about their rear axles  50 ,  52 , respectively, and slide forward while rotating about their front axles  16 ′ and  17 ′, respectively, thus allowing the foot platform  15  to move from the high to the low position. Linkage  17  is connected through axle  17 ′ to the driving mechanism  18 . 
       FIG. 4  shows the transportation device  10  in the braking stage. It should be understood that braking may be performed by any conventional braking system. In the preferred embodiment, the user simply tilts his or her feet and body slightly backward to actuate braking. A bend  56  formed in the front end of a sliding groove  54  in which the front axle  16 ′ is mounted allows the foot platform  15  to tilt about the rear axle  52  of linkage  17 . This tilting action causes the braking pad  20  (shown in the embodiment of  FIG. 8 ) to come into direct contact with the rear wheel  13 . The more the rider tilts the foot platform  15 , the stronger the braking effect, as the pressure between the braking pad  20 , which is mounted on the rear of the platform  15 , is increased. Further, one of the wheels can also be activated to engage the gear assembly for slowing down. The gear assembly, shown in  FIG. 5 , includes gear  22 , driving gear  24 , gear set  26  and axle assembly  27 . 
     The braking of the rear wheel  13  provides stability to the transportation device  10 , since the rear wheel  13  will pull the device  10  backward; i.e., opposite to the direction of movement. Tilting the foot platform  15  and the user&#39;s body backward provides additional stability during braking, since the body of the rider still has forward momentum. Moreover, the low position of the foot platform  15  during braking provides further stability by lowering the center of mass of the overall device  10 . 
     The driving mechanism  18  converts the forward linear movement of the front axle  17 ′, forced by the weight of the rider, to forward rotational movement of the front wheel  12 . The rider repeats moving his or her feet up and down in an oscillating pedaling-type or walking-type motion to accelerate or to maintain speed. The greater the frequency of the user&#39;s up-down foot motion, the greater the user accelerates. The front wheel  12  is used to drive the transportation device to provide more stability to the rider during acceleration due to its pulling effect in the direction of movement. 
       FIG. 5  shows the driving mechanism  18  in detail. The driving mechanism  18  stores, amplifies, and converts the linear movement of the front axle  17 ′ to revolution of the front wheel  12 . The central pivot of the X-type configuration of the linkage mechanisms  16 ,  17  is designated generally as  58  in  FIG. 5 . As the user pushes his or her foot down, lowering the foot platform  15 , the scissor arms  17  rotate about pivot  58  and pivot pin  52 . As the front axle or pivot pin  17 ′ is forced by the weight of the rider to slidably move forward within slots or grooves  60  (as best shown in  FIGS. 3 and 4 ) in the frame of the transportation attachment  11 , it pulls sliding linkage or crank member  21 , causing the gear  22  to rotate. The gear  22  is connected to a spring and axle assembly  23 . The spring and axle assembly  23  performs two tasks. First, it stores the rotational force as spring potential energy by twisting the spring (a torsion spring), compressing the torsion spring portion of the assembly  23 , which is connected to the gear  22  by a one-way clutch  23 ′. Second, the torsion spring acts like a mainspring, and expansion of the torsion spring rotates the axle portion of the assembly  23 , on which the drive wheel  24  of a chain and sprocket mechanism  25  is mounted. The driven wheel or gear set  26  of the chain and sprocket mechanism is coaxial with a bevel gear or the like, which engages a gear on the axle  27  of the front wheel  12  of the inline skate, thereby driving the front wheel  12 . As an alternative, an auto-shift gear set can be added to the driving mechanism  18  instead of the gear set  26  for long-distance and high-speed versions of the transportation device  10 . 
     One-way clutches are used internally in the gear  22  and in the axle and gear assembly  27  to force rotation to be in one direction while pressing, and to allow free backward rotation in another direction. Introducing the spring and axle assembly  23  into the driving mechanism  18  allows the foot platform  15  to move from the higher to the lower position instantly for better stability, while also storing the downward force in the spring to drive the device  10  continuously and smoothly. 
     One-way clutches can also be used in wheels  12 ,  13  and  19  to allow the transportation device to move only in the forward direction. This will aid the rider in climbing steep ramps by pushing one of the transportation devices  10 ,  10 ′ forward while being supported by the other one, and so on. 
     It should be understood that the foot platform  15  may be of different shapes and configurations. Preferably, a hard and hinged shoe or boot  14  is used to support and to protect the foot of the rider from accidental lateral bending. The shoe  14  can be detached from the transportation device  10  so that rider can use it in a manner similar to that of an ordinary shoe before and after riding the transportation device  10 . This configuration is more suitable for long distance trips and while using public transportations. 
       FIG. 6  illustrates an alternative shoe configuration  14 ′, which allows the user to use his or her ordinary shoes, by providing a secure support frame for the shoe in all directions, using rods, grooves, straps and the like. A support arm  40  is used to protect the foot from accidental lateral bending, while allowing the leg to tilt forward and backward in a natural manner by rotating about axle  40 ″. The gears of the driving mechanism  18  can be engaged with the front wheel  12  to slow it down. 
       FIG. 7  shows another configuration for the linkage and driving mechanisms. In this embodiment, the linkage mechanisms  16  and  17  have rotating arms, and a sliding linkage  21  for transferring force to the driving mechanism  18 , which is in direct contact with the front wheel  12 . 
       FIG. 8  shows another configuration of a personal transportation device, in which linkages  16  and  17  have an X-shape configuration, and the driving mechanism  18  is embedded inside the wheel  12 . A spring and sliding link assembly  23  is used to store and transfer the force, which is generated by the weight of the user, to the driving mechanism  18 . 
     An alternative driving mechanism is shown in  FIG. 9 , where air is used as a pneumatic fluid to transform the weight of the user into power for driving the personal transportation device  30 . A supporting frame  11  is used to support front and back wheels  12  and  13 . An air-cushion (or bellows-type air pump)  31  is placed between the foot platform  14  and the supporting frame  11  and may enclose the stability mechanism (i.e., the scissor linkage arms  16 ,  17 ). The air-cushion  31  is preferably a sealed, bellows-type enclosure, as shown. 
     As the user forces the foot platform  14  to go down under his or her own weight, air is compressed inside the air-cushion  31 . A tube  34  passes the compressed air to a pneumatic motor  33 , which is mounted at and drives the front wheel  12  (the motor shaft may be the front axle), thus moving the transportation device  30  forward until the compressed air is consumed. It should be understood that the pneumatic motor may be either a vane-type air motor or a piston-type air motor Following compression, the user then pulls his or her foot up again, which expands the air cushion  31 . A one-way valve  37 , mounted within the air-cushion housing, allows ambient air to fill the expanding air-cushion  31  again, thus preparing the device for another cycle. Thus, the air cushion  31  serves as an air pump. The more frequent the user repeats this cycle, the faster the device travels. 
     It should be understood that braking may be actuated by any conventional braking system. Preferably, as shown in  FIG. 9 , an actuator  38  is embedded inside the shoe  14  so that the user can use his or her toes to activate a brake  35  placed in the rear wheel  13  through braking wire or tube  38 ′. It should be understood that any suitable type of wire or tube braking system may be utilized, such as those commonly associated with bicycles. Examples of such brakes are shown in U.S. Pat. Nos. 4,896,753; 5,538,270; and 6,592,129, each of which is hereby incorporated by reference in its entirety. Further, as shown in  FIG. 9 , a separate line  39 ′, which is in communication with line  38 ′, is joined to a valve  39 , which is in communication with the tube  34 . Upon actuation of the brake actuator  38 , the valve  39  closes, thus ceasing air flow through the tube  34  and cutting fluid power to the motor  33 . 
     As in the previous embodiments, the device  30  includes a foot platform  15 , which holds the weight of the user and transfers it to linkage  17 . Linkage  16  is used to keep the platform  15  in a parallel position with respect to the transportation attachment  11 . The two linkages are interconnected in the middle by a common axle to form an X-shape or scissors configuration. The two linkages  16 ,  17  are free to rotate about their rear axles  50 ,  52 , respectively, and slide forward while rotating about their front axles  16 ′ and  17 ′, respectively, thus allowing the foot platform  15  to move from the high to the low position. As in the previous embodiments, the front axle  16 ′ is slidable and pivotal within a groove  54  in the platform  15 , and the front axle  17 ′ is slidable and rotatable within the groove  60  in the frame of the transportation attachment. 
     Another mechanism allows the foot platform  15  to be tilted backward, as shown in  FIG. 10 . In this embodiment, linkage  16  is replaced by a pair of linkages  32 ′ and  32 , which may pivot with respect to one another about the central pivot  58  of the X-shaped connection. The device  30  of  FIG. 10  operates in a manner similar to that of  FIG. 9 , but with the brake actuator  38  being removed. Instead, a braking line  38 ′ is secured at its front end to linkage  32 ′, and the bending motion of linkage  32 ′ when the user tilts his or her foot back pulls on line  38 ′, thus actuating brake  35 . 
       FIG. 11  shows the interconnection between linkages  32 ,  32 ′ and linkage  17  about the central pivot  58 . In use, the front upper linkage  32 ′ is rotated clockwise (in the orientation of  FIG. 11 ) to actuate braking. This occurs when the user tilts his or her foot backward. One or more pins  70  may be mounted on the lower end of front upper linkage  32 ′ to cease further rotation of the linkage  17  after braking. As shown in  FIG. 12 , a leaf spring  72  or the like may be used to restore linkage  32 ′ to its original straight position with respect to linkage  32  following braking. 
     Any suitable material, such as aluminum, composite materials, carbon fibers, hard plastics, polymers, fabrics, steel and metal alloys, etc. may be used to make the different components of the transportation device. Light reflective materials may be added on all sides of the device for safety purposes. Similarly, LED lamps or the like can also be used at night for safety, as well as decorative, purposes. As a further alternative, distance meters or other performance measures may also be added. 
     In order to maintain forward movement, the rider simply raises and lowers his or her right and left feet in an alternating pattern, as if moving up a set of stairs. 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.