Abstract:
In accordance with one implementation of the present principles, the toy model tires are designed to be divided into sections. Each divided tire section independently pivots on its own fixed fulcrum point. In response to terrain conditions, the tires can transform by the pivoting of the tire sections outward, thus increasing the outer diameter and causing the tire to take on a claw like form to assist in overcoming rough terrain or obstacles on a running surface.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority from U.S. Provisional Patent Application Ser. No. 61/228,283 filed on Jul. 24, 2009, the entire contents of which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to radio control toy models. More particularly, it relates to a radio control toy model with a transforming tire capability. 
         [0004]    2. Description of Related Art 
         [0005]    There are several conventional ways to increase the “grip” of a tire. For example, increasing height of treads, suspension adjustments, use of different rubber materials, use of larger-scale wheels, etc. However, since the shape and outer diameter of a tire are fixed, acceptable terrains or running surfaces for vehicles with normal round tires are limited. Vehicles with conventional round tires of any size can suffer from slipping uneven roads, grass or sands, due to lack of grip. In addition, these vehicles can become stuck altogether if the tires cannot overcome the road surface or terrain. 
       SUMMARY 
       [0006]    In accordance with one implementation of the present principles, the round tire can be specially designed to be divided into several sections. Each divided tire section independently pivots on its own fixed fulcrum point. Thus, the outer diameter of tire can become larger after all tire pieces or sections start transforming and spread out. These and other aspects are achieved in accordance with an implementation of the invention where the toy model includes a chassis, at least one motor, a gear mechanism connected to the at least one motor, and at least two transforming tires connected to the gear mechanism. Each transforming tire includes at least two tire sections configured to pivot outward beyond an outer circumference of the tire when a load on the tire exceeds a predetermined threshold. 
         [0007]    In accordance with one implementation, the tire transforming mechanism includes a tire link connecting each tire section to the transmission link, a pivot point about which each tire section pivots, and a torsion spring around each of said pivot points and configured to bias each tire section inward. The torsion spring provides the predetermined load threshold for tire transforming. 
         [0008]    Other aspects and features of the present principles will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the present principles, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    In the drawings wherein like reference numerals denote similar components throughout the views: 
           [0010]      FIG. 1  is perspective view of the toy model with transforming tire mechanism according to an implementation of the invention; 
           [0011]      FIG. 2  is a perspective view of the toy model with the tires transformed according to an implementation of the invention; 
           [0012]      FIG. 3  is an exploded perspective view of the tire transforming mechanism according to an implementation of the invention; 
           [0013]      FIG. 4  is a cross sectional view of a transforming tire prior to transformation according to an implementation of the invention; 
           [0014]      FIG. 5  is a cross sectional view of the transforming time after transformation according to an implementation of the invention; 
           [0015]      FIG. 6  is a perspective view of the transforming tire prior to transformation, according to an implementation of the invention; 
           [0016]      FIG. 7  is perspective view of the transforming tire after transformation, according to an implementation of the invention; 
           [0017]      FIG. 8  is a cross sectional view of the transforming tire showing the locking mechanism in an unlocked position; and 
           [0018]      FIG. 9  is a cross sectional view of the transforming tire showing the locking mechanism in a locked position. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    In accordance with one implementation show in  FIG. 1 , the toy model  10  includes a body (not shown), a chassis  12 , wheels  14 , motors  16 R,  16 L, a gear assembly  20 , a power source such as, for example a battery  24  (not shown), and a RX PCB (receiver printed circuit board)  22 , etc. The driving motors  16 L and  16 R are located at left and right of Chassis  12  respectively. The left motor  16 L drives left wheels  14  in front and rear, and vice versa with the right motor  16 R. The RX PCB  22  receives signal from a remote or transmitter (TX) and controls left and right motors  16 L and  16 R individually and lets the motors turn either clockwise, counter-clockwise or stop. The user can control the vehicle to move forward, backward, left turn, right turn or stop by using various combinations of rotation from the left and right motors. 
         [0020]    Referring to  FIGS. 3 ,  4  and  5 , the transformable wheel  14  of the present invention consists of outer wheel  50 , an inner wheel  32 , a lock button  48 , a cam  46 , a lock pin holder  44 , a center pipe  40 , a transmission link  34 , a tire assembly  30  made up of at least two separate tire parts, a push spring  38 , a shaft,  42 , screws  52  and an axle/end gear  54  (as shown in  FIG. 3 ). The speed of the motors  16  can be reduced by a gear train and is finally transmitted to axle or end gear  54 . The axle/end gear  54  and transmission link  34  are firmly fixed and rotate simultaneously. The transmission link  34  can travel within sector shaped gap  56  at inner wheel  32  as shown in  FIGS. 4 and 5 . 
         [0021]    As shown in  FIGS. 6 and 7 , each tire assembly  30  is divided into three tire sections  30   a ,  30   b , and  30   c , each of which pivots around a fulcrum  68  at the center, and shaft  42 , which is fixed into the lock pin holder  44 , is connected to the tire link  60  and transmission link  34  are connected and can move together. When transmission link  34  rotates against inner wheel  32  (in the presence of a load on the tires), the divided tire sections  30  spread out as shown in FIG.  7  and thereby increase the outer diameter of the tire. The torsion springs  70  are fixed at a location between each tire section  30  and inner wheel  32  and positioned around the fulcrum  68 . The torsion springs  70  operate to bias the divided tire sections back to a direction of the original round-shape as shown in  FIG. 6 . Thus, torsion springs  70  provide a predetermined threshold of load which the tires can accept before transforming and expanding outward into the claw like configuration. Although shown and described in the context of three (3) tire sections  30 A- 30 C, the present invention can be applied to any tire assembly having at least two (2) tire sections. 
         [0022]    The rotation of driving motors  16  is transmitted to transmission link  34  through axle/end gear  54 . When the axle/end gear  54  turns to move forward, and the load applied to the wheel is lower than a predetermined threshold, the force of central torsion springs  70  exceeds the rotary force. As a result, transmission link  34  does not travel and stays in a position shown in  FIG. 4 . Thus, the tire does not transform and stays in the original round shape, and then rolls forward normally. 
         [0023]    Referring to  FIGS. 4 and 5 , and in accordance with a preferred implementation, a sector shaped gap  56  can be set up between axle gear  54  and the transmission link  34 . Thus, when excess load is applied to wheels  14  of a running vehicle, wheels  14  are forced to stop, but on the contrary, axle/end gears  54  still try to continue to rotate. The rotary force of wheel against axle/end gear  54  can be twisted or delayed due to rotary movement within sector shaped gap  56 . The torque or delayed rotary force can be utilized to make all divided tire sections  30 A- 30 C of the tire assembly  30  spread out simultaneously. The torsion springs  70  mounted inside the wheel (See  FIGS. 6 and 7 ) keeps pulling (or biases) the transformed and divided tire sections inward in the direction of the original round-shape of the wheel, so the wheels  14  will automatically transform back to their original round-shape when the load on the same is reduced. 
         [0024]    In other words, the load to wheels is less (i.e., lower coefficient of friction) when the vehicle runs on flat surfaces, so the vehicle runs normally with the original round-shaped tires. When an excess load is applied to wheels when vehicle runs on rough terrains (i.e., coefficient of friction increases), the normal round tire will transform into a different shape like a wheel wearing saw blades or extended claws (as shown, for example, in  FIG. 2 ). The transformed wheels increase the vehicle&#39;s “grip” on/over obstacles and also functions to increase the ground clearance of the vehicle (i.e., makes the vehicle taller) due to the increased outside diameter of the wheels. Thus, the vehicle can run over the obstacles with less difficulty due to higher effective ground clearance. 
         [0025]    When axle/end gear  54  turns to move forward, and also an excess load is applied to the wheel, the rotary force exceeds the force of torsion springs  70 . In response, the transmission link  34  travels to a position which is shown in  FIG. 5 . In connection with this motion, the divided tire pieces  30  start turning around their respective fulcrum  68  at the center, and a whole tire transforms into a totally different shape like a wheel with saw blades or extended claws, and which also makes the tire have a larger outside diameter. The vehicle with the transformed tires can run off-road dynamically. 
         [0026]    When there are not any obstacles or when the load to wheel is reduced, the tire automatically transforms back to the original round-shape as shown in  FIG. 4  because force of central Torsion Spring  36  now exceeds rotary force. The pulling force of outer torsion springs  70  can be changed, so the timing of transformation by the amount of load to wheel is adjustable. As shown in  FIG. 2 , left and right Wheels are symmetrical, so Tire can transform when it moves forward only. 
         [0027]    In one implementation, there is included a lock mechanism installed at both the starting point and the end of a sector shaped gap  56  inside the wheel.  FIGS. 8 and 9  shows cross sectional views of the wheels  14  showing this locking mechanism. As shown in  FIG. 8 , when the lock button  48  is pulled outward away from the tire, the cam  46  and shafts  42  are controlled such that the ends of the shafts do not enter a locking gap  80 , thus allowing tire transformation in accordance with the present principles. When the lock button is pushed in as shown in  FIG. 9 , the cam  46  and shafts  42  cooperate to cause the ends of the shafts to enter the locking gap  80  and thereby lock rotation of the lock pin holder  44  and thereby prevent tire transformation according to the invention. 
         [0028]    Thus, when the wheel is locked at starting point of the sector shaped gap, rotary motion of axle gear and wheel cannot be twisted. The tire cannot be transformed and stays in the original round-shape even if excess load is applied to the wheels, so vehicle normally runs with the round-shape tires. When it is locked at the end of sector shaped gap, rotary motion between axle/end gear and wheel will be maximized continuously. Vehicle can run with transformed tires even if load is not applied to the wheels. 
         [0029]    In an automatic mode (i.e., a state of operation when the Lock Button is not being pressed) is shown in  FIG. 8 . Shaft  42  is located inside transmission link  34 , so transmission link and inner wheel  32  cannot be locked to each other, and transmission link  34  can freely travel from a position shown in  FIG. 4  to a position shown  FIG. 5 . Transmission link moves back-and-forth within sector shaped gap at inner wheel, so the Tire can either transform or return to the original round-shape depending on the amount of load. 
         [0030]    When lock button is pressed in as shown in  FIG. 9 , it also presses down lock pin holder  44  via Cam  46 . Lock pin shafts  42  is now inserted into a position between transmission link  34  and inner wheel  32 , so it locks both parts, and transmission link  34  cannot travel within sector shaped gap  80  at inner wheel  32 . 
         [0031]    When Lock Button  48  is pressed into the position  42 A as shown in  FIG. 4 , tire  30  can be firmly fixed without transformation. The tire stays in the original round-shape and normally rolls forward even if excess load is applied to wheels. 
         [0032]    When lock button  48  is pressed into the position  42 B as shown in  FIG. 5 , the tire can be locked into the transformed position with the tire sections  30 A- 30 C extended as shown. 
         [0033]    Once the lock button  48  is pressed in, it stays in the same position due to the cam mechanism. The push spring  38  operates in conjunction with the lock button  48 , such that when lock button  48  is pressed again, it is released and goes back to the original position. Either lock (at  42 A or  42 B position) or unlock is alternatively selectable. 
         [0034]    In order for this mechanism to be efficient, a driven axle is required, so AWD (all-wheel drive) vehicles are preferable. However, transformation at either front or rear wheels (2WD vehicles) can occur with the transforming mechanism of the present invention. A vehicle with 2-motor differential drive is explained above as an exemplary embodiment. However, it is to be understood that this mechanism can be applied to vehicles that have a conventional front steering system. Also, the described example shows a tire with 3 divided sections, however the number of tire sections can vary without departing from the scope of this disclosure, with the provision that the present tire transforming mechanism can be applied to a tire having at least two sections (i.e., more than one section). 
         [0035]    While there have been shown, described and pointed out fundamental novel features of the present principles, it will be understood that various omissions, substitutions and changes in the form and details of the methods described and devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the same. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the present principles. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or implementation of the present principles may be incorporated in any other disclosed, described or suggested form or implementation as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.