Abstract:
Two versions of recumbent human powered three wheeled vehicles are disclosed. Both are of the tadpole type with two front wheels and one rear drive wheel. Both versions lean into turns causing weight transfer toward the inside of turns to prevent rollover during turns at speed.

Description:
The Lean to Steer Vehicle is a multi-wheeled vehicle wherein steering is related to operator lean. 
     CROSS REFERENCE TO RELATED APPLICATIONS 
     There are no applications related to this application. 
     STATEMENT REGARDING FEDERAL SPONSORSHIP 
     No invention claimed in this application was made under Federally sponsored research or development. 
     BACKGROUND OF INVENTION 
     A large number of Bicycles, Tricycles, and other multi-wheeled human powered vehicles, both recumbent and upright, are known. 
     The utility patent application by Hill (US Utility Patent Application Publication No. 20060035760) is typical of a class of cycles designed to promote fitness through exercise by providing the user with the exercise generally associated with the cycling while remaining in a fixed location. The present invention is directed to providing human powered locomotion. 
     The utility patent application by Nacer (US Utility Patent Application publication No. 20050253355) is typical of a class of cycles designed to enhance human powered cycling by provision of power assistance in times of need climbing steep inclines. The present invention is directed to a human powered vehicle which may or may not include such a power assist scheme and is independent of any power assist mechanism which might be provided. 
     The utility patents to Clapper (U.S. Pat. No. 5,544,906), Wiener (U.S. Pat. No. 4,548,421), Hayashi (U.S. Pat. No. 6,367,824), Nunes et al (U.S. Pat. No. 5,484,152), Owsen (U.S. Pat. No. 5,240,267), Langkamp (U.S. Pat. No. 5,145,196), Sato et al (U.S. Pat. No. 4,360,224), and Rosengrant et al (U.S. Pat. No. 5,069,469) are typical of a class of cycles in which the operator steers the vehicle using his hands to steer the vehicle. The present invention is directed to a cycle which the operator steers by leaning in the direction of the turn. 
     The utility patent to Maurer (U.S. Pat. No. 6,402,174) is typical of a class of cycles designed to provide or permit the operator to lean to the inside of a turn in response to vehicle turns resulting from steering. In this class of cycles the steering is produced by operator manual actions and the stability of the vehicle is enhanced by permitting the operator to lean toward the center of the turning circle. The present invention is directed to a cycle which the operator steers by leaning in the direction of the turn. 
     The utility patent to Krumm (U.S. Pat. No. 5,419,574) is typical of a class of cycles in which the relative position of the seat, pedals, and steering handles may be adjusted by adjusting the length of the connecting members. The present invention is directed to a vehicle in which these adjustments can be made by relocating the seat, pedals, and steering mechanism along a central support member. 
     BRIEF SUMMARY OF THE INVENTION 
     Both types of this invention are three wheeled leaning recumbent, human powered vehicles. They are of the tadpole type with two wheels in front and one wheel in back. They are meant for able bodied adults who desire a fun safe ride while getting exercise out of doors. 
     The lean to steer version leans all three wheels while negotiating turns. This causes a weight transfer toward the inside of the turning circle. This action offers greater stability than prior art while using fewer parts. 
     In the steer lean version only the rear wheel main frame, seat, and pedals lean. The front axle pivots about its center in a castering type movement. This also causes a weight transfer for better stability. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the Lean to Steer Vehicle. 
         FIG. 2  is a top view of  FIG. 1 . 
         FIG. 3  is a front view of  FIG. 1 . 
         FIG. 4  is a front detail view of a kingpin assembly. 
         FIG. 5  is a top detail view of a tie rod and wheel spindle. 
         FIG. 6  is a perspective detail view of a steering knuckle and tie-rod connection. 
         FIG. 7  is a perspective detail view of a first and second tie rod connection and tortion bar. 
         FIG. 8  is a perspective view of the invention in use. 
         FIG. 9  is a perspective view of a second embodiment of the invention. 
         FIG. 10  is a front perspective view of  FIG. 9 . 
         FIG. 11  is a top detail view of  FIG. 10 . 
         FIG. 12  is a perspective detail view of a mechanical connection from  FIG. 9 . 
         FIG. 13  is a long frame configuration assembled from components of the invention. 
         FIG. 14  is a short frame configuration assembled from components of the invention. 
         FIG. 15  is an elevational view of a wheel from the invention. 
         FIG. 16  is a sectional view of  FIG. 14 . 
         FIG. 17  is a detail view of a second tie rod embodiment. 
         FIG. 18  is a detail view of a third tie rod and steering embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The Lean to Steer Vehicle  1  is a multi-wheeled vehicle wherein steering is relate to operator  2  lean. In one embodiment, said vehicle  1  comprises: a longitudinal main frame  3  having a seat  4 , and at least one rear wheel  5 , a perpendicular frame  6 , means for axially pivotally connecting  7  said main frame  3  to said perpendicular frame  6  for providing pivotal motion of said longitudinal main frame  3  through an approximately 90 degree arc about a generally longitudinal axis  19 , a pair of wheel spindles  9 , a pair of steering knuckle assemblies  11  for axially pivotally attaching said wheel spindles  9  to opposite ends  12  of said perpendicular frame  6  wherein the pivot axis  10 , implemented by said steering knuckle assemblies  11 , of said wheel spindles  9  is selected to cause left-right steering of said vehicle  1  when said wheel spindles  9  tilt and each steering knuckle assembly  11  further comprising a trailing arm  13  connection  14  positioned to cause tilt and steer of said wheel spindle  9  via said trailing arm  13  attachment means  16 , a second end of tie rod  15  having a first end  17  connected to said longitudinal frame by a vertical arm  35  and extending past said perpendicular frame  6  and a second end  18 , a first trailing arm  13  connected to said second end  18  of said tie rod  15  and to the trailing arm  13  connection  14  of one steering knuckle assembly  11 , a second trailing arm  13  connected to said second end  18  of said second end of tie rod  15  and to the trailing arm  13  connection  14  of the other steering knuckle assembly  11 . 
     The front wheels support the Lean to Steer Vehicle  1  via rotatable attachment to the wheel spindles  9 . The wheel spindles  9  in turn support the steering knuckle assemblies  11  which in turn support the perpendicular frame  6 . In some embodiments wheel spindles are a part of steering knuckle weldments. The perpendicular frame  6  is axially pivotally attached to the longitudinal main frame  3  to provide support for the longitudinal main frame  3  and permit the longitudinal main frame  3  to rotate about its tortion bar axis  19  producing steering of the Lean to Steer Vehicle  1 . 
     With the operator  2  seated and facing forward, Steering of the Lean to Steer Vehicle  1  is achieved by applying counterclockwise torque, relative to the forward motion of the vehicle, to the longitudinal main frame  3  to turn to the operator&#39;s  2  left and clockwise torque to turn to the operator&#39;s  2  right. This rotary motion is conveyed to the means for axially pivotally connecting  7  to the longitudinal main frame  3  and thereby on to the connecting points  13  of the steering knuckle assemblies  11 . This in turn causes the steering knuckle assemblies  11  to pivot the wheel spindles  9  about the steering knuckle pivot axis  10 . The pivoting of the wheel spindles  9  about the pivot axis  10  causes the wheel spindles  9  to tilt and steer in the direction corresponding to the direction of motion of the trailing arm  13 . This tilt and steer of the wheel spindles  9  in turn cause a corresponding tilt and steer of wheels  20  attached to the wheel spindles  9 . 
       FIG. 9  illustrates another embodiment of the Lean to Steer Vehicle  1  which achieves steering by pivoting the perpendicular frame  6  about an inclined axis  26 . In this embodiment the multi-wheeled vehicle  1  steering is derived from operator input on steering handles  29 . Tie rod second ends  15  are connected to a pivotal attachment  30  to the perpendicular frame  6  to pivot about a vertical axis. However, the connection to the longitudinal main frame  3  is a generally inclined axis  26 . This causes the longitudinal mainframe  3  to tilt left or right, causing weight to transfer toward the inside of any turn. The front wheels on the steer lean tricycle do not tilt, but have a castering action. 
     The Lean to Steer Vehicle  1  may further comprise a centering mechanism  21  for causing the longitudinal main frame  3  to return to a preset position relative to said perpendicular frame  6 . The centering mechanism  21  may be a torsion bar assembly  22  or coil spring under tension. 
     It will be apparent to those of ordinary skill in the art that the longitudinal frame  3  may be configured to accommodate three or more wheels  20  and remain within the scope of the present invention  1 . 
     It is also apparent to those of ordinary skill in the art that the perpendicular frame  6  may be replaced by one fork and one wheel attached the longitudinal main frame  3  by an attachment means  16  preserving the ability to adjust the wheelbase of the lean to steer vehicle. 
     The wheels  20  may be of any construction which provides support to the vehicle and allow for rotational attachment to the wheel spindles  9 .  FIGS. 15 and 16  illustrate an embodiment of a suitable wheel featuring a concave shape permitting rotational attachment to the spindle  9  with reduced overall horizontal dimensions by virtue of the attachment means, and other devices such as brakes, being placed within the circumference of the wheel  20 . 
     It will be appreciated from  FIG. 14  that the Lean to Steer Vehicle  1  may be implemented using modular construction. The modular components include: a longitudinal main frame  3 , a seat  4 , a rear wheel  5 , a pedal assembly  33 , a single front wheel assembly  34 , and a perpendicular frame  6 . The relative positions of the seat  4 , rear wheel  5 , pedal assembly  33 , and single front wheel assembly  34  are chosen for the best fit to the operator  2  and the envisioned application. In applications where stability of the vehicle  1  is paramount, a perpendicular frame  6  would be chosen over the single front wheel assembly  34 . It will also be appreciated that the placement of the seat  4  relative to the pedal assembly  33  is a function of the size of the operator  2  and length of the operator&#39;s  2  legs, while the relationship between the rear wheel  5  and the single front wheel  34  or perpendicular frame  6  is significant in determining the vehicle&#39;s  1  turning radius. These relationships, and others, will dictate the relative positioning of the components along the longitudinal main frame  3  so that any specific sequence of components to be found in any particular configuration along the longitudinal main frame  3  is envisioned.