Summary of the Invention
The invention pertains to a foot operated vehicle of the type wherein one foot is placed on a foot support platform while the other foot is used as a means of propulsion. Various such wheeled devices are popular in use for recreation particularly among younger persons. Turning of such devices by the operator can be hazardous and is accompolished by leaning in the intended direction of the turn. The turning maneuver is more easily accompolished if a wheel is provided that pivots according to the turn. Such a pivoting wheel can be prone to rotate more than is needed for the turn and, in addition, can pose difficulties in recovering after the turn and resuming a straight ahead orientation, also producing a hazard.
The foot operated vehicle of the present invention includes a frame having a flat foot support platform supported by front and rear wheels. The front wheel assembly permits pivoting of the front wheel about a generally upright axis during a turn. A front wheel is mounted on an axle which is in turn mounted between bifurcated legs of a fork member. An upright shaft of the fork member is pivotally assembled in a collar fixed to the frame for pivotal movement about a generally upright axis. Bias means assembled between the shaft and the collar tends to center the wheel or bias it in a straight ahead orientation. Upon execution of a turn, the wheel pivots against the influence of the bias means, but upon recovery from the turn, the wheel is returned to the straight ahead orientation. Means are provided on the collar for limitation of the amount of permissible rotation of the front wheel in the execution of a turn.
In the Drawings
FIG. 1 is a side elevational view of a foot operated vehicle according to the invention with a foot being supported thereon;
FIG. 2 is a top plan view of the foot operated vehicle of FIG. 1;
FIG. 3 is an enlarged sectional view of a portion of the foot operated vehicle of FIG. 2 taken along the line 3--3 thereof;
FIG. 4 is an enlarged sectional view of the portion of the foot operated vehicle of FIG. 3 taken along the line 4--4 thereof;
FIG. 5 is an enlarged sectional view of the portion of the foot operated vehicle of FIG. 3 taken along the line 5--5 thereof;
FIG. 6 is a top plan view of a foot operated vehicle of the invention in the execution of a right turn; and
FIG. 7 is a top plan view of a foot operated vehicle of the invention in the execution of a left turn.
Description of a Preferred Embodiment
Referring to the drawings, there is shown in FIGS. 1 and 2 a foot operated vehicle 10 having a frame 11 including a longitudinal generally rectangular rigid foot support platform 12. Platform 12 supports a foot 14. A pair of arms 15, 16 extend rearwardly from the trailing edge of platform 12 in converging relationship, terminating in flat, parallel spaced apart end portions 18, 19. End portions 18, 19 of arms 15, 16 carry a transverse rear axle 20 secured by end mounting nuts 21, 22. Axle 20 rotatably carries a rear wheel 24. The arms 15, 16 also extend upwardly whereby the axis of rotation of wheel 24 on axle 20 is elevated above the upper plane of platform 12 by approximately one half the radius of wheel 24. A resilient arcuate rear fender 25 extends from the rear edge of platform 12 up and over rear wheel 24. A brake pad 26 is mounted on the under side of fender 25 over the wheel 24. Foot pressure applied to the top of the fender 25 is effective to deflect the fender 25 and move the brake pad 26 into contact with the rear wheel 24 to retard or stop rotation of rear wheel 24 and vehicle 10.
An arcuate neck 27 extends upwardly and forwardly from the leading edge of platform 12. A cylindrical tubular collar 29 is fixed to the outward end of neck 27 as by welding or the like. Collar 29 has an axis that is generally upright and slightly rearwardly inclined. A front wheel fork 30 has a steering shaft 31 rotatably assembled in collar 29. The lower end of shaft 31 extended outward of collar 29 is fixed to a transverse cross bar 32. Bifurcated parallel legs 34, 35 extend downwardly from the outer ends of cross bar 32 in straddling relationship to a front wheel 36. The lower ends of legs 34, 35 carry a transverse front axle 38 which rotatably mounts the front wheel 36. Mounting nuts 39, 40 are assembled on the opposite ends of axle 38 to keep it in position. Front axle 39 is located at the same vertical position as rear axle 20 when vehicle 10 is on a level surface. Platform 12 is in a horizontal plane located below the rear axle 20 and front axle 38.
A tubular sleeve bearing 42 surrounds the portion of steering shaft 31 located in collar 29 to facilitate relative rotation between collar 29 and shaft 31. Sleeve bearing 42 has a lower, outwardly extended lip 43 disposed between the lower edge of collar 29 and the adjacent surface of cross bar 32. The upper end of steering shaft 31 extends outwardly of collar 29. A cylindrical end cap 44 is assembled to the upper end of shaft 31 and has sidewalls that straddle the upper end of collar 29. Shaft 31 has a reduced, threaded upper end portion 46 extending through an opening in the end of cap 44. A nut 47 is threaded on the end 46 bearing against the end of cap 44 to secure the cap 44 to the shaft 31.
Bias means are provided to bias front wheel 36 in a centered or straight ahead orientation. A helical spring 48 has one end 49 fixed to the steering shaft 31 near the upper end thereof as by having the end 49 inserted through a small opening 50 in the sidewall of shaft 31 near the upper edge. Helical spring 38 coils around the shaft 31 and extends downwardly. The opposite end 51 of helical spring 48 is fixed to the collar 29. The end 51 is securely fastened in an opening in the upper edge of the collar 29. Spring 48 is neutral when the front wheel 36 is centered in a straight ahead orientation. Relative rotation between the steering shaft 31 and the collar 29 to turn the front wheel 36 in one direction or another results in a force exerted by the spring 48 to tend to return the front wheel to the straight ahead orientation.
Means are provided to limit the permissible amount of rotational movement of the front wheel 36 in steering of vehicle 10. A circumferential horizontal recess 53 is formed in shaft 31 near the top edge thereof at a location of overlap with cap 44, encompassing an arc corresponding to the permissible steering arc of front wheel 36. A bolt assembly has a wing nut-type head 54 fixed to a threaded shank 55. A threaded nut 56 is fixed to the outside of cap 44. Nut 56 is centered with respect to recess 53 over an opening through cap 44 when wheel 36 is in a centered position. The shank 55 is threaded through the nut 56 and through the corresponding opening in cap 44 into the area of recess 53. When cap 44 and shaft 31 rotate relative to the collar 29, the end of shank 55 moves in recess 53. The circumferential edges 59, 60 of the recess 53 limit further movement of the end of shank 55 and thus limit the permissible relative rotation of cap 44 and shaft 31 with respect to the collar 29. A central opening 58 extends from the bottom of recess 53 through the remainder of collar 29. Shank 55 can be threaded into the central opening 58 whereby cap 44 and shaft 31 are locked relative to collar 29 thereby locking the front wheel 36 in the centered position when it is so desired to do so. Shank 55 can be threaded outwardly of recess 53 by rotation of wing nut 54 to a position out of the recess 53 whereby rotation of the front wheel 36 is unlimited.
In operation of the vehicle 10, the operator places one foot on the platform 12 and uses the other foot to propel the vehicle. In straight ahead movement, the spring 48 biases the front wheel 36 in a centered position. Shank 55 is threaded to a position normally within the recess 53. Upon execution of a right turn, as illustrated in FIG. 6, the operator leans slightly to the right. This causes turning motion of vehicle 10 in addition to rotation of front wheel 36 in the direction of the turn. The amount of rotation of the front wheel 36 in a direction of the turn is limited when the end of shank 55 reaches an edge of recess 53. Upon recovery from the return, the operator stands in an upright orientation and, as the vehicle recovers from the turn, the helical spring 48 returns the front wheel 36 to the centered orientation. In the execution of a left turn, as illustrated in FIG. 7, the operator leans to the left and, as the turn is entered, the front wheel 36 rotates to the direction of the turn. The amount of rotation of the front wheel 36 in the direction of the turn is again limited by movement of the end of shank 55 and recess 53. Upon recovery from the turn, the helical spring 48 again biases the front wheel 36 to the centered position.
While there has been shown and described a preferred embodiment of a foot operated vehicle according to the invention, it will be apparent that certain deviations can be had from the embodiment shown without departing from the scope and spirit of the invention. For example, a shoe could be affixed to platform 12 to facilitate balancing thereon or, in like fashion, shoe straps could be provided.