Land vehicles – Wheeled – Occupant propelled type
Reexamination Certificate
2001-04-03
2002-05-14
Johnson, Brian L. (Department: 3618)
Land vehicles
Wheeled
Occupant propelled type
C280S259000, C192S217200, C192S217600, C188S024170
Reexamination Certificate
active
06386566
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
This invention generally relates to pedal powered wheeled vehicles, or velocipedes. More particularly, this invention relates to a direct drive system having coaster brake functionality with the additional ability to be pedaled in reverse.
2. Background
Likely, the very first pedal powered velocipede employed a direct drive mechanism consisting of an axle having a pair of opposing crank arms, including attached pedals, extending radially out from the ends of the axle to convert reciprocal pedaling motion to rotational motive force. This drive system is characteristic of Penny Farthings, old fashioned high wheel bicycles, and is still commonly found on current day tricycles and unicycles. The direct couple between the pedals and wheel allows a user to pedal in both forward and backward directions and to apply braking resistance to the pedals to slow and stop the vehicle. However, it does not allow the user to coast, i.e. freewheel or stop their pedaling motion while the wheel is still turning, without removing their feet from the pedals.
Reed, U.S. Pat. No. 5,027,930, teaches a direct drive system for velocipedes which includes a coaster brake and coasting functionality. The details of the Reed system will be addressed and explained in more detail later in this disclosure. The Reed system does not allow reverse pedaling. The drive wheel of Reed can only be reversed when no pressure is applied to the pedals. While the reverse function may be less desirable in bicycles, it is very important to tricycle riders as tricycles are more cumbersome to navigate.
The system disclosed in the Reed patent has a drive shaft or crankshaft rotatably supported within a freewheeling hub. A clutch positioned around the crankshaft axially translates along the crank shaft between a drive engagement position and a braking position. The clutch can generally be described as a sleeve which includes internal threads that engage external threads formed on the crankshaft. Rotation of the crankshaft in one direction translates the clutch toward a first end of the crankshaft while rotation of the crankshaft in the other direction causes the clutch to translate toward the second end of the crankshaft. The clutch includes one or more tapered surfaces for engaging either a tapered flange formed on the internal surface of the hub or brake shoes. A braking cone rotatably supports the second end of the crankshaft and is fixed with respect thereto by a brake reaction lever, which in turn is affixed to a stationary point such as the velocipede's frame. Additionally, the braking cone supports one end of the brake shoes. When the clutch is translated toward the brake shoes, one of the tapered surfaces on the clutch forces the free ends of the brake shoes out toward the internal surface of the hub, eventually stopping the hub. When the clutch is translated the other direction, a tapered surface frictionally engages the tapered flange to couple the drive shaft to the hub and drive rotation of the wheel. Other embodiments of the Reed device replace the drive function of the clutch with a one way coupler, such as a “Torrington” roller bearing, between the hub and the drive shaft. This couple allows freewheeling rotation of the crank shaft in the braking direction but couples the shaft to the hub when the crankshaft is rotated in the drive direction.
What is needed is a freewheeling direct drive system which allows forward drive rotation, coasting, braking and reverse drive rotation.
SUMMARY OF THE INVENTION
One embodiment of the invention provides a freewheeling drive system for a velocipede such as a tricycle. The velocipede is of the general type propelled by directly driving a front wheel via pedals. A wheel hub on the front wheel is mounted on a crankshaft or driveshaft. The ends of the driveshaft have a pair of crank arms radially extending therefrom. Pedals are connected to each crank arm. The drive shaft is mounted on a pair of bearing assemblies supported by front forks of the velocipede.
The drive system is assembled within the wheel hub and works as follows.
When the crank arms are turned in a clockwise direction as viewed from the right side of the velocipede, the drive shaft rotates to drive wheel in the same direction, thereby driving the velocipede forward. When the crank arms rotate at a slower speed relative to the wheel hub or cease rotation, the wheel hub continues to rotate about the driveshaft, which is now stationary. The velocipede is now coasting under its own inertia. When the crank arms are turned in the reverse direction, the components of the drive system within the wheel hub operate to slow or to brake wheel from further forward rotation. Additional reverse rotation of the crank arms result in reverse rotation of the driveshaft, wheel hub and wheel.
The drive system is similar to that found in a traditional coaster brake, single speed bicycle with the major exception being that the brake reaction lever is replaced by a multi-component one-way bearing assembly. This bearing assembly, in connection with other more standard coaster drive components, allows forward pedal drive, coasting, braking and reverse pedal drive.
Additional advantages and novel features of the invention will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention.
REFERENCES:
patent: 2091586 (1937-08-01), Glacy
patent: 2113177 (1938-04-01), Glacy
patent: 2246191 (1941-06-01), Schmitz
patent: 5027930 (1991-07-01), Reed
patent: 5570760 (1996-11-01), Lai
patent: 5657836 (1997-08-01), Bevier
patent: 5669467 (1997-09-01), Chiang
patent: 6283486 (2001-09-01), Huang
Freeberg John G.
Luikart Robert C.
Luikart Robert F.
Holland Joseph W.
Johnson Brian L.
Luby Matt
Progress Place, L.L.C.
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