WO2002002395A1

WO2002002395A1 - Pedal vehicle with low center of gravity

Info

Publication number: WO2002002395A1
Application number: PCT/US2001/021036
Authority: WO
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-07-03
Filing date: 2001-07-03
Publication date: 2002-01-10
Anticipated expiration: 2003-01-03
Also published as: AU2001271764A1

Abstract

A low center of gravity pedal vehicle includes at least one driven wheel (44). The vehicle includes a frame (12), first and second drive mechanisms (26, 34) secured to the frame (12) and in driving communication with each other, and a drive transfer mechanism (52) connecting the second drive mechanism (34) with the at least one driven wheel (44) for transmitting a drive force. The first and second drive mechanisms are provided with crank arms (30, 32, 40, 42). A pair of drive platforms (54, 56) is provided, each platform being connected to both the first and second mechanisms (26, 34) for synchronous movement. The drive platforms (54, 56) are large enough to accommodate an operator's foot and are connected to each of the crank arms (30, 32, 40, 42) of the first and second drive mechanisms (26, 34) via mounting brackets (68, 77, 58, 67).

Description

PEDAL VEHICLE WITH LOW CENTER OF GRAVITY

FIELD OF THE INVENTION

The present invention relates to human-powered vehicles. More

specifically, the present invention relates to human-powered, low

center-of-gravity vehicles propelled by pedal mechanisms.

BACKGROUND OF THE INVENTION

Human-powered vehicles, perhaps the most familiar and widely-used of

which is the bicycle, are used throughout the world for transportation and

recreation. The ubiquitous bicycle has evolved from wooden-wheeled

velocipedes propelled by foot contact with the ground, to banana-seated sting

rays, to composite-framed, full-suspension mountain bikes.

One variant of the bicycle is the scooter, a low-slung wheeled vehicle

typically propelled in a manner similar to that used with a skateboard. Such

scooters are relatively safe and fun due to their low center of gravity, but are

limited by their relatively primitive propulsion method.

Not surprisingly, there have been attempts to combine mechanical drive

mechanisms with scooter characteristics. For example, U.S. Patent No.

3,820,819 to Ivkovich et al. is directed to an accessory for a bicycle for allowing a second person rider to assist the first person in propelling the rear or driving

wheel of a bicycle by employing a rearward extension of the foot pedals

supported by a roller, and a framework secured to the rear axle of the bicycle.

United States Patent N° 5,368,321 to Berman et al. Discusses an exercise

cycle is propelled by a stair-stepping action of the driver's legs, with the feet

placed on a pair of front-hinged footboards located along opposite sides of the

vehicle. A novel cable and chain drive system delivers driving torque to the rear

wheel assembly to propel the vehicle forward in response to the driver's weight

being applied via the legs and feet to depress the footboards alternately: the

driving mechanism is located in a lower forward portion of the cycle so as to keep

the mechanism below the rear wheel height and thus provide a low profile.

United States Patent N° 5,294,140 to Rinkewich shows a

self-propelled vehicle includes a frame having a pair of foot treadles mounted in

side-by-side relation and depressible with respect to the frame; an overrunning

clutch for each of the foot treadles and having a drive member coupled to its

respective foot treadle and a driven member coupled to the drive wheel; and a

planetary gear assembly for each of the overrunning clutches for coupling the

drive member to the respective foot treadle such as to multiply, by a factor of at

least two, the displacement of the clutch driven member by its respective foot

treadle.

United States Patent N° 5,192,089 to Taylor is directed to a

Pedal-operated scooter which is characterized by a scooter frame having front

and rear wheels, handle bars for steering the front wheel and a pedal-operated drive mechanism for unidirectionally propelling the rear wheel. The drive

mechanism includes a pedal pivotally mounted on the scooter frame, with front

and rear cables extending around corresponding cable pulleys and attached to

corresponding sprocket chains. The sprocket chains engage corresponding

parallel sprockets adapted for alternately driving the rear wheel when rotated in

the forward direction and disengaging for free rotation in the opposite direction,

responsive to pivoting of the pedal. A spring connects one end of the sprocket

chains and engages a pair of spaced chain pulleys for alternately maintaining

one set of the sprocket chains and connecting cables in tension responsive to

free rotation of the corresponding sprocket when the opposite sprocket is being

driven by the opposing sprocket chain and cable.

In another example, United States Patent N° 4,779,863 to Yang discusses

a running exercise bicycle is ridden by a user who alternately pedals two pedals

to drive two rotary wheels into unidirectional rotation via two sets of individual

mechanical drive devices to make the exercise bicycle move forward in a zigzag

or straight path. A clutch device can inter-connect the wheels for co-rotation so

that the bicycle can be driven on a straight path.

United States Patent N° 4,186,934 to Collings shows a Scooter vehicle

having a chassis, and a front wheel mounted on the center line of the chassis, a

rear wheel mounted on the chassis, and a steering column attached to the front

wheel. A pair of ratchet gears are connected one to each of the rear wheels. A

platform is rotatively mounted on the chassis. The platform has front and rear

foot portions mounted with an angle of less than 180° between them. First chain means connects the front of the platform for driving one of the ratchet drive

wheel gears and second chain means connects the rear of the platform for

driving the other of the ratchet drive wheel gears.

As represented by these devices, known mechanically driven, low center

of gravity vehicles are relatively complex, and rely on skilled vehicle operation for

their effectiveness. It can thus be seen that the need exists for a

human-powered, low center-of-gravity vehicle having features that ameliorate the

disadvantages of those used in known vehicles.

SUMMARY OF THE INVENTION

These and other objects are achieved by providing a wheeled,

human-powered pedal vehicle including at least one driven wheel. The vehicle

includes a frame, with a first drive mechanism secured to the frame. A second

drive mechanism is secured to the frame in driving engagement with the first

drive member. A drive transfer mechanism connects the second drive .

mechanism with the at least one driven wheel of the vehicle. A pair of drive

platforms are also provided. Each of the drive platforms is connected to both the

first drive mechanism and the second drive mechanism for synchronous driving

thereof. The respective drive platforms are of sufficient size to accommodate a

respective foot of a human driving the vehicle.

The first and second drive members can be provided as crank assemblies. A first sprocket can be secured to the first drive mechanism, and a second

sprocket can be secured to the second drive mechanism. A drive chain can

engage the first sprocket with the second sprocket.

In an embodiment, a third sprocket is secured to the second drive mechanism, with a drive gear secured to the driven wheel of the vehicle. A drive

chain engages the third sprocket with the drive gear.

First and second crank arms can be secured to opposite sides of the

second drive mechanism. First and second mounting brackets can be

respectively secured to the drive platforms, the first and second mounting

brackets having lateral and lower interior mounting surfaces adapted to receive

mounting extensions of the first and second crank arms. A space is provided

between the lateral interior mounting surfaces and the mounting extensions

when the mounting extensions are secured within the mounting brackets. The

space provided between the lateral interior mounting surfaces and the mounting

extensions can be approximately 0.25 inches, and cylindrical bushings,

preferably nylon bushings, can surround the mounting extensions.

The vehicle can be constructed as a two-wheeled vehicle, with the at least

one driven wheel including a rear wheel of the vehicle. The frame can be

constructed of tubular material such as tubular steel or composite material.

The features of the invention believed to be patentable are set forth with

particularity in the appended claims. The invention itself, however, both as to

organization and method of operation, together with further objects and advantages thereof, may be best understood by reference to the following

description taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side elevational view of a vehicle in accordance with

the principles of the present invention.

FIG. 2 is a schematic plan view of the vehicle of FIG. 1.

FIG. 3 is a schematic cross-sectional illustration of a vehicle taken

generally along lines Ill-Ill of FIG. 2.

FIG. 4 is a schematic cross-sectional illustration of a vehicle taken

generally along lines IV-IV of FIG. 2.

FIG. 5 is a schematic cross-sectional illustration of a vehicle taken

generally along lines V-V of FIG. 2.

FIG. 6 is a schematic cross-sectional illustration of a vehicle taken

generally along lines VI-VI of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

A vehicle 10 in accordance with the principles of the present invention is

shown in FIGS. 1 and 2. The vehicle 10 includes a frame 12, which can be

constructed of any suitable material, such as tubular steel, alloys, or composite

material. It has been found that steel tubing having a diameter of 1.0 inch

provides sufficient strength and rigidity. The vehicle 10 includes a front wheel 14, which is secured to the vehicle

10 via a steering assembly 16. The steering assembly 16 is constructed in a

conventional manner known to those familiar with bicycle construction, and

includes a fork 18, a head tube 20, and handlebars 22.

A drive assembly 24 is secured to the frame 12. The drive assembly 24

includes a first drive mechanism 26 secured to the frame 12 at a forwardmost

position. The first drive mechanism 26 can be provided as a crank assembly,

such as the crankset shown in FIG. 3. The first drive mechanism 26 includes a

first sprocket 28. The first drive mechanism 26 also has a first crank arm 30 with

a mounting extension 31 , and a second crank arm 32 with a mounting extension

33, secured to opposite sides of the first drive mechanism 26.

The drive assembly 24 also includes a second drive mechanism 34

secured to the frame 12 at a rearward position. The second drive mechanism 34

can be provided as a crank assembly, such as the crankset shown in FIG. 4. The

second drive mechanism 34 includes a second sprocket 36 and a third sprocket

38. The second drive mechanism 34 also has a first crank arm 40 with a

mounting extension 41 and a second crank arm 42 with a mounting extension

43, secured to opposite sides of the second drive mechanism 34.

The vehicle 10 also includes a rear driven wheel 44. The driven wheel 44

is secured to the frame 12 in a conventional manner via a rear fork 46. A drive

gear 48 is secured to the rear wheel 44, also in a conventional manner. As seen in FIG. 2, a first drive transfer mechanism 50 connects the first

sprocket 28 to the second sprocket 36. A second drive transfer mechanism 52

connects the second sprocket 36 to the drive gear 48.

A pair of drive platforms 54, 56 are also provided. Each of the drive

platforms 54, 56 is connected to both the first drive mechanism 26 and the

second drive mechanism 34 for synchronous driving thereof. The respective

drive platforms 54, 56 are of sufficient size to accommodate a respective foot of

a human driving the vehicle 10.

The drive platforms 54, 56 are secured to the drive mechanisms 26, 34

using mounting brackets. As illustrated in FIG. 5, a first mounting bracket 58

having lateral interior mounting surfaces 60, 62 and a lower interior mounting

surface 64 is adapted to receive the mounting extension 41 of the crank arm 40.

A space S is provided between the lateral interior mounting surfaces 60, 62 and

the mounting extension 41 when the mounting extension is secured within the

mounting bracket 58. The space S provided between the lateral interior mounting

surfaces and the mounting extensions can be between 0.0 and 0.5 inches per

side. It has been found that a gap of approximately 0.25 inches serves to

accommodate typical manufacturing tolerances. A cylindrical bushing 66

surrounds the mounting extension 41. The cylindrical bushing 66 can be

constructed of any suitable material, such as nylon. The space S permits some

movement of the mounting extension 41 within the bracket 58 during operation of

the vehicle 10, thus accommodating chain adjustments and variations in

manufacturing tolerances that might otherwise interfere with smooth and synchronous rotation of the drive mechanisms. The crank arm 42 is mounted to

the drive platform 56 using mounting bracket 67 and mounting extension 43 in a

similar manner.

As also illustrated in FIG. 5, a second mounting bracket 68 having lateral

interior mounting surfaces 70, 72 and a lower interior mounting surface 74 is

adapted to receive the mounting extension 31 of the crank arm 30. The lateral

interior mounting surfaces 70, 72 of the mounting bracket 68 are in direct and

secure engagement with the mounting extension 31. A cylindrical bushing 76

surrounds the mounting extension 31. The cylindrical bushing 76 can be

constructed of any suitable material, such as nylon. The crank arm 32 is mounted

to the drive platform 56 using mounting bracket 77 and mounting extension 33 in

a similar manner.

A hub assembly 78 is illustrated in FIG. 6. The hub assembly 78 includes

a cylindrical housing 80 enclosing an eccentric 82 surrounding an axle 84. The

eccentric 82 can be rotated by the insertion of a spanner into a pair of apertures

86. The axle 84 can thus be adjusted along the longitudinal axis of the vehicle 10

to achieve the desired chain tension and spacing. Once in a desired position, the

hub assembly 78 can be locked in place by a pair of set screws 88.

Those of skill in the art will appreciate that the present invention is

susceptible to variations in specific components and designs. For example, the

rim sizes of the wheels can range from 14 inches to 28 inches. The sprockets

can be provided as 32 tooth idlers and 48 tooth drives, with the rear drive gear

being a 16 tooth drive. The rear wheel may be provided with a multi-speed hub, such as a SUGINO XD. The crank length can vary from 4.5 inches to 7.5 inches,

and the vehicle wheelbase, contemplated at 43.0 inches, can vary from 35.0

inches to 48.0 inches. Ground clearance can vary from 7.0 inches to 8.0 inches,

with approximately 3.0 inches of pedal clearance. The drive mechanisms can be

mounted on 9.0 inch centers, and can range from 7.5 inches to 10.0 inches.

The features of the invention believed to be patentable are set forth with

particularity in the appended claims. The invention itself, however, both as to

organization and method of operation, together with further objects and

advantages thereof, may be best understood by reference to the following

description taken in conjunction with the accompanying drawings.

Claims

CLAIMSWhat is claimed is:

1. A wheeled, human-powered pedal vehicle including at least one

driven wheel, the vehicle comprising the following:

a frame;

a first drive mechanism secured to the frame;

a second drive mechanism secured to the frame and in driving

engagement with the first drive member;

a drive transfer mechanism connecting the second drive mechanism with

the at least one driven wheel of the vehicle; and

a pair of drive platforms, each of the drive platforms being connected to

both the first drive mechanism and the second drive mechanism for synchronous

driving thereof, each of the drive platforms being of sufficient size to

accommodate a respective foot of a human driving the vehicle.

2. A pedal vehicle in accordance with claim 1 , wherein the first and

second drive members comprise crank assemblies.

3. A pedal vehicle in accordance with claim 2, further comprising the

following:

a first sprocket secured to the first drive mechanism;

a second sprocket secured to the second drive mechanism; and a drive chain engaging the first sprocket with the second sprocket.

4. A pedal vehicle in accordance with claim 3, further comprising the

following:

a third sprocket secured to the second drive mechanism;

a drive gear secured to the driven wheel of the vehicle; and

a drive chain engaging the third sprocket with the drive gear.

5. A pedal vehicle in accordance with claim 2, further comprising the

following:

first and second crank arms secured to opposite sides of the second drive

mechanism; and

first and second mounting brackets respectively secured to the drive

platforms, the first and second mounting brackets having lateral and lower

interior mounting surfaces adapted to receive mounting extensions of the first

and second crank arms;

whereby a space is provided between the lateral interior mounting

surfaces and the mounting extensions, when secured the mounting extensions

are secured within the mounting brackets.

6. A pedal vehicle in accordance with claim 5, wherein the space is

provided between the lateral interior mounting surfaces and the mounting

extensions is approximately 0.25 inches.

7. A pedal vehicle in accordance with claim 5, further comprising a

cylindrical bushing surrounding the mounting extensions.

8. A pedal vehicle in accordance with claim 7, wherein the cylindrical

bushing comprises a nylon bushing.

9. A pedal vehicle in accordance with claim 1 , wherein the vehicle is a

two-wheeled vehicle, and the at least one driven wheel comprises a rear wheel of

the vehicle

10. A pedal vehicle accordance with claim 1 , wherein the frame is

constructed of tubular material

11. A pedal vehicle accordance with claim 10, wherein the frame is

constructed of tubular steel.

11. A pedal vehicle accordance with claim 10, wherein the frame is

constructed of composite material.

13. A two-wheeled, human-powered pedal vehicle including a front

wheel adapted to steer the vehicle and a rear wheel adapted to drive the vehicle,

the vehicle comprising the following:

a frame;

a crankset secured to the frame, the first crankset having a first sprocket;

a second crankset secured to the frame, the second crankset having a

second sprocket and a third sprocket secured on opposite sides of the frame;

a drive gear secured to the rear wheel of the vehicle;

a first chain connecting the first sprocket to the second sprocket;

a second chain connecting the third sprocket to the drive gear; and

a pair of drive platforms, each of the drive platforms being connected to

both the first crankset and the second crankset for synchronous driving thereof,

each of the drive platforms being of sufficient size to accommodate a respective

foot of a human driving the vehicle.

14. A pedal vehicle in accordance with claim 13, further comprising the

following:

first and second crank arms secured to opposite sides of the second

crankset; and

first and second mounting brackets respectively secured to the drive

platforms, the first and second mounting brackets having lateral and lower

interior mounting surfaces adapted to receive mounting extensions of the first

and second crank arms;

whereby a space is provided between the lateral interior mounting

surfaces and the mounting extensions, when secured the mounting extensions

are secured within the mounting brackets.

15. A pedal vehicle in accordance with claim 14, wherein the space is

provided between the lateral interior mounting surfaces and the mounting

extensions is approximately 0.25 inches.

16. A pedal vehicle in accordance with claim 14, further comprising a

cylindrical bushing surrounding the mounting extensions.

17. A pedal vehicle in accordance with claim 16, wherein the cylindrical

bushing comprises a nylon bushing.

18. A pedal vehicle in accordance with claim 13, further comprising the

following:

third and fourth crank arms secured to opposite sides of the first crankset;

and

third and fourth mounting brackets respectively secured to the drive

platforms, the third and fourth mounting brackets having lateral and lower interior

mounting surfaces adapted to receive mounting extensions of the third and fourth

crank arms;

whereby the lateral interior mounting surfaces of the third and fourth

mounting brackets are in direct and secure engagement with the mounting

extensions of the third and fourth crank arms.

19. A pedal vehicle accordance with claim 13, wherein the frame is

constructed of tubular material

20. A pedal vehicle accordance with claim 19, wherein the frame is

constructed of tubular steel.