Chainless drive mechanism

A chainless drive mechanism for transferring power from the pedals to the rear wheel of a bicycle. The chainless drive mechanism has a pedal-driven drive mechanism, a rear drive mechanism for rotating the rear wheel of a bicycle, and a drive shaft being extended between the drive mechanisms. Each of the drive mechanisms has an annular inboard casing, an annular outboard casing, an annular gear wheel and a bevel gear. The annular outboard casings are coupled to the inboard casings. The annular gear wheels are rotatably positioned between the inboard and outboard casings and have a plurality of concentrically geared rings on a side thereof facing the rearward inboard casing. The bevel gears are rotatably disposed between the rearward gear wheels and the rearward inboard casings. The bevel gears engage the geared rings of the gear wheels. The bevel gears engage toothed ends of the drive shaft.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to bicycle drive mechanisms and more 
particularly pertains to a new chainless drive mechanism for transferring 
power from the pedals to the rear wheel of a bicycle. 
2. Description of the Prior Art 
The use of bicycle drive mechanisms is known in the prior art. More 
specifically, bicycle drive mechanisms heretofore devised and utilized are 
known to consist basically of familiar, expected and obvious structural 
configurations, notwithstanding the myriad of designs encompassed by the 
crowded prior art which have been developed for the fulfillment of 
countless objectives and requirements. 
Known prior art bicycle drive mechanisms include U.S. Pat. No. 5,299,819; 
U.S. Pat. No. 4,005,611; U.S. Pat. No. 4,831,889; U.S. Pat. No. 5,316,327; 
U.S. Pat. No. 5,482,306; and U.S. Pat. No. 2,181,424. 
While these devices fulfill their respective, particular objectives and 
requirements, the aforementioned patents do not disclose a new chainless 
drive mechanism. The inventive device includes a pedal-driven drive 
mechanism, a rear drive mechanism for rotating the rear wheel of a 
bicycle, and a drive shaft being extended between the drive mechanisms. 
Each of the drive mechanisms has an annular inboard casing, an annular 
outboard casing, an annular gear wheel and a bevel gear. The annular 
inboard casings are adapted for fixed coupling to a portion of a frame of 
a bicycle. The annular outboard casings are coupled to the inboard 
casings. The annular gear wheels are rotatably positioned between the 
inboard and outboard casings and have a plurality of concentrically geared 
rings on a side thereof facing the rearward inboard casing. The bevel 
gears are rotatably disposed between the rearward gear wheels and the 
rearward inboard casings. The bevel gears engage the geared rings of the 
gear wheels. The bevel gears engage toothed ends of the drive shaft. 
In these respects, the chainless drive mechanism according to the present 
invention substantially departs from the conventional concepts and designs 
of the prior art, and in so doing provides an apparatus primarily 
developed for the purpose of transferring power from the pedals to the 
rear wheel of a bicycle. 
SUMMARY OF THE INVENTION 
In view of the foregoing disadvantages inherent in the known types of 
bicycle drive mechanisms now present in the prior art, the present 
invention provides a new chainless drive mechanism construction wherein 
the same can be utilized for transferring power from the pedals to the 
rear wheel of a bicycle. 
The general purpose of the present invention, which will be described 
subsequently in greater detail, is to provide a new chainless drive 
mechanism apparatus and method which has many of the advantages of the 
bicycle drive mechanisms mentioned heretofore and many novel features that 
result in a new chainless drive mechanism which is not anticipated, 
rendered obvious, suggested, or even implied by any of the prior art 
bicycle drive mechanisms, either alone or in any combination thereof. 
To attain this, the present invention generally comprises a pedal-driven 
drive mechanism, a rear drive mechanism for rotating the rear wheel of a 
bicycle, and a drive shaft being extended between the drive mechanisms. 
Each of the drive mechanisms has an annular inboard casing, an annular 
outboard casing, an annular gear wheel and a bevel gear. The annular 
inboard casings are adapted for fixed coupling to a portion of a frame of 
a bicycle. The annular outboard casings are coupled to the inboard 
casings. The annular gear wheels are rotatably positioned between the 
inboard and outboard casings and have a plurality of concentrically geared 
rings on a side thereof facing the rearward inboard casing. The bevel 
gears are rotatably disposed between the rearward gear wheels and the 
rearward inboard casings. The bevel gears engage the geared rings of the 
gear wheels. The bevel gears engage toothed ends of the drive shaft. 
There has thus been outlined, rather broadly, the more important features 
of the invention in order that the detailed description thereof that 
follows may be better understood, and in order that the present 
contribution to the art may be better appreciated. There are additional 
features of the invention that will be described hereinafter and which 
will form the subject matter of the claims appended hereto. 
In this respect, before explaining at least one embodiment of the invention 
in detail, it is to be understood that the invention is not limited in its 
application to the details of construction and to the arrangements of the 
components set forth in the following description or illustrated in the 
drawings. The invention is capable of other embodiments and of being 
practiced and carried out in various ways. Also, it is to be understood 
that the phraseology and terminology employed herein are for the purpose 
of description and should not be regarded as limiting. 
As such, those skilled in the art will appreciate that the conception, upon 
which this disclosure is based, may readily be utilized as a basis for the 
designing of other structures, methods and systems for carrying out the 
several purposes of the present invention. It is important, therefore, 
that the claims be regarded as including such equivalent constructions 
insofar as they do not depart from the spirit and scope of the present 
invention. 
Further, the purpose of the foregoing abstract is to enable the U.S. Patent 
and Trademark Office and the public generally, and especially the 
scientists, engineers and practitioners in the art who are not familiar 
with patent or legal terms or phraseology, to determine quickly from a 
cursory inspection the nature and essence of the technical disclosure of 
the application. The abstract is neither intended to define the invention 
of the application, which is measured by the claims, nor is it intended to 
be limiting as to the scope of the invention in any way. 
It is therefore an object of the present invention to provide a new 
chainless drive mechanism apparatus and method which has many of the 
advantages of the bicycle drive mechanisms mentioned heretofore and many 
novel features that result in a new chainless drive mechanism which is not 
anticipated, rendered obvious, suggested, or even implied by any of the 
prior art bicycle drive mechanisms, either alone or in any combination 
thereof. 
It is another object of the present invention to provide a new chainless 
drive mechanism which may be easily and efficiently manufactured and 
marketed. 
It is a further object of the present invention to provide a new chainless 
drive mechanism which is of a durable and reliable construction. 
An even further object of the present invention is to provide a new 
chainless drive mechanism which is susceptible of a low cost of 
manufacture with regard to both materials and labor, and which accordingly 
is then susceptible of low prices of sale to the consuming public, thereby 
making such chainless drive mechanism economically available to the buying 
public. 
Still yet another object of the present invention is to provide a new 
chainless drive mechanism which provides in the apparatuses and methods of 
the prior art some of the advantages thereof, while simultaneously 
overcoming some of the disadvantages normally associated therewith. 
Still another object of the present invention is to provide a new chainless 
drive mechanism for transferring power from the pedals to the rear wheel 
of a bicycle. 
Yet another object of the present invention is to provide a new chainless 
drive mechanism which includes a pedal-driven drive mechanism, a rear 
drive mechanism for rotating the rear wheel of a bicycle, and a drive 
shaft being extended between the drive mechanisms. Each of the drive 
mechanisms has an annular inboard casing, an annular outboard casing, an 
annular gear wheel and a bevel gear. The annular inboard casings are 
adapted for fixed coupling to a portion of a frame of a bicycle. The 
annular outboard casings are coupled to the inboard casings. The annular 
gear wheels are rotatably positioned between the inboard and outboard 
casings and have a plurality of concentrically geared rings on a side 
thereof facing the rearward inboard casing. The bevel gears are rotatably 
disposed between the rearward gear wheels and the rearward inboard 
casings. The bevel gears engage the geared rings of the gear wheels. The 
bevel gears engage toothed ends of the drive shaft. 
Still yet another object of the present invention is to provide a new 
chainless drive mechanism that is cleaner and more reliable than 
chain-driven bicycles in that there is no oily chain that can slip off of 
the gears. 
Even still another object of the present invention is to provide a new 
chainless drive mechanism that permits selection of variable gearing 
ratios. 
These together with other objects of the invention, along with the various 
features of novelty which characterize the invention, are pointed out with 
particularity in the claims annexed to and forming a part of this 
disclosure. For a better understanding of the invention, its operating 
advantages and the specific objects attained by its uses, reference should 
be made to the accompanying drawings and descriptive matter in which there 
are illustrated preferred embodiments of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference now to the drawings, and in particular to FIGS. 1 through 5 
thereof, a new chainless drive mechanism embodying the principles and 
concepts of the present invention and generally designated by the 
reference numeral 10 will be described. 
As best illustrated in FIGS. 1 through 5, the chainless drive mechanism 10 
comprises an annular forward inboard casing 20 that is adapted for fixed 
coupling to a central portion of a frame 5 of a bicycle 1. The forward 
inboard casing 20 has an aperture 80 that extends through its center. An 
annular forward outboard casing 23 is coupled to the forward inboard 
casing 20, such as by a plurality of fasteners extending through holes 
positioned towards an outer perimeter of the forward outboard casing 23. 
The forward outboard casing 23 also has an aperture 81 that extends 
through its center. 
An annular forward gear wheel 25 is rotatably positioned between the 
forward inboard casing 20 and the forward outboard casing 23. The forward 
gear wheel 25 has a plurality of concentrically geared rings 26 on a side 
thereof facing the forward inboard casing 20 and, preferably, a plurality 
of ridges 27 that extend from the forward gear wheel 25. Each of the 
ridges 27 is positioned between a pair of the geared rings 26. Preferably, 
the forward gear wheel 25 has between about three and ten geared rings 26. 
Ideally, the forward gear wheel 25 has five geared rings 26. The forward 
gear wheel 25 has a toothed aperture 82 extending through it. 
A forward bevel gear 28 is rotatably disposed between the forward gear 
wheel 25 and the forward inboard casing 20 and engages the geared rings 26 
of the forward gear wheel 25. In the preferred embodiment, the forward 
bevel gear 28 has about 16 teeth extending from its outer perimeter. 
Preferably, the forward bevel gear 28 has a toothed aperture extending 
through it. 
Preferably, a first biasing means 84 applies pressure to the geared wheel 
for pushing the forward gear wheel 25 against the forward bevel gear 28 so 
that the teeth of the gears don't slip out of mesh with each other. The 
first biasing means is positioned between the forward gear wheel 25 and 
the forward outboard casing 23. Ideally, the first biasing means 84 
comprising a tri-legged spring 30, as shown in FIG. 1. 
Preferably, a first forward bearing 31 is positioned between the forward 
gear wheel 25 and the forward inboard casing 20. A second forward bearing 
32 is positioned between the tri-legged spring 30 and the forward outboard 
casing 23. 
A pedal axle 33 has a geared end region 85 and extends through the 
apertures of the casings. The geared end region 85 engages the toothed 
aperture 82 of the forward gear wheel 25. The pedal axle 33 is operatively 
coupled to a pair of pedals 2. 
Preferably, the forward inboard casing 20 has a slot 21 extending through 
it and an arcuate recess 22 that extends inwardly from the outer 
perimeter. 
A drive shaft means 50 is rotatably coupled to the forward inboard casing 
20 and has a toothed portion 54 that is positioned towards an end of it. 
The forward bevel gear 28 engages the toothed portion 54. The drive shaft 
means 50 is adapted for engaging a rear drive means 59 for rotating a rear 
wheel 3 of the bicycle 1. 
Preferably, the drive shaft means 50 comprises a forward drive shaft 51 
that is rotatably coupled to the forward inboard casing 20 and has first 
and second ends 52,53. The first end 52 of the forward drive shaft 51 has 
a toothed portion 54. The first end 52 of the forward drive shaft 51 is 
slidably disposed in the toothed aperture 83 of the forward bevel gear 28 
such that the forward bevel gear 28 is positionable along the toothed 
portion 54 between the first and second ends 52,53 of the forward drive 
shaft 51. 
Also preferably, a forward bevel gear actuator assembly 40 adjustably 
positions the forward bevel gear 28 between the aperture 82 and an outer 
perimeter of the forward gear wheel 25 such that the bevel gear engages 
different geared rings 26 as it moves between the aperture and the outer 
perimeter of the forward gear wheel 25 thereby changing the gearing ratio. 
The forward bevel gear 28 actuator has a gear adjusting member 41 and an 
outer coupling member 42. The gear adjusting member 41 is rotatably 
coupled to the forward bevel gear 28 and is slidably coupled to the 
forward inboard casing 20. The outer coupling member 42 is positioned 
adjacent an outer surface of the forward inboard casing 20 and is coupled 
to the gear adjusting member 41 such as by a fastener that extends through 
the slot 21 in the forward inboard casing 20. 
Ideally, the forward drive shaft 51 has a forward tension spring 43 
extending around its first end 52. The forward tension spring 43 biases 
the gear adjusting member 41 towards the aperture of the forward inboard 
casing 20. Ideally, a forward cable 44 extends between a gearshift handle 
(not shown) on the handlebars of the bicycle 1 and the forward bevel gear 
actuator assembly 40 to permit remote positioning of the forward bevel 
gear 28. 
Preferably, a rearward drive shaft 55 is coupled to the forward drive shaft 
51. A second end 86 of the rearward drive shaft 55 is coupled to the 
forward drive shaft 51 by a universal joint 56. Ideally, as seen in FIGS. 
1 and 5, a support assembly 35 accommodates the drive shafts above a cross 
member 4 of the bicycle 1 that extends between the rear wheel 3 and the 
pedal axle 33, which is especially necessary if the cross member 4 would 
interfere with the path of the drive shafts between the forward and 
rearward inboard casings 60. The support assembly 35 has a pair of support 
bars 36 that extends from the cross member 4 of the bicycle 1. A pair of 
cylindrical collars 37 is coupled to the support bars 36. A pair of 
bushings 38 are inserted in the cylindrical collars 37 to reduce friction 
and create a replaceable point of wear. Ideally, the bushings 38 are made 
of nylon for reduced weight and inexpensive replacement. The drive shafts 
extend through the bushings 38 such that the universal joint 56 is 
positioned between the cylindrical collars 37. 
In the preferred embodiment, an annular rearward inboard casing 60 is 
adapted for fixed coupling to a rear portion of the frame 5 of the bicycle 
1. An annular rearward outboard casing 63 is coupled to the rearward 
inboard casing 60 such as by a plurality of fasteners extending through 
holes positioned towards an outer perimeter of the rearward outboard 
casing 63. The rearward inboard and outboard casings 60,63 each have an 
aperture 87,88 that extends through its center. 
An annular rearward gear wheel 65 is rotatably positioned between the 
rearward inboard casing 60 and the rearward outboard casing 63. The 
rearward gear wheel 65 has a plurality of concentrically geared rings 66 
on a side thereof facing the rearward inboard casing 60. Preferably, a 
plurality of ridges 67 extend from the rearward gear wheel 65. Ideally, 
each of the ridges 67 is positioned between a pair of the geared rings 66. 
Also ideally, the rearward gear wheel 65 has between about two and ten 
geared rings 66. Most ideally, three geared rings 66 are provided. The 
rearward gear wheel 65 has a toothed aperture 89 extending through its 
center. The rearward gear wheel 65 has a smaller outer diameter than the 
forward gear wheel 25. 
A rearward bevel gear 68 is rotatably disposed between the rearward gear 
wheel 65 and the rearward inboard casing 60. Preferably, the rearward 
bevel gear 68 has a plurality of teeth 90, ideally about 16 teeth, that 
extend from its outer perimeter. The teeth 90 of the rearward bevel gear 
68 engage the geared rings 66 of the rearward gear wheel 65. Ideally, a 
first end 91 of the rearward drive shaft 55 has a toothed portion 92 that 
is slidably disposed in the toothed aperture 89 of the rearward bevel gear 
68 such that the rearward bevel gear 68 is positionable along the toothed 
portion 92 of the rearward drive shaft 55 between opposed ends thereof. 
Preferably, a second biasing means 93 applies pressure to the rearward 
geared wheel 65 for pushing the rearward gear wheel 65 against the 
rearward bevel gear 68 so that the gears don't slip. The second biasing 
means 93 is positioned between the rearward geared wheel 65 and the 
rearward outboard casing 63. Ideally, the second biasing means comprising 
a tri-legged spring 70. 
Ideally, a first rearward bearing 71 is positioned between the rearward 
gear wheel 65 and the rearward inboard casing 60. A second rearward 
bearing (not shown) is positioned between the tri-legged spring 70 and the 
rearward outboard casing 63. A wheel axle 73 has a geared end region 94 
and extends through the apertures of the rear casings. The geared end 
region 94 engages the toothed aperture 89 of the rearward gear wheel 65. 
The wheel axle 73 is adapted for fixed coupling of a wheel to opposite 
ends thereof. 
Preferably, the rearward inboard casing 60 has a slot 61 extending 
therethrough and an arcuate recess 62 that extends inwardly from the outer 
perimeter. 
Also preferably, a rearward bevel gear actuator assembly 75 adjustably 
positions the rearward bevel gear 68 between the aperture and an outer 
perimeter of the rearward gear wheel 65 such that the bevel gear engages 
different geared rings 66 as it moves between the aperture 89 and the 
outer perimeter of the rearward gear wheel 65 thereby changing the gearing 
ratio. The rearward bevel gear 68 actuator has a gear adjusting member 76 
and an outer coupling member 77. The gear adjusting member 76 is rotatably 
coupled to the rearward bevel gear 68 and is slidably coupled to the 
rearward inboard casing 60. The outer coupling member 77 is positioned 
adjacent an outer surface of the rearward inboard casing 60 and is coupled 
to the gear adjusting member 76 such as by a fastener that extends through 
the slot 61 in the rearward inboard casing 60. 
Ideally, the rearward drive shaft 55 has a rearward tension spring 78 
extending around its first end. The rearward tension spring 78 biases the 
gear adjusting member 76 towards the aperture 87 of the rearward inboard 
casing 60. Also ideally, a rearward cable 79 extends between a gearshift 
handle (not shown) on the handlebars of the bicycle 1 and the forward 
bevel gear actuator assembly 75 to permit remote positioning of the 
rearward bevel gear 68. 
In use, the forward gear wheel 25 is rotated by the pedal axle 33. The 
forward gear wheel 25 rotates the forward bevel gear 28, which in turn 
rotates the forward and rearward drive shafts 51,55. The rearward drive 
shaft 55 rotates the rearward bevel gear 68, which in turn rotates the 
rearward gear wheel 65. The rearward gear wheel 65 rotates the rear wheel 
3 of the bicycle 1. The forward bevel gear 28 actuator assembly 40 permits 
sliding of the bevel gear between the aperture 82 and the outer perimeter 
of the forward gear wheel 25 to change the gearing ratio. The forward 
bevel gear 28 is held on a particular geared ring 26 by the ridges 27. The 
rearward bevel gear actuator assembly 75 functions in the same way. 
As to a further discussion of the manner of usage and operation of the 
present invention, the same should be apparent from the above description. 
Accordingly, no further discussion relating to the manner of usage and 
operation will be provided. 
With respect to the above description then, it is to be realized that the 
optimum dimensional relationships for the parts of the invention, to 
include variations in size, materials, shape, form, function and manner of 
operation, assembly and use, are deemed readily apparent and obvious to 
one skilled in the art, and all equivalent relationships to those 
illustrated in the drawings and described in the specification are 
intended to be encompassed by the present invention. 
Therefore, the foregoing is considered as illustrative only of the 
principles of the invention. Further, since numerous modifications and 
changes will readily occur to those skilled in the art, it is not desired 
to limit the invention to the exact construction and operation shown and 
described, and accordingly, all suitable modifications and equivalents may 
be resorted to, falling within the scope of the invention.