Semi-recumbent bicycle and conversion kit

The present invention relates to semi-recumbent bicyles. A regular upright bicyle is transformed in to a semi-recumbent style bicycle with a minimum number of new parts. An extension appliance, a seat assembly, an extended-length brake and derailleur cables, an extended-length chain, and an extended-length handlebar are used to completely convert a standard bicycle to a semi-recumbent bicyle. The extention appliance connects to the head tube of the standard bicycle. The handle bars and forks of the standard bicyle are relocated to a forward position in the extention applicance. The crank and front sprocket are relocated to a new crank case in the extension appliance. An extended-length chain is used to connect the front sprocket in the new position to the rear sprocket. Extended-length brake and derailleur cables are added if necessary. A new set assebly may be added. This new set assembly includes a back rest portion. An extended-length handlebar may be added if necessary.

BACKGROUND OF THE INVENTION 
The present invention relates generally to bicycles. More specifically, the 
present invention relates to a semi-recumbent bicycle created using safety 
bicycle parts and a kit for creating a semi-recumbent bicycle in 
combination with safety bicycle parts. 
A bicycle is a two-wheeled vehicle which is self-propelled by its rider. 
Generally considered one of the most energy-efficient forms of 
transportation, the bicycle is used throughout the world, and particularly 
in developing countries--most notably China, where some 300 million 
bicycles are on the road. 
The most traditional form of a bicycle is the "safety bicycle," which is 
generally considered to have been invented by H. J. Lawson in 1879. The 
safety bicycle includes a chain and sprocket driving a rear wheel, and 
generally has two wheels of equal size. Pedals to propel the safety 
bicycle are positioned below the seat of the rider, such that rider shifts 
the rider's weight from one foot to the other during forward propulsion. 
The safety bicycle is steered by handlebars which are attached to and 
positioned above the front wheel through connection by a head tube. The 
rider's torso and the handlebars are both positioned above the front 
wheel. Improvements to the safety bicycle include the use of pneumatic 
tires in the 1880s, three-speed hub gears in the 1890s, and a derailleur 
system in 1899. The derailleur system is a sophisticated gearshift that 
allows the bicycle chain to be shifted among sprockets of different sizes 
on front and rear hubs. 
In general, a longer wheelbase and a lower center of gravity provide 
greater stability. A relatively new design, the recumbent bicycle, is 
generally longer than a conventional safety bicycle, positions the rider 
in a lower position to the ground, and is characterized by the rider 
sitting slightly reclined in a high-backed seat. The recumbent bicycle 
provides increased comfort, greater pedal efficiency, and a lower center 
of gravity when compared with the conventional safety bicycle. 
The Recumbent Bicyclist News, RCN, characterizes single rider recumbent 
bicycles into three types, namely a Short Wheelbase (SWB), a Compact Long 
Wheelbase (CLWB), and a Long Wheelbase (LWB). The SWB recumbent bicycles 
are characterized by being between 33"-47" in length, with the pedal crank 
being placed ahead of the head tube, such that the front wheel is tucked 
underneath or just ahead of the rider's knees. The CLWB recumbent bicycle 
is between 47"-60", provides the front wheel ahead of the pedal crank, and 
maintains a relatively short wheelbase. To provide for this relatively 
short wheelbase, the CLWB recumbent bicycle seat is generally positioned 
higher on the bicycle above the pedal crank. The CLWB recumbent bicycle 
may have the rear wheel being 20" with the front wheel being 16". The CLWB 
recumbent bicycle may also have a dual 20" wheel configuration. The CLWB 
recumbent bicycle offers a higher seat and lower pedal crank, which makes 
provides for easier riding, especially for the novice. The CLWB recumbent 
bicycle also offers higher rider placement for better visibility. The LWB 
recumbent bicycle is 60"-71+" and is characterized by the front wheel 
being placed ahead of the pedal crank. The rear wheel is generally 26" 
while the front wheel is usually 20". Due to the longer wheelbase, the LWB 
recumbent bicycle generally has a lower center of gravity, but sacrifices 
maneuverability. 
SUMMARY OF THE INVENTION 
The present invention relates to semi-recumbent bicyles. A regular upright 
bicyle is transformed in to a semi-recumbent style bicycle with a minimum 
number of new parts. An extension appliance, a seat assembly, an 
extended-length brake and derailleur cables, an extended-length chain, and 
an extended-length handlebar are used to convert a safety bicycle into a 
semi-recumbent bicyle. The extention appliance connects to the head tube 
of the safety bicycle. The handle bars and forks of the safety bicyle are 
relocated to a forward position in the extention applicance. The crank and 
front sprocket are relocated to a new crank case in the extension 
appliance. An extended-length chain is used to connect the front sprocket 
in the new position to the rear sprocket. Extended-length brake and 
derailleur cables are added, if necessary. A new horizontally and 
vertically adjustable seat assembly may also be added. This new seat 
assembly includes a back rest portion. An extended-length handlebar may 
also be added if necessary.

DESCRIPTION OF PREFERRED EMBODIMENTS 
The converted bike 10 of the present invention is shown by FIG. 1. The 
converted bike 10 includes several safety bicycle parts (shown by dashed 
lines). The word "standard is used" to distinguish between a safety 
bicycle part and a semi-recumbent or recumbent bicycle part. The standard 
bicycle frame 12, the standard rear wheel 14, the standard rear sprocket 
16, the standard crank assembly 18, the standard front forks 20, and the 
standard front wheel 22 from a safety bicycle are all retained. The 
conversion kit for the safety bicycle includes an extension appliance 30, 
extended length handle bars 32, an extended length chain 34, and a seat 
assembly 36. These new parts are shown by solid lines. The standard 
bicycle frame 12 includes a standard head tube 13, a standard crank case 
15, a standard rear sprocket 16 and a standard seat tube 17. 
FIG. 2 shows a side view detail of the extension appliance 30. The 
extension appliance 30 includes a connection means 33 (for connecting the 
extension appliance 30 to the standard head tube 13), a forwardly disposed 
head tube 42, and a forwardly disposed crank case 44. The extension 
appliance 30 may optionally include a front derailleur stalk (not shown). 
The connection means 33 includes a support plate 50, "U" shaped bolts 52, 
and fitted spacers 54. The support plate 50 is mounted to the extension 
appliance 30 and mounted to the support plate 50 are the fitted spacers 
54. These spacers allow the standard head tube 42 which generally has a 
circular outer circumference to mount securely to the support plate 50. 
The standard head tube 42 is held securely to the fitted spacers 54 by "U" 
shaped bolts 52. 
FIG. 8 shows an alternative embodiment in which connection means 84 may be 
used. The alternative connection means 84 includes a U-shaped support 
plate 86, a head tube stop 88, and a U-shaped clamp 90. The standard head 
tube 13 is pressed against the support plate 86 by the clamp 90. The 
support plate 86 and the clamp 90 both have holes which line up. They can 
be bolted together to hold the standard head tube 13 in place. The bottom 
of the standard head tube 13 rests on the head tube stop 88. 
In FIGS. 5, 6, 7(A) and 7(B), the seat assembly 36 including its components 
are shown. The seat assembly 36 includes a seat frame 60, seat cushions 
62, and a seat post 64. The seat frame 60 is shaped to support a human 
body in a seated position or a reclined seated position. In other words, 
back support is provided. The seat post 64 fits into the standard seat 
tube 17 replacing the standard seat post (not shown). The seat post 64 
includes a means for connecting to the seat frame 60. The seat cushions 62 
mount to the seat frame 60. Together, these components replace the 
standard seat (not shown). 
To install the conversion kit, and with reference to FIG. 1, the standard 
handle bars (not shown) and front forks 20 are removed from the standard 
head tube 13. The extension appliance 30 is mounted to the standard head 
tube 13 using the connection means 33. The extended length handle bars 32 
are installed along with the front forks 20 in the forwardly disposed head 
tube 42. The standard seat (not shown) is removed from the standard seat 
tube 17 and the seat assembly 36 is installed by inserting the seat post 
64 into the standard seat tube 17. The standard crank-assembly 18 is 
removed from the standard crank case 15 and then installed in the 
forwardly disposed crank case 44. The extended length chain 34 is now 
installed to connect the forwardly disposed crank case 44 to the rear 
sprocket 16. The standard chain (not shown), standard seat (not shown), 
and standard handle bars (not shown) can all be discarded. An extended 
length brake cable 70 can be connected between a standard brake handle 74 
and standard brake assemblies 72 for the front wheel 22 and/or the rear 
wheel 14.