Title of Invention

"AN IMPROVED POWER TRANSMISSION MECHANISM FOR A CYCLE RICKSHAW"

Abstract Three wheeled human power driven vehicles - popularly known as cycle rickshaws are used for transporting goods, passengers and children in their different versions. The aim of the presently developed device is to reduce the human effort required in driving and save energy of the driver. In the conventional design of the rickshaw the rear shaft always has to rotate along with one of the rear wheels- adding to the rolling resistance for the vehicle movement. The rear shaft has to transmit the driving torque, transfer vertical load of the chassis & body coming on it via bearing pads to the rear wheels and take care of any side thrust acting on the wheels. Continuously rotating rear shaft on a moving vehicle in itself absorbs a definite amount of energy. In the new developed " Cycle rickshaw with intermediate shaft, the cranking power of the rickshaw puller comes first from crank wheel to an intermediate shaft- placed between the crank wheel & rear shaft. The intermediate shaft gets supported through bearings attached to the frame. A " Cycle rickshaw with intermediate shaft" allows the transfer of driving torque directly to one of the rear wheels supported on bearings. Thus the introduction of an intermediate shaft reduces the driving effort requirement - as both rear wheels are now on bearings and no other component - other than wheels - rotate - in case the driver stops pedalling. A " Cycle rickshaw with intermediate shaft " allows the three wheels of a tricycle to rotate freely on bearings without any attached shaft rotating with the wheels. New device results in significant reduction in rolling resistance of the vehicle. That ultimately results in reduced effort requirement in pedalling the rickshaw hence saving in human energy and comfort to the rickshaw puller. The driver can also now carry more loads for the equivalent effort addition as compared to the earlier device. The new developed rickshaw is successfully running on Allahabad roads since February 2000.
Full Text Field of Invention: Cycle rickshaw - new type.
Background of Invention: Three wheeled human power driven vehicles - popularly known as cycle rickshaws are used for transporting goods, passengers and children in their different versions. The aim of the presently developed device is to reduce the human effort required in driving and save energy of the driver.
Design of a conventional rickshaw (Prior - art):
The power transmission system being used in a rickshaw brings pedal power from the crank wheel to the rear shaft. One of the two rear wheels of a tricycle rickshaw remains permanently fixed to the rear shaft. The required thrust to move ahead gets transferred to rickshaw frame through the two attached supports in form of leaf springs - from the rear shaft. When the rickshaw puller drives the crank wheel -through pedalling - the chain makes the connected rear shaft rotate and along with the shaft - the firmly attached wheel also rotates. Out of the two-rear wheels- one wheel remains fixed permanently to the rear shaft and the other rear wheel remains supported on the rear shaft through some form of bearing. The weight of the whole chassis frame along with the body gets transferred to the two rear wheels through two bearing pads supported on the rear shaft. The bearing pads can either be a journal bearing or an antifriction bearing. Whenever rickshaw moves - the rear shaft has to rotate along with the firmly connected rear wheel. The rotating rear shaft always gets resisting frictional force from the loaded bearing pads.
Figure 1 illustrates the arrangement of a conventional rickshaw. Crank 1 transfer's power through chain 6and free wheel 5 to rear shaft 3. When the driver stops pedalling- the rear shaft 3 keeps on rotating and the friction at the bearing pads 4 adds to the resistance during movement. Further, out of the two-rear wheels- only one wheel remains supported on the bearing while the other remains fixed to the rear shaft. The rolling resistance of the fixed wheel remains more as compared to the other wheel resting on bearings. Hence in the conventional design following weak points exist:
i) The rear shaft always has to rotate along with one of the rear wheels-adding to the rolling resistance for the vehicle movement.
ii) One of the rear wheels - permanently fixed to the rear shaft is not supported on bearings - hence causing more friction as compared to the wheel hub supported on bearings.
iii) The rear shaft has to accomplish the following duties
a) transfer driving torque to the wheel.
b) transfer vertical load of the chassis & body coming on it via bearing
pads to the rear wheels and finally to the ground.
c) take care of any side thrust acting on the wheels and transfer the same
to the chassis such that the overall stability of the vehicle gets
maintained.
All the above actions demand an over designed heavy weight rear shaft, iv) Because of the rotating rear shaft on a moving vehicle- the bearing pads ( component 4 in figure 1) always introduces a certain amount of frictional force- trying to stop the shaft. Continuously rotating rear shaft on a moving vehicle in itself absorbs a definite amount of energy.

v) The inner race of the bearing pads are rotated which create more frictional force as compared to the case when the inner race remaining stationary and outer race rotating or both inner and outer race of the bearing being stationary.
In the new "Cycle rickshaw with intermediate shaft" - the weak points of the earlier design has been removed with the aim of reducing friction and making the machine easier to drive requiring less human effort.
The changes introduced in the new developed " Cycle rickshaw with intermediate shaft " are as follows:
i) The cranking power of the rickshaw puller comes first from crank wheel to an intermediate shaft- placed between the crank wheel & rear shaft. The intermediate shaft gets supported through bearings attached to the frame.
ii) The intermediate shaft is provided with two free wheels. The free wheels with their outer teeth's allow the chain to transfer torque. The Cranking power of the driver is transferred first from the crank wheel to the one-way clutch (free wheel) on the intermediate shaft that makes the intermediate shaft turn causing the other free wheel on it also to turn. The other free wheel on the intermediate shaft gets connected to one of the rear wheels of the rear shaft through chain. In order to adjust the alignment of the intermediate shaft free wheels with the respective gears on the wheel hub and crank wheel, the free wheels are mounted on an adjustable bush. For transferring the torque directly to one of the rear wheels- a specially designed wheel hub was used. The new wheel hub was supported on bearings and was provided with an attachment to carry the free wheel and hence was capable to take the driving torque from the intermediate shaft through chain.
iii) Now, both the rear wheels of the rickshaw are supported on bearings.
The rear shaft supporting the rear wheels now remains stationary. The duty of the rear shaft now remains the following:
a) transfer vertical load of the chassis & body coming on it via bearing
pads to the rear wheels and finally to the ground.
b) take care of any side thrust acting on the wheels and transfer the
same to the chassis such that the overall stability of the vehicle
gets maintained
Hence, when the driver stops pedalling, only the two rear wheels turn freely on bearings supported on stationary rear shaft.
vi) The intermediate shaft rotates only when the driver drives the vehicle through crank wheel.

The new introduced arrangement of the developed device is shown in Figure 2. The pedalling of the crank brings power through chain 1 to an intermediate shaft 2 via free wheel 6 connected through bush on the shaft. The intermediate shaft 2 is held on two bearings supported through bearing pads on the extended frame 4. The rotating intermediate shaft brings power to the wheel hub 7 connected through free wheel via chain2. The wheel hub on which the power of the driver is being made available is supported on bearings. Figure 2 A shows the cross sectional detail of the assembled rear shaft arrangement showing the wheel hub resting on it through bearings. Wheel hub has been designed and manufactured specially with an attachment for connecting the free wheel and hence it becomes capable of taking driving torque through chain from intermediate shaft.
Figure 3 shows another arrangement of the assembly allowing the other wheel to get the driving torque as compared to the arrangement shown in Figure 2. The wheel hub for taking driving torque from intermediate shaft is designed separately in the second case allowing torque transmission in one direction.
Figure 4 shows one complete system of the new developed device.
The new device has the changed rear shaft arrangement as has been shown in figure 2A as compared to the earlier arrangement of figure 1A.
Accordingly there is provided An improved power transmission mechanism for a cycle rickshaw comprising a base frame (5); a pair of wheels supporting the said base frame for movement along a surface; a crank wheel (9) attached to the said base frame for transmitting the power; an extended frame (4) being attached to the base frame; said extended frame having two bearing pads (3) axially aligned at the opposite ends; an intermediate shaft (2) being placed on the extended frame (4) through the two axially aligned bearing pads (3); said intermediate shaft having two free wheels (6 & 6') attached at both the ends of the intermediate shaft; a wheel hub (7) supported on a bearing being attached to the rear side of the base frame; said wheel hub having an attachment to carry a free wheel (6"); a first chain (1) connecting the crank wheel (9) to the free wheel (6) on the intermediate shaft ; a second chain (10) connecting the other free wheel (6') on the intermediate shaft to the free wheel (6") attached on to the specially designed wheel hub (7); wherein when the crank wheel (9) is cranked, the power is transmitted to the intermediate shaft through free wheel (6) by the chain (1) and in turn the other free wheel (6') on the intermediate shaft transmits the power to the rear wheel through the free wheel (6") on the hub (7) through the chain (10) resulting in the movement of the wheels.
The main advantage of the above introduced changes remain:
New device results in significant reduction in rolling resistance of the vehicle. That ultimately results in reduced effort requirement in pedalling the rickshaw hence saving in human energy and comfort to the rickshaw puller. The driver can also now carry more loads for the equivalent effort addition as compared to the earlier device.
Based on the above




I Claim:
1 . An improved power transmission mechanism for a cycle rickshaw comprising a base frame (5); a pair of wheels supporting the said base frame for movement along a surface; a crank wheel (9) attached to the said base frame for transmitting the power; an extended frame (4) being attached to the base frame; said extended frame having two bearing pads (3) axially aligned at the opposite ends; an intermediate shaft (2) being placed on the extended frame (4) through the two axially aligned bearing pads (3); said intermediate shaft having two free wheels (6 & 6') attached at both the ends of the intermediate shaft; a wheel hub (7) supported on a bearing being attached to the rear side of the base frame; said wheel hub having an attachment to carry a free wheel (6"); a first chain (1) connecting the crank wheel (9) to the free wheel (6) on the intermediate shaft ; a second chain (8) connecting the other free wheel (6') on the intermediate shaft to the free wheel (6") attached on to the specially designed wheel hub (7); wherein when the crank wheel (9) is cranked, the power is transmitted to the intermediate shaft through free wheel (6) by the chain (1) and in turn the other free wheel (6') on the intermediate shaft transmits the power to the rear wheel through the free wheel (6") on the hub (7) through the chain (8) resulting in the movement of the wheels.
2. An improved power transmission mechanism for a cycle rickshaw as claimed in
claim 1, wherein the free wheels (6 & 6') on the intermediate shaft are mounted on
the adjustable bush for easy alignment with crank (9) and new hub (7).
3. An improved power transmission mechanism for a cycle rickshaw as claimed in
claim 1 or 2, wherein the rear ends of the base frame (5) are connected with a rear
shaft (10) which remains stationary.
4. An improved power transmission mechanism for a cycle rickshaw as claimed in
claim 3 wherein the rear shaft acts as a structural member transferring vertical load of
chassis and body coming on it via bearing pads to the rear wheels and finally to the
ground.
5. An improved power transmission mechanism for a cycle rickshaw as claimed in any
of the preceding claims wherein the rear shaft / Stationary member of frame takes
care of any side thrust acting on the wheels and provides overall stability of vehicle.
6. An improved power transmission mechanism for a cycle rickshaw as claimed in
claim 1 wherein the extended frame (4) can be attached on either side of the base
frame (5).
7. An improved power transmission mechanism for a cycle rickshaw as claimed in
claim 1 wherein the power from the intermediate shaft can be transmitted to any of
the rear wheels depending upon the position of the extended frame.
8. A cycle rickshaw having an improved power transmission mechanism as claimed in
claim 1.
9. An improved power transmission mechanism for a cycle rickshaw substantially as
herein described with reference to the accompanying drawings.

Documents:

603-del-2001-abstract.pdf

603-del-2001-claims.pdf

603-del-2001-correspondence-others.pdf

603-del-2001-correspondence-po.pdf

603-del-2001-description (complete).pdf

603-del-2001-drawings.pdf

603-del-2001-form-1.pdf

603-del-2001-form-19.pdf

603-del-2001-form-2.pdf


Patent Number 199481
Indian Patent Application Number 603/DEL/2001
PG Journal Number N/A
Publication Date 20-Oct-2006
Grant Date 08-Sep-2006
Date of Filing 22-May-2001
Name of Patentee DR. HARI SHARAN GOYAL READER
Applicant Address MECHANICAL ENGINEERING DEPARTMENT MOTILAL NEHRU REGIONAL ENGINEERING COLLEGE, A-104 MEHDAURI COLONY ALLAHABAD, U.P. INDIA.
Inventors:
# Inventor's Name Inventor's Address
1 DR. HARI SHARAN GOYAL READER MECHANICAL ENGINEERING DEPARTMENT MOTILAL NEHRU REGIONAL ENGINEERING COLLEGE, A-104 MEHDAURI COLONY ALLAHABAD, U.P. INDIA.
PCT International Classification Number B62K 19/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA