Abstract- The socio economic conditions of peoples living in
village sides of developing countries like India, ever increasing
energy crises, and the increasing awareness to ourselves
physically fit are the driving forces for the development of pedal
operated mechanisms for performing many day to day activities.
Such human energized mechanisms are used to generate power,
to operate flour mill etc. But one common oblivious question that
stuck in everyone’s mind is about the level of comfort that it
provide during its operation.
Wheat and wheat flour forms the staple food of majority of
population in India. Hence to encompass all these needs and
facts, in this paper an attempt is made to develop an pedal
operated flour mill with giving due respect to human capabilities.
To make this design of pedal operated flour mill is ergonomically
viable the structure (geometry) of the flour mill is made by
taking into consideration the anthropometric data so as to provide
comfortable posture during its operation.
heat and wheat flours are the integral of daily diet of
Indian population. The wheat kernels are processed in
chakki (flour mill) to produce wheat flour is which is then used
to make breads, biscuits, pastas etc. In India chapatti and other
variants of wheat forms the staple food of majority of population.
In manual process the flour is produced by hand cranking the
conventional stone wheels. But this method is characterized by
slow operation, low production rate. Further this hand cranking
process is physically demanding through energy and postural
requirements. It may also leads to clinical and anatomical
disorders which may affect operator’s health.
In order to make it possible to operate the system effectively
and efficiently it is necessary to develop this system by giving
due respect to human limitation. Hence ergonomic system of
pedal operated flour mill is developed. The ergonomic
consideration mainly includes the selection of components of
system which suits the human capability and develops the
posture to operate system to reduce the fatigue and chances of
musceletole disorders.
II. PEDAL OPERATED FLOUR MILLCONSTRUCTION
AND WORKING
In construction the pedal operated flour mill basically consists
of two units namely the drive unit and processing unit. The drive
unit mainly concerns with transmission of human power to
processing unit. This transmission of human power to processing
unit is accomplished in two stages. In first stage the operator uses
his feet and legs to rotate pedal around the crank axel. The pedals
in turn are fixed to chain ring (sprocket) with the teeth’s that
engages continuous chain. The chain then transmits the pedaling
action to cog on the front wheel causing the front sprocket to
rotate and then drive shaft on which pulley is mounted. In second
stage this power from shaft and pulley is transmitted to
processing unit through belt drive.
The processing unit essentially consists of stone wheels,
hopper, and hemispherical collector. The stone wheels are
operated by power from the belt drive where the wheat kernels
which are fed into hopper are crushed and powered wheat flour is
collected in hemispherical collector.
III. ERGONOMICS DESIGN OF PEDAL OPERATED
FLOUR MILL
Making this design ergonomically viable mainly concerns with
developing the posture to provide best possible comfortable
posture to operator during its working so as to get maximum
throughput. This can be achieved by selecting and arranging the
components of system that best suits to human capabilities.
Since the thigh or quadriceps is largest and most powerful
muscles in human body with the body in seat and legs can
produce pedal work . The person can generate four times more
power (1/4 horsepower (hp)) by pedaling than by hand cranking.
At the rate of 1/4 hp, continuous pedaling can be done for only
short time, about 10 minutes. However pedaling at half of this
power (1/8 hp)can be sustained for around 60 minutes Maximum
power produced with legs is generally limited by adoptions
within the oxygen transportation system. On the other hand the
capacity for arm exercise is dependent upon the amounts of
muscle mass engaged and that is why a person can generate more
power by pedaling than hand cranking . Pedal power enables a
person to drive device at same rate as achieved by hand. Thus it
makes sense to utilize this human muscle for generating as much
as energy from human body.
In order to provide the ergonomically comfortable system it is
necessary to locate the various elements of system so that a
person can operate the system with less effort and hence the
fatigue. As the thigh is being utilized to generate the power
continuously it was decided to develop a posture which is similar
to cycling posture. And subsequently the ergonomic design
mainly concerned with the saddle (seat) position, handle position.
Saddle position includes the height of saddle, distance between
saddle and pedal crank center, seat tube angle.