Abstract:
A power operated coconut husking machine consists of a mechanized opening
of blades with manual feeding of coconut one at a time. A half way cam is designed
and is mounted on a cam shaft and is fixed to the frame. The follower is a cage, made
of mild steel, which is connected to the movable blade by means of a rectangular
extension which acts as a pivoted joint. Stationary blade is fixed on the frame. A 2.0
Hp motor of 1440 rpm is connected to the speed reduction box to reduce the speed by
means of pulleys of suitable diameter. The whole components are fixed on the frame.
Initially, the coconut is impaled with both the hands of the two juxtaposed wedge-like
blades oriented upwards during its closed position. The power from the motor is
conveyed to the speed reduction box with the help of a V belt. The power from the
motor is reduced by speed reduction box. This power is transfered to cam shaft by
using another V belt. The cam rotating at 24 rpm pulls the follower which inturn
connected to the movable blade and thus the blade is opened. The cam is designed in
such a manner that when the cam displaces the follower by 50mm, the tip of the
movable blade moves180mm away from the tip of fixed blade. A quick return
mechanism for quick resetting of the movable wedge or blade is also provided by
using a spring arrangement at the rear end of the follower. When the cam pulls the
follower backward, movable blade will get an angular path and it separates the husk
of the coconut. The coconut is then turned and the operations are then repeated till
complete husk is removed. The mean husking durations for 25 each green and dry
coconut was respectively 14.1s and 15.1s. The maximum durations for husking the
green and the dry coconuts were respectively 20s and 24s and the minimum 12s and
9s respectively. The number of pieces into which the whole husk of a coconut was
split came to 3 to 5 for both green and dry coconuts. As a whole, considering its
performances, the mechanism developed in this study appeared to be promising.
Higher efficiency of this machine can be achieved by incorperating some slight
modifications.
