150 attached to one end of a shaft 152 that extends through a tubular structure 154 toward the center of the hopper 36 the shaft 152 is supported by bearings within the tubular structure 154 the other end of the shaft 152 has another lever arm 156 thereon the upper or free end of the last mentioned arm 156 has a flexible rope or cable 158 attached thereto so that when pulled the shaft 152 is oscillated through a sufficient angle to cause the rocker arm 142 to be pivoted sufficiently so that the shaft 130 acting through the one way or overrunning clutch 140 correspondingly rotates the tubular shaft 132 with the consequence that the next adjacent flat 136h on the cam 134 will be brought into juxtaposition with the wear plate 126 inasmuch as the flat 136h is spaced a greater distance from the center of rotation of the cam 134 it follows that the arm 110 will be urged in a clockwise direction to compress the coil spring 96 withdrawing the clutch member 92 from the other clutch member 90 of the clutch mechanism 88 as can be seen in fig7 the sprocket 94 when the clutch mechanism 88 is disengaged as just described will not rotate under these circumstances as the wheels 18 20 rotate it will be observed from fig7 that the rocker arm 142 has another aperture 160 in addition to the earlier mentioned aperture 144 in this way one end of a return coil spring 162 is engaged with the rocker arm 142 by having this end.