mounted on this side of gear reducer 60 is a cam 94 and an air valve 96 the cam 94 whose peripheral configuration is depicted in fig6 operates air valve 96 which in turn controls the flow of air to cylinder 54 cam 94 is configured such that cylinder 54 and support vane 48 will be in the extended position for approximately 3 4 of the cam cycle which corresponds to 3 4 of the operational folding cycle and is withdrawn for the remaining 1 4 of the cycle the overall machine operation will be best understood by referring to fig7 a d as seen in fig7 a lower feeder vane 40 has just completed its fold by deflecting the material of blanket 7 so that it extends in a direction away from the upper face of support member 32 in completing this fold vane 40 pushes the folded block along support member 32 by an amount generally equal to twice the material thickness immediately following vane 40 reaching this position cam 94 triggers air valve 96 causing cylinder 54 to elevate support vane 48 fingers 50 fit between plates 44 on the material engaging face of folder vane 40 so as not to disturb the position of the material the folds are fully supported at this point and folder vane 40 may be oscillated out of the folding zone preparatory to the arrival of folder vane 36 this withdrawal takes place as a result of the continuous rotation.