position a bracket 65 is mounted on the housing 11 below the substantially horizontal portion of the probe 60 and supports a pair of microswitches 66 and 67 the microswitch 66 is normally open but closed when the probe is pivoted downwardly and rests thereon the microswitch 67 is normally closed but opened when the probe is pivoted downwardly and rests thereon the microswitches are so positioned that when they support the probe the detector portion 62 thereof is disposed within the housing closely adjacent to the bat 56 when it is of an acceptable thickness this position is shown in dashed line in fig3 when the bat becomes objectionably thick and threatens to jamb the feed rollers the lint of the bat forces the probe outwardly as the probe pivots to the dot dash position the microswitch 67 is first disengaged and permitted to close as will subsequently be described this actuates an alarm if the pivotal movement of the probe continues outwardly to the full line position under the urging of a bat of increased thickness the microswitch 66 is next released and opens to interrupt the operation of the drum 20 doffers 23 and 26 and feed rollers 31 33 and 40 through 43 as previously noted the door 51 is pivotally mounted at 52 for movement between a position closing the opening 50 as shown in fig2 and 3 and an open position shown in fig1 a pair of chains 70 interconnect the door and the housing so as to limit the extent of opening.