Compression crimping apparatus

Apparatus for compression crimping fibrous material comprising means defining a compression crimping zone in which a plug of compression crimped fibrous material is formed, means for feeding fibrous material into the compression crimping zone, means for withdrawing compression crimped fibrous material from the compression crimping zone, means for sensing the presence of the plug at a predetermined position in the zone and for regulating at least one of the fibrous material feeding means and fibrous material withdrawing means in response to said sensing thereby to prevent said plug from moving substantially beyond said position, the sensing means comprising a light-emitting diode and a sensor for the light emitted by the diode, said diode and said sensor being arranged on opposite sides of said zone with a path being defined for passage of the light from the diode to the sensor on a line which intersects the compression crimping zone at said predetermined position, said apparatus further comprising at least one movable member defining a lateral wall of the zone and being biased toward the fibrous material to restrict egress of the fibrous material from the zone and thereby exert a back pressure on the fibrous material, causing the fibrous material to buckle and thereby crimp in the zone, and means for deactuating the fibrous material feeding means and withdrawing means in response to displacement beyond a predetermined extent of the movable member in a direction opposite to the direction in which the movable member is biased, the deactuating means being arranged to operate if the plug advances substantially beyond said light path, whereby operation of the apparatus is interrupted in response to malfunctioning of control of the position of the plug in the crimping zone.