Abstract: Apparatus for collecting and discharging waste material comprises peripheral rows of teeth arranged on rotatable cylindrical shafts. The teeth on each shaft intercalate so that an entrapment zone for waste material is formed thereat during contra-wise rotation of the shafts. The teeth in each row pass through respective slits formed between the blade edges of rectilinear scaper blades placed between the rows and resting on the shaft. The scraper blades remove waste material from and between the teeth for discharge from the machine.