29 ensp 0183 ensp Vibratory Screen Patenten US3378142A US33548164A US3378142A US 3378142 A US3378142 A US 3378142A US 33548164 A US33548164 A US 33548164A US 3378142 A US3378142 A US 3378142A Authority US United States Prior art keywords screen frame support members driving system oscillatory Prior art d05 Legal status The legal status is an assumption and is not a …