Description  Claims  Drawing  Cited references 

US1444010A   [0003] 
US2303469A   [0003] 
DE3431904   [0003]  [0003] 
WO0147388A   [0003]  [0003] 
GB08074A   [0003]  [0003] 
FR941278   [0003] 
FR982758   [0003] 
CH286472   [0003] 
US2473207A   [0003] 
US2362237A   [0004] 
US1356509A   [0004]