Method of fabricating centrifugal fan impellers

Claim 1

A METHOD OF MANUFACTURING A CENTRIFUGAL IMPELLER FOR A FAN, A PUMP OR THE LIKE COMPRISED OF TWO SHEET METAL END DISKS AND FORMED SHEET METAL BLADES SECURED THEREBETWEEN, SAID METHOD INCLUDING THE STEPS OF: BLANKING OUT A SET OF LIKE IMPELLER BLADES FROM SHEET METAL HAVING A BODY PORTION TAPERING IN WIDTH FROM A BROADER INNER END TO A NARROWER OUTER END AND HAVING LONGITUDINALLY SPACED EARS ON EACH LONGITUDINAL EDGE OF THE BODY, THE TOTAL WIDTH OF THE BLANK BETWEEN THE ENDS OF THE EARS ON ONE EDGE TO A LINE THROUGH THE ENDS OF THE EARS ON THE OTHER EDGE BEING AT LEAST AS GREAT AS SUCH WIDTH AT THE INNERMOST EARS AS IS REQUIRED TO PROVIDE A HEADING PROJECTION OF EACH INNERMOST EAR BEYOND A CORRESPONDING SAID DISK; BLANKING OUT OF A FIRST FLAT SHEET METAL DISK HAVING A SAMLL CENTRAL SHAFT ECEIVING APERTURE AND A SECOND FLAT SHEET METAL DISK HAVING A LARGER APERTURE THAN THE FIST TO SERVE AS A CENTAL AIR INLET, SAID DISKS HAVING A SRIES OF SPACED SETS OF BLADE EAR RECEIVING SLOTS; ASSEMBLING A CORRESPONDING SET OF BLADES BETWEEN SAID FLAT DISKS IS UNDEFLECTED CONDITION WITH LARGER ENDS ADJACENT THE CENTER REGION OF THE DISK AND WITH SAID EARS ESTENDING THROUGH CORRESPONDING SLOTS; AND HEADING SAID EARS INTO RIVET-LIKE ENGAGEMENT WITH SAID DISKS PROGRESSIVELY FROM THE INNERMOST TO THE OUTERMOST EARS AND THEREBY BRINGING THE DISKS INTO CONFORMING ENGAGEMENT WITH THE BLADE EDGES.

Claim 2

A METHOD OF MANUFACTURING A CENTRIFUGAL IMPELLER FOR A FAN, A PUMP OR THE LIKE COMPRISED OF TWO SHEET METAL END DISKS AND FORMED SHEET METAL BLADES SECURED THEREBETWEEN, SAID METHOD INCLUDING THE STEPS OF: BLANKING OUT A SET OF LIKE IMPELLER BLADES FROM SHEET METAL HAVING A BODY PORTION TAPERING IN WIDTH FROM A BROADER INNER END TO A NARROWER OUTER END AND HAVING LONGITUDINALLY SPACED EARS ON EACH LONGITUDINAL EDGE OF THE BODY, THE TOTAL WIDTH OF THE BLANK BETWEEN THE ENDS OF THE EARS ON ONE EDGE TO A LINE THROUGH THE ENDS OF THE EARS ON THE OTHER EDGE BEING AT LEAST AS GREAT AS SUCH WIDTH AT THE INNERMOST EARS AS IS REQUIRED TO PROVIDE A HEADING PROJECTION OF EACH INNERMOST EAR BEYOND A CORRESPONDING SAID DISK; BLANKING OUT OF A FIRST FLAT SHEET METAL DISK HAVING A SAMLL CENTRAL SHAFT ECEIVING APERTURE AND A SECOND FLAT SHEET METAL DISK HAVING A LARGER APERTURE THAN THE FIST TO SERVE AS A CENTAL AIR INLET, SAID DISKS HAVING A SRIES OF SPACED SETS OF BLADE EAR RECEIVING SLOTS; ASSEMBLING A CORRESPONDING SET OF BLADES BETWEEN SAID FLAT DISKS IS UNDEFLECTED CONDITION WITH LARGER ENDS ADJACENT THE CENTER REGION OF THE DISK AND WITH SAID EARS ESTENDING THROUGH CORRESPONDING SLOTS; AND HEADING SAID EARS INTO RIVET-LIKE ENGAGEMENT WITH SAID DISKS PROGRESSIVELY FROM THE INNERMOST TO THE OUTERMOST EARS AND THEREBY BRINGING THE DISKS INTO CONFORMING ENGAGEMENT WITH THE BLADE EDGES.