Axial fan construction

Claim 1

A BLADE CONSTRUCTION ADAPTED TO BE MOUNTED IN FIRM CLAMPED ENGAGEMENT ON A PORTION OF A HUB HAVING AN INTERNAL PERIPHERAL WALL PORTION AND AN EXTERNAL PERIPHERAL WALL PORTION COMPRISING A BLADE PORTION HAVING A BASE, A HUB HAVING AN INTERNAL AND AN EXTERNAL PERIPHERAL WALL PORTION, SAID BLADE PORTION INCLUDING A COLLAR LOCATED PROXIMATE THE BASE THEREOF, SAID COLLAR HAVING A FIRST SURFACE ADAPTED TO ENGAGE SAID EXTERNAL PERIPHERAL WALL PORTION OF SAID HUB, A PLATE MEMBER HAVING A SECOND SURFACE ADAPTED TO ENGAGE SAID INTERNAL PERIPHERAL WALL PORTION OF SAID HUB, SAID BLADE PORTION AND SAID PLATE HAVING A CLEARANCE THEREBETWEEN IN THEIR MOUNTED POSITION, APERTURE MEANS IN SAID HUB, TIE MEANS ON OPPOSITE SIDES OF SAID BLADE PORTION EXTENDING THROUGH SAID APERTURE MEANS AND BETWEEN SAID COLLAR AND SAID PLATE MEMBER FOR DRAWING SAID COLLAR AND SAID PLATE MEMBER TOWARD EACH OTHER UNTIL SAID COLLAR AND SAID PLATE MEMBER MOUNT SAID BLADE CONSTRUCTION AGAINST MOVEMENT ON SAID HUB BY SANDWICHING A PORTION OF SAID HUB IN FIRM CLAMPED ENGAGEMENT BETWEEN SAID FIRST AND SECOND SURFACES, MEANS FORMING A PART OF SAID TIE MEANS AND LOCATED PROXIMATE AND PERIPHERAL EXTERNAL SURFACE FOR EFFECTING LOOSENING AND TIGHTENING OF SAID TIE MEANS FROM A POSITION EXTERNAL TO SAID HUB, SAID LOOSENING OF SAID TIE MEANS PERMITTING ADJUSTMENT OF SAID BLADE CONSTRUCTION ON SAID HUB BY INCREASING THE CLEARANCE BETWEEN SAID PLATE MEMBER AND SAID COLLAR AND THEREBY PERMITTING MOVEMENT OF SAID BLADE CONSTRUCTION ON SAID HUB, AND MEANS ASSOCIATED WITH SAID TIE MEANS FOR LOCKING SAID TIE MEANS AGAINST UNDERSIRED LOOSENING AFTER SAID TIE MEANS HAVE BEEN TIGHTENED.