Propeller having angularly disposed tip

Claim 2

A propeller which is to be power driven rotatively about a predetermined generally horizontal axis and in a predetermined direction to cause horizontal advancement of an airplane: said propeller having a blade projecting generally radially outwardly away from said axis and which has a leading edge, and a trailing edge, and a tip edge extending therebetween; said tip edge being disposed at a pitch angle with respect to a plane extending perpendicular to said axis of the propeller; said leading and trailing edges having outer portions at substantially their outermost ends which extend approximately radially with respect to said axis and which essentially meet opposite ends of said tip edge; said tip edge being so shaped that, as it advances generally circularly from said approximately radial outer portion of the leading edge to said approximately radial outer portion of said trailing edge, the tip edge also advances progressively radially outwardly away from said axis, throughout essentially the entire circular distance between said approximately radial outer portions of said leading and trailing edges, and at an angle of 71.5* with respect to a line extending directly radially outwardly from said axis and intersecting the tip edge; said blade in extending between said tip edge and said trailing edge having an airfoil cross section in all planes perpendicular to a radial line and intersecting both the tip edge and trailing edge, which airfoil cross section is defined by a convexly curved forward face of the blade and a substantially flat rear face following a straight line between said tip edge and said trailing edge; said airfoil cross section, in all of said planes, tapering to thin substantially sharp shapes at both the tip edge and trailing edge of the blade.

Claim 3

A propeller which is to be power driven rotatively about a predetermined generally horizontal axis and in a predetermined direction to cause horizontal advancement of an airplane: said propeller having a blade projecting generally radially outwardly away from said axis and which has a leading edge, and a trailing edge, and a tip edge extending therebetween; said tip edge being disposed at a pitch angle with respect to a plane extending perpendicular to said axis of the propeller; said leading and trailing edges having outer portions at substantially their outermost ends which extend approximately radially with respect to said axis and which essentIally meet opposite ends of said tip edge; said tip edge being so shaped that, as it advances generally circularly from said approximately radial outer portion of the leading edge to said approximately radial outer portion of said trailing edge, the tip edge also advances progressively radially outwardly away from said axis, throughout essentially the entire circular distance between said approximately radial outer portions of said leading and trailing edges, and at an angle of 71.5* with respect to a line extending directly radially outwardly from said axis and intersecting the tip edge; said blade in extending between said tip edge and said trailing edge having an airfoil cross section, in all planes perpendicular to a radial line and intersecting both the tip edge and trailing edge, which airfoil cross section is defined by a convexly curved forward face of the blade and a substantially flat rear face following a straight line between said tip edge and said trailing edge; said airfoil cross section, in all of said planes, being a fifty percent airfoil cross section having its maximum thickness at a point midway between said tip edge and said trailing edge, and tapering to thin substantially sharp shapes at both the tip edge and trailing edge of the blade.

Claim 4

A propeller which is to be power driven rotatively about a predetermined generally horizontal axis and in a predetermined direction to cause horizontal advancement of an airplane: said propeller having a blade projecting generally radially outwardly away from said axis and which has a leading edge, and a trailing edge, and a tip edge extending therebetween; said tip edge being disposed at a pitch angle with respect to a plane extending perpendicular to said axis of the propeller; said leading and trailing edges having outer portions at substantially their outermost ends which extend approximately radially with respect to said axis and which essentIally meet opposite ends of said tip edge; said tip edge being so shaped that, as it advances generally circularly from said approximately radial outer portion of the leading edge to said approximately radial outer portion of said trailing edge, the tip edge also advances progressively radially outwardly away from said axis, throughout essentially the entire circular distance between said approximately radial outer portions of said leading and trailing edges, and at an angle of 71.5* with respect to a line extending directly radially outwardly from said axis and intersecting the tip edge; said blade in extending between said tip edge and said trailing edge having an airfoil cross section, in all planes perpendicular to a radial line and intersecting both the tip edge and trailing edge, which airfoil cross section is defined by a convexly curved forward face of the blade and a substantially flat rear face following a straight line between said tip edge and said trailing edge; said airfoil cross section, in all of said planes, being a fifty percent airfoil cross section having its maximum thickness at a point midway between said tip edge and said trailing edge, and tapering to thin substantially sharp shapes at both the tip edge and trailing edge of the blade.

Claim 5

A propeller which is to be power driven rotatively about a predetermined generally horizontal axis and in a predetermined direction to cause horizontal advancement of an airplane: said propeller having a blade projecting generally radially outwardly away from said axis and which has a leading edge, and a trailing edge, and a tip edge extending therebetween; said tip edge being disposed at a pitch angle with respect to a plane extending perpendicular to said axis of the propeller; said leading and trailing edges having outer portions at substantially their outermost ends which extend approximately radially with respect to said axis and which essentially meet opposite ends of said tip edge; said tip edge being so shaped that, as it advances generally circularly from said approximately radial outer portion of the leading edge to said approximately radial outer portion of said trailing edge, the tip edge also advances progressively radially outwardly away from said axis, throughout essentially the entire circular distance between said approximately radial outer portions of said leading and trailing edges, and at an angle of 71.5* with respect to a line extending directly radially outwardly from said axis and intersecting the tip edge; said blade in extending between said tip edge and said trailing edge having an airfoil cross section, in all planes perpendicular to a radial line and intersecting both the tip edge and trailing edge, which airfoil cross section is defined by a convexly curved forward face of the blade and a substantially flat rear face following a straight line between said tip edge and said trailing edge; said airfoil cross section, in all of said planes, being a 50 percent airfoil cross section having its maximum thickness at a point midway between said tip edge and said trailing edge, and tapering to thin substantially sharp shapes at both the tip edge and trailing edge of the blade; said blade also having an airfoil cross section through at least a portion of its radial extent radially inwardly of said tip edge, in planes intersecting both said leading edge and said trailing edge, which airfoil cross seciton is defined by a convexly curved forward face and an essentially flat rear face following a straight line between said leading edge and said trailing edge.

Claim 6

A propeller which is to be power driven rotatively about a predetermined generally horizontal axis and in a predetermined direction to cause horizontal advancement of an airplane: said propeller having a blade projecting generally radially outwardly away from said axis and which has a leading edge, and a trailing edge, and a tip edge extending therebetween; said tip edge being disposed at a pitch angle with respect to a plane extending perpendicular to said axis of the propeller; said leading and trailing edges having outer portions at substantially their outermost ends which extend approximately radially with respect to said axis and which essentially meet opposite ends of said tip edge; said tip edge being so shaped that, as it advances generally circularly from said approximately radial outer portion of the leading edge to said approximately radial outer portion of said trailing edge, the tip edge also advances progressively radially outwardly away from said axis, throughout essentially the entire circular distance between said approximately radial outer portions of said leading and trailing edges, and at an angle of 71.5* with respect to a line extending directly radially outwardly from said axis and intersecting the tip edge; said blade in extending between said tip edge and said trailing edge having an airfoil cross section, in all planes perpendicular to a radial line and intersecting both the tip edge and trailing edge, which airfoil cross section is defined by a convexly curved forward face of the blade and a substantially flat rear face following a straight line between said tip edge and said trailing edge; said airfoil cross section, in all of said planes, being a 50 percent airfoil cross section having its maximum thickness at a point midway between said tip edge and said trailing edge, and tapering to thin substantially sharp shapes at both the tip edge and trailing edge of the blade; said blade also having an airfoil cross section through at least a portion of its radial extent radially inwardly of said tip edge, in planes intersecting both said leading edge and said trailing edge, which airfoil cross seciton is defined by a convexly curved forward face and an essentially flat rear face following a straight line between said leading edge and said trailing edge.