Rotary lawn mower

• US 5,775,078 A
• Filed: 07/19/1996
• Issued: 07/07/1998
• Est. Priority Date: 07/19/1996
• Status: Expired due to Term

• Current Assignee: Toro Company (Toro)
• Original Assignee: Toro Company (Toro)
• Inventors: Warren, Richard C.
• Primary Examiner(s): Melius, Terry Lee
• Assistant Examiner(s): PEZZUTO, ROBERT ERIC
• Application Number:
  US08/684,526
• Time in Patent Office: 718 Days
• Field of Search: 56/17.5, 56/255, 56/295, 56/DIG. 9, 56/DIG. 17, 56/17.3, 56/DIG. 20
• US Class Current: 56/255
• CPC Class Codes: A01D 34/73 Cutting apparatus

Abstract

A rotary mower (42) suitable for mowing ground vegetation including a cutting system (76) having a cutting deck (105). Mounted beneath the cutting deck (105) is a plurality of rotatable cutting blades (16), wherein each cutting blade (16) comprises a central portion (60) and first and second spaced apart tip portions (62a, b), wherein each tip portion (62) comprises a leading edge (56 ) having a sharpened cutting surface (64) for cutting the vegetation, a trailing edge (58), and an extending surface or "sail" (70) generally extending from the tip portion (62), whereby the sail (70a) of the first tip portion (62a) is different from than the sail (70b) of the second tip portion (62b).

Claims

1. A mower blade for cutting ground vegetation which is edgewise rotatable about a center of rotation, said cutting blade comprising:

a central portion and first and second outer end portions substantially equally spaced from the central portion, each outer end portion comprising (i) a leading edge including a sharpened cutting surface for cutting the vegetation, (ii) a trailing edge, and (iii) a sail member having a sail surface upwardly extending away from a generally horizontal plane containing the cutting surface, wherein the sail member of the first outer end portion and the sail member of the second outer end portion are differently configured from one another, and wherein the mower blade is not rotationally symmetrical about the center of rotation.

2. A lawn mower for cutting ground vegetation, said lawn mower comprising:

a cutting blade having an axis of rotation and a direction of rotation, said cutting blade having a central portion and first and second outer end portions and a longitudinal axis extending lengthwise between the outer end portions, the first and second outer end portions being substantially equally spaced from the central portion along the longitudinal axis, each outer end portion comprising (i) a leading edge including a sharpened cutting surface for cutting the vegetation, (ii) a trailing edge, and (iii) a sail member, each sail member having a sail surface extending upwardly away from a generally horizontal plane containing its associated cutting surface, each sail surface having a projected area with reference to a plane generally parallel to the longitudinal axis and generally perpendicular to the direction of rotation, and the projected area of the first sail member is substantially larger than the projected area of the second sail member, wherein said cutting blade is not rotationally symmetrical about said axis of rotation.

3. A mower according to claim 2, wherein the projected area of the first sail member is at least about 20% larger that the projected area of the second sail member.

4. A mower according to claim 2, wherein the projected area of the first sail member is approximately 55% larger than the projected area of the second sail member.

5. A lawn mower for cutting ground vegetation, said lawn mower comprising:

a rotatable cutting blade, said cutting blade having a central portion and substantially equally spaced apart outer end portions and a longitudinal axis extending lengthwise between the outer end portions, each outer end portion comprising (i) a leading edge including a sharpened cutting surface for cutting the vegetation, (ii) a trailing edge, and (iii) a sail member having a sail surface, said sail surface generally upwardly extending along a transition line away from a generally horizontal plane containing its associated cutting surface, wherein the transition lines are generally non-parallel, and wherein said cutting blade is not rotationally symmetrical.

6. A mower according to claim 5, wherein the sail surface of the first outer end portion generally upwardly extends along a transition line which is substantially parallel with the longitudinal axis, and wherein the surface of the second outer end portion generally upawardly extends along a transition line which is obliquely angled with respect to the longitudinal axis.

7. A mower according to claim 6, wherein the oblique transition line of the second outer end portion is approximately angled at 20 degrees with respect to the longitudinal axis.

8. An elongated mower blade of a predetermined length having top and bottom surfaces, generally parallel longitudinal edges, and opposite end edges, said blade being edgewise rotatable in one direction inside a mower housing about an axis of rotation concentric to the center of the blade, said end edges being substantially equally spaced from the axis of rotation, said blade comprising:

first and second leading edges each sufficiently sharp along a portion of the length to provide a cutting surface, the mower blade further having first and second upwardly inclined sail members respectively behind the first and second leading edges, the first and second sail members each having a sail surface extending upwardly away from the top surface and each sail member being substantially distinctly configured such that first and second sail member cross-sectional profiles taken along transverse cross-sectional planes which are radially equidistant from the axis of rotation and generally perpendicular to the longitudinal edges are generally dissimilar as one moves radially outwardly along the mower blade, wherein the mower blade is not rotationally symmetrical about its axis of rotation.

9. A lawn mower for cutting ground vegetation, said lawn mower comprising:

a rotatable cutting element which is edgewise rotatable about a center of rotation, the cutting element having a central portion and a plurality of radially spaced apart outer end portions, each outer end portion being substantially equally radially spaced from the center of rotation, each outer end portion includes a corresponding sail member, each sail member having a sail surface extending upwardly away from a generally horizontal plane containing its associated cutting surface, wherein the sail members of at least two outer end portions are differently configured, and wherein said cutting element is not rotationally symmetrical about its center of rotation.

10. A mower for cutting ground vegetation, said mower comprising:

a cutting blade which is rotatable about a substantially vertical axis of rotation; and

a cutting housing within which the cutting blade is positioned, the cutting blade having a central portion and substantially equally radially spaced apart outer end portions, each outer end portion including a leading and a trailing edge taken with reference to a forward direction of rotation of the blade, the leading edge of each outer end portion having a sharpened cutting surface creating vegetation clippings during operation, each outer end portion further including a sail member for pneumatic and mechanical influence of clippings associated with each tip portion, each sail member having a sail surface upwardly extending away from a top surface of the cutting blade, wherein the sail members of at least two outer end portions have different shapes, and wherein the cutting blade is not rotationally symmetric about its axis of rotation.

11. A lawn mower for cutting ground vegetation, the lawn mower comprising:

a rotatable cutting blade, said cutting blade having a central portion, a top surface, and first and second outer end portions substantially equally radially spaced apart along a longitudinal blade axis, each outer end portion comprising (i) a leading edge, (ii) a trailing edge, and (iii) an extending sail member having a sail surface generally upwardly extending away from the top surface along a transition line, the transition line of the sail member of the first outer end portion being generally aligned with the longitudinal axis such that the sail surface is generally rectangularly configured and substantially parallelly aligned with the longitudinal axis, and the transition line of the sail member of the second outer end portion being generally obliquely aligned with respect to the longitudinal axis at approximately 20 degrees such that the sail surface of the second outer end portion is generally triangularly configured being substantially obliquely aligned with the longitudinal axis, wherein said cutting blade is not rotationally symmetric about its center.