Thin lawn mower blade

• US 6,769,236 B2
• Filed: 09/27/2002
• Issued: 08/03/2004
• Est. Priority Date: 11/14/2000
• Status: Expired due to Fees

• Current Assignee: Mtd Products Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Mtd Products Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Schaedler, Axel
• Primary Examiner(s): Will, Thomas B.
• Assistant Examiner(s): PETRAVICK, MEREDITH C
• Application Number:
  US10/260,977
• Publication Number:
  US 20030074874A1
• Time in Patent Office: 676 Days
• Field of Search: 562/55, 562/95, 561/75, 56D/IG.16, 56D/IG.20
• US Class Current: 56/295
• CPC Class Codes: A01D 34/73 Cutting apparatus

Abstract

A lawn mower blade having a thickness of approximately 0.075 inches comprises a main body, an elevational profile, and end portions equidistant from the center of the blade. The elevational profile consists of a raised portion that reaches a height at the plateau portion at the center of the blade. The elevational profile increases at an angle α as the end portions approach the plateau. Each of the first and second end portions has a cutting edge portion. The height to blade thickness ratio is at least two-to-one. Further, since the mower blade is generally not heat treated, ribbing is added to the mower blade to provide strength.

Claims

1. A mower blade adapted to be used on an associated mower deck, the mower blade comprising:

a main body portion having a thickness t, a length L, a width W and first and second end portions substantially equidistant from a center of rotation, each of said first and second end portions having a cutting edge;

a raised center portion having an elevational profile, said elevational profile having a height h, such that the main body portion thickness and the height form a ratio h/t being at least 2 to 1, said center portion having a top and first and second flanges, said flanges extending downwardly from said top, said flanges extending substantially the length of said main body portion; and

,

wherein said elevational profile increases at an angle α

as said first and second end portions approach a plateau portion, said main body portion remaining substantially planar.

2. The mower blade of claim 1, wherein said angle α

is in the range of approximately ten to fifteen degrees.

3. The mower blade of claim 2, wherein said raised center portion has its highest elevation point about the center of rotation.

4. The mower blade of claim 3, wherein said center portion defines a cavity thereunder.

5. The mower blade of claim 4, further comprising:

a pair of oppositely disposed flange positions operatively connected to said end portions opposite of said cutting edge, each flange portion extending upwardly from each respective end portion such that air flow properly positions the associated underlying vegetation to be cut.

6. A mower blade adapted to be used on an associated mower deck, the mower blade comprising:

a main body portion having a thickness t, a length L, a width W and first and second end portions substantially equidistant from a center of rotation, each of said first and second end portions having a cutting edge;

a raised center portion defining a cavity thereunder and having its highest elevation point about said center of rotation, said raised center portion comprises a width, said width being greatest about a transverse axis of said blade, said transverse axis intersecting said center of rotation, said width gradually decreasing as said raised center portion extends towards said first and second end portions;

said raised center portion having an elevational profile, said elevational profile having a height h, such that the main body portion thickness and the height form a ratio h/t being at least 2 to 1, said center portion having a top and first and second flanges, said flanges extending downwardly from said top, said flanges extending substantially the length of said main body portion;

wherein said elevational profile increases at an angle α

as said first and second end portions approach a plateau portion, said main body portion remaining substantially planar, wherein said angel α

is in the range of approximately ten to fifteen degrees; and

a pair of oppositely disposed flange portions operatively connected to said end portions opposite of said cutting edge, each flange portion extending upwardly from each respective end portion such that air flow properly positions the associated underlying vegetation to be cut.

7. The mower blade of claim 6, wherein said raised center portion width is less than the width W of said main body portion.

8. The mower blade of claim 7, wherein said raised center portion and first and second end portions are an integral piece of metal material.

9. The mower blade of claim 8, wherein said cutting edge has a higher yield strength than said raised center portion and said first and second end portions.

10. The mower blade of claim 9, wherein said main body portion thickness to height ratio h/t is at least 10 to 1.

11. The mower blade of claim 9, wherein said main body portion thickness to height ratio h/t is about 16 to 1.

12. A mower blade adapted to be used on an associated mower deck, the mower blade, comprising:

a main body portion having a thickness of approximately 0.075 inches, a length L, a width W and first and second end portions substantially equidistant from a center of rotation, each of said first and second end portions having a cutting edge; and

a raised center portion having a elevational profile, said elevational profile having a height h, such that the main body portion thickness and the height form a ratio h/t being at least 2 to 1, said center portion having a top and first and second flanges, said flanges extending downwardly from said top, said flanges extending substantially the length of said main body portion.

13. The mower blade of claim 12, wherein said elevational profile increases at an angle α

as the first and second end portions approach a plateau portion.

14. The mower blade of claim 13, wherein said angle α

is in the range of approximately ten to fifteen degrees.

15. The mower blade of claim 14, wherein said raised center portion has its highest elevation point about the center of rotation.

16. The mower blade of claim 15, wherein said raised center portion defines a cavity thereunder.

17. The mower blade of claim 16, further comprising:

a pair of oppositely disposed flange portions operatively connected to said end portions opposite of said cutting edge, each flange portion extending upwardly from each respective end portion such that air flow properly positions the associated underlying vegetation to be cut.

18. The mower blade of claim 17, wherein said raised center portion comprises a width, said width being greatest about a transverse axis of said blade, said transverse axis intersecting said center of rotation, said width gradually decreasing as said raised center portion extends towards said first and second end portions.

19. The mower blade of claim 18, wherein said raised center portion width is less than the width W of said main body portion.

20. The mower blade of claim 19, wherein said raised center portion and first and second end portions are an integral piece of metal material.

21. The mower blade of claim 20, further comprising a ribbing portion.

22. The mower blade of claim 21, wherein said ribbing portion is an indentation integrally formed with said main body portion.

23. The mower blade of claim 22, wherein said main body portion thickness to height ratio h/t is at least 10 to 1.

24. The mower blade of claim 22, wherein said main body portion thickness to height ratio h/t is about 16 to 1.

25. The mower blade of claim 23 or 24, wherein said cutting edge has a higher yield strength than said raised center portion and said first and second end portions.

26. The mower blade of claim 25, wherein said raised center portion and said first and second end portions are formed of a non-heat treated material.

27. The mower blade of claim 26, wherein said non-heat treated material is 1018 mild carbon steel.

28. A mower blade adapted to be used on an associated mower deck, the mower blade comprising:

a main body portion having a thickness t, a length L, a width W and first and second end portions substantially equidistant from a center of rotation, each of said first and second end portions having a cutting edge;

a raised center portion having a high elevational profile, said raised center portion having its highest elevation point about the center of rotation, said raised center portion comprising a plateau portion and a width, said width being greatest about a transverse axis of said blade, said transverse axis intersecting said center of rotation, said width gradually decreasing as said raised center portion extends past said plateau portion and towards said first and second end portions, said raised center portion width being less than the width W of said main body portion, said high elevational profile having a maximum height h, such that the ratio of said main body portion thickness to said maximum height h/t is at least 2 to 1, said high elevational profile defining a cavity, said high elevational profile increasing at an angle α

as the first and second end portions approach said plateau portion at angle α

being in the range of approximately ten to fifteen degrees;

a pair of oppositely disposed flange portions operatively connected to said end portions opposite of said cutting edge, each flange portion extending upwardly from each respective end portion such that air flow properly positions the associated underlying vegetation to be cut, said flange portions, said raised center portion, and first and second end portions being an integral piece of non-heat treated 1018 mild carbon steel, said cutting edge having a higher yield strength than said raised center portion, first and second end portions and said flange portions; and

a plurality of ribbing portions, each of said plurality of ribbing portions being an indentation integrally formed with said main body portion and being positioned in a substantially symmetric orientation about the center of rotation.