AU2013101342A4 - Blade with debris disbursing air lift - Google Patents

Abstract

Various embodiments of the invention may include a lawn mower blade having a central 5 portion configured to be mounted to an axis of a rotary lawn mower. The blade may further include at least one air lift disposed on an inner portion of the blade, between the central portion and an end portion. The end portion adjacent the air lift may be substantially flat (e.g. flat over a width of the blade). The air lift may angle upwardly from the cutting plane as the air lift moves away from the cutting edge. * ALL. ---------

Description

BLADE WITH DEBRIS DISBURSING AIR LIFT Cross Reference to Related Applications [0001] The present application claims priority to U.S. Provisional Patent 5 Application No. 61/439,691, filed February 4, 2011, entitled "Blade with Shielded Air Lift," the entire disclosure of which is hereby incorporated by reference in its entirety. [0001 a] The present application is a divisional from Australian patent application 2012212002, the entire disclosure of which is incorporated herein by reference. 10 Technical Field [0002] Embodiments herein relate to the field of lawn mower blades, and, more specifically, to lawn mower blades with one or more air lifts. 15 Background [0002a] A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims. 20 [0003] Lawn mower blades are widely used in rotary lawn mowers to cut grass. Rotary lawn mower blades typically have a generally rectangular shape with a hole through the center for mounting to the vertical axle of the lawn mower. The blade generally includes cutting edges on opposite sides of each end of the blade. Additionally, many lawn mower blades include an angled portion on the rear edge, called an air lift, 25 which creates an upward air flow as the blade rotates. The air lift typically spans only part of the length of the blade and extends to the end of the blade. The upward air flow caused by the air lift makes the grass to stand up straighter, which increases the effectiveness of the cutting edge. Additionally, the upward air flow helps clear the clippings from the blade after the grass is cut. This reduces clogging of the blade and 30 also draws the clippings toward the bagging element (if present) of the lawn mower. [0004] However, the air lift and the centrifugal force of the blade push the air flow to the ends of the blade. As such, the air lift is subject to considerable wear, especially when the lawn mower is used in areas with loose debris in the soil, such as sand. The pattern of air flow of a typical air lift causes the air lift to wear from the outside edge 35 inward. Furthermore, because of the air flow, only the ends of the cutting edge are 1 utilized for cutting grass. Thus, the inward portions of the cutting edge are not utilized, and the cutting edge wears from the outside edge inward. Brief Description of the Drawings 5 [0005] Embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings and the appended claims. Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings. 10 [0006] Figures 1A-1 E illustrate various views of a blade with a debris disbursing air lift, including: A) a top view; B) a side view; C) a bottom view; D) a front view; and E) a perspective view, in accordance with various embodiments. Summary of the Invention 15 [0006a] The present invention provides a lawn mower blade, comprising: a blade bar having a central portion configured to be mounted to a lawn mower, an end portion, and an inner portion disposed between the end portion and the central portion; a cutting edge disposed on a leading edge of the blade; and an air lift on the inner portion, the air lift angled upward and away from the cutting edge. 20 [0006b] The present invention provides a lawn mower blade, comprising: a central portion configured to be mounted to a lawn mower; a first cutting edge and a second cutting edge disposed on opposite sides of the central portion; a first air lift disposed on a first inner portion of the blade, the first air lift separated from a first end edge of the blade by a first end portion; a second air lift disposed on a second inner portion of the 25 blade opposite the central portion from the first inner portion of the blade, the second air lift separated from a second end edge of the blade by a second end portion; wherein the first and second air lifts are angled upward from a cutting plane of the blade. Detailed Description of Disclosed Embodiments 30 [0007] In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration embodiments that may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope. Therefore, the following detailed description is not to be taken 35 in a limiting sense, and the scope of embodiments is defined by the appended claims and their equivalents. 2 [0008] Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments; however, the order of description should not be construed to imply that these operations are order 5 dependent. [0009] The description may use perspective-based descriptions such as up/down, back/front, and top/bottom. Such descriptions are merely used to facilitate the discussion and are not intended to restrict the application of disclosed embodiments. [0010] The terms "coupled" and "connected," along with their derivatives, may be 10 used. It should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, "connected" may be used to indicate that two or more elements are in direct physical or electrical contact with each other. "Coupled" may mean that two or more elements are in direct physical or electrical contact. However, "coupled" may also mean that two 3

Claims (18)

1. A lawn mower blade, comprising: a blade bar having a central portion configured to be mounted to a lawn mower, 5 an end portion, and an inner portion disposed between the end portion and the central portion; a cutting edge disposed on a leading edge of the blade; and an air lift on the inner portion, the air lift angled upward and away from the cutting edge. 10

2. The lawn mower blade of claim 1, wherein the end portion is substantially flat over a width of the blade.

3. The lawn mower blade of claim 1 or 2, wherein an upper surface of the end 15 portion is substantially parallel to a cutting plane of the blade.

4. The lawn mower blade of any one of claims 1 to 3, wherein the end portion comprises a first end portion, the inner portion comprises a first inner portion, and the air lift comprises a first air lift, and the blade further comprising: 20 a second end portion opposite the first end portion, the second end portion being substantially flat over a width of the blade; a second inner portion disposed between the second end portion and the central portion, the second inner portion including a second air lift. 25

5. The lawn mower blade of any one of claims 1 to 4, wherein the blade bar is substantially rectangular.

6. The lawn mower blade of any one of claims 1 to 5, wherein the end portion has a length of 0.5 inches to 3 inches. 30

7. The lawn mower blade of any one of claims 1 to 6, wherein the air lift has an angle with respect to the cutting plane of 20 degrees to 80 degrees.

8. The lawn mower blade of any one of claims 1 to 6, wherein the air lift has an 35 angle with respect to the cutting plane of 45 degrees to 75 degrees. 4

9. The lawn mower blade of any one of claims 1 to 8, further comprising a gap that longitudinally separates a distal end of the air lift from the end portion of the blade bar.

10. The lawn mower blade of claim 9, wherein the gap comprises a first gap, and the 5 blade further comprising a second gap that longitudinally separates a proximal end of the air lift from the central portion of the blade bar.

11. A lawn mower blade, comprising: a central portion configured to be mounted to a lawn mower; 10 a first cutting edge and a second cutting edge disposed on opposite sides of the central portion; a first air lift disposed on a first inner portion of the blade, the first air lift separated from a first end edge of the blade by a first end portion; a second air lift disposed on a second inner portion of the blade opposite the 15 central portion from the first inner portion of the blade, the second air lift separated from a second end edge of the blade by a second end portion; wherein the first and second air lifts are angled upward from a cutting plane of the blade. 20

12. The lawn mower blade of claim 11, wherein the first and second end portions are substantially flat over a width of the blade.

13. The lawn mower blade of claim 11 or 12, wherein respective upper surfaces of the first and second end portions are substantially parallel to the cutting plane. 25

14. The lawn mower blade of any one of claims 11 to 13, wherein the blade bar is substantially rectangular.

15. The lawn mower blade of any one of claims 11 to 14, wherein the first end portion 30 has a length of 0.5 inches to 3 inches.

16. The lawn mower blade of any one of claims 11 to 14, wherein the first air lift has an angle with respect to the cutting plane of 45 degrees to 75 degrees. 5

17. The lawn mower blade of any one of claims 11 to 16, further comprising a gap that longitudinally separates a distal end of the first air lift from the first end portion of the blade. 5

18. The lawn mower blade of claim 17, wherein the gap comprises a first gap, and the blade further comprising a second gap that longitudinally separates a proximal end of the first air lift from the central portion of the blade bar. 6