Patent US3888072A successfully refreshed from Google Patents.
US3888072A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary lawn mower
Assignee: Individual
•
Filing: 1973-05-16
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Granted: 1975-06-10
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Expires: 1993-05-16
Abstract
Abstract A rotary lawn mower having a specially configured blade and guard housing to effect a positive shearing of grasses and to eliminate the accumulation of grass clippings within the guard housing even when the blade is rotated at speeds which are about one-third that used in present day mowers. The blade shearing edges are hook-shaped to draw grasses inwardly therealong to assure a positive shearing action. U-shaped deflectors are provided behind the shearing edges to deflect clippings forwardly of the blade. The U-shaped deflectors are cocked at such an angle as will neutralize the tendency of the clippings to travel radially inwardly and outwardly of the blade. An air inlet opening is provided on one side of the cylindrical guard housing, and a raised discharge chute of increasing cross-sectional area extends from the inlet opening to a discharge opening on the other side of the guard housing. A stream of air drawn into the guard housing through the inlet opening entrains grass clippings and carries then out through the discharge opening.
Inventors
- 👤 William E Templeton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:55
CPC Classifications
A; A01; A01D; A01D34/00; A01D34/01; A01D34/412; A01D34/63; A01D2101/00; F; F02; F02B; F02B1/00; F02B1/02; F02B1/04
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
239 words
A rotary lawn mower comprising: a. a guard housing supported on ground engaging wheels and defining a downwardly opening chamber which is generally cylindrical about a vertical axis; b. power drive means carried by said guard housing and having a drive shaft positioned along said axis and depending into said chamber; c. blade means mounted on said drive shaft for rotation in a generally horizontal plane; d. said blade means having radially extending portions projecting outwardly from a central region and having an axis of symmetry coincident with the axis of said drive shaft; e. said radially extending portions each defining an end region including forward and trailing blade edge portions, said forward edge portions being sharpened to form shearing surfaces, and said trailing edge portions carrying forwardly opening generally U-shaped deflectors; f. said guard housing defining a peripheral discharge opening communicating with one side of said chamber and an inlet opening communicating with said chamber at a position spaced circumferentially from said discharge opening; g. said guard housing further defining a curved channel of increasing cross section extending in the direction of rotation of said blade means from said inlet opening to said discharge opening for permitting a stream of air to be drawn into said housing through said inlet opening and channeled smoothly through said housing along said channel to entrain grass clippings in the air stream and to discharge the entrained clippings through said discharge opening.
Claim 2
Dependent Claim
239 words
A rotary lawn mower comprising: a. a guard housing supported on ground engaging wheels and defining a downwardly opening chamber which is generally cylindrical about a vertical axis; b. power drive means carried by said guard housing and having a drive shaft positioned along said axis and depending into said chamber; c. blade means mounted on said drive shaft for rotation in a generally horizontal plane; d. said blade means having radially extending portions projecting outwardly from a central region and having an axis of symmetry coincident with the axis of said drive shaft; e. said radially extending portions each defining an end region including forward and trailing blade edge portions, said forward edge portions being sharpened to form shearing surfaces, and said trailing edge portions carrying forwardly opening generally U-shaped deflectors; f. said guard housing defining a peripheral discharge opening communicating with one side of said chamber and an inlet opening communicating with said chamber at a position spaced circumferentially from said discharge opening; g. said guard housing further defining a curved channel of increasing cross section extending in the direction of rotation of said blade means from said inlet opening to said discharge opening for permitting a stream of air to be drawn into said housing through said inlet opening and channeled smoothly through said housing along said channel to entrain grass clippings in the air stream and to discharge the entrained clippings through said discharge opening.
Claim 3
Dependent Claim
73 words
The lawn mower of claim 1 wherein: a. said guard housing comprises an inverted pan-like structure including a generally planar top wall and a circular side wall; b. said planar top wall having a semi-annular slot formed therethrough adjacent peripheral regions thereof; and, c. said channel being defined by a raised structure of downwardly opening U-shaped cross section overlying said semi-annular slot, said openings being formed at opposite ends of said raised structure.
Claim 4
Dependent Claim
65 words
The lawnmower of claim 1 wherein said U-shaped deflectors are each of substantially uniform U-shaped cross section along their length and are cocked at an angle whereby the radially inward ends of the deflectors are forward of the radially outward deflector ends, said angle being selected to effectively neutralize the radially inward and outward flow of grass clippings at a selected speed of blade rotation.
Claim 5
Dependent Claim
16 words
The lawnmower of claim 3 wherein said forward edge portions define forwardly facing hook-shaped shearing edges.
Claim 6
Dependent Claim
22 words
The lawnmower of claim 3 wherein said arcs subtended by said U-shaped trailing blade portions are generally within the range of 125*-150*.
Claim 7
Dependent Claim
31 words
The lawnmower of claim 1 wherein said forward edge portions define forwardly facing hook-shaped shearing edges for drawing grasses radially inwardly along the blade to effect positive shearing of the grasses.
Claim 8
Dependent Claim
246 words
In a rotary lawnmower of the type having a guard housing supported on ground engaging wheels and defining a downwardly opening chamber which is generally cylindrical about a vertical axis and has a discharge opening adjacent a peripheral region thereof, a power Drive unit carried by the guard housing and having a drive shaft depending centrally into the chamber, and a blade mounted on the drive shaft for rotation therewith in a generally horizontal plane, the improvement of a system for positively propelling grass clippings out of the guard housing through the discharge opening, comprising: a. U-shaped deflector means carried by the blade and positioned behind the cutting edge portions of the blade, said deflector means being configured to propel grass clippings in directions forwardly of the blade and to substantially neutralize the tendency of the clippings to travel radially inwardly and outwardly of the blade; b. an air inlet opening formed in the guard housing at a location on the opposite side of the mower from the discharge opening; c. said inlet opening being of smaller cross-sectional area than said discharge opening and being arranged to admit air to the chamber region above the blade; and d. said guard housing defining a channel of increasing cross-sectional area in said region above the blade extending from said inlet opening to the discharge opening whereby air is drawn into the chamber region above the blade for entraining grass clippings and discharging them smoothly through the discharge opening.
Claim 9
Dependent Claim
246 words
In a rotary lawnmower of the type having a guard housing supported on ground engaging wheels and defining a downwardly opening chamber which is generally cylindrical about a vertical axis and has a discharge opening adjacent a peripheral region thereof, a power Drive unit carried by the guard housing and having a drive shaft depending centrally into the chamber, and a blade mounted on the drive shaft for rotation therewith in a generally horizontal plane, the improvement of a system for positively propelling grass clippings out of the guard housing through the discharge opening, comprising: a. U-shaped deflector means carried by the blade and positioned behind the cutting edge portions of the blade, said deflector means being configured to propel grass clippings in directions forwardly of the blade and to substantially neutralize the tendency of the clippings to travel radially inwardly and outwardly of the blade; b. an air inlet opening formed in the guard housing at a location on the opposite side of the mower from the discharge opening; c. said inlet opening being of smaller cross-sectional area than said discharge opening and being arranged to admit air to the chamber region above the blade; and d. said guard housing defining a channel of increasing cross-sectional area in said region above the blade extending from said inlet opening to the discharge opening whereby air is drawn into the chamber region above the blade for entraining grass clippings and discharging them smoothly through the discharge opening.
Claim 10
Dependent Claim
36 words
The lawnmower of claim 7 wherein the cutting edge portions of the blade define forwardly facing hook-shaped shearing edges adapted to draw grasses radially inwardly along the blade to effect a positive shearing of the grasses.
Claim 11
Dependent Claim
66 words
The lawnmower of claim 7 wherein the blade includes a supporting member, said U-shaped deflector means are carried on said supporting member, and connection means is interposed between said supporting member and said U-shaped deflector means for adjusting the orientation of said U-shaped deflector means relative to said supporting means, whereby said deflector means can be adjusted to operate efficiently at various speeds of blade rotation.
Claim 12
Dependent Claim
220 words
In a rotary lawn mower of the type having a guard housing supported on ground engaging wheels and defining a downwardly opening chamber which is generally cylindrical about a vertical axis, a power drive unit carried by the guard housing and having a drive shaft depending centrally into the chamber, and a blade mounted on the drive shaft for rotation therewith in a generally horizontal plane and having forwardly facing U-shaped deflectors carried on the blade end regions, the improvement, comprising the combination of: a. a discharge opening formed in the guard housing and communication peripherally with the chamber; b. an air inlet opening formed in the guard housing at a location spaced circumferentially from said discharge opening; c. said inlet opening being of smaller cross sectional area than said discharge opening and being arranged to admit air to the chamber region above the blade; d. said guard housing defining a curved channel of increasing cross sectional area in a region above the blade and extending in the direction of blade rotation from said inlet opening to said discharge opening for permitting a stream of air to be drawn into the chamber region above the blade for entraining grass clippings in the air stream and for propelling the grass clippings smoothly through the chamber for discharge through said discharge opening.
Claim 13
Dependent Claim
220 words
In a rotary lawn mower of the type having a guard housing supported on ground engaging wheels and defining a downwardly opening chamber which is generally cylindrical about a vertical axis, a power drive unit carried by the guard housing and having a drive shaft depending centrally into the chamber, and a blade mounted on the drive shaft for rotation therewith in a generally horizontal plane and having forwardly facing U-shaped deflectors carried on the blade end regions, the improvement, comprising the combination of: a. a discharge opening formed in the guard housing and communication peripherally with the chamber; b. an air inlet opening formed in the guard housing at a location spaced circumferentially from said discharge opening; c. said inlet opening being of smaller cross sectional area than said discharge opening and being arranged to admit air to the chamber region above the blade; d. said guard housing defining a curved channel of increasing cross sectional area in a region above the blade and extending in the direction of blade rotation from said inlet opening to said discharge opening for permitting a stream of air to be drawn into the chamber region above the blade for entraining grass clippings in the air stream and for propelling the grass clippings smoothly through the chamber for discharge through said discharge opening.
Claim 14
Dependent Claim
22 words
The lawn mower of claim 10 wherein said discharge and inlet openings are located substantially on opposite sides of said guard housing.
Claim 15
Dependent Claim
34 words
The lawn mower of claim 10 wherein said guard housing has a substantially planar top surface and said channel is formed by portions of said guard housing which extend above said planar top surface.
Claim 16
Dependent Claim
18 words
The lawn mower of claim 12 wherein said inlet opening is formed at one end of said channel.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-09 | 1978-12-09 | 1979-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-09 | 1982-12-09 | 1983-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-09 | 1986-12-09 | 1987-06-10 | $7700.00 | Window Closed / Lapsed |