US4171608A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Safety attachment for lawn mowers
Assignee: Individual
•
Filing: 1977-11-21
•
Granted: 1979-10-23
•
Expires: 1997-11-21
Abstract
Abstract A safety attachment is provided for use with a rotary lawn mower to prevent substantial injury to anyone whose extremity may accidentally strike the cutter. The attachment includes a relatively large annular disc mounted to the drive shaft of the motor for rotation about a vertical axis and at least one cutter bar mounted diametrically across the disc on the underside thereof. The disc diameter is substantially equal to the length of the cutter bar. In one embodiment slots are provided adjacent to the leading edges of the cutter bar and impellers are provided on the upper side of the disc adjacent the slot fordischarging cut grass through the side of the machine. The combination of the disc and the cutter bar provides good grass cutting action and at the same time greatly reduces the risk of serious injury in the event that one's foot, for example, accidentally slips in under the mower.
Inventors
- 👤 Glenn C. Hetrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:36
CPC Classifications
A; A01; A01D; A01D34/00; A01D34/01; A01D34/412; A01D34/63; A01D34/82; A01D34/828; A01D34/73; A01D2101/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
202 words
A safety attachment for a rotary lawn mower having a motor and a drive shaft mounted thereto, comprising: a generally rigid disc mountable to the lower end of said shaft, the underside of said disc presenting a substantially flat, smooth continuous surface and the periphery thereof presenting a smooth, continuous substantially circular edge; and a cutter bar having substantially planar upper and lower surfaces and being detachably mounted diametrically across and with said upper surface directly flushly against the underside surface of said disc over substantially the full upper surface of the bar, the length of said cutter bar being substantially equal to the diameter of said disc with the ends of said bars being substantially even with the peripheral edge of said disc, said cutter bar being rectangular in cross-section, each longitudinal edge of said bar providing a cutting edge when in cutting position with respect to said disc, the cutting position of each longitudinal edge being that position occupied by said longitudinal edge when disposed at a lower forward edge of said bar relative to the direction of rotation of said disc and said bar, the bar acting in a horizontal cutting plane to cut material brought into contact therewith.
Claim 2
Dependent Claim
202 words
A safety attachment for a rotary lawn mower having a motor and a drive shaft mounted thereto, comprising: a generally rigid disc mountable to the lower end of said shaft, the underside of said disc presenting a substantially flat, smooth continuous surface and the periphery thereof presenting a smooth, continuous substantially circular edge; and a cutter bar having substantially planar upper and lower surfaces and being detachably mounted diametrically across and with said upper surface directly flushly against the underside surface of said disc over substantially the full upper surface of the bar, the length of said cutter bar being substantially equal to the diameter of said disc with the ends of said bars being substantially even with the peripheral edge of said disc, said cutter bar being rectangular in cross-section, each longitudinal edge of said bar providing a cutting edge when in cutting position with respect to said disc, the cutting position of each longitudinal edge being that position occupied by said longitudinal edge when disposed at a lower forward edge of said bar relative to the direction of rotation of said disc and said bar, the bar acting in a horizontal cutting plane to cut material brought into contact therewith.
Claim 3
Dependent Claim
34 words
A safety attachment, according to claim 1, including at least a second cutter bar diametrically and detachably mounted to and directly flat against the lower face of said disc and intersecting said first bar.
Claim 4
Dependent Claim
12 words
A safety attachment, according to claim 1, wherein the bar is straight.
Claim 5
Dependent Claim
21 words
A safety attachment, according to claim 1, and further comprising releasable connecting means for detachably mounting said bar to said disc.
Claim 6
Dependent Claim
141 words
A safety attachment for a rotory lawn mower having a motor and drive shaft mounted thereto, comprising: a disc mountable to the lower end of said shaft, the underside of said disc presenting a substantially planar, continuous surface with the periphery of the disc presenting a continuous substantially circular edge; a cutter bar mounted diametrically across the underside of said disc, full upper surfaces of the cutter bar being mounted flushly against the underside surface of said disc, a lower forward edge of said bar acting in a horizontal cutting plane to cut material brought into contact therewith, the length of said cutter bar being substantially equal to the diameter of said disc with the ends of said bar being substantially even with the peripheral edge of said disc; and releasable connecting means for detachably mounting said bar to said disc.
Claim 7
Dependent Claim
141 words
A safety attachment for a rotory lawn mower having a motor and drive shaft mounted thereto, comprising: a disc mountable to the lower end of said shaft, the underside of said disc presenting a substantially planar, continuous surface with the periphery of the disc presenting a continuous substantially circular edge; a cutter bar mounted diametrically across the underside of said disc, full upper surfaces of the cutter bar being mounted flushly against the underside surface of said disc, a lower forward edge of said bar acting in a horizontal cutting plane to cut material brought into contact therewith, the length of said cutter bar being substantially equal to the diameter of said disc with the ends of said bar being substantially even with the peripheral edge of said disc; and releasable connecting means for detachably mounting said bar to said disc.
Claim 8
Dependent Claim
34 words
A safety attachment, according to claim 5, wherein said connecting means includes a groove formed diametrically across the underside of said disc, said groove having a depth less than the thickness of said bar.
Claim 9
Dependent Claim
50 words
A safety attachment, according to claim 5, wherein said connecting means includes a pair of diametrically spaced studs mounted to the underside of said disc, said bar being formed with a pair of longitudinally spaced openings adapted to receive said studs when said bar is in position against said disc.
Claim 10
Dependent Claim
13 words
A safety attachment, according to claim 7, wherein said openings are keyhole shaped.
References Cited (Backward Citations)
US3097469A
Cited
US2859581A
Cited
US3283488A
Cited
US3327460A
Cited
US3399519A
Cited
US3420043A
Cited
US3534534A
Cited
US3805502A
Cited
DE2327356A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-10-22 | 1983-04-23 | 1983-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-22 | 1987-04-23 | 1987-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-22 | 1991-04-23 | 1991-10-23 | $7700.00 | Window Closed / Lapsed |