US3698523A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-propelled random motion lawnmower
Assignee: Mowbot Inc
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Filing: 1969-10-20
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Granted: 1972-10-17
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Expires: 1989-10-20
Abstract
Abstract Disclosed is a self-propelled lawnmower for cutting grass in a completely random and unattended manner. The unit is preferably propelled by a battery and comprises a frame supported on a pair of front caster wheels and a pair of rear drive wheels. The drive wheels are coupled to a continuously rotating drive shaft by individual clutch-brake mechanisms. When a boundary wire is sensed by coils on the frame, the drive wheel furthest away from the broader is unclutched and braked to pivot or turn the mower. No backup motor or complex steering control is required. A pair of adjustable rotary cutter blade assemblies are carried on the frame.
Inventors
- 👤 S Lawrence Bellinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:46
CPC Classifications
A; A01; A01D; A01D34/00; A01D34/006; A01D34/008; A01D69/00; A01D69/02; A01D69/08; G; G05; G05D; G05D1/00; G05D1/02; G05D1/021; G05D1/0259; G05D1/0265; A01D2101/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
102 words
A combination clutch-brake comprising rotatable driving and driven members, a helical coil spring surrounding said members and coupling said driving member to said driven member, a metal band secured to the drive end of said spring, the opposite end of said spring being secured to said driven member, a pivoted lever, a coil and core mounted on said lever, said core including means for frictionally engaging said band and means for energizing said coil to pivot said lever and cause said core to engage and stop said band whereby said spring expands and releases said driving member and brakes said driven member.
Claim 2
Dependent Claim
102 words
A combination clutch-brake comprising rotatable driving and driven members, a helical coil spring surrounding said members and coupling said driving member to said driven member, a metal band secured to the drive end of said spring, the opposite end of said spring being secured to said driven member, a pivoted lever, a coil and core mounted on said lever, said core including means for frictionally engaging said band and means for energizing said coil to pivot said lever and cause said core to engage and stop said band whereby said spring expands and releases said driving member and brakes said driven member.
Claim 3
Dependent Claim
19 words
Apparatus according to claim 1 including a pair of levers, coils and cores on opposite sides of said band.
Claim 4
Dependent Claim
15 words
Apparatus according to claim 1 wherein said core and coil are pivoted to said lever.
Claim 5
Dependent Claim
18 words
Apparatus according to claim 1 including a spring biasing said lever, coil and core away from said band.
References Cited (Backward Citations)
US2976976A
Cited
US3228497A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |