US3670413A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coupling for tool element
Assignee: Black and Decker Corp
•
Filing: 1970-08-21
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Granted: 1972-06-20
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Expires: 1990-08-21
Abstract
Abstract An electric grass trimming device comprising a handle including a grip and trigger switch at one end and an electric motor at the other end, the motor being arranged to drive a cutting blade mounted beneath the motor. An improved coupling arrangement between the blade and the motor shaft is described.
Inventors
- 👤 Edwin J Weber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:34
CPC Classifications
A; A01; A01D; A01D34/00; A01D34/01; A01D34/412; A01D34/63; A01D34/67; A01D34/68; A01D34/6806; A01D34/82; A01D34/828; A01D69/00; A01D69/08; A01D75/00; A01D75/20; A01D75/206; F; F16; F16D; F16D1/00; F16D1/06; F16D1/08; F16D1/0852; F16D1/0858; F16D7/00; F16D7/02; A01D2034/6843; A01D2101/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
129 words
In a portable, hand-held grass trimming device including an electric motor, a housing for said motor and a handle extending from said housing; said motor having an output shaft extending therefrom, and an elongated cutting blade mounted at the end of said output shaft for cutting grass upon rotation of said shaft, the improvement comprising an insulating coupling member mounted on the end of said shaft, said member having an annular groove in the surface thereof; and means for retaining said blade tightly against the end of said member, said retaining means and said blade being insulated from said shaft by said member; said retaining means comprising spring means coupled to said blade and engaged in said groove, said spring means providing a slip clutch drive for said blade.
Claim 2
Dependent Claim
129 words
In a portable, hand-held grass trimming device including an electric motor, a housing for said motor and a handle extending from said housing; said motor having an output shaft extending therefrom, and an elongated cutting blade mounted at the end of said output shaft for cutting grass upon rotation of said shaft, the improvement comprising an insulating coupling member mounted on the end of said shaft, said member having an annular groove in the surface thereof; and means for retaining said blade tightly against the end of said member, said retaining means and said blade being insulated from said shaft by said member; said retaining means comprising spring means coupled to said blade and engaged in said groove, said spring means providing a slip clutch drive for said blade.
Claim 3
Dependent Claim
17 words
The combination claimed in claim 1 wherein said spring means comprises an integral extension of said blade.
Claim 4
Dependent Claim
29 words
The combination claimed in claim 1 wherein said spring means comprises an independent, cup-shaped member for receiving said blade and including spring elements for engaging in said annular groove.
References Cited (Backward Citations)
US2539619A
Cited
US3146007A
Cited
US3270467A
Cited
US3264016A
Cited
US3342273A
Cited
US3436875A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |