US3760570A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Centrifugally responsive brake for rotary tool
Assignee: Black and Decker Corp
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Filing: 1972-09-05
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Granted: 1973-09-25
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Expires: 1992-09-05
Abstract
Abstract An edger-trimmer including a housing supported for movement over the ground and having an upstanding handle. A motor within the housing drives a shaft having a cooling fan and a centrifugal brake means associated therewith, the brake including means normally biased into braking engagement with a stator about which the fan is circumposed, and releasable therefrom during operation of the edger-trimmer.
Inventors
- 👤 S Ehrlich
- 👤 J Dwyer
- 👤 H Klein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:32
CPC Classifications
A; A01; A01D; A01D34/00; A01D34/01; A01D34/412; A01D34/63; A01D34/67; A01D34/68; A01D34/6806; A01D34/6812; A01D34/835; A01D34/84; A01D2101/00
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
171 words
A power operated edger-trimmer comprising a housing supported for movement over the ground, a motor in said housing and driving a rotatable shaft, an upstanding handle fixed to said housing for control and manipulation of said edger-trimmer, switch control means on said handle for turning said edger-trimmer on and off, a blade operatively connected to said shaft, a brake assembly for said shaft and including a stationary hub, a plurality of pins carried by means fixed to said shaft, said pins being generally radially disposed with respect to the axis of rotation of said shaft and being symmetrically arranged about said axis, means normally biasing said pins radially inwardly of said shaft axis of rotation and into frictional rubbing engagement with said hub, said pins being movable generally radially outwardly under centrifugal force to release from rubbing engagement with said hub, whereby said pins are automatically disengaged from said hub upon energization of said motor and are automatically engaged in frictional rubbing relation with said hub upon de-energization of said motor.
Claim 2
Dependent Claim
171 words
A power operated edger-trimmer comprising a housing supported for movement over the ground, a motor in said housing and driving a rotatable shaft, an upstanding handle fixed to said housing for control and manipulation of said edger-trimmer, switch control means on said handle for turning said edger-trimmer on and off, a blade operatively connected to said shaft, a brake assembly for said shaft and including a stationary hub, a plurality of pins carried by means fixed to said shaft, said pins being generally radially disposed with respect to the axis of rotation of said shaft and being symmetrically arranged about said axis, means normally biasing said pins radially inwardly of said shaft axis of rotation and into frictional rubbing engagement with said hub, said pins being movable generally radially outwardly under centrifugal force to release from rubbing engagement with said hub, whereby said pins are automatically disengaged from said hub upon energization of said motor and are automatically engaged in frictional rubbing relation with said hub upon de-energization of said motor.
Claim 3
Dependent Claim
106 words
An electric powered device comprising a housing having an electric motor therein, rotable output shaft means driven by said motor and supported upon said housing, tool means driven by said shaft, said shaft supporting means comprising a hub rigid with said housing and having bearing means therein engaged with said shaft, operable brake means rotatable with said shaft and including means movable generally radially thereof and generally aligned with said hub, said operable brake means being normally biased into frictional rubbing engagement with said hub and being operable, upon rotation of said shaft above a predetermined speed, to move out of rubbing engagement with said hub.
Claim 4
Dependent Claim
106 words
An electric powered device comprising a housing having an electric motor therein, rotable output shaft means driven by said motor and supported upon said housing, tool means driven by said shaft, said shaft supporting means comprising a hub rigid with said housing and having bearing means therein engaged with said shaft, operable brake means rotatable with said shaft and including means movable generally radially thereof and generally aligned with said hub, said operable brake means being normally biased into frictional rubbing engagement with said hub and being operable, upon rotation of said shaft above a predetermined speed, to move out of rubbing engagement with said hub.
Claim 5
Dependent Claim
164 words
A power operated, rotary tool comprising a motor, output rotary shaft means driven by said motor and having tool means driven thereby, a fan fixed to said shaft and adapted to move cooling air through said motor, a plurality of radially movable members carried by said fan and normally biased in a generally radially inward direction, means defining a stationary surface circumscribing said shaft and within said fan and generally aligned with said radially movable members, said radially movable members being adapted to frictionally engage said surface when said shaft and fan are rotating below a predetermined speed, and being adapted to be released from rubbing engagement with said surface under the action of centrifugal force when said shaft and fan are rotating above said predetermined speed, whereby said movable members will be disengaged from said stationary surface during normal operation of said tool and will frictionally engage said stationary surface and bring said tool to an abrupt halt upon de-energization of said motor.
Claim 6
Dependent Claim
164 words
A power operated, rotary tool comprising a motor, output rotary shaft means driven by said motor and having tool means driven thereby, a fan fixed to said shaft and adapted to move cooling air through said motor, a plurality of radially movable members carried by said fan and normally biased in a generally radially inward direction, means defining a stationary surface circumscribing said shaft and within said fan and generally aligned with said radially movable members, said radially movable members being adapted to frictionally engage said surface when said shaft and fan are rotating below a predetermined speed, and being adapted to be released from rubbing engagement with said surface under the action of centrifugal force when said shaft and fan are rotating above said predetermined speed, whereby said movable members will be disengaged from said stationary surface during normal operation of said tool and will frictionally engage said stationary surface and bring said tool to an abrupt halt upon de-energization of said motor.
Claim 7
Dependent Claim
155 words
A power operated, rotary tool comprising a housing, a motor supported by said housing, a rotary member supported for rotation by said housing and driven by said motor, said rotary member having tool means driven thereby, centrifugal brake means associated with said rotary member, said brake means comprising rotor means rotatable with said rotary member and adapted to frictionally engage stator means, spring means normally biasing said rotor means into frictional rubbing engagement with said stator means, said rotor means being operable upon rotation of said rotary member above a predetermined speed and solely under the influence of centrifugal force, to move against said spring means and out of frictional engagement with said stator means, said rotor means being operable solely under the force of said spring means and at rotational speeds below said preselected level to reengage said stator means, whereby to apply a frictional braking force to said rotary member and said tool.
Claim 8
Dependent Claim
155 words
A power operated, rotary tool comprising a housing, a motor supported by said housing, a rotary member supported for rotation by said housing and driven by said motor, said rotary member having tool means driven thereby, centrifugal brake means associated with said rotary member, said brake means comprising rotor means rotatable with said rotary member and adapted to frictionally engage stator means, spring means normally biasing said rotor means into frictional rubbing engagement with said stator means, said rotor means being operable upon rotation of said rotary member above a predetermined speed and solely under the influence of centrifugal force, to move against said spring means and out of frictional engagement with said stator means, said rotor means being operable solely under the force of said spring means and at rotational speeds below said preselected level to reengage said stator means, whereby to apply a frictional braking force to said rotary member and said tool.
Claim 9
Dependent Claim
125 words
A power operated, rotary tool comprising a housing, a motor in said housing and having a rotatable armature shaft, a bearing carried by said housing and supporting said shaft adjacent one end, said shaft one end extending beyond said bearing and having tool means fixed thereto, said housing defining a stationary hub surrounding said bearing, a rotor body secured to said shaft between said hub and said tool means and having a portion confronting said hub, operable brake means carried by said rotor and normally biased into frictional rubbing engagement with said hub, said operable brake means being subject to centrifugal force during rotation of said shaft and said rotor whereby to move said operable brake means out of frictional engagement with said stationary hub.
Claim 10
Dependent Claim
125 words
A power operated, rotary tool comprising a housing, a motor in said housing and having a rotatable armature shaft, a bearing carried by said housing and supporting said shaft adjacent one end, said shaft one end extending beyond said bearing and having tool means fixed thereto, said housing defining a stationary hub surrounding said bearing, a rotor body secured to said shaft between said hub and said tool means and having a portion confronting said hub, operable brake means carried by said rotor and normally biased into frictional rubbing engagement with said hub, said operable brake means being subject to centrifugal force during rotation of said shaft and said rotor whereby to move said operable brake means out of frictional engagement with said stationary hub.
Claim 11
Dependent Claim
127 words
A centrifugally operated brake assembly for a rotary shaft comprising a housing having a bearing support, a bearing within said support and rotatably supporting a shaft extending therethrough, said support defining an annular surface, a brake band fitted over said annular surface and releasably secured to said hub, a rotor fixed to said shaft adjacent said hub, a plurality of generally radially disposed brake members carried by said rotor and symmetrically located with respect to its axis of rotation, means normally biasing said brake members into frictional engagement with said brake band, said brake members being retractable out of engagement with said brake band when said rotor travels above a preselected speed and being reengageable with said brake band when said rotor speed drops below preselected level.
Claim 12
Dependent Claim
127 words
A centrifugally operated brake assembly for a rotary shaft comprising a housing having a bearing support, a bearing within said support and rotatably supporting a shaft extending therethrough, said support defining an annular surface, a brake band fitted over said annular surface and releasably secured to said hub, a rotor fixed to said shaft adjacent said hub, a plurality of generally radially disposed brake members carried by said rotor and symmetrically located with respect to its axis of rotation, means normally biasing said brake members into frictional engagement with said brake band, said brake members being retractable out of engagement with said brake band when said rotor travels above a preselected speed and being reengageable with said brake band when said rotor speed drops below preselected level.
Claim 13
Dependent Claim
147 words
A powered device comprising a housing having an electric motor therein, said electric motor having a rotatable armature shaft, said housing including a hub surrounding said shaft and having a bearing therein rotatably supporting said shaft, said hub having an outer annular surface, an annular brake band generally complimentary to said hub surface and releasably secured thereto, a rotor fixed to said armature shaft and having a portion generally aligned with said brake band, a plurality of weighted members carried by said rotor at symmetrical locations therearound and movable under centrifugal force away from said brake band, spring means carried by said rotor and normally biasing said weighted members into frictional engagement with said brake band, said weighted members being movable radially outwardly out of frictional engagement with said brake band in response to rotation of said rotor at a speed in excess of a predetermined level.
Claim 14
Dependent Claim
147 words
A powered device comprising a housing having an electric motor therein, said electric motor having a rotatable armature shaft, said housing including a hub surrounding said shaft and having a bearing therein rotatably supporting said shaft, said hub having an outer annular surface, an annular brake band generally complimentary to said hub surface and releasably secured thereto, a rotor fixed to said armature shaft and having a portion generally aligned with said brake band, a plurality of weighted members carried by said rotor at symmetrical locations therearound and movable under centrifugal force away from said brake band, spring means carried by said rotor and normally biasing said weighted members into frictional engagement with said brake band, said weighted members being movable radially outwardly out of frictional engagement with said brake band in response to rotation of said rotor at a speed in excess of a predetermined level.
Claim 15
Dependent Claim
36 words
A device as defined in claim 7 wherein said hub and said brake band are generally frustro-conical in configuration, said weighted members being movable along a line generally normal to planes tangent to said frustro-conical surfaces.
Claim 16
Dependent Claim
26 words
A device as defined in claim 7 wherein said rotor includes a fan having blades and adapted, when rotated, to draw cooling air through said motor.
Claim 17
Dependent Claim
38 words
A device as defined in claim 6 wherein said band includes resilient fingers integral therewith and releasably receivable in slots in said support, whereby to releasably retain said band against axial and rotational movement relative to said support.
Claim 18
Dependent Claim
119 words
A centrifugal brake assembly for a rotary powered device which includes rotating shaft means, said brake comprising a bearing support including an annular hub surrounding said shaft means, a rotatable member fixed to said shaft and rotatable therewith, said rotatable member having centrifugally operated means normally biased toward said annular surface and movable away therefrom under centrifugal force generated by rotation of said shaft means and said rotatable member, a brake band releasably fitted over said annular surface, said band including a radial inturned flange at one end extending radially inwardly of said hub, said band having resilient means integral therewith adjacent the other end thereof and cooperable with said hub to releasably retain said band in position thereon.
Claim 19
Dependent Claim
119 words
A centrifugal brake assembly for a rotary powered device which includes rotating shaft means, said brake comprising a bearing support including an annular hub surrounding said shaft means, a rotatable member fixed to said shaft and rotatable therewith, said rotatable member having centrifugally operated means normally biased toward said annular surface and movable away therefrom under centrifugal force generated by rotation of said shaft means and said rotatable member, a brake band releasably fitted over said annular surface, said band including a radial inturned flange at one end extending radially inwardly of said hub, said band having resilient means integral therewith adjacent the other end thereof and cooperable with said hub to releasably retain said band in position thereon.
Claim 20
Dependent Claim
155 words
An edger-trimmer comprising a motor housing supported for movement over the ground, a motor in said housing and driving a rotatable output shaft, an edger-trimmer blade fixed to said shaft for rotation therewith, fan means fixed to said shaft and adapted to draw cooling air through said motor and discharge it outwardly of said housing, support means for said shaft including a bearing support adjacent said fan and rigid with said housing, a bearing within said support and rotatably supporting said shaft, an annular band releasably secured to said bearing support and having a portion extending radially inwardly thereof and overlaying at least a portion of said bearing, said fan including centrifugally operating, weighted means normally biased into frictional engagement with said band and movable away therefrom under centrifugal force developed during rotation of said fan, said band serving to isolate said bearing from the air moved by said fan during operation of said edger-trimmer.
Claim 21
Dependent Claim
155 words
An edger-trimmer comprising a motor housing supported for movement over the ground, a motor in said housing and driving a rotatable output shaft, an edger-trimmer blade fixed to said shaft for rotation therewith, fan means fixed to said shaft and adapted to draw cooling air through said motor and discharge it outwardly of said housing, support means for said shaft including a bearing support adjacent said fan and rigid with said housing, a bearing within said support and rotatably supporting said shaft, an annular band releasably secured to said bearing support and having a portion extending radially inwardly thereof and overlaying at least a portion of said bearing, said fan including centrifugally operating, weighted means normally biased into frictional engagement with said band and movable away therefrom under centrifugal force developed during rotation of said fan, said band serving to isolate said bearing from the air moved by said fan during operation of said edger-trimmer.
Claim 22
Dependent Claim
154 words
A powered device comprising a housing having an electric motor therein, said electric motor having a rotatable armature shaft, said housing including a hub surrounding said shaft and having a bearing therein rotatably supporting said shaft, said hub having an outer annular surface, an annular brake band generally complimentary to said hub surface and releasably secured thereto, a rotor fixed to said armature shaft and having a portion generally aligned with said brake band, a plurality of weighted members carried by said rotor at symmetrical locations therearound and movable under centrifugal force away from said brake band, spring means cArried by said rotor and normally biasing at least one of said weighted members into frictional engagement with said brake band, said at least one weighted member being movable radially outwardly out of frictional engagement with said brake band in response to rotation of said rotor at a speed in excess of a predetermined level.
Claim 23
Dependent Claim
154 words
A powered device comprising a housing having an electric motor therein, said electric motor having a rotatable armature shaft, said housing including a hub surrounding said shaft and having a bearing therein rotatably supporting said shaft, said hub having an outer annular surface, an annular brake band generally complimentary to said hub surface and releasably secured thereto, a rotor fixed to said armature shaft and having a portion generally aligned with said brake band, a plurality of weighted members carried by said rotor at symmetrical locations therearound and movable under centrifugal force away from said brake band, spring means cArried by said rotor and normally biasing at least one of said weighted members into frictional engagement with said brake band, said at least one weighted member being movable radially outwardly out of frictional engagement with said brake band in response to rotation of said rotor at a speed in excess of a predetermined level.
References Cited (Backward Citations)
US1162411A
Cited
US3228177A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |