Patent US3712438A successfully refreshed from Google Patents.
US3712438A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Centrifugal friction clutch
Assignee: Emerson Electric Co
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Filing: 1971-03-15
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Granted: 1973-01-23
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Expires: 1991-03-15
Abstract
Abstract A centrifugal friction clutch having a cup-shaped driven member with a hub receiving a driven shaft and a generally cylindrical driving member freely entered therein for rotation in one direction and comprising two generally semicylindrical shoes, a central hub receiving a driving shaft and a pair of flexible arms extending oppositely outward from the hub between the adjacent flat surfaces of the shoes and connecting the opposite trailing ends of the shoes to the hub, whereby centrifugal force moves the shoes radially into frictional engagement with the annular wall of the cup and whereby the frictional force is increased as the arms flex when stressed between peripheral frictional force and driving torque, both driving and driven members being formed as castings of synthetic plastic material and the cup-shaped driven member having a flexible bottom wall and a long flexible hub which flex to compensate for slight non-parallelism and misalignment of the driving and driven shafts to which the device is connected.
Inventors
- 👤 J Roddy
- 👤 W Page
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:59
CPC Classifications
F; F16; F16D; F16D43/00; F16D43/02; F16D43/04; F16D43/14; F16D43/18
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
170 words
A centrifugal friction clutch comprising a driven member having an annular wall and a driving member of general cylindrical form loosely entered into said annular wall, said driving member being adapted to rotate in one direction and being formed as a casting of synthetic plastic material and comprising as integral portions thereof a pair of shoe members of general semicylindrical form with flat sides facing each other in spaced relationship, a central hub member adapted to receive a driving shaft, and a flexible arm connecting each of said shoes to said hub, said connecting arms extending oppositely and radially from said hub between the adjacent flat sides of said shoes to connection with the oPposite trailing ends of said shoes whereby said shoes are movable radially to engage said annular wall, said shoes being segments sufficiently less than semicylindrical to provide space between the flat sides thereof for the positioning and flexing of said arms and the flat sides of said shoes being recessed to provide clearance for said hub.
Claim 2
Dependent Claim
170 words
A centrifugal friction clutch comprising a driven member having an annular wall and a driving member of general cylindrical form loosely entered into said annular wall, said driving member being adapted to rotate in one direction and being formed as a casting of synthetic plastic material and comprising as integral portions thereof a pair of shoe members of general semicylindrical form with flat sides facing each other in spaced relationship, a central hub member adapted to receive a driving shaft, and a flexible arm connecting each of said shoes to said hub, said connecting arms extending oppositely and radially from said hub between the adjacent flat sides of said shoes to connection with the oPposite trailing ends of said shoes whereby said shoes are movable radially to engage said annular wall, said shoes being segments sufficiently less than semicylindrical to provide space between the flat sides thereof for the positioning and flexing of said arms and the flat sides of said shoes being recessed to provide clearance for said hub.
Claim 3
Dependent Claim
46 words
The clutch claimed in claim 1 in which said connecting arms are substantially straight and spaced from coextending portions of the flat shoe surfaces and each including a short arcuate portion at its outer end connecting its outer end with the end of its respective shoe.
Claim 4
Dependent Claim
54 words
The clutch claimed in claim 1 in which said driven member is a cup-shaped member formed as a casting of synthetic plastic material and includes in addition to said annular wall as integral portions thereof a central hub for receiving a driven shaft and a bottom wall joining said hub with said annular wall.
Claim 5
Dependent Claim
69 words
The clutch claimed in claim 1 in which the plastic material of which said driving member is formed includes glass fibers dispersed therein in sufficient quantity to provide the elasticity required in said connecting arms to permit outward travel of said shoes under centrifugal force with sufficient recovery force to retract them and to provide the strength required in said connecting arms to transmit the torque without undue flexing.
Claim 6
Dependent Claim
56 words
The clutch claimed in claim 3 in which said driven member is formed of a synthetic plastic material other than the material of which said driving member is formed, and which includes dispersed therein small metal particles in an amount to substantially increase dissipation of heat developed in small local areas of the frictionally engaged surface.
Claim 7
Dependent Claim
34 words
The clutch claimed in claim 5 in which the material of which said driven member is formed further includes dispersed therein glass fibers in an amount necessary to attain the flexibility and strength required.
Claim 8
Dependent Claim
149 words
In a centrifugal friction clutch, a cup-shaped driven member comprising an annular side wall, a bottom wall, and a hub receiving a driven shaft, a generally cylindrical driving member loosely entered into said driven member and comprising a pair of generally semicylindrical shoes with flat sides facing each other in spaced relationship, a central hub, and a pair of flexible arms connecting the opposite ends of the shoes with the hub whereby the shoes are moved radially outward by centrifugal force into engagement with said annular wall, driving means including a drive shaft entered into said central hub operative to drive said driving member in a predetermined direction of rotation, said flexible arms being substantially straight and extending radially between the adjacent flat sides of said shoes and connecting that end of each shoe with said hub member which is trailing with respect to said predetermined direction of rotation.
Claim 9
Dependent Claim
149 words
In a centrifugal friction clutch, a cup-shaped driven member comprising an annular side wall, a bottom wall, and a hub receiving a driven shaft, a generally cylindrical driving member loosely entered into said driven member and comprising a pair of generally semicylindrical shoes with flat sides facing each other in spaced relationship, a central hub, and a pair of flexible arms connecting the opposite ends of the shoes with the hub whereby the shoes are moved radially outward by centrifugal force into engagement with said annular wall, driving means including a drive shaft entered into said central hub operative to drive said driving member in a predetermined direction of rotation, said flexible arms being substantially straight and extending radially between the adjacent flat sides of said shoes and connecting that end of each shoe with said hub member which is trailing with respect to said predetermined direction of rotation.
Claim 10
Dependent Claim
49 words
The subject matter claimed in claim 7 in which said driven member is formed as a casting of synthetic plastic material and in which said bottom wall is flexible, thereby to permit tilting of the annular side wall to compensate for slight non-parallelism of said driving and driven shafts.
Claim 11
Dependent Claim
35 words
The subject matter claimed in claim 7 in which said hub of said driven member is relatively long and flexible whereby it flexes to compensate for any slight misalignment of said driving and driven shafts.
Claim 12
Dependent Claim
83 words
The subject matter claimed in claim 7 in which said driven member further includes an internal axially extending guide pin and in which said hub of said driving member includes an axial bore receiving said guide pin, the fit of said guide pin in said hub being such as to permit the free rotation of the driving member therein while preventing contact of the driving member with the annular wall of the driven member when said driving member is in a retracted position.
Claim 13
Dependent Claim
50 words
The subject matter claimed in claim 7 in which the arcuate surfaces of said generally semicylindrical shoes each include an intermediate, raised, arcuate suRface portion arranged to frictionally engage said annular wall of said driven member and to space the remainder of the arcuate shoe surface from said annular wall.
Claim 14
Dependent Claim
32 words
The subject matter claimed in claim 11 in which said raised arcuate surface portions have a radius substantially equal to the radius of curvature of said annular wall of said driving member.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-23 | 1976-07-24 | 1977-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-23 | 1980-07-24 | 1981-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-23 | 1984-07-24 | 1985-01-23 | $7700.00 | Window Closed / Lapsed |