US3760922A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary couplings
Assignee: FERGUSON H LTD GB
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Filing: 1971-07-16
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Granted: 1973-09-25
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Expires: 1991-07-16
Abstract
Abstract A device for controlling or limiting difference in rotational speed or acceleration between relatively rotatable shafts, for example the front and rear propeller shafts in a four-wheel drive motor vehicle transmission, employs a viscous liquid such as a silicone fluid in contact with relatively rotatable sets of mutually interleaved and mutually spaced annular plates the working surfaces of which are provided with through openings in the form of holes and/or radial slots from which are derived in combination with the inclusion of a pre-determined quantity of air in the viscous liquid advantages including inter alia improved compactness in relation to torque capacity and in relation to dissipation of heat generated during shearing of the viscous fluid. A transmission unit incorporating an interaxle differential gear and such a device is described.
Inventors
- 👤 A Rolt
- 👤 D Gardner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 02:42
CPC Classifications
B; B60; B60K; B60K17/00; B60K17/34; B60K17/344; B60K17/346; B60K17/3462; B60K17/3465; F; F16; F16D; F16D35/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
124 words
A control coupling comprising mutually spaced and mutually interleaved elements arranged for rotation about a common axis within an enclosure containing a viscous fluid in contact with adjacent surfaces of said elements, alternate ones of said elements constituting a first set of elements for driving connection with a first rotatable member, remaining ones of said elements constituting a second set of elements for driving connection with a second rotatable member, the torquetransmitting capability of the coupling in relation to rotational speed-difference between the sets of elements being progressive throughout a desired speed-difference range by virtue of the inclusion of a pre-determined quantity of gas in the viscous fluid in combination with the provision of means defining openings through the said surfaces of the elements.
Claim 2
Dependent Claim
124 words
A control coupling comprising mutually spaced and mutually interleaved elements arranged for rotation about a common axis within an enclosure containing a viscous fluid in contact with adjacent surfaces of said elements, alternate ones of said elements constituting a first set of elements for driving connection with a first rotatable member, remaining ones of said elements constituting a second set of elements for driving connection with a second rotatable member, the torquetransmitting capability of the coupling in relation to rotational speed-difference between the sets of elements being progressive throughout a desired speed-difference range by virtue of the inclusion of a pre-determined quantity of gas in the viscous fluid in combination with the provision of means defining openings through the said surfaces of the elements.
Claim 3
Dependent Claim
46 words
A control coupling according to claim 1, wherein the quantity of gas included in the viscous fluid is such that the volume of the gas at a selected ambient temperature is equal to or less than fifteen per cent of the volume of the viscous fluid.
Claim 4
Dependent Claim
72 words
A control coupling according to claim 2, wherein each of said elements is an annular plate, and said means defining openings in respect of the plates in one of the sets comprises a plurality of through apertures arranged around the said common axis, and the said means defining openings in respect of the plates of the other of the sets comprises a plurality of open-ended slots arranged around the said common axis.
Claim 5
Dependent Claim
47 words
A control coupling according to claim 3, wherein the quantity of gas included in the viscous fluid is such that the volume of gas within the enclosure at an ambient temperature in the region of 25*C is approximately 10 percent of the volume of the viscous fluid.
Claim 6
Dependent Claim
70 words
A control coupling according to claim 4, wherein the said enclosure includes mutually concentric cylindrical walls relatively rotatable about said common axis and adapted respectively for driving connection with first and second rotatable members, the plates of one of said sets being in driving connection with the outer of said walls, and the plates of the other of said sets being in driving connection with the inner of said walls.
Claim 7
Dependent Claim
48 words
A control coupling according to claim 5, wherein the plates having the said plurality of through apertures are in driving connection with the said outer of said walls, and the plates having the plurality of open-ended slots are in driving connection with the said inner of said walls.
Claim 8
Dependent Claim
15 words
A Control coupling according to claim 6, wherein the viscous fluid is a silicone fluid.
Claim 9
Dependent Claim
46 words
A control coupling according to claim 1, wherein the quantity of gas included in the viscous fluid is such that the volume of the gas at an ambient temperature in the region of 25*C is approximately 10 per cent of the volume of the viscous fluid.
Claim 10
Dependent Claim
16 words
A control coupling according to claim 1, wherein each of said elements is an annular plate.
Claim 11
Dependent Claim
63 words
A control coupling according to claim 9, wherein said means defining openings in respect of the plates in one of the sets comprises a plurality of through apertures arranged around the said common axis, and the said means defining openings in respect of the plates of the other of the sets comprises a plurality of open-ended slots arranged around the said common axis.
Claim 12
Dependent Claim
15 words
A control coupling according to claim 1, wherein the viscous fluid is a silicone fluid.
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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 |