US3894446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power transmission having friction clutch bias differential with automatic clutch release
Assignee: Twin Disc Inc
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Filing: 1974-06-03
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Granted: 1975-07-15
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Expires: 1994-06-03
Abstract
Abstract A power transmission for an all-wheel drive earth moving truck of the off-highway type. More specifically, an inter-axle friction clutch biased differential with automatic clutch release for such a power transmission. The differential is equipped with a clutch which provides a predetermined amount of torque differential, or bias, between the two shafts that drive the front and rear wheels, for thereby accommodating slipping conditions. The amount of differential or bias torque is determined by the load capability of the drive train which is located downstream of the differential. The clutch serves to protect the drive train from excessive loads in that, when the predetermined torque value is attained, the friction clutch will slip. Thus means are provided for sensing the slip of the friction clutch and for completely releasing the clutch before high speed slip values of the clutch are developed. Otherwise continuous slip of the clutch at high speed slip values and rated torque would cause failure of the clutch.
Inventors
- 👤 Joseph B Snoy
- 👤 Michael E Gill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:10
CPC Classifications
F; F16; F16H; F16H48/00; F16H48/20; F16H48/22; B; B60; B60K; B60K17/00; B60K17/34; B60K17/344; B60K17/346; B60K17/3462; B60K17/3465; F16H48/06; F16H48/08; F16H48/27; F16H48/30; F16H48/32; F16H48/34; F16H2048/082; F16H2048/204; F16H48/38; F16H48/40; F16H2048/405; F16H2200/00; F16H2200/20; F16H2200/203; F16H2200/2071
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
189 words
A power transmission comprising, two co-axially arranged power output shafts, differential gear means between said shafts for drivingly connecting said shafts together, a hydraulically actuated friction clutch connected between said shafts for releasably connecting said shafts together through said differential gear means for driving both of said shafts; a fluid pressure pump located between said shafts and having two portions, one connected to each of said shafts and so constructed and arranged that said pump acts to pump pressure fluid when said shafts are rotating relative to one another; and fluid pressure control means communicable with the discharge of said pump when siad shafts are rotating relative to one another, said pressure fluid control means comprising a pressure apply valve shiftable between positions for admitting pressure fluid to and preventing pressure fluid from actuating said friction clutch and also including a shiftable slip sensing valve movable relative to said pressure apply valve whereby when said shafts are rotating relative to one another, said pump discharges pressure fluid to shift said control valve means and consequently shut off pressure fluid from said clutch, thereby causing the latter to become disengaged.
Claim 2
Dependent Claim
189 words
A power transmission comprising, two co-axially arranged power output shafts, differential gear means between said shafts for drivingly connecting said shafts together, a hydraulically actuated friction clutch connected between said shafts for releasably connecting said shafts together through said differential gear means for driving both of said shafts; a fluid pressure pump located between said shafts and having two portions, one connected to each of said shafts and so constructed and arranged that said pump acts to pump pressure fluid when said shafts are rotating relative to one another; and fluid pressure control means communicable with the discharge of said pump when siad shafts are rotating relative to one another, said pressure fluid control means comprising a pressure apply valve shiftable between positions for admitting pressure fluid to and preventing pressure fluid from actuating said friction clutch and also including a shiftable slip sensing valve movable relative to said pressure apply valve whereby when said shafts are rotating relative to one another, said pump discharges pressure fluid to shift said control valve means and consequently shut off pressure fluid from said clutch, thereby causing the latter to become disengaged.
Claim 3
Dependent Claim
46 words
The transmission set forth in claim 1 further characterized in that said shiftable slip sensing valve is shiftable by discharge pressure fluid from said pump to consequently shift said pressure apply valve to said position in which it prevents fluid pressure from actuating said friction clutch.
Claim 4
Dependent Claim
61 words
The transmission set forth in claim 2 including pressure fluid passage means in said slip sensing valve and means on said pressure apply valve for closing said passage means in said slip sensing valve when said valves abut against one another to thereby prevent said pump from shifting said valves to said position for admitting fluid pressure to actuate said clutch.
Claim 5
Dependent Claim
260 words
A vehicle having front and rear driving wheels, a power plant, a change speed gear transmission drive by said power plant and having an output which can be varied as to rotative speed and direction, and a friction clutch bias differential mechanism connecting said gear transmission output to both said front and rear wheels, said mechanism comprising: two co-axially arranged power output shafts, differential gear means between said shafts for drivingly connecting said shafts together, a hydraulically actuated friction clutch connected between said shafts for releasably connecting said shafts together through said differential gear means for driving both of said shafts; a fluid pressure pump located between said shafts and having two portions, one connected to each of said shafts and so constructed and arranged that said pump acts to pump pressure fluid when said shafts are rotating relative to one another; and fluid pressure control means communicable with the discharge of said pump when said shafts are rotating relative to one another, said pressure fluid control means comprising a pressure apply valve shiftable between positions for admitting pressure fluid to and preventing pressure fluid from actuating said friction clutch and also including a shiftable slip sensing valve movable relative to said pressure apply valve whereby when said shafts are rotating relative to one another, said pump discharges pressure fluid to shift said control valve means and consequently shut off pressure fluid from said clutch, thereby causing the latter to become disengaged; and power transmitting means for connecting said two power output shafts to their respective front and rear wheels.
Claim 6
Dependent Claim
260 words
A vehicle having front and rear driving wheels, a power plant, a change speed gear transmission drive by said power plant and having an output which can be varied as to rotative speed and direction, and a friction clutch bias differential mechanism connecting said gear transmission output to both said front and rear wheels, said mechanism comprising: two co-axially arranged power output shafts, differential gear means between said shafts for drivingly connecting said shafts together, a hydraulically actuated friction clutch connected between said shafts for releasably connecting said shafts together through said differential gear means for driving both of said shafts; a fluid pressure pump located between said shafts and having two portions, one connected to each of said shafts and so constructed and arranged that said pump acts to pump pressure fluid when said shafts are rotating relative to one another; and fluid pressure control means communicable with the discharge of said pump when said shafts are rotating relative to one another, said pressure fluid control means comprising a pressure apply valve shiftable between positions for admitting pressure fluid to and preventing pressure fluid from actuating said friction clutch and also including a shiftable slip sensing valve movable relative to said pressure apply valve whereby when said shafts are rotating relative to one another, said pump discharges pressure fluid to shift said control valve means and consequently shut off pressure fluid from said clutch, thereby causing the latter to become disengaged; and power transmitting means for connecting said two power output shafts to their respective front and rear wheels.
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) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |