US4393957A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of eliminating truck hunting in railway trucks
Assignee: Individual
•
Filing: 1981-01-27
•
Granted: 1983-07-19
•
Expires: 2001-01-27
Abstract
Abstract Truck hunting is eliminated in railway vehicles by applying a low coefficient of friction material to the vehicle wheels so that a lubricating film is provided between the vehicle wheels and the rail on which they ride which serves to increase the critical speed of a rail vehicle, i.e., the speed at which truck hunting occurs, to a value above its operating speed.
Inventors
- 👤 V. T. Hawthorne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:31
CPC Classifications
B; B61; B61F; B61F5/00; B61F5/50; B61F5/52; B61K; B61K3/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
158 words
In the operation of a rail vehicle having trucks with rail contacting wheels and brakes with brake shoes associated with each of said wheels, said rail vehicle being associated with other similar rail vehicles and pulled by a locomotive means, said trucks on each of said pulled rail vehicles tending to vibrate or hunt when pulled by said locomotive means at a speed above a critical speed, a method of eliminating said vibration or hunting to increase the critical speed of said rail vehicle to a value above its operating speed comprised of: sensing the speed of said vehicle and producing a correlated speed signal; comparing said speed signal to a fixed reference signal correlated to the critical speed; and applying a low coefficient of friction material to the wheels of said rail vehicle to provide a lubricating film between said wheels and the rail on which they ride only when said speed signal exceeds said reference signal.
Claim 2
Dependent Claim
158 words
In the operation of a rail vehicle having trucks with rail contacting wheels and brakes with brake shoes associated with each of said wheels, said rail vehicle being associated with other similar rail vehicles and pulled by a locomotive means, said trucks on each of said pulled rail vehicles tending to vibrate or hunt when pulled by said locomotive means at a speed above a critical speed, a method of eliminating said vibration or hunting to increase the critical speed of said rail vehicle to a value above its operating speed comprised of: sensing the speed of said vehicle and producing a correlated speed signal; comparing said speed signal to a fixed reference signal correlated to the critical speed; and applying a low coefficient of friction material to the wheels of said rail vehicle to provide a lubricating film between said wheels and the rail on which they ride only when said speed signal exceeds said reference signal.
Claim 3
Dependent Claim
13 words
The method of claim 1, wherein said low coefficient friction material is water.
Claim 4
Dependent Claim
60 words
The method of claim 1, wherein said step of applying draws water by gravity flow to nozzles located above each wheel from a reservoir located on each of said rail vehicles through a fluid conduit connecting said nozzles and said reservoir, and includes constantly dripping the water from the nozzle onto each of said wheels to provide a lubricating film.
Claim 5
Dependent Claim
20 words
The method of claim 3, including ceasing said gravity flow of water to said wheels when said brakes are actuated.
Claim 6
Dependent Claim
141 words
In the operation of a rail vehicle having trucks with rail contacting wheels and brakes with brake shoes associated with each of said wheels, said rail vehicle being associated with other similar rail vehicles and pulled by locomotive means, said trucks on each of said pulled rail vehicles tending to vibrate or hunt when pulled by said locomotive means at a speed above a critical speed, a method of eliminating said vibration or hunting and increasing the critical speed of said rail vehicle to a value above its operating speed comprised of: sensing truck hunting in said vehicle truck and producing a correlated hunting signal; and applying a low coefficient friction material to the wheels of said rail vehicles to provide a lubricating film between the wheels and the rail on which they ride only when a hunting signal is produced.
Claim 7
Dependent Claim
141 words
In the operation of a rail vehicle having trucks with rail contacting wheels and brakes with brake shoes associated with each of said wheels, said rail vehicle being associated with other similar rail vehicles and pulled by locomotive means, said trucks on each of said pulled rail vehicles tending to vibrate or hunt when pulled by said locomotive means at a speed above a critical speed, a method of eliminating said vibration or hunting and increasing the critical speed of said rail vehicle to a value above its operating speed comprised of: sensing truck hunting in said vehicle truck and producing a correlated hunting signal; and applying a low coefficient friction material to the wheels of said rail vehicles to provide a lubricating film between the wheels and the rail on which they ride only when a hunting signal is produced.
Claim 8
Dependent Claim
14 words
The method of claim 5, wherein said low coefficient of friction material is water.
Claim 9
Dependent Claim
67 words
The method of claim 5, wherein said step of applying draws water by gravity flow to nozzles located above each wheel from a reservoir located on each of said rail vehicles through a fluid conduit connecting said nozzles and said reservoir, and includes constantly dripping the water from the nozzle onto each of said wheels to provide said lubricating film only when said hunting signal is produced.
Claim 10
Dependent Claim
20 words
The method of claim 7, including ceasing said gravity flow of water to said wheels when said brakes are actuated.
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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) | 1986-07-18 | 1987-01-17 | 1987-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-18 | 1991-01-17 | 1991-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-18 | 1995-01-17 | 1995-07-19 | $7700.00 | Window Closed / Lapsed |