Claims
- 1. A method of damping relative movement between components of a railway car which is selectively operable in a loaded and unloaded condition and wherein a closed hydraulic damping system having relatively movable portions is located within a spring group normally supporting such components, comprising the steps of: maintaining at least one of said portions out of operative engagement with the adjacent one of said components such that said hydraulic damping system is in standby to damp said relative movement when said railway car is normally operating in said unloaded condition; and damping said relative movement by maintaining operative engagement of both of said portions with respective adjacent ones of said components when said railway car is normally operating in said loaded condition.
- 2. A method as specified in claim 1 including the additional step of continuously biasing said closed hydraulic damping system towards one of said components.
- 3. A method as specified in claim 2 including the additional step of partially overcoming said biasing during said last mentioned maintaining.
- 4. A method as specified in claim 2 wherein said additional step of continuously biasing includes biasing said closed hydraulic system into engagement with said one of said components.
- 5. A method as specified in claim 2 wherein said components are said bolster member and said side frame member.
- 6. A method as specified in claim 5 wherein said one of said components is said side frame member and said other of said components is said bolster member.
- 7. A method as specified in claim 5 wherein said one of said components is said bolster member and said other of said components is said side frame member.
- 8. A method as specified in claim 2 including the additional step of continuously biasing said one of said portions away from the other of said portions in a direction opposite the direction towards said one of said components.
- 9. A method as specified in claim 8 wherein said continuously biasing said closed hydraulic damping system towards said one of said components is by biasing means located externally of said closed hydraulic damping system and said continuously biasing said one of said portions away from the other of said portions is by biasing means located internally of said closed hydraulic damping system.
- 10. A method as specified in claim 2 wherein said relatively movable portions reciprocate along an axis and said continuously biasing is applied to said closed hydraulic system at a location adjacent an axial end of the other of said portions and intermediate the axial ends of said other of said portions.
Parent Case Info
This application division of application Ser. No. 134,126, filed Apr. 17 1971 (now U.S. Pat. No. 3,837,292) which in turn is a continuation-in-part of application Ser. No. 857,274, filed Aug. 22, 1969, now U.S. Pat. No. 3,595,350, which in turn is a continuation-in-part of application Ser. No. 709,142 filed Feb. 28, 1968, now abandoned.
The structure of this invention provides an external reservoir for hydraulic fluid which cooperates with the snubber cylinder space to virtually eliminate the dead space or ullage volume normally necessary, at the top, within a closed hydraulic cylinder to provide for the volume of hydraulic liquid displaced by the piston rod when the piston is forced to the bottom of the cylinder. In the structure of this invention the external reservoir provides the ullage volume necessary for the operation of the piston within the cylinder so that the cylinder can be designed to operate effectively over its full stroke, with practically zero ullage volume within the cylinder.
It is therefore an object of this invention to provide a new and improved side frame snubber designed to operate at full efficiency as an energy absorbing structure throughout the full stroke of the piston within the cylinder to damper the movement of the bolster.
US Referenced Citations (8)
Divisions (1)
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Number |
Date |
Country |
| Parent |
134126 |
Apr 1971 |
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Continuation in Parts (2)
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Number |
Date |
Country |
| Parent |
857274 |
Aug 1969 |
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| Parent |
709142 |
Feb 1968 |
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Patent Grant
3995720
