CA1036985A - End of car cushioning unit - Google Patents
End of car cushioning unitInfo
- Publication number
- CA1036985A CA1036985A CA206,788A CA206788A CA1036985A CA 1036985 A CA1036985 A CA 1036985A CA 206788 A CA206788 A CA 206788A CA 1036985 A CA1036985 A CA 1036985A
- Authority
- CA
- Canada
- Prior art keywords
- car
- piston
- cushioning unit
- cylinder
- passage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000012530 fluid Substances 0.000 claims description 8
- 230000035939 shock Effects 0.000 claims description 3
- 238000013016 damping Methods 0.000 claims description 2
- 239000007789 gas Substances 0.000 description 4
- 230000002093 peripheral effect Effects 0.000 description 4
- 238000011068 loading method Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 101100273206 Arabidopsis thaliana CAR3 gene Proteins 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 101150008711 carC gene Proteins 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B61—RAILWAYS
- B61G—COUPLINGS; DRAUGHT AND BUFFING APPLIANCES
- B61G9/00—Draw-gear
- B61G9/04—Draw-gear combined with buffing appliances
- B61G9/08—Draw-gear combined with buffing appliances with fluid springs or fluid shock-absorbers; Combinations thereof
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Fluid-Damping Devices (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A hydraulic end of car cushioning device for use in railway freight cars. The device is intended for use between the coupler shank and car under-frame of a fixed sill type car and is designed so as to provide a long cushioning stroke under high impact loads. A load responsive check valve is interposed in the metering system of the cushioning device for preventing changes in lengthof the unit under lower buff and draft forces as occur in train action.
A hydraulic end of car cushioning device for use in railway freight cars. The device is intended for use between the coupler shank and car under-frame of a fixed sill type car and is designed so as to provide a long cushioning stroke under high impact loads. A load responsive check valve is interposed in the metering system of the cushioning device for preventing changes in lengthof the unit under lower buff and draft forces as occur in train action.
Description
~3~9~5 Ti~i~ inv(~ rel.ltes to a c~l~;lli()n;llg unit Ind more particularly to a cu.cl):iolli1lg un:it adal)ted ior use aL the ends of raLlway carC;, It has been the practice to upgrc-~de existing, fixed sill railway cars by providing them with end of car cushiorling devices. ~Iydraullc cushioning units have been proposed for this purpose. The cushioning unit, however, experiences widely different types of loadings. When making up a train in a switching or classification yard, the car receives extreme shock loadings due to high velocity impacts. Under such conditions, it is desirable to provide an extremely long cushioning stroke to effectively absorb these impacts. Long stroke end of car cushioning units, however, are not desirable when the train has been made up and is in transit. The units have a tendency to extend the length of the train considerably during these condition and cause considerable problems when the slack is taken up.
An object of the invention is to provide an end of car cushioning unit that provides a long stroke under high impacts but which resists changes in length under lower loading.
It is a further object of the invention to provide an end of car cushioning unit that requires a predetermined force to be applied to it before its cushioning operation becomes effect-ive.
According to the present invention there is provided an end of car cushioning unit adapt:ed to be interposed between a coupler and a car frame of a railway car for damping shock forces.
The cushioning unit includes a cylinder, a piston received within the cylinder, and means including the piston and cy:Linder defining first and second chamber sections adapted to receive a fluid. A
passage means ineludes primary metering means is in eommunication ~ith said ehamber seetions for passin~ fluid bet-~een said ehamber seeticn at a restricted rate upon relative movement of ,,i ~ ~
~36~5 the piston and the cylinder. The primary metering means is adapted to experience flow in one direction upon relative movement of the piston and the cylinder in a first direction and in an opposite dlrection upon relative movement of the piston and cylinder in an opposite direction. Means are provided for precluding the flow of flu:Ld through the primary metering means in each direction until a predtermined force is 8 applied in the respective direction to the cushioning, the means being a pressure responsive valve means in the passage.
- jb/ - 2a -~o~ s unit .
Figure 1 is a longitudinal crosssectional view taken through the end of a railway car having a cushioning unit embodying this invention with the car structure being shown in phantom.
Figure 2 is an enlarged view showing the metering device of the cushion-ing unit as it appears under buff forces.
Figure 3 is an enlarged view, in part similar to Figure 2, showing the device as it appears when it experiences draft forces.
Figure 1 illustrates an end of car cushioning unit embodying this invention, identified generally by the reference numeral 11. The end of car cushioning unit 11 is adapted to be interposed between a coupler shank 12 and the car underframe 13. The installation may be accomplished in any of a variety of manners and, for this reason, the car structure has been shown only in phantom.
Certain details of the illustrated installation will be described, but should only be considered as exemplary in nature.
The cushioning unit 11 includes a cylinder assembly 14 comprised of a cylinder head 15, a tubular cylinder 16 and a closure plug 17. The cylinder16 defines a cylindrical bore 18 closed at one end by the cylinder head 15 and at the other end by the plug 17 to define a fluid receiving chamber 19.
The chamber 19 is divided into two sections by means of a piston assembly 21 that is slidably supported within the bore 18. The piston assembly 21 includes an orifice plate 22 that is affixed to a main piston 23 by means of bolts 24, only one of which appears in the drawings. An antifriction bushing 25 engages the bore 18 and i8 trapped between outstanding flanges of the orifice plate 22 and the main piston 23. The piston 23 is also formed with an annular groove 26 in which a piston ring 27 is positioned to sealingly engage the bore 18.
A piston rod 28 is affixed in any known manner to the piston assembly 21 and extends through an opening 29 formed in the closure plug 17. A bushing 31 and seal assembly 32 carried by the closure plug 17 supports and sealingly ~3fà~S
engages the piston rod 28.
The piston rod 28 ha~ affixed to it~ outer end a draft collar 33 that is trapped in a draft lug a6sembly, indicated by the reference numeral 34 that is fixed in any suitable manner to the underframe of the as~ociated railway car.
The cooperation of the draft lug assembly 34 with the draft collar 33 couples the piston rod 28 and piston assembly 21 to the car underframe 13. That is, the piston assembly 21is held against any substantial movement relative to the underframe structure 13. :
The cylinder head 15 is formed at its outer end with a socket 35 that ;~
10 receives the coupler shank 12. Alligned openings 36 and 37 are formed on opposite sides of the socket 35 to receive a draft key (not shown) for fixing the coupler shank to the cylinder head 15. Thus, the cylinder assembly 14is affixed for movement with the coupler shank 12. A stop block 38 is fixed to the underframe 13 and i~
abuttingly engaged by the cylinder head 15 when the cushioning unit 11 i~ in its ;~
fully extended draft position (Figure 1) .
A metering rod 39 of predetermined configuration is affixed to the cylinder head 15 and extends concentrically into the cavity 19. An appropriately sized orifice opening 41 is formed in the orifice plate 22 for cooperation with the . .
metering rod 39. The piston rod 28 is formed with an elongated cylindrical opening .
42 that is alligned with the orifice opening 41 and which is adapted to receive, without restriction, the metering rod 39 at the extreme position of the piston assembly 21 relative to the cylinder assembly 14 in the buff condition.
In order to preclude relative movement of the piston assembly 21 and cylinder assembly 14 until large impact forces are received, there is provided a pressure responsive valve assembly, indicated generally by the reference numeral 43 and shown in most detail in Figures 2 and 3. The pressure responsive valve ~
assembly 43 includes one or more passages 44 that extend axially through the piston - -23 between a cavity 45 formed between the main piston 23 and orifice plate 22 and an annular relief 46 formed in the main piston 23. The flow through the passage ' 1~36g~S
44 is controlled by a conical disk spring valve member 47. In the nonflow condition the outer peripheral edge 48 of the valve rnember 47 sealingly engages the main piston 23. An opposite peripheral edge 49 sealingly engages a collar 51 that is received around a recess 52 at the outer end of the piston rod 28 and which is axially held in position by the main piston 23. ~s will become apparent, the valve member 47 acts as a twoway, pressure responsive valve.
The chamber 19 is partially filled with hydraulic fluid to a level indicated by the phantom line 53. Gas, such as Nitrogen, at a high pressure i9 charged into the cavity 19 above the oil level 53. The gas pressure acts as a return spring to 10 hold the cushioning unit 11 in the position shown in Figure 1. For a reason which will become more apparent, one or more passages 54 extend through the collar 51 at a point radially inwardly of the valve member 47.
As has been noted, Figure 1 illustrates the cushioning unit 11 in its normal installed position. Impact forces applied to the cushioning unit from the coupler shank 12 or from the car frame structure 13 via the draft lug assembly 34 tend to cause relative movement between the piston assembly 21 and the cylinder assembly 14. This relative movement can only be accomplished by forcing the oil through the orifice opening 41. If the valve assembly 43 were not provided, any force greater than the force required to overcome the gas pressure in the chamber 20 19 would result in such relative movement. Under low impact forces, such relative movement is undesirable since it will result in considerable changes in train length and attendant problems.
The valve 43, however, precludes any flow through the orifice opening 41 by blocking the passage 44 until a predetermined force is applied. When this predetermined force is reached, the pressure acting through the passage 44 on the valve member 47 will cause its peripheral edge 48 to deflect away from the main piston 23 as shown in Figure 2 and permit flow. The metering rod 39 and orifice opening 41 will provide fluid resistance to continued movement, as is well known .
1(~3~5 When the force is relieved, the valve member 47 will again move to its closed position. The gas pressure acting on the oil 53 will, however, cause the unit to return to its normal position (Figure 1) since the oil can be forced through the restricted passage 54 past the closed valve assembly 43. ThiS return will occur at an extremely slow rate.
In the event a draft force is exerted on the cushioning unit 11 before return to the normal position is reached, the cushioning unit 11 will also be operative to resist such forces. Rapid runout will be precluded by the closure of the valve 43. If the draft force is sufficiently large, however, the valve member 47 will deflect 10 so that its peripheral portion 49 moves away from the collar 51 (Figure 3) and permits flow back through the opening 41. Thus, it should be readily apparent that the valve assembly 43 acts as a pressure responsive valve for controlling flow in either direction through the orifice opening 41.
It is to be understood that the foregoing description is that of a preferred embodiment of the invention. Various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. EAB/jp
An object of the invention is to provide an end of car cushioning unit that provides a long stroke under high impacts but which resists changes in length under lower loading.
It is a further object of the invention to provide an end of car cushioning unit that requires a predetermined force to be applied to it before its cushioning operation becomes effect-ive.
According to the present invention there is provided an end of car cushioning unit adapt:ed to be interposed between a coupler and a car frame of a railway car for damping shock forces.
The cushioning unit includes a cylinder, a piston received within the cylinder, and means including the piston and cy:Linder defining first and second chamber sections adapted to receive a fluid. A
passage means ineludes primary metering means is in eommunication ~ith said ehamber seetions for passin~ fluid bet-~een said ehamber seeticn at a restricted rate upon relative movement of ,,i ~ ~
~36~5 the piston and the cylinder. The primary metering means is adapted to experience flow in one direction upon relative movement of the piston and the cylinder in a first direction and in an opposite dlrection upon relative movement of the piston and cylinder in an opposite direction. Means are provided for precluding the flow of flu:Ld through the primary metering means in each direction until a predtermined force is 8 applied in the respective direction to the cushioning, the means being a pressure responsive valve means in the passage.
- jb/ - 2a -~o~ s unit .
Figure 1 is a longitudinal crosssectional view taken through the end of a railway car having a cushioning unit embodying this invention with the car structure being shown in phantom.
Figure 2 is an enlarged view showing the metering device of the cushion-ing unit as it appears under buff forces.
Figure 3 is an enlarged view, in part similar to Figure 2, showing the device as it appears when it experiences draft forces.
Figure 1 illustrates an end of car cushioning unit embodying this invention, identified generally by the reference numeral 11. The end of car cushioning unit 11 is adapted to be interposed between a coupler shank 12 and the car underframe 13. The installation may be accomplished in any of a variety of manners and, for this reason, the car structure has been shown only in phantom.
Certain details of the illustrated installation will be described, but should only be considered as exemplary in nature.
The cushioning unit 11 includes a cylinder assembly 14 comprised of a cylinder head 15, a tubular cylinder 16 and a closure plug 17. The cylinder16 defines a cylindrical bore 18 closed at one end by the cylinder head 15 and at the other end by the plug 17 to define a fluid receiving chamber 19.
The chamber 19 is divided into two sections by means of a piston assembly 21 that is slidably supported within the bore 18. The piston assembly 21 includes an orifice plate 22 that is affixed to a main piston 23 by means of bolts 24, only one of which appears in the drawings. An antifriction bushing 25 engages the bore 18 and i8 trapped between outstanding flanges of the orifice plate 22 and the main piston 23. The piston 23 is also formed with an annular groove 26 in which a piston ring 27 is positioned to sealingly engage the bore 18.
A piston rod 28 is affixed in any known manner to the piston assembly 21 and extends through an opening 29 formed in the closure plug 17. A bushing 31 and seal assembly 32 carried by the closure plug 17 supports and sealingly ~3fà~S
engages the piston rod 28.
The piston rod 28 ha~ affixed to it~ outer end a draft collar 33 that is trapped in a draft lug a6sembly, indicated by the reference numeral 34 that is fixed in any suitable manner to the underframe of the as~ociated railway car.
The cooperation of the draft lug assembly 34 with the draft collar 33 couples the piston rod 28 and piston assembly 21 to the car underframe 13. That is, the piston assembly 21is held against any substantial movement relative to the underframe structure 13. :
The cylinder head 15 is formed at its outer end with a socket 35 that ;~
10 receives the coupler shank 12. Alligned openings 36 and 37 are formed on opposite sides of the socket 35 to receive a draft key (not shown) for fixing the coupler shank to the cylinder head 15. Thus, the cylinder assembly 14is affixed for movement with the coupler shank 12. A stop block 38 is fixed to the underframe 13 and i~
abuttingly engaged by the cylinder head 15 when the cushioning unit 11 i~ in its ;~
fully extended draft position (Figure 1) .
A metering rod 39 of predetermined configuration is affixed to the cylinder head 15 and extends concentrically into the cavity 19. An appropriately sized orifice opening 41 is formed in the orifice plate 22 for cooperation with the . .
metering rod 39. The piston rod 28 is formed with an elongated cylindrical opening .
42 that is alligned with the orifice opening 41 and which is adapted to receive, without restriction, the metering rod 39 at the extreme position of the piston assembly 21 relative to the cylinder assembly 14 in the buff condition.
In order to preclude relative movement of the piston assembly 21 and cylinder assembly 14 until large impact forces are received, there is provided a pressure responsive valve assembly, indicated generally by the reference numeral 43 and shown in most detail in Figures 2 and 3. The pressure responsive valve ~
assembly 43 includes one or more passages 44 that extend axially through the piston - -23 between a cavity 45 formed between the main piston 23 and orifice plate 22 and an annular relief 46 formed in the main piston 23. The flow through the passage ' 1~36g~S
44 is controlled by a conical disk spring valve member 47. In the nonflow condition the outer peripheral edge 48 of the valve rnember 47 sealingly engages the main piston 23. An opposite peripheral edge 49 sealingly engages a collar 51 that is received around a recess 52 at the outer end of the piston rod 28 and which is axially held in position by the main piston 23. ~s will become apparent, the valve member 47 acts as a twoway, pressure responsive valve.
The chamber 19 is partially filled with hydraulic fluid to a level indicated by the phantom line 53. Gas, such as Nitrogen, at a high pressure i9 charged into the cavity 19 above the oil level 53. The gas pressure acts as a return spring to 10 hold the cushioning unit 11 in the position shown in Figure 1. For a reason which will become more apparent, one or more passages 54 extend through the collar 51 at a point radially inwardly of the valve member 47.
As has been noted, Figure 1 illustrates the cushioning unit 11 in its normal installed position. Impact forces applied to the cushioning unit from the coupler shank 12 or from the car frame structure 13 via the draft lug assembly 34 tend to cause relative movement between the piston assembly 21 and the cylinder assembly 14. This relative movement can only be accomplished by forcing the oil through the orifice opening 41. If the valve assembly 43 were not provided, any force greater than the force required to overcome the gas pressure in the chamber 20 19 would result in such relative movement. Under low impact forces, such relative movement is undesirable since it will result in considerable changes in train length and attendant problems.
The valve 43, however, precludes any flow through the orifice opening 41 by blocking the passage 44 until a predetermined force is applied. When this predetermined force is reached, the pressure acting through the passage 44 on the valve member 47 will cause its peripheral edge 48 to deflect away from the main piston 23 as shown in Figure 2 and permit flow. The metering rod 39 and orifice opening 41 will provide fluid resistance to continued movement, as is well known .
1(~3~5 When the force is relieved, the valve member 47 will again move to its closed position. The gas pressure acting on the oil 53 will, however, cause the unit to return to its normal position (Figure 1) since the oil can be forced through the restricted passage 54 past the closed valve assembly 43. ThiS return will occur at an extremely slow rate.
In the event a draft force is exerted on the cushioning unit 11 before return to the normal position is reached, the cushioning unit 11 will also be operative to resist such forces. Rapid runout will be precluded by the closure of the valve 43. If the draft force is sufficiently large, however, the valve member 47 will deflect 10 so that its peripheral portion 49 moves away from the collar 51 (Figure 3) and permits flow back through the opening 41. Thus, it should be readily apparent that the valve assembly 43 acts as a pressure responsive valve for controlling flow in either direction through the orifice opening 41.
It is to be understood that the foregoing description is that of a preferred embodiment of the invention. Various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. EAB/jp
Claims (3)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An end of car cushioning unit adapted to be interposed between a coupler and a car frame of a railway car for damping shock forces, said cushioning unit comprises a cylinder, a piston received within said cylinder, means including said piston and said cylinder defining first and second chamber sections adapted to receive a fluid, passage means including primary metering means in communication with said chamber sections for passing fluid between said chamber sections through said passage means at a restricted rate upon relative movement of said piston and said cylinder, said primary metering means being adapted to experience flow in one direction upon relative movement of said piston and said cylinder in a first direction and in an opposite direction and pressure responsive valve means in said passage for precluding the flow of fluid through said primary metering means in each direction until a predetermined force is applied to said cushioning unit in the respective direction.
2. An end of car cushioning unit as set forth in Claim 1 wherein the pressure responsive valve means comprises a single valve element movable between a closed position and an open position in response to a predetermined pressure.
3. An end of car cushioning unit as set forth in claim 2 wherein the valve element controls the flow in either direction through an associated passage.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA298,388A CA1054096A (en) | 1973-08-13 | 1978-03-07 | End of car cushioning unit |
| CA304,468A CA1065802A (en) | 1973-08-13 | 1978-05-31 | End of car cushioning unit |
| CA304,467A CA1059071A (en) | 1973-08-13 | 1978-05-31 | End of car cushioning unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US388330A US3929232A (en) | 1973-08-13 | 1973-08-13 | End of car cushioning unit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1036985A true CA1036985A (en) | 1978-08-22 |
Family
ID=23533683
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA206,788A Expired CA1036985A (en) | 1973-08-13 | 1974-08-12 | End of car cushioning unit |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US3929232A (en) |
| CA (1) | CA1036985A (en) |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3493124A (en) * | 1968-01-15 | 1970-02-03 | Pullman Inc | Hydraulic draft gear arrangement |
| US3638807A (en) * | 1970-01-21 | 1972-02-01 | Miner Enterprises | Hydraulic friction draft gear |
| US3729101A (en) * | 1970-05-04 | 1973-04-24 | Riv Officine Di Villar Perosa | Damper device for railway vehicle automatic couplings |
-
1973
- 1973-08-13 US US388330A patent/US3929232A/en not_active Expired - Lifetime
-
1974
- 1974-08-12 CA CA206,788A patent/CA1036985A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US3929232A (en) | 1975-12-30 |
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