US831418A

US831418A - Automatic air-brake system.

Info

Publication number: US831418A
Application number: US18579403A
Authority: US
Inventors: Fred B Corey
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1903-12-19
Filing date: 1903-12-19
Publication date: 1906-09-18
Anticipated expiration: 1923-09-18

Description

No. 831,418. PATENTED SEPT. 18, 1906.

{ F. B. COREY.

AUTOMATIC AIR BRAKE SYSTEM.

APPLIOATION FILED DIS-0.19, 1903.

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No. 831,418. v PATE'NTED SEPT.18, 1906.

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AUTOMATIG- AIR BRAKE SYSTEM. APPLICATION FILED 13110.19, 1903.

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UNITED STATES PATENT OFFICE.

FRED B. COREY, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

AUTOMATIC AIR-BRAKE SYSTEM.

Specification of Letters Patent.

Patented Sept. 18, 1906.

Application filed December 19, 1903. Serial No. 185,794.

Ton whom it may concern.-

Be it known that I, FRED B. COREY, a citizen of the United States, residing at Schenectady, in the county of Schenectady and State of New York, have invented certain new and useful Improvements in Automatic Air-Brake Systems, of which the following is a specification.

In automatic air-brake systems in common use the construction and arrangement of the parts are such as to permit the brakes to be given a graduated application, but not a graduated release. In applying the brakes a reduction of the train-pipe pressure brings the auxiliary reservoir and brake-cylinder into direct communication, and this communication is maintained until the auxiliary-reservoir air by expanding into the brake-cylinder lowersits pressure slightly below the train pipe pressure, and the communication is thereby cut off. Upon further reductions of train-pipe pressure the above operation is repeated, and the brake-cylinder is further charged and the brakes more strongly applied. On the other hand, in releasing the brakes any increase in the train-pipe pressure which is sufficient to operate the triple valve will open the brake-cylinder to atmosphere through a passage which Will remain unaffected by further increases in train-pipe pressure and which can only be closed by a reduction of such pressure.

A number of special arrangements of valves have been suggested heretofore for the purpose of obtaining a graduated release in automatic air-brake systems; but none of the arrangements suggested has gone into common use.

The principal object of the present invention is to provide automatic air-brake systems of this type with more eflicient and sensitive means for obtaining a graduated release of the brakes than has been devised heretofore, and to this end my invention in one aspect comprises, in connection with the usual brake-cylinder, triple valve, and auxiliary reservoir, a release-valve for controlling an exhaust-passage leading from the brake cylinder and a relay-valve for controlling the operation of said release-valve. These valves are so constructed and arranged with reference to the other parts of the system that they may be operated by increases in train-pipe pressure to discharge more or less of the brake-cylinder air according to the extent of the train-pipe variation, so that by increasing the train-pipe pressure by gradual steps the braking action may be gradually reduced. This construction is of particular advantage in controlling trains on long grades and in making accurate stops-that is, stops at definite points. In controlling trains on long grades it is necessary to provide some means for charging the auxiliary reservoir without releasing the brakes. Heretofore this has been accomplished by the employment of pressure-retaining valves which operate to retain a definite pressure, usually fifteen pounds, in the brake-cylinder. My present invention possesses not only the advantages of an automatic system equipped with such pressure-retaining valves, but also the advantage of obtaining a gradual smooth stop, such as has been obtainable heretofore only by the use of straight air-brake systems.

In another aspect my invention consists in the combination in an automatic air-brake system of a triple valve, a brake-cylinder, and means for controlling the discharge from the brake-cylindercomprising a differential mechanism subjected to substantially constant pressure on one side, opposing trainpipe and brake-cylinder pressures on the other, the point of connection of the brakecylinder being remote from the point at which brake-cylinder pressure is discharged to atmosphere. With this arrangement the brake-cylinder pressure in the differential mechanism corresponds always to the true pressure in the cylinder instead of being lower than brake-cylinder pressure, as would be the case if the connection to brake-cylinder were made near the point at which brakecylinder pressure is discharged to atmosphere.

My invention comprises other obj ectsand advantages which will more fully ap e-ar upon reference to the following detaile de scription, taken in connection with the accompanying drawings, in which I have illustrated a release-valve constructed in accordance with my invention.

In said drawings, Figure 1 is a partial sectional view of said release-valve shown in connection with the common form of triple valve and brake-cylinder, the section of the releasevalve being taken on the line 1 1 of Fig. 3;

Fig. 2 is a side elevation of the release-valve detached from the triple valve and brakecylinder, and Fig. 3 is a vertical section of said valve on the line 3 3 of Fig. 2.

Throughout the several figures like characters refer to like parts.

The triple valve 10 is of the usual construc-- tion and comprises a main piston 11 for operating the slide-valve 12 and a graduatingvalve 13 for establishing communication be tween the auxiliary-reservoir chamber 14 and the port 15 by way of the slide-valve port 1 6 to charge the brake-cylinder, or between said port 15 and the exhaust-port 17 to exhaust the brake-cylinder. This valve is provided with the usual train-pipe connection 18 for admitting air to the left of the piston 11. The brake-cylinder 19 is also of the wellknown construction and comprises a spring pressed piston 20, which is adapted to be operatively connected to suitable brake-lever mechanism and to be operated by air-pressure acting upon the left of the piston and supplied through the port 21, located. in line with the triple-valve port 15.

The release-valve is preferably mounted between the triple val ve 10 and the brakecylinder 19, and for that pupose the body 22 of the valve 18 provided with flanges and openings adapted to fit the triple valve on the one hand and the brake-cylinder on the other. In applying this valve to existing equipments it is only necessary to shorten the train-pipe connection 18 and to replace the usual bolts for connecting the triple valve and the brake-cylinder by bolts of sufficient length to pass through the body 22, whi ch is provided with suitable holes 23 for that purpose. The interior of this body is provided with chambers 24 and 25, which are in d rect communication through the port 26. The former chamber communicates directly with the auxiliary-reservoir chamber 14 of the triple valve and the latter chamber with a pipe connection 27, which leads to the auxiliary reservoir, so that auxiliary-reservoir air in passing to the triple. valve passes through chamber 25, port 26, and chamber 24 to the triple-valve chamber 14. The valve-body 22 is also provided with upper alined cylindrical chambers 28 29 and lower alined chambers 30 31. The chamber 28 communicates di- 7 rectly with the chamber 30, through the port 32 and with the chamber 31 through the port 33. The chamber 31 is provided with a port 34, which communicates with the brakecylinder port 21. From this it follows that air at brake-cylinder pressure may fill

chambers

28, 30, and 31. The chamber 29 connects wlth the irregular port 35,which terminates in the opposite side of the release valve from and in line with the port 34 and communicates directly with the triple-valve port 15, so that the chamber 29 in the releasevalve may be placed directly in communication with the auxiliary reservoir or with atmosphere, according to the position of the triple valve.

The passage between the

chambers

28 and 29 is controlled by the release-valve 36, which is normally seated by a light spring 37. This valve 36 acts as a check-valve to allow air to pass from the chamber 29 to the chamber 28 or, in other words, from auxiliary reservoir to brake-cylinder when the pressure in the chamber 29 exceeds that in the chamber 28 sufficiently to overcome the pressure of the spring 37. From this it will be seen that the operation of the triple valve in charging the brake-cylinder is not interfered with, for

as soon as the triple valve is moved to application position the air in the chamber 29 will open the valve 36 and air will be allowed to flow into the brake-cylinder through chamber 28, port 33, chamber 31, ports 34 and 21. However, when the triple valve is removed to release position, so as to bring the ports 15 and 17 into communication, as illustrated in Fig. 1, thus reducing the pressure of the air in the chamber 29 to that of atmosphere, the releasevalve 36 will prevent the exhaust of air from the brake-cylinder unless operated by some auxiliary means. For this purpose the release-valve is provided with a piston 36, which bears against the bushing 38, forming the lining of the chamber 28. This piston 37 is provided with a small port 39, which allows the pressures on the opposite sides of the piston to equalize, but does not prevent the movement of the piston when the pressure of the air on one side of it is suddenly decreased. A spring-pressed auxiliary or relay valve 39 seated in a bushing 40 and controlling an exhaust-passage leading from the chamber 30 through the exhaust-port 41, provides means for reducing the pressure of the air in the chamber 30 and at the left of the piston 36. This reduction at the left of the piston 36 causes the greater pressure at its right to force the valve 36 open against the pressure of its spring 37, and thereby allow the air in the brake-cylinder to escape through the chamber 31, port 33, and chamber 28 to the chamber 29 and thence to atmosphere through the triple valve. The size of the equalizing-port 39 in the piston 36 is suflicient to permit a practically instantaneous equalization of the pressures on the opposite sides of said piston whenever the relay-valve 39 is seated by its spring so as to close the exhaust passage from the chamber 28 through the port 32, chamber 30, relay-valve port, and port 41,

but is of relatively small size compared to the size of said exhaust-passage, so that its equalizing action does not interfere with the immediate opening of the valve 36 when the relayvalve 39 is opened and the air to the left of the piston 36 is exhausted.

For the purpose of operating the relayvalve 39 a differential mechanism is employed which operates under the action of train-pipe, brake-cylinder, and spring pressures. This mechanism comprises two diaphragms 42 and 43, the former of which has the larger effective area, held at their peripheries between

suitable rings

44, 45, and 46, mounted in theinterior of the chamber 31, and held at their center by

heads

47, 48, 49, and 50 to a rod 51, which is provided at its opposite end with a head 52, which serves as an abutment for the spring 53, which bears at its opposite end against the ring 46 and normally operates -to,move the head 47 out of engagement with the lower end of the relayvalve 39*. for regulating the tension of the spring 53. This nut serves to guide the rod 51 by engaging the walls of a suitable recess in the head 55, which forms the end wall of the chamber 31. A train-pipe connection 56 is provided for furnishing air at train-pipe pressure to the chamber 57 between the diaphragms 42 and 43. In operation when the pressure of the air in the chamber 57 is increased the rod 51 will be moved against the tension of the spring 53 by reason of the greater effective area of the diaphragm 42 over the diaphragm 43, so as to open the relay-valve 39 Suitable lugs 58 on the bushing 40 prevent the head 47 from closing the exhaust-port 41. As soon as the valve 39- is opened the pressure on the left of the pis ton 36 is reduced, the release-valve 36 is opened, and air is allowed to flow from the chamber 31 through the chamber 29 to atmosphere, as shown by the position of parts in Fig. 3, andthis flow of air continues until the pressure in the chamber 31 has fallen off sufficiently to neutralize the action of the increased pressure in the chamber 57, and thereby allow the rod 51 and its connecting parts to return to normal position. This movement of the rod 51 allows the relayvalve 39 to be seated by its spring, so as to cut off the exhaust-passage leading from the left of the piston 36, thereby allowing the pressures on the opposite sides of said piston to equalize and permit the spring 37 to seat the valve 36 and cut off the escape of air from the brake-cylinder. It will be noted that the chamber 31 is in direct connection with brake-cylinder and is remote from the point at which brake-cylinder pressure is discharged to atmosphere'viz., the triplevalve exhaust-port. Consequently the pressure in the chamber 31 always corresponds to the true brake-cylinder pressure instead of being lower than the brake-cylinder pressure during discharge, as would be the case if the connection to this chamber were made from the brake-cylinder exhaust-passage near the point where it discharges into atmosphere.

From the foregoing description it will be seen that the operation of the triple valve in charging the brake-cylinder to apply the An adjusting-nut 54 is providedbrakes is substantially unchanged, since the valve 36 operates merely as a check-valve. On the other hand, when the train-pipe pressure has increased sufficiently to move the triple valve into the release position (shown in Fig. 1) the same pressure will cause the relay-valve 39 to be opened and the controlling-valve 36 to be operated to allow the brake-cylinder to exhaust sufficiently to restore the rod 51 to normal position and allow the relay-valve and subsequently the controlling-valve to close. The point at which this closing action takes place depends upon the degree of train-pipe-pressure variation, so that if a small reduction in brake application is desired a small increase of train-pipe pressure will be all that is required, provided, of course, that it is sufficient to bring the triple valve to release position. Further reductions in brake-cylinder pressure may be readily obtained by furthcr increasing the train-pipe pressure and again operating the release-valve 36. Furthermore, it should be noted that very slight increases of pressure in the train-pipe will be sufiicient to open the relay-valve 39 to produce a positive, strong, and effective opening of the valve 36, so that the decrease of brake application comes as a ready response to the increase in the train-pipe.

It will be apparent from the foregoing description that in the organization which I have developed there are many features and subcombinations of elements that are capable of general application. I therefore do not wish claims drawn thereto to be unduly limited, but intend to cover thereby all such applications; nor do I wish to be limited to the specific embodiment of the invention shown, since it is clear that many modifications and alterations may be made therein without departing from the spirit and scope of my invention; but I aim to cover by the terms of the appended claims all such alterations and modifications.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1.. In an automatic air-brake system, the combination of a triple valve, a brake-cylinder, a release-valve controlling the discharge of the brake-cylinder, a relay-valve for controlling the operation of said release-valve, and means operated by the differential action of spring-pressure on one side opposing train-pipe and brake-cylinder pressures on the other for actuating said relay-valve.

2. In an automatic air-brake system, the combination of a triple valve, a brake-cylinder, a release-valve controlling the discharge of the brake-cylinder, a relay-valve for controlling the operation of said release-valve, and means operated by the conjoint actionof the train-pipe and brake-cylinder pressures for actuating said relay-valve.

3, In an automatic air-brake system, the

combination of a triple valve, a brake-cylinder, a releasevalve controlling the discharge of the brake-cylinder, a relay-valve for controlling the operation of said release-valve, and means controlled by the conjoint action of the train-pipe and brake-cylinder pressures operating against a fixed pressure for actuating said relay-valve.

4. In an automatic air-brake system, the combination of a triple valve, a brake-cylinder, a release-valve located in and controlling a passage between the triple valve and the brake-cylinder, and a relay-valve for con trolling the operation of said release-valve.

5. In an automatic air-brake system, the combination of a triple valve, a brakecylinder, a release-valve located in and controlling a passage between the triple valve and the brake-cylinder, and a pneumatically-operated relay-valve for controlling the operation of said release-valve.

6. In an automatic air-brake system, the combination of a triple valve, a brake-cylin der, a release-valve located in and controlling a passage between the triple valve and the brake-cylinder, and a relay-valve operated by variations of train-pipe pressure for controlling the operation of said releasevalve.

7. In an automatic air-brake system, the combination of a triple valve, a brake-cylinder, a release-valve located in and controlling a passage between the triple valve and the brakecylinder, a relay-valve for control ling the operation of said release-valve, and means operated by the differential action of pneumatic and spring pressures for actuating said relay-valve. I

8. In an automatic air-brake system, the combination of a triple valve, a brake-cylinder, a check-valve located in the passage between the triple valve and the brake-cylinder and arranged to allow compressed air to flow toward the brake-cylinder, and a relayvalve for controlling the operation of said check-valve to allow air to flow in the opposite direction.

9. In an automatic air-brake system, the combination of a brake-cylinder, a triple valve, a release-valve for controlling the exhaust-passage established by the triple valve from the brake-cylinder to atmosphere, and a re1ay-valve for operating said release-valve.

10. In an automatic air-brake system, the combination of a brake-cylinder, a triple valve, a release-valve for controlling the exhaust-passage established by the triple valve from the brake-cylinder to atmosphere, and a pneumatically-operated relay-valve for operatin said release-valve.

11. ii an automatic air-brake system, the combination of a brakecylinder, a triple valve, a release-valve for controlling the exhaustassage established by the triple valve from t e brake-cylinder to atmosphere, and

a relay-valve operated by train-pipe-pressure variations to operate said release-valve.

12. In an automatic air-brake system, the combination of a brake-cylinder, a releasevalve for controlling a passage leading from said brake-cylinder, a relay-valve for controlling the operation of said release-valve, and means responsive to variations in both trainpipe pressure and brake-cylinder pressure for actuating said relay-valve.

13. In an automatic air-brake system, the combination of a triple valve, a brake-cylinder, a release-valve for controlling a passage between the triple valve and the brake-cylinder, a piston for operating said valve, and pneumatically-operated means for reducing the pressure on one side of said piston to operate said release-valve.

14. In an automatic air-brake system, the combination of a triple valve, a brake-cylinder, a release-valve located in and controlling the passage between the triple valve and the brake-cylinder, a piston for operating said valve, and a relay-valve for controlling the movement of said piston to operate said release-valve.

15. In an automatic air-brake system, the combination of a brake-cylinder, a releasevalve for controlling the exhaust-passage leading from said brake-cylinder, a piston for operating said valve, and a relay-valve responsive to variations in both train-pipe pressure and brake-cylinder pressure for varying the pressure on one side of said piston to operate said release-valve.

16. In an automatic air-brake system, the combination of a brake-cylinder, a releasevalve for controlling an exhaust-passage leading from said brake-cylinder, a piston for operating said valve, an auxiliary valve for controlling the pressure on one side of said piston, operating mechanism for said auxiliary valve comprising two rigidly connected springpressed diaphragms having different efiective areas, means for admitting train-pipe air into the space between said diaphragms, and means for admitting brake-cylinder air to the opposite side of the diaphragm of smaller area, said train-pipe and brake-cylinder airpressures acting in opposition to said springpressure.

17. In an automatic air-brake system, the combination of a release-valve, a piston for operating said release-valve normally subjected on its opposite sides to brake-cylinder pressure, and means for reducing the pressure on one side of said piston in advance of the other to operate said valve.

18. In an automatic air-brake system, the combination of a brakecylinder, a release valve for controlling a passage leading from said cylinder, a piston for operating said valve normallylsubjected on its opposite sides to brake-cylinder pressures, and means for reducing the pressure on one side of said p1ston in advance of the other to operate said valve.

19. In an automatic air-brake system, the combination of a brake-cylinder, a springpressed valve normally closing an exhaustpassage leading from the brake-cylinder, a piston operatively connected to said valve and normally subjected on its opposite sides to brake-cylinder pressure, and means for reducing the pressure on one side of said piston in advance of the other to'open said valve against said spring-pressure.

20. In an automatic air-brake system, the combination of a triple valve, a brake-cylinder, a spring-pressed valve normally closing a passage between the triple valve and the brake-cylinder, a piston operatively connected to saidvalve and subjected on its opposite sides to brake-cylinder pressure, and means for reducing the pressure on one side of said piston in advance of the other to open said valve against said springpressure.

21. In an automatic air-brake system, the combination of a triple valve, a brake-cylinder, a check-valve located in the passage between the triple valve and the brake-cylinder and arranged to allow compressed air to flow toward the brake-cylinder, and pneumatically-operated means for operating said valve to allow air to flow inthe opposite direction, said means being actuated by the same increases of train-pipe pressure which operate the triple valve.

22. In an automatic air-brake system, a triple valve, a brake-cylinder, and means for controlling the discharge from the brake-cylinder comprising a differential mechanism subjected to substantially constant pressure on one side opposing train-pipe and brakecylinder pressures on the other, the point of connection of said mechanism to brakecylin der being remote from the point at which.

brake-cylinder pressure is discharged to atmosphere.

23. In an automatic air-brake system, a triple valve, a brake-cylinder, a release-valve controlling the exhaust-passage established by the triple valve from brake-cylinder to atmosphere, and differential controlling means for said release-valve subjected to substantially constant pressure on one side opposing train-pipe and brake-cylinder pressures on the other, the point of connection of said mechanism to brake-cylinder being remote from the discharge end of said exhaust-passage.

In witness whereof I have hereunto set my hand this 17th day of December, 1903.

' FRED B. COREY.

Witnesses:

BENJAMIN B. HULL, HELEN OXFORD.