US784910A - Air-brake. - Google Patents

Description

vN0. 784,910. PATENIED MAR. 14, 1905. A. J. WISNER. AHIR BRAKE.

APPLICATION FILED OUT. 3, 1903. RENEWED MAY 14, 1904.

2 SHEETS-SHEET 1.

WITNESSES INVENTOR i No. 784,910. PATENTED MAR. 14, 1905.

A. J. WISNER.

AIR BRAKE.

APPLICATION FILED OUT. 3, 1903. RENEWED MAY 14, 1904.

' 2 SHEETS-SHEET 2.

WITNESSES: INVEN T0]? TORNFY.

UNITED STATES Patented March 14, 1905.

PATENT OFFICE.

AIR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 784,910, dated March 14, 1905. Application filed October 3, 1903. Renewed May 14, 1904. Serial No. 207,916.

To all whom it may concern:

Be it known that I, ANDREW J. TISNER, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Air-Brakes, of which the following is a specification.

This invention relates to that class of airbrakes wherein compressed air is employed to apply or release the brakes, as occasion may require, the application of the brakes being effected by the pressure in a previouslycharged auxiliary air-reservoir.

The primary object of the invention is to provide a simple and eflicient construction and arrangement of mechanism whereby the brakes cannot be released until the auxiliary reservoir has been charged with suflicient pressure to effect their immediate reapplication.

IVith this object in view the invention consists in the novel construction and combinations of parts, which will be hereinafter fully described and claimed.

In the drawings, Figure 1 is a diagrammatic view, partly in side elevation and partly in plan, illustrating my invention. Fig. 2 is a longitudinal vertical section through the auxiliary reservoir, the brake-cylinder, and adjuncts. Fig. 3 is a sectional detail as on the line a a: of Fig. 2.

1 is the main air-reservoir, 2 the pump for supplying air thereto, and 3 the engineers valve.

4 is a pipe leading from the reservoir 1 to between the reservoir 1 and the train-pipe 7 to increase the air-pressure in the latter, or communication may be opened between the train-pipe? and the pipe 5, leading to the open air, for the purpose of decreasing the air-pressure in the train-pipe.

The parts thus far described are of well known construction and need no detailed description herein.

The train-pipe? extends throughout the length of the train of cars, and each car of the train is provided with an auxiliary air-reservoir 8 and a brake-cylinder 9, the rod 10 of the brake-piston 11 extending through the rearward head of the brake-cylinder and being connected to the brake-actuating devices 12 in the usual manner, as shown in Fig. 1. The area of the rearward face of the piston 11 is somewhat less than the area of the forward face thereof, owing to the piston-rod 10. Thus it will be seen that if the pressure on both sides of the piston be equal the excess of force against the forward face of the piston will move the latter to the rearward end of the brake cylinder. After this operation takes place the brakes are released. IV hen, however, the pressure in the forward end of the brake-cylinder is reduced below that in the rearward end thereof, the greater pressure will drive the piston toward the forward end of the brake-cylinder. This latter operation elfects the application of the brakes.

The auxiliary reservoir 8 and the brakecylinder 9 of each car are operatively connected to each other and to the train-pipe by a novel series of air-passages and valves by means of which the maximum air-pressure may be simultaneously introduced to the forward end of the brake-cylinder and the auxiliary reservoir when the air-pressure in the train-pipe 7 is increased, thereby not only effecting the release of the brakes, but at the same time charging the auxiliary reservoir with the maximum pressure, and by means of which the air-pressure in the forward end of the brake-cylinder may be discharged into the open air when the pressure in the trainpipe is decreased, thereby permitting the air in the auxiliary reservoir to enter the rearward end of the brake-cylinder and effect the application of the brakes. Thus it will be seen that the brakes may be applied or released by increasing or decreasing the pressure in the train-pipe 7, as desired.

The novel series of air-passages and valves above referred to form the subject of my present invention, which in its preferred embodiment is as follows: The casting forming the forward head of the auxiliary reservoir wil and brake-cylinder is provided with three chambers 13, 14, and 15. The chamber 13is divided into upper and lower parts by a vertically-movable piston 16, and the chamber 14 is divided into upper and lower parts by a horizontal partition-wall17. Rising from the piston 16 is a laterally-perforated sleeve 18, to the upper end of which and the piston 16 is slidingly fitted a vertically-movable valvestem 19. This valve-stem extends down into chamber 15 and is provided with two valves and 21, one, 20, of which is seated in the piston 16 and controls two ports 22, leading from the upper part of chamber 13 to the lower part thereof, and the other, 21, of which controls two ports 23, leading from the chamber 15 to the open air. \Vithin the sleeve 18 and encircling the upper portion of the valvestem 19is a spring 34*, which bearing against the upper portion of the sleeve 18 and the top of the valve 20 supports the piston 16 and seats the valve 20 at a 1 )redetermined pressure. The valve 21 resting in its seat supports the piston-rod 19. The partition- Wall 17 of the chamber 14 is provided with a port 24 to afford communication between the upper and lower parts thereof. Seated in the port 24 is a valve 25, the stem 26 of which is secured to a diaphragm 27, which constitutes, in effect, the outer wall of the lower part of chamber 14. The diaphragm is clamped to the casing by the flange 28 of a sleeve 29, into which the valve-stem 26 extends. Encircling the lower end of the valve-stem 26 is a spring 30, which bearing against a collar 31 on the valve-stem and a head 32, screwed onto the sleeve 29, maintains the valve normally seated under a predetermined pressure. By adjusting the head 32 the pressure of the spring may be nicely regulated. The trainpipe leads into and out of the chamber 13, the latter constituting, in effect, a portion of the train-pipe. The lower part of chamber 13 and the lower part of chamber 14 communicate with each other by means of a passage 33, the upper end of which is controlled by a port 34 in the piston*that is to say, when the piston 16 is in the raised position, as shown, the port 34 is out of register with the passage 33 and communication between the latter and the lower part of chamber 13 is suspended, and when the piston 16 is depressed the port 34 is in register with the passage 33 and communication between thelatter and the chamber 13 is established. The upper part of chamber 14 and chamber 15 communicate with each other and the forward end of the brake-cylinder by a passage 35. The lower part of chamber 13 communicates with the auxiliary reservoir by a port 36, and thcrearward end of the brake-cylinder communicates with the auxiliary reservoir by a port 37.

Assuming that the brakes are applied and that the parts occupy the position shown in the drawings, the operation may be brieli y described as follows: hen the valve3 is operated to increase the pressure in the train-pipe 7, the piston 16 is forced down against the action of the spring 34 away from the valve 20, thereby opening the ports 22 22 and bringing the port 34 into register with the passage 33. The increased air-pressure in the train-pipe passes through the ports 22 22 into the lower part of chamber 13 and from the latter into the auxiliary reservoir 8 and rearward end of the brake-cylinder 9 through the ports 36 and 37 and through the port 34 and passage 33 into the lower part of chamber 14. The air-pressure accumulating in the lower part of chamber 14 acts upon the diaphragm 27, and when suilicient pressure is accumulated to overcome the action of the spring 30 the valve-stem 26 is moved downwardly to unseat the valve 25 and open the port 24, thereby permitting the pressure to pass through the port 24, the upper part of chamber 14, and passage into the forward end of the brake-cylinder. The pressure now beingthe same on both sides of the piston 11, the latter, due to the great area of its forward face, is moved rearwardly to release the brakes, as previously explained. hen the maximum pressure has passed below the piston 16, the spring 34 raises the latter into engagement with the valve 20, thereby moving the port 34 out of register with the passage 33 and leaving the auxiliary reservoir 8 and brake-cylinder 9 charged with the maximum pressure. When it is desired to apply the brakes, the valve 3 is operated to discharge air from the train-pipe 7, and thus effect a reduction of pressure in the latter. When the pressure of the train-pipe is reduced below that of the auxiliary reservoir, the pressure in the latter will raise the piston 16 and therewith the stem 19 and unseat the valve 21, thereby opening communication between chamber 15 and the open air through the ports 23 23. The air-pressure in the forward end of the brake-cylinder being thus permitted to pass through passage 35, chamber 15, and ports 23 23 to the open air, the pressure in the auxiliary reservoir passes through port 37 to the rearward end of the brake-cylinder and moves the piston forward to effect the application of the brakes. The instant the pressure in the auxiliary reservoir is reduced to train-pipe pressure, due to the forward movement of the piston and the escape of air from the forward end of the brake-cylinder, the piston 16 and the valve 19 drop by gravity, thereby closing the ports 23 23 and preventing the further discharge of air from the forward end of the brake-cylinder, and consequently the further movement of the piston 11. Thus it will be seen that the greater the reduction of train-pipe pressure the more severe will be the application of the brakes. As previously explained, the air-pressure entering the lower part of chamber 14 acts against the diaphragm, but does not unseat the valve 25 until suflicient predetermined pressure has been attained ,to overcome the force of the spring 30, such pressure being suflicient to control the train. Thus it follows that before the brakes can be released the auxiliary reservoir will be recharged with sufficient pressure to control the train. Therefore if for any purpose it be desirable to slightly release the brakes the operator can safely do so, inasmuch as he is sure to have sufficient pressure in the auxiliary reservoir for their instant reapplication.

I claim 1. In an air-brake system, the combination of the brake-cylinder, its piston, the auxiliary reservoir having communication with one end of the cylinder, the train-pipe, a passage-way leading from the train-pipe to the auxiliary reservoir, a passage-way leading from the train-pipe to the reverse end of the cylinder, means adapted to be operated by train-pipe pressure for openingand closing communication between said passage-ways and between said passage-ways and the train-pipe, means adapted to be operated by a predetermined pressure in said passage-ways for opening and closing communication between said secondnamed passage-way and said reverse end of the cylinder, and means operatively connected to the first-named means for opening and closing communication between said reverse end of the cylinder and the open air, substantially as described.

2. In an air-brake system, the combination of the brake-cylinder, its piston, the auxiliary reservoir having communication with one end of the cylinder, a chamber, a piston dividing said chamber into two parts, the train-pipe communicating with one part of the chamber, two passage-ways leading from the other part of said chamber one of said passage-ways leading to the auxiliary reservoir and the other of said passage-ways leading to the reverse end of the brake-cylinder, a valve controlling communication between the two parts of said chamber and being adapted to be opened and closed by the movement of the second-named piston, means operatively connected to the second-named piston for opening and closing communication between said passage-ways, means adapted to be operated by a predetermined pressure in said passage-ways for open ing and closing communication between said passage-ways and said reverse end of the cylinder, and means operatively connected to the second-named piston for opening and closing communication between said reverse end of the cylinder and the open air, substantially as described.

3. In an air-brake system, the combination of the brake-cylinder, its piston, the auxiliary reservoir having communication with one end of the cylinder, the train-pipe, a passage-way leading from the train-pipe to the auxiliary reservoir, a passage-way leading from the train-pipe to the reverse end of the cylinder, means adapted to be operated by train-pipe pressure for opening and closing communication between said passage-ways and between said passage-ways and the train-pipe, a valve controlling communication between the second-named passage-way and said reverse end of the cylinder, a diaphragm connected to said valve and adapted to be operated by airpressure in said passage-ways to open said valve, means acting upon the diaphragm in opposition to such pressure, and means operatively connected to the first-named means for opening and closing communication between said reverse end of the cylinder and the open air, substantially as described.

4. In an air-brake system, the combination of the brake-cylinder, its piston, the auxiliary reservoir having communication with one end of the cylinder, a chamber, a piston dividing said chamber into two parts, the train-pipe communicating with one part of the chamber, two passage-ways leading from the other part of said chamber one of said passage-ways leading to the auxiliary reservoir and the other of said passage-ways leading to the reverse end of the brake-cylinder, a valve controlling communication between the two parts of said chamber and being adapted to be opened and closed by the movement of the second-named piston, means operatively connected to the second-named piston for opening and closing communication between said passage-ways, a valve controlling communication between said passage-ways and said reverse end of the cylinder, a diaphragm connected to said valve and adapted to be operated by air-pressure in said passage-ways to open said valve, means acting upon the diaphragm in opposition to such pressure, and means operatively connected to the secondnamed piston, for opening and closing communication between said reverse end of the cylinder and the open air, substantially asdescribed.

5. In an air-brake system, the combination of the brake-cylinder, its piston, the auxiliary reservoir having communicatlon with one end of the cylinder, a chamber, a piston dlviding said chamber into twoparts, the train-pipe.

communicating with one part of the chamber, two passage-ways leading from the other part of said chamber one of said passage-ways leading to the auxiliary reservoir and the other of said passage-ways leading to the reverse end of the cylinder,a valve-stem extending through said piston and carrying a valve adapted to control communication between the two parts of the chamber by the movement of the second-named piston, a spring tending to maintain said valve normally seated, means operatively connected to the second-named piston for opening and closing communication beizo tween said passage-ways, means adapted to be operated by a predetermined pressure in said passage-ways for opening and closing communication between said passage-ways and said reverse end of the cylinder, a passageway leading from said reverse end of the cylinder t0 the open air, a valve controlling the last-named passage-way, and connections between the last-named valve and said valve-- stem, substantially as described. 10

In testimony whereof I. aflix my signature in presence of two witnesses.

ANDREWV J. \VISNER. lVitnesses:

ANDREW V. GROUPE, RALPH H. GAMBLE.

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