US802286A - Fluid-pressure brake. - Google Patents

Description

No. 802,286. PATENTED OCT. 1'7, 1905. M., W. HIBBARD. FLUID PRESSURE BRAKE.

APPLICATION FILED MAR. 13, 1905.

, Zwan/arf nllllllllll 52% MAURY W. HIBBARI), OF CHICAGO, ILLINOIS.

lFLUIlD-'FFIESSURE BRAKE.

Specification of Letters Patent.

Patented Oct. 17, 1905.

Application filed March 13, 1905. Seriai No. 249,779.

To t/Z 1o/'tom it may concern,.-

Be it known that I, MAURY WV. HIBBARD, a citizen oi' the United States, residing at Hawthorne avenue and Rees street, Chicago, in the county of Cook and State of Illinois, have invented anew and useful Improvement in Fluid- Pressure Brakes, ot' which the following is a specification.

My object is to provide certain improvements in the construction of the emergency mechanism of automatic airbrake triple valves; and my present invention is in the nature of an improvement upon the construction shown in application, Serial No. 238,463, filed by me December 27, 1904:.

The drawing shows a partly broken vertical central section ot' my improved valve device.

A is the valve-body, having' the train-pipe port e, auxiliary-reservoir port 7), and brakecylinder port c. In the valve-body is a chamber B, having a bushing d, in which works the emergency-valve piston or movable abutment C. The chamber B is in open communication with the train-pipe through the port (t, and in said chamber in the position shown is a small port c, from which extends the auxiliary-reservoir feed-passage j', containing' a non-return valve g and terminating at a chamber 71 in which is a downwardly-seating valve c', known as the "feed-valve. Beneath the cap A/, which contains the chamber it, is a space I), from which extends a passage if: to the exhaust-port Z ot' the device. The space I) is in a ring portion A2 oiE the shell or body portion of the valve, formed on its inner side with a spider containing' a hub m. In the hub mf is a chamber a, from which a passage p extends through one of the spider-arms and the shell to the brake-cylinder port or passage c. Fitting and sliding upon the hub is a preferably sectional spacer or distance-block g, which may be of the exact construction shown in my aforesaid application. Ooniined between the cap A and ring A2 is a flexible diaphragm fr, and contined between the rings A2 and A3 is a tiexible diaphragm s. Confined between the ring A3 and the top of the main body portion A is a flexible diaphragm t. The diaphragms fr s bear against opposite sides of the spacer (1, whereby they move together undervariations of air-pressure. In the chamber a is a release-valve e. In the upper part of the main body portion is a chamber f2.0, communicating through a passage a' with a chamber y/ in rear of the chamber B. In the chamber w and fastened to the diaphragm t is a service-valve e', working against a seat over a port 2, which communicates with the brake-cylinder port c through a passage 3. The auxiliary-reservoir port or passage b communicates with the chamber feo, and extending' from the said passage to the space above the diaphragm r is a reservoir feed-passage 4. Extending from the feedpassage f to the upper side of the diaphragm t is a branch passage 5.

The parts thus far described, embracing the feed, release, and service features of the valve device, are in all main particulars like those shown, described, and claimed in my aforesaid application, and a more detailed description is thought to be unnecessary in the present connection. Their operation, briefly stated, is as follows: Air entering the chamber B from the train-pipe passes through the port c, passage f', and branch passage 5 to the space above the diaphragm t, pressing the latter down and seating' the service-valve e.

`The air also passes through the center oi' the ring ASto the under side ot' the double-diaphragm device, pressing the latter upward to first unseat the release-valve n and then the feed-valve f/. This permits pressure to iiow from the feed-passage f into the space above the diaphragm fr, thence through the feedpassage 41: to lill the auxiliary reservoir and chambers 'w y. Then the latter are charged with pressure approximately equaling that of the train-pipe, the parts will be in balance, the service-valve remaining closed under the relative suction action at the port 2. A service reduction of pressure in the trainpipe causes the same reduction to be felt between the diaphragme s z5', permitting the then superior reservoir-pressure bearing upon the diaphragm fr to lower the double-diaphragm device, which causes the feed and release valves to close, and the reservoir-pressure acting against the under surface ol the diaphragm t raises the latter and unscats the service-valve, whereby pressure will liow to the brake-cylinder to apply brakes. When the auxiliary-reservoir pressure drops nearly to the then reduced train-pipe pressure, the service-valve will close under the suction at the port 2. The same operations will take place under 'further slight reductions of trainpipe pressure for graduations. Willen trainpipe pressure is raised to release brakes, the pressure enters between the diaphragme st to press the service-valve iirmly toits seat, open thc release-valve fr, and then in the 'lur- IOO IIO

ther rise of the double-diaphragm device open the feed-valve Thus exhaust of pressure from the brake-cylinder commences before the feed-valve z' is opened to replenish the auxiliary reservoir.

Extending' between the chambers B y is a large central opening v/, surrounded by a bushing' 6, forming a seat for a valve-ring 7 on the rear side of the emergency-piston C. In the bushing CZ of the chamber B, in the position shown, are ports 8, leading to an emergency-passage 9, terminating in an enlargement or chamber 10. The chamber lO communicates with the brake-cylinder passage c through a port surrounded by a bushing 11, forming a valve-seat. Extending' between the chambers 1/ 10 is a guide-opening y2, surrounded by a bushingl 12, presenting a valve-seat in the chamber y. The stem 13 of the piston C extends through the opening y' and is provided toward its end with a screwthread 14 and in its end with a recess or chamber 15. Screwed upon the end of the stem 13 is a cup 16, having a central guideopening 17. Confined between the inner end of the cup 16 and the rear face of the piston C is a cylindrical spacer or ring 18, carrying' a seating-ring 19, bearing against the end of the cup and pressing' at its forward end against the ring' 7 to hold the latter in place. The rings 7 19 are preferably of rubber or other suitable material, which will conform to the seats 6 12 and form air-tight joints.

E is the emergency-valve, having a seatingring 2O fitting the seat 11. The valve is upon a sliding extension 21 of the piston-stem 13. This extension comprises a shank which carries the valve E and an enlarged head portion 22 in the chamber 15 and moving or sliding therein between the stops formed by the base of said chamber and the flanged portion of the cup 16, surrounding the guide-opening 17. The rear end face 23 of the cup 16 may be concave, as shown, and the rear face 24 of the valve E about the stem 21 is convex. /Vhen the parts are in vnormal position, as shown, a space 25 exists between the cup 16 and valve E, and the head or shoulder 22 is separated a short distance from both the stops formed by the base of the chamber 15 and the inwardprojecting end portion of the cup 16.

During the operations of the valve device for service application of brakes and while all the parts are in running position the piston C, emergency-valve E, and attendant parts will occupy the relative positions shown, the piston being held with desired firmness against the seats 6 12 by the emergency-spring 26 shown. To prevent this spring from buc kling, I provide therein a loose tube 27. At all times when the train-pipe pressure exceeds the pressure in the brake-cylinder the valve E will be held to its seat bythe force of trainpipe pressure exerted against the rear side of said valve in the space 25. The piston C fits loosely the bushing (Z, so that the rear side of the piston around the seat 6 is in restricted communication with the train-pipe air. Reservoir-air pressure is normally exerted against the rear side of the piston over the annular space bounded at its inner annular edge by the seating projection of the bushing 12 and at its outer annular edge by the seating projection of the bushing 6. Thus as the area against which reservoir-pressure exerts itself against the piston is comparatively small a comparatively weak and sensitive emergencyspring 26 may be provided. fjcient to cause the reservoirpressure under emergency reduction of train-pipe pressure to overcome the resistance of the spring' 26 and move the piston C from the seat 6 until the vshoulder at 17 engages the emergency-valve stem. This unseating of the piston permits the reservoir-air to bear against the entire area of the rear side of the piston, thereby overcoming the resistance of the emergency-valve against unseating and forcing the piston to the position where its annular seating edge 28 bears against the gasket or seat 29. Then the emergency-valve is thus initially opened, a rush of pressure will take place from the train-pipe through the ports 8 and passage 9 to the brake-cylinder to effect serial or quick action emergency application of brakes in the manner well understood. Seating of the piston against the seat 29 shuts ofll communication between the feed-passage e and train-pipe and also between the ports 8 and train-pipe. so that during emergency application of brakes there can be no retrogression of pressure from the brake-cylinder to the train-pipe. hen train-pipe pressure is raised following emergency action, it will, as soon as it, supplemented by the spring 26, is capable of overcoming the reservoir and brakecylinder pressures, move the piston in the direction of seating the einergency-valve. As the piston in its backward movement opens the ports 8 a sudden retrogression of pressure will take place from the brake-cylinder and reservoir to the trainpipe, thereby producing, as explained in my aforesaid application` serial release following emergency action. Willen the auxiliary reservoir and brake cylinder are emptied of pressure, there is of course no pressure behind the emergency-piston C. Then a car with empty reservoir and brake-cylinder is coupled to a train, usually the full force of train-pipe pressure is suddenly let into the triple valve and must pass through the small feed-port and feed-valve to charge the auxiliary reservoir and the chamber behind the emergency-piston. In the meantime pressure passes more quickly into the emergency-passage 9, and where, as in my former construction referred to, this pressure can exert itself This area is suf-l IOO IIO

against the emergency-valve-in the direction of unseating it, it is apt to open the valve ISO I have shown my improvements in the form in which I now prefer to provide them; but it will be obvious that changes may be made in the matter of details of construction without departing from the spirit of my invention as set forth in the appended claims.

What I claim as new, and desire to secure by Letters Patent, is"- 1. In a device for actuating air-bral es, the combination with feed, release and service mechanisms, of a valve-body having an emergency-port and passage extending from the train-pipe connection to said port, an emergency-valve-operating movable abutment, and a valve for said port movably connected with said abutment and independently exposed on one side to seating pressure from said passage.

2. In a device for actuating air-brakes, a valve-body having an emergency-port and passage extending from the train-pipe connection to said port, a movable abutment exposed on one side to train-pipe pressure only and exposed on its opposite side to reservoir and restricted train-pipe pressures,and a valve for said port movably connected with said abutment and independently exposed on one side to seating pressure from said passage.

3. In a device for actuating air-brales, the combination with a tri ple-valve body, of quickaction emergency-valve mechanism physically and operatively independent of the service valve mechanism and comprising a movable abutment exposed on one side to train-pipe pressure only and on its opposite side to auxiliary-rcservoir and restricted train-pipe pressures, and an emergency-valve loosely connected with said abutment and independently exposed at one side to seating' pressure from the train-pipe.

4. In a triple valve for air-brakes, emergency-val vc-operating mechanism comprising a piston, a piston-stem, a cup on the end of the stem, a spacer around thestem interposed between the piston and cup, and seating-rings at opposite ends of the spacer, in combination with an emergency-valve slidably mounted in the cup.

MAURY W. HIBBARD.

In presence oi"-4 J. I'I. LANDES, E. P. RICH.

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