US419508A

US419508A - And william l

Info

Publication number: US419508A
Authority: US
Publication date: 1890-01-14
Anticipated expiration: 1907-01-14

Description

(No Model.) 3 Sheets-Sheet 1. H. D. DUNBAR & W. L. AUSTIN.

STEAM BRAKE VALVE. No. 419,508.

Patented Jan. 14, 1890.

Wiinwses 5 their A/LbZor-neys (No Model. a Sheets-Sheet 2. H. D. DUNBARKE W. L, AUSTIN.

STEAM BRAKE VALVE. N 419 50 Patented Jan. 14, 1890.

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W////////%1lii%|ll' w g I I s 7% Inventors ark/ 7 H68 1 217M501 8r? (No Model.) 3 Sheets-8heet 3.

H. D. DUNE-A1281; W. L. AUSTIN. STEAM BRAKE VALVE.

N0. 419,508. Patented Jan. 14, 1890.

UNITED STATES PATENT OFFICE. 5

HENRY D. DUN BAR, OF HARTLAND, VERMONT, AND IVILLIAM L. AUSTIN, OF PHILADELPHIA, PENNSYLVANIA.

STEAM-BRAKE VALVE.

SPECIFICATION forming part of Letters Patent No. 419,508, dated January 14, 1890.

Application filed March 5. 1888- Sen'al No. 266,148. (No model.)

To all whom it may concern.-

Be it known that we, HENRY D. DUNBAR, of Hartland, WVindsor county, Vermont, and \VILLIAM L. AUSTIN, of Philadelphia; Pennsylvania, botlrcitizens of the United States, have invented certain Improvements in Steam-Brake Valves, of which the following is a specification.

The object of our invention is to so construct valve mechanism for steam-brakes, &c., that the pressure of steam admitted to the brake-cylinders can be regulated and the brakes applied to the wheels of the locomotive or cars with different degrees of pressure, and so that a circulation of steam through the pipes and passages can be constantly maintained, if desired, to prevent freezing of the water of condensation in said pipes or passages in cold weather.

In the accompanying drawings, Figure 1 is a diagram showing steam-brake cylinders having connections and valve in accordance with our invention. Fig. 2 is a side view of part of the same on a larger scale. Fig. 3 is a vertical section, partly in elevation, of our improved valve. Fig.4 is a sectional plan on the line 1 2, Fig. 3, with the valve removed to show the valve-seat. Fig. 5 is an inverted plan view of the valve. Fig. 6 is a section of the valve on the line 3 4, Fig.5; and Figs. 7, 8, 9, and 10 are diagrams showing the valve in different positions in respect to the ports of the seat.

The steam-brakes to which our invention more particularly relates are used to brake the wheels of a locomotive, and the valves regulating these brakes have been hitherto constructed so as either to apply full pressure to the brakes or to out off the steam entirely; hence a light ,or gradually-increasing pressure could not be'applied to the brakes,

the usual plan adopted when the locomotive is traveling downgrade being to hold, the brakes off until it is necessary to check the speed, and then to apply the brakes with full power until the momentum is checked, whereupon the brakes are again released, to be again applied when the speed becomes excessive, thus causing a series of sudden shocks.

or jars, which are very injurious to the working parts of the engine.

By our invention we overcome the objection above described and provide a valve whereby any desired pressure of steam up v to the full pressure of the boiler can be applied to the brakes and maintained as long as circumstances require by simply operat ing the handle of the valve.

Referring to the drawings, A is the main valve-casing, having the valve-seat a, I being the inlet-port, situated in the center of the casing and communicating with the supplypipe I at the side of the casing, as shown in Fig. 2, E being the exhaust-port, communicating with the exhaust-pipe E.

Bis the induction-port, communicating with the steam-brake cylinders O C through the pipes B O, and D is the eduction-port, communicating with the cylinders through the pipes O D. Y I

G is the valve, the under face of which rests upon the seat a of the valve-casing, said valve having formed in it an induction-chamber t', a portion 2" of which is V-shaped, as shown in Fig. 5, for the purpose of gradually opening or closing communication between the induction-chamber and the steam-cylinders through the induction-port B, as described hereinafter. The valve G has also an eduction-chamber e, that portion of which between the lines 00 a), Fig. 7, is open to the bottom of the valve,'while the remaining portion from the line 00' to the line 00 has at the bottom a partition-plate e, in which is ,the' eduction-port g and a smaller port j. An opening it in the top of the valve provides for the passage of steam from the inductionchamber to the space above the valve, so that the steam pressure on the valve will be slightly greaterthan the pressure beneath the same, thus causing the valve to seat itself at all times.

A is a cap inclosing the valve G and secured to the casing A by means of screwbolts.

The valve-spindle H is adapted to a pocket in the valve and passes through a stuffing-box in the cap A, said spindle being provided with a suitable handle H, by which the valve may be turned, a stop h on the cap serving by cont-act with a lug 72. on the valve G to arrest the movement of the latter when the port 13 is fully open.

The operation of the device is as follows: Referring to the diagrams, Figs. 7, 8, 9, and 10, Fig. 7 illustrates the valve in position to cut off the steam from the brake-cylinder (J, the exhaust-pipe E communicating through the medium of the pipes B, C, and D and ports B, D, g, and E with said brake-cylinders. If the handle is operated to turn the valve to the position shown in Fig. 8, steam will enter the port 13 and circulate through the pipes B, C, and D, through the cylinders, and through the ports D and and eduction-chamber e to the exhaust-port E, the inlet and outlet for the steam being about equal, and consequently no pressure being brought to bear upon the brakes; but if the handle is operated so as to turn the valve to the position shown in Fig. 0 the available area of the induction-port B is increased considerably without any corresponding enlargement of the area of the portj, thus giving a partial pressure to the brakes, suflicient in most instances to reduce the speed of the engine on downgrades. The valve can be held in this position while traveling downgrade, so as to properly reduce the speed of the locomotive, as it will be seen that the full pressure of the boiler is applied, minus the reduction due to leakage to the exhaust through the small leakage-port When full pressure is required, the valve is turned still farther, or to the position shown in Fig. 10, which entirely cuts elf leakage to the exhaust and fully opens the induction-port l3; hence it will be seen that any degree of pressure can be applied to the brakes.

Another important feature in this form of brake-valve is that the steam may be allowed to circulate through the brake-cylinders and their connecting-pipes in cold weather, when the steam is liable to condense quickly, so that the steam can be in constant circulation through the cylinders and pipes, thereby preventing to a great degree the rapid condensation of the steam and preventing freezing of the water in the pipes, any condensed steam tion and eduction ports communicating with the steam-brake cylinder or cylinders with a valve having induction and eduction chambers and having in the latter an exhaust-port and a leakage-port, said leakage-port being located as described in respect to the induction-chamber of the valve, whereby it will be open to the eduction-port of the chest when.

the induction-chamber of the valve is slightly open, all substantially as specified.

2. The combination of the valve-chest having inlet and exhaust and induction and eduction ports with the valve having induction and eduction chambers, said eduction-chamher having apartition with eduction and leakage ports, all substantially as specified.

3. The combination of the valve-chest having inlet and exhaust and induction and eduction chambers with the valve having an indu ction-chainber with tapering front end and an eduction-chamber having a partition with eduction and leakage ports, all substantially as specified.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

HENRY D. DUNBAR. \VM. L. AUSTIN. W'itnesses:

J. R. MAssEY, FRANK R. JORDAN.