US2491344A

US2491344A - Air brake

Info

Publication number: US2491344A
Application number: US675883A
Authority: US
Inventors: Erwin C Vroman
Original assignee: New York Air Brake LLC
Current assignee: New York Air Brake LLC
Priority date: 1946-06-11
Filing date: 1946-06-11
Publication date: 1949-12-13
Anticipated expiration: 1966-12-13

Description

1.949 E. c. VROMAN 2,491,344

AI?! BRAKE Filed June 11, 1946 TO MA 1N RES.

T0 BRAKE PIPE INVENTOR. Erwin C.Vroma.n

AHornegs Patented Dec. 13, 1949 AIR BRAKE Erwin C. Vrornan, Water-town, assignot to I The New York Air Brake Company, a corporation of New Jersey Application June 11, 1946; Serial No. 375,833

4 Claims.

This invention relates to air brakes and particularly to a device which indicates with reasonable certainty whether the brakes on the rear cars of a train have or have not released.

With modern heavy locomotives used to pull long trains there is need for a device which will indicate to theengineer, during a release of the brakes, the condition of brakes at the rear end of the train. The result is secured, according to the invention, by sensing the rate of flow of air to the brake pipe while the engineer's brake valve is in running position. i

It has the advantage that rate of flow is determined by measuring the pressure drop through the engineers brake valve, so that no special orifices or other flow restricting means are interposed in the path of feeding flow to the brake pipe.

The device is adjustable through a suflicient range to permit the same indicating mechanism to be used with different types of engineers brake valves (such as No. 6 and No. 8) and different iced valves, such as the F and the M types.

The indicator responds also to the unusual de mands for air such as would be occasioned by an open back up valve or an unusually heavy brakepipe leak.

The invention will now be described as. used with an H fi brake valve and an F feed valve,

each of which is an accepted standard on Amerii can railroads.

In the drawing, the single figure shows the pressure responsive device in section, with connections to the signal, the brake valve, the feed valve and the brake pipe.- sponsive device is drawn on as large a scale aspraeticable and the brake system parts are drawn in miniature and in elevation since their internal construction is well known.

The main reservoir connection I leads to the H-6 brake valve 2 and from the latter leads the brake pipe 3 with the usual double-heading cock 4. From main reservoir pipe I a branch 5 leads to the model F feed valve 6, and. from the feed 'yalve, line 1 leads to the engineers brake valve ,2. The line 8 is the external pressure transmitting connection from brake pipe 3 to feed valve 6, and is a familiar distinguishing characteristic of the model F valve. The knob 9 is the pressure adjusting member of the feed valve.

The parts and connections so far described are standard on American railroads, as persons skilled in the art will recognize.

The signal device comprises a pressure operated switch and appropriate signal controlled thereby,

The pressure rethe switch responding to the pressure differential caused by resistance to flow through the engineers brake valve (in running position) from the feed valve outlet to the brake pipe. This differential is approximately proportional to the rate of flow.

The housing of the pressure switch comprises a body H, a top cap 12 and bottom cap l3. Cap I2 is sealed by a gasket Id and held by machine screws, one of which appears at M Mounted in cap l2 aretwo binding posts l5 insulated and sealed at ii. p v

Clamped at its margin between body II and cap I3 is a combined gasket and diaphragm I1. A- thrust-plate l8 reacts upward on the central area of the diaphragm and is loaded by a coil compression spring I 9. The spring is sustained by spring seat 2| which is adjustable by turning thrust screw 22. The latter is locked and sealed air tight by cap nut 23.

The upper face of diaphragm l'l carries at its center a thrust disc 24 and this reacts upward on a plunger 25 guided vertically in bracket 26 formed integrally with body ll.

Fixedly supported within body H is an electric switch indicated by the numeral 21 applied to its housing. This should be a sensitive snap type switch preferably biased to close, and consequently opened by upward motion of plunger 25. Such switches will control substantial currents and will function in response to motions of a few thousandths of an inch.

As arranged; switch 21 closes on downward motion of plunger 25 which is interposed between disc 24 and the actuating member of the switch. The switch terminals are electrically connected with thebindiiig posts It as indicated and;

through them to a circuit including a source of current 28, shown as a battery, and a signal 29, shown as a lamp. Any suitable current source, and any preferred signal, audible, visible or other, could be substituted.

With an H-6 brake valve, the space within body H (i. e., the space above the diaphragm) is connected by a pipe 3| with'line I, and the space within cap l3 (i. e., the space below the diaphragm) is connected by pipe 32 to the brake pipe 3 at a point between the brake valve 2 and the double-heading cock 4.

With a No. 8 valve connection 3| would lead to the feed valve supply passage at the brake valve pedestal, usually designated as connection 20 and connection 32 would conveniently lead to the brake pipe gage connection. These connections are functionally the same as those illustrated.

During release when flow to the brake pipe is rapid, brake pipe pressure will be sufliciently below pressure at the feed valve outlet to cause diaphragm I! to move down far enough to permit switch 21 to close and cause light 29 to glow. Assuming no excessive losses from the brake pipe by leakage or the like, releasing movement of the AB valves or triple' valve's at the'end of the train will reduce the demand for air, and by reducing the pressure drop incident to air flow will allow diaphragm I! to rise and open switch 21.

Thus, extinction of light 29 is caused to signal release of end brakes. It is considered better to have the light burn to indicate that release has not reached the end of the train. Reversal of the switch action would cause the light to light up when release action reaches the end of the train-a possible alternative arrangement.

The device is calibrated for any particular brake valve by adjusting screw 22. It'will operate satisfactorily with an M feed valve, but its action is more positive with an F feed valve because of the more precise operating characteristics of that valve.

The general principle of the invention involves the sensing of a pressure differential occasioned by flow through the engineers brake valve during release. This can be done in various ways, of which the simplest now known has been chosen for illustrative purposes, but without limiting implication. The scope of the invention will be defined solely by the claims.

What is claimed is:

l. The combination of an automatic air brake system comprising an engineers brake valve, a feed valve connected to supply air to the brake valve and a normally charged brake pipe connected to be charged and vented by the brake valve; and means for indicating at or near the engineers brake valve conditions existing'at the remote end of the brake pipe, said indicating means comprising a device arranged to sense thecharacteristic of running condition with the system fully charged, and adjustable means for selecting the differential pressure at which said signal functions.

3. The combination of an automatic air brake system comprising an engineers brake valve, a feed-valve connected to supply air to the brake valve, and a normally charged brake pipe connected to be charged and vented by the brake valve; and means for indicating ator near the engineers brake valve conditions at the remote end of the brake pipe, said indicating means comprising, a pressure motor responsive to the vpressure differential between the feed valve discharge and the brake pipe; means imposing a definite yielding bias on said motor in the direction to assist brake pipe pressure; and a signal operable by shifting of said motor in the direction of said bias.

4. The combination of an automatic air brake system comprising an engineers brake valve, a feed-valve connected to supply air to the brake valve, and a normally charged brake pipe connected to be charged and vented by the brake valve; and means for indicating at or near the engineers brake valve conditions at the remote end of the brake pipe, said indicating means comprising a diaphragm subject in opposite directions to the pressure existing at a point between the feed valve and engineers brake valve and to the pressure simultaneously existing in the brake pipe; adjustable means for yieldingly loading said diaphragm in a direction to assist the action of brake pipe pressure; an electric switch arranged to be opened and closed by motion of said diaphragm; and a circuit including a signal'controlled by said switch.

ERWIN C. VROMAN.

REFERENCES CITED UNITED STATES PATENTS Name Date Campbell Nov. 28, 1933 Number