US1104693A - Automatic air-brake system. - Google Patents

Description

. MILLER.

AUTOMATIC AIB BRAKE SYSTEM.

. APPLICATION FILED NOV. 7, 1913.

Patented July 21, 1914.

THE NORRIS PETERS 50.. PHOTO-LITHOV. wAsuuvumu n l WILLIAM MILLER, OF GILMAN, MONTANA.

AUTOMATIC AIR-BRAKE SYSTEM.

Application filed November 7, 1913.

Specification of Letters Patent.

Patented July 21, 1914.

Serial No. 799,773.

To all whom it may concern:

Be it known that I, WILLIAM MILLER, a citizen of the United States, residing at Gilman, in the county of Lewis and Clark and State of Montana, have invented certain new and useful Improvements in Automatic Air-Brake Systems; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it-appertains to make and use the same.

This invention comprehends improvements in airbrake systems for use in connection with vehicles, such as trolley and railway cars, and relates more particularly to such a system as will automatically operate to stop a train when a predetermined speed has been reached.

One of the objects of the invention is to provide in a system of this nature a brake cylinder into which air is continually forced by atraction operated pump, the pressure within the brake cylinder being dependent upon the speed at which the vehicle is traveling and this cylinder being provided with a discharge valve which will automatically close when the train is traveling at such a speed as to produce a predetermined pressure within the cylinder.

Another object of the invention is to provide in an airbrake system of this nature,

means whereby the brakes may be applied at any time by manually closing an air valve.

With these and other objects in view as willbecome more apparent as the description proceeds, the invention consists in certain novel features of construction, combination and arrangement of parts as will be hereinafter more fully described and claimed.

For a complete understanding of my in vention, reference is to be had to the following description and accompanying drawings, in which- Figure 1 is a vertical longitudinal sectional view through a car, showingin elevation my improved airbrake system applied thereto, Fig. 2 is a vertical longitudinal sectional view, partly in elevation showing the construction of the pump and brake cylinder, and Fig. 3 is a fragmentary detail sectional view, showing the automatically operated valve which closes the discharge from the brake cylinder, whereby the brakes are applied.

Referring in detail to the drawings by numerals, 5 designates, as an entirety, a car body and 6 designates the supporting wheels for the car.

In carrying out my invention, I provide a brake cylinder 7, having two discharge ports 8 and 9 formed in one end thereof and being also provided with an intake port 10 through which air is forced from a pump 11. shown in Fig. 2, the pump is of the double acting type, having a pair of intake ports 12 other and that the manner in which they are supported upon the car is immaterial. In

the present instance I have shown the pump positioned above the brake cylinder and It will be understood that the straps 16 surrounding the brake cylinder,

whereby the latter is secured to the bottom of the car 5.

The piston 17 of the pump is operated by means of a connecting rod or pitman'18 connected atone end to the crosshead 19 and at its other end to a friction wheel 20 carried upon the inner end of a lever 21.

The friction wheel 20 is adapted to engage a similar wheel or disk 22 which is secured to the rotatable axle 23; In order that the wheel 20 may be thrown into engagement with the wheel or disk 22, or held from engagement therewith, I provide a vertical rod 24 having a hand wheel 25 secured to its upper end and being connected at its lower end to, the forward or outer end of the lever 21. This rod is threaded intermediate its ends, as indicated by the numeral 26 and the threaded portion works through a sleeve or nut 27 rigidly securedin the floor of the car,

so it will be apparent that a rotation'of the rod 24 will either raise or lower the wheel 20. When the two friction wheels are engaged and the car is in motion, the piston 17 will be continually operated to force a steady stream of air'into the forward end of the brake cylinder 7. Now when suflicient pressure is obtained withinthe cylinder 7, the piston-28 will be forced rearwardly against the tension of thespring29, causing the brake block or shoe: 30 to engage the wheel and slow down the car. Any

system of levers, which are suitable for-the purpose, may be employed for connecting the piston rod 31 and the brake shoe 30.

The valve is held in alinement with the port 9 and is adapted to seat against the beveled portions 36 of the walls thereof, as will be clearly apparent upon reference to Figs. 2 and 3. To hold the valve in its proper position, I employ a U-shaped frame 37 the ends of which are connected to the cylinder head on opposite sides of the port 9. A guide 38 connects the arms of the frame 37 and is centrally apertured to permit the passage of the valve rod 35, said rod also extending through an opening 39 in the central portion of the frame. The valve stem 35 is threaded and carries nuts 40 and 41, the latter of which bears against anexpansive spiral spring 42 coiled about the stem between the guide 38 and the central portion of the frame. The nut 41 is used to adjust the tension of the spring 42 so that the valve 34 may be caused to close when any predetermined pressure is created within the cylinder 7. v

A pipe 43 leads from the discharge port 9 along the bottom ofthe car and then upwardly through the same, as indicatedby the numeral 44, and has a valve 45 connected to its free extremity. A second pipe 46 is connected to the discharge port 8, extends parallel to the pipe 43 and carries a valve 47 on its extremity.

Having described the construction ofmy improved airbrake system, it now remains to explain the operation thereof: Then the system is in its normal working order, the valves 34 and 45 are open and the valve 47 closed. Now supposing, for example, the spring 42 to be adjusted so the valve 34 will close when a pressure of fifty pounds per square inch has been produced in the cylinder7, said pressure being caused by the pump when the car is running at a speed of seventy-five miles per hour. Then for any speed below this rate, the pressure will be below fifty pounds per square inch and the valve 34 will remain open, allowing the air in the brake cylinder to escape through the pipe 43 and valve 45. When the car or train reaches a speed of seventy-five miles per hour, the valve 34 will close, whereupon the pressure within the cylinder 7 will rapidly'increase, causing the piston 28 to move rearwardly and force the brake shoe 30 against one of the wheels and so reduce the speed of the vehicle. This same result can be produced by closing the valve 45 and therefore it will be obvious that the brakes maybe applied irrespective of the speed of the car. To release the brake, the valve 47 is opened to allow air to escape from the brake cylinder 7 and then when the valve 45 has again been opened, the system is in its normal position and will again automatically operate to stop the car when a predetermined speed has been reached.

From the foregoing description taken in connection with the accompanying drawings, it will be apparent that I have provided a very simple, etlicient and reliable air brake system and it will be understood that variouschanges in the construction, po-

sition and size ofthe various parts may be changed without departing from the scope and spirit of the invention as claimed.

Having thus described my invention, I claim 1. In an airbrakesystem, the combinatio of a brake cylinder, a traction operated pump adapted to force air into said cylinder, the cylinder being formed with a discharge port, a valve automatically operated by thepressure within the brake cylinder to close said discharge port, a piston positioned within the brake cylinder, a brake shoe means operatively connecting the piston and brake shoe, whereby a movement of the piston in one direction will cause the brake shoe to become operative and valve mechanism operable independently of said valveto reduce the pressure within the cylinder.

2. In an airbrake system of the character described, the combination with a car, of a brake cylinder, a traction operated pump adapted to force air into said cylinder, the cylinder being formed with a discharge port, an adjustable valve positioned within the cylinder to automatically close the discharge port when a fixed pressure is obtained within said cylinder, a piston operable within the brake cylinder, and brake mechanism operatively connected to said piston.

3. In an airbrake system of the character described, the combination with a vehicle, of a brake cylinder, a traction operated pump connected to said cylinder, the cylinder being formed with a pair of discharge ports, a manually operated valve normally closing one of said ports, a second valve adapted to automatically close the other discharge port when the pressure within the brake cylinder reaches a certain degree, a piston operable within the brake cylinder, and brake mechanism connected to said piston, the piston operating when the second mentioned valve is closed to apply the brakes.

4. In an airbrake system of the character described, a brake cylinder, means for forcing air into said cylinder, brake mechanism actuated by certain predetermined pressure within the brake cylinder, said cylinder being formed with a pair of discharge ports, a manually operated valve for closing one of said ports, a spring pressed valve adapted to close the other of said ports when a fixed pressure 15 created 1n the brake cylinder, and spring means connected to said second mentioned Valve, whereby the pressure nec-c essary to close said valve may beregulated.

5. In an airbrake system of the character described, a brake cylinder, a means for forcing air into said cylinder, the cylinder being tormedwith a pair of discharge ports, manually operated means for opening and closing one of said. ports, a valve positioned within the cylinder to close the other of said ports when a certain pressure is created within said cylinder, a valve stem secured to said valve, a U-shaped ,frame through which the valve stem extends, spring means for holding the valve normally open, adjusting means whereby the tension of said spring means maybe varied, brake mechanism operable when said second mentioned valve is closed, and means for manuallyclosing the second mentioned port-s.

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

WILLIAM MILLER. Witnesses:

v D. N. WILSON, LAWRENCE M. MCDONNELL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of .Patents,

' Washington, D. G.

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