US976925A - Automatic pressure-controlling device for brake mechanisms. - Google Patents

Description

, H; ROWNTREE. AUTOMATIC PRESSURE CONTROLLING DEVICE FOR BRAKE MECHANISMS.

APPLICATION FILED JAN. 19, 1910.

Patented Nov. 29, 1910.

\N N 1 Q Q YR W rt! IIIIIIIIIII I! UNITED STATES PATENT orrron,

HAROLD ROWNTRE OF CHICAGO, ILLINOIS, ASSIGNOR T0 NATIONAL PNEUMATIC COMPANY, A CORPORATION O15 WEST VIRGINIA.

AUTOMATIC IRESSURE-CONTROLLING DEVICE FOR BRAKE MECHANISMS.

Specification of Letters Patent.

Application filed January 19, 1910 Serial No. 538,848.

a specification.

This invention relates to automatic pressure COI1t1Oll]Il devices for brake mechamsm.

The object of, the invention is to provide means for regula'lting the application'of the brake pressure according to the speed of movement-of the car.

A further object is to providemeans for :uttomatically controllingthe application of the brake pressure proportionately; to the. speed of movement of the car. 7 t

A further object is to provide means whereby the maximum pressure permissible to be applied by the brake mechanism is automatically varied in proportion to the speed of the car.

A further object is to provide means controllable conjointly by the pressure itself and by the speed 'of the car for regulating the application of the pressure to the brake mechanism.

Other objects of the invention will appear more fully hereinafter.

The invention consists substantially in the construction, combination location and relative arrangement of parts, all as will be more fully hereinafter set forth, as shown in the accompanying drawing and finally pointed out in the appended claims.

The drawingshows partly in diagram and, parts in section, an arrangement of automatic pressure controlling mechanism embodying the principles of my invention.

In stopping the motion of a car, or of a train by the application of air brakes it is desirable that the pressure applied shall not increase beyond a certain point as the application of too great an amount of pressure will cause the brake shoes to freeze to the wheels and stop the car or train too suddenly, thereby causing trouble, and fre quently disastrous andcven fatal accidents. The amount of pressure permissible to be applied depends on the speed of the train or car, the faster the train or car is moving at i the instant the brakes are applied, the greater the pressure 'which it is permlssible to apply withoutdanger. I11 the ordinary form of brake control, the motorman or engineer in order'to stop his car or train, manipulates his control handle to admit a fairly heavy pressure to the brake cylinders without knowing the maximum pressure allowable to be applied for the particular speed at which the car or train is moving without danger, the amount of pressure so applied being governed only by the judgment and experience of the motorman or engineer. As the car or train slows down unxler this application of pressure the motorman or engineer bleeds the pressure out so as to reduce thesame. It'is among the special purposes of my lnvention to provide means whereby the motorman or engineer -by merely moving his control handle to a certain position effects an application of the maximum degree of pressure permissible without danger according" to the speed at which the car or train happens to be moving at the instant of such application, and without depending on his own skill, judgment,

discretion or experience, which may be faulty. And I also .propose to provide means whereby as the car or train diminishes in speed the brake pressure is proportionately and automatically decreased, thereby enabling the train or car to slow down and stop at all times with great smoothness, and without. danger of injury, and within a minimum distance.

' In carrying outmy invention I provide means controlled conjointly by the pressure Patented Nov. 29, 1910.

medium and the speed at which the car or train is moving, for automatically regulating the supply of pressure to the brake mechanism.

Many specifically different constructions and arrangements of devices and. appliances may be devised forcarrying my invention into practical operation; While, therefore, I;

the motormans control handle u on which,

is mounted a contact member B, w itch is arranged to make contact with a conductor C, in whatever position to which the handle A, may be moved. The conductor C, is shown one or the other-of the strips Q, Y, accordin the form of 'a ring concentric with the axis about which the handle A turns. The conductor 0, is connected through wire a, to

In a small cfylinder G, is arranged a piston H, one side 0 which is exposed to the pressure medium as supplied to the brake mechanism, and'the other side of which is acted -'upon by a spring I,"the tension' of the latter being normally exerted to move the piston H, toward that end of the cylinder G, which is in communication with the pressure supply connections to the brake mechanism. The piston H is connected by'a rod J, to the free end of arock lever K, pivotally'mounted to rock or swing about an, axis L. Mounted concentric with the axis of, or in cooperative relation with'respect to lever K, is a member N, which, inthis instance, is in the form ofa rotative disk. This diskis designed to be rotatively displaced to a degree proportionate tothe speed at which the car is moving. For this purpose I propose to rotativelyactuate said disk from an axle orother convenient running part of the car. Any suitable form of well known speedometer which is driven from a-rotating'part of the running gear of the'car, and which rotatively'displaces the disk proportionally to the speed of the car will answer. A speedmeter such for instance andas illustrative of one form of embodiment of operative means, for the purpose, as is shown in the patent to .Weston No. 277,179, dated May 8th, 1883, will serve my purposes but I do not wish to be limited or restricted in this respect.

By-employing a disk rotatively displaced as above explained, it will be seen that the faster the train or car is traveling the greater will be the degree of rotative displacement of said disk, the arrow indicating the direction of rotative displacement thereof. The disk N has mounted on the face thereof two circular contact strips Q, Y, separated from each other and also a contact ring-R; The lever K, carries a contactstrip M, arranged tobri'dge. the space between the ring R and ing to the relative positions of the disk and lever. Bearing against the strip Q, is a brush or contact 0, and bearing a ainst strip Y, is a brush or contact P. A similar brush or contact S, bears against contact ring R. Reference signs. T, U, designate electro-magnets respectively arranged to "operate valves 10i111. These valves control the supply and ex aust of air to and from the bra ergized the valve 10, is moved from its seat I thereby admitting the pressure medium from the tank or othersource (not shown) pressure.

e cylinder.- When the magnet T is en;

cylinder, (not shown). When the magnet U, is energized the valve 11, is moved from its seat thereby opening the brake cylinder to exhaust through pipes 12, \V and X. The

pressure connection NV, 12, is also incom-- municatlon with one end of cylinder Gr, so

that the pressure medium is enabled to act against the inner face of the piston H.

The brush contacts 0, P, are respectively in electrical connection with contact points D, F, through wire or other connections 13, 14, and also through wire or other connections 15, 16, with one of the terminals of the windings of the electroanagnets U, T,

the other terminals'of the magnet windings position-for the contact B, to make contact with contact point D, the circuit j ust' traced is broken While another circuit is completed fromthe source of currentthrough the positive supply main a, to contact C, and thence through strip 13, contact D, connection 13, brush 0, connection '15, the windings of magnet U, to the negative'main Z). The re sulting energization of magnet U, causes valve-l1, to be unseated thereby opening the brake cylinder, cylinder G, pipes 12 and w, to exhaust, and relieving the brakes of all If now the control handle is shifted into position for strip B, to make contact with point F, the circuit from the source ofenergy is completed from main a throughcontact C, strip B, contact F, connection l4, brush P, connection 16, the windings of electro-magnet T, and to thereturn main 6. The resulting energization of magnet T, causes valve 10, to be unseated thereby admitting pressure to the brake mechanism. In this way by suitably .and properly manipulating the handle A back or forth from D to F or from F to D, that is to and from on and off positions the ap-. plieation of the brakes and the bleeding of the pressure is accomplished in the present usual way. If, however, it is desired to apply the maximum pressure that can be applied with safety, the motorman places his control handle in position for the strip B, to contact with point E. Thereupon the following circuit is completed from'the main (1,

throughcontact C, strip B, point E, connection l7, brush S, ring R, and strip M. -If

the car is in motion at this instant, then thesition, in the-direction indicated y the arstrip Q, brush P, connection 16, magdisk N will be in 'rotatively dis laced porow, and 'consequentlytstrip-M,will also be in contact with strip Q, consequently the above-traced circuit will continue from strip x 1 net'c pressure will be supplied and thebrakes applied. As the bra to pressure builds up behind piston H, said piston is' forced out wardly in cylinder G, against the llCtlOIl; of spring I, thereby moving'rod J, and rocking lever K, in .the' direction of the arrow. When contact M, in this rotat'ivemove'ment of lever K, reaches the space between the'adof stri s Q,

jacent ends of strips Q, Y, the last traced circuit is broken and the'magnet T 1s deenergizd, The distance through which the 'lever K- is moved before the contact M reaches the 8%?(36 between the adjacent ends will of course depend upon the extent to which the disk N has been rotatively' displaced, and this, in turn, is dependent upon the speed at which the car is traveling. As the speed of the car begins to diminish under the application of the braking pressure, as above described, the disk N begins its return rotation in a direction 015 osite that of the-arrow and. eventually strip-1a, will contact with strip Y, and then the circuit from strip M, will be completed through strip Y, brush 0, connection 15, magnet U, to return Y), thereby opening the bra e mechanism to exhaust. This will reduce the pressure in cylinder G, and the piston H,'w1 ll begin its travel unde'rthe influence of spring I, thereby rockin'glever K,

in a direction opposite that indicated by the arrow until the strip M again reaches the jaa'p between the adjacent ends of strips Y, thereby opening the circuit. If the car still has any headway the disk N will still be snore or less displaced rotatively in the direction indicated by the arrow, and

"hence the strip M, will again be brought into contact with strip Q, for another application'of pressure. This action continues as long as the controller handle remains in its central position, that is, in position for disk N, as to determine the maximum degree of pressure which would be safe to be applied to the brake for the particular speed "at which the car is moving at any given instant. .Thus the piston H, is balanced between the brake pressure and the spring I,

and since this balance is controlled by the.

brake pressure and since .the lever K cooperates with the rotatively dis laceable d1sk N, which latter is cbntrolle by the speed of the car, it will be seen that the dc sired automatic control of the brake pressure is effected through the conjoint action of the pressure and the speed of the car, and therefore this control is so regulated that not only is the maximum safe pressure always initially ap lied but also this application as well as t e continued application of brake pressure is controlled automatically so as to remain proportional to the speed of the 'car and all that is required of the motorman is to move his control handle into position for strip B, thereon to make contact with point a By the use of a'brake pressure controlling apparatus such as above described, a car or train can be operated at a higher speed between stations or stoppin points than heretofor, or at a lower hea way between succ I I 0 I V ceedlng cars or trams, since the slowing down of the car or train in approaching a station. or stopping oint may-commence at a point closer to t e station or stopping point than'has heretofore been the case or custom in practice. In other Words with the use of the apparatus embodying my inventibn the car or train will be brought to a stop with 'absolutenniformity and smooth ness in the minimum time and distance after the application of the brake mechanism,

7 thereby not onlyavoiding danger of disaster or injury resulting in a too sudden or powerful application of the brake mechanism, but also greatly reducing' the time required in coming to a stop. These are particularly desirable characteristics of a brake control mechanism for use on interurban, subway, elevated 01' surface street cars where it is desirable with congested traffic to operate the trains or cars as closely as possible together, or with the least-interval of space between them, and as rapidly as possible, in order. to secure rapid transit of heavy or congested passenger traflic. Moreover, the danger of serious or fatal accident through collision'is also largely reduced as a car or train can be stopped by the application of a control mechanism embodying the principles of my invention in the short- 1. In a brakemechanism for cars, the

combination with pressure supply controlhng devices, of actuating devices therefor,

' and means controlled conjointlyby the presv erases sure supplyand the speed ofthe car for controlling said actuating devices.

2. In a brake mechanism for cars, the-- combination with "ressure sup ly and ex haust controlling. evices, of. .eectrical devices for operating the same, and means contrglled by the .speedof the car for controlling the circuits of said electrical devices.

'3. In a brake mechanism for cars, the combination with a pressure supply controllin valve and an independent exhaust controIling valve, of means controlled by the speed of thecar for respectively controlling the operation of said valves.

4. In a brake mechanism for cars, the

combination with pressure supply and exhaust controlling valves, of means controlled conjointly by the pressure medium and the speed of the ca'rfor respectively controlling the operation of said valves.

5. In a.brake mechanism for cars, the

combination with pressure supply, and ex-, haust controlling. valves, of electrical devices' for 0 erating said valves, and means controlled y the speed of the car for controlling the circuits of said electrical devices 6. In a brake mechanism for cars, the

combination with pressure supply and exhaust controlling valves, of electrical devices for operating said valves, and means controlled conjointly by, the pressure. medium' and the speed of the car for controlling .the,circuits of said electrical devices.

7. In a brake mechanism'for cars, the combination with respectively independent pressure supply and exhaust controlling valves, of means for operating the same, and means controlled conjointly by the speed of the car and the pressure medium .for respectively controlling said operating means.

8. In a brake mechanism forcars, th

combination with,pressure supply and exhaust controlling valves, of means for operating the same, and means co'ntrolledby the conjoint action ofthe'pressure medium and the speed of the car for controlling said operating means;

9. In a brakemechanism for cars,"the combination with pressure supply and exhaust controlling devices, of means for con-.

trolling saiddevices, said means including coeperatingcontacts, respectively controlle by the pressure supply and the speed of the car.'--. 1 10. In a brake mechanism to cars, the combination with ressure sup y and ex haust controlling evices and e ectricalde-,

. vices ton-"operating the-same, of meansfor controlling the circuits of said electrical devices,"said means including a contact device arrang I speed ofhe can 11. In a ,brakemechanism? for: cars the combination with pressure supply "and exmeans therefor includin haust controllin to be moved proportionately to the haust controlling devices of means for oper-- ating thesame'alternately according to the speed of the car. 7 a 12. In a brake mechanlsm for cars, the

combination with respectivelyindependent pressure supply and exhaust cont'rollingfde vices, of means for operating the same alternately, said operating means being con: trolled conjointl and the speed 0 the car.

- 13. In. a brake mechanism for cars, the Q.

combination with pressure supply and ex haust controlling devices, and means for by the pressure medium operating the same, of'means for controlling said operating means, including-a contact arranged to be displaced in proportion to I the speed of the car, and a coiiperating contact arranged to be'displaced 1n.-proport'ion to the pressure applied. I

14. 1n a brake mechanism for cars, the combination with pressure su ply and ex haust cont-rolling devices, 0% controlling means therefor, and including coeperating controlling the same including a rotatable disk carrying contacts, a lever carrying a cooperating contact, said. disk arranged to displaced proportionately to 'the speed 0 X the car, a plston connected to be rotativel the lever, and acted u on on one side by the pressure supply' to t e brake mechanism, and yielding means acting upon the other side of said piston. I

17. In a brake mechanism for cars the combination with ressure supply and ex haust controlling evices, of operating devices therefor and means for controlling the operating devices includin coiiperating de-- vices respectively operate by the ressu're supply'and the speed of the car, an a control-handle cotiperating with said last'named devices.

'controllin contacts, said disk arranged to be 181 In a brake 1 mechanism for cars the I combination with evices, and e ectrical devices for control ing the same, of means for controlling the electrical devices including coiiperating movable contacts-respectively operated by the pressure sup ly and thespeed of the car, and a contro ndle for completing circuit to saidcontacts. I

ressure sup ly an ex 19. In a brake inechanism for cars; the

' combination with pressure supply and ex 'manually controlling the circuits of said electrical means, and automatic-means, controlled by thespeed of the carfor controlling said circuits.

20 111 a brake mechanism for cars, the. combination with pressure supply and ex-.

, haust controlling devices, and electrical means for operating the same, of a manually operated handle for controlling the circuits of said electrical means, and relatively movable .contacts also controlling said circuits,-

said movable contacts operated respectively by the speed of the car and the pressure f medium.

In testimony whereof lhave hereunto set my hand in the presence of the subscribing w tnesses, on this 7th day of January A. D.

, HAROLD ROWNTREE. Witnesses:

D. SELOV'ER', M. H. MARTIN.

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