US839893A - Fluid-pressure brake. - Google Patents

Description

.PATENTBD JAN. 1, 1907. W. H. SAUVAGE.

FLUID PRESSURE BRAKE.

APPLICATION FILED DEO. 1, 1905.

FIGA.

'I nllll! miligrglww @bh/Le es @muto/c Www f/. Q M W to sur e ahead, while the quiekly-biaked car the brakes are a UNITED sTAgEs PATENT oEEicE.

WILLIAM HENRY SAUVAGE, OF NEW YORK, N. Y. FLUID-PRESSURE BRAKE.

Specification of Letters Patent. Application filed December 1,1905. Serial No. 289,908.

No. 839,893. Patented Jan. 1, 1907.

To (LU whom t 71u14/ consent:

Be it known that I, WiLLiAM HENRY SAUVAGE, a citizen oi the United States oi nerica, and a resident of the borough of Manhattan, city, county, and State of New York, have invented certain new and useful Improveii'ients in `liluid-Pressuie Brakes, of which the following is a speeiiieation.

long train adjust themselves in their roper position quietly upon the adual application of the brakes before the fu l power is applied, so that all jerking and bumping is avoided. In the same way a gradual release tends to ment of complete release.

The preferred form of apparatus embodyrakes, and is designed to remedy ceitain deing my invention with some modifications fects and diliiculties encountered in the usc thereoi aie shown in the accompanying sheet of what is commonly known as the airof dravmngs, 1n which` Figure 1 is a side elevation and partial section of the standard freight brake-cylinder,

brake system on railroad and electric cars. With the present air-brake apparatus it is impossible to apply in brake-slice more than about ninety per cent.

ly reduces the Fig. 4 shows the saine form in effective dran' of the brakes and lengthens the operative position.

distance run efore the train comes to astandiroughout the drawings like reference` still, but it also ruins the wheels b flattening figures indicate like arts. them. This limits the maximum rake-presl is the brake-ey inder; 2, the piston; 3,

sure usable with the present system. Moreover, even with the present quick-action triple valves there is always more or less joltng between the cars of a long train when a heavy application of brakes is made. is due in part to unequal wear of brake-shoes in different cars ke-rigging, both o which resultan unequal piston travel in the brake-cylinders and one cai' to act more than those on its the slowly-braked car triple ipe 5 2. This consists, preferabl or choking valve 6 of suitable such, `for instance, as shown in Fig. 3-whicll g t e openin cross-section- Normally t 's valve is` held o en by the spring 8 or other means. It is e osed by airpressure in cylinder 9 operating on piston I0, connected to valve-stein 11. hnder 9 is connected by pipe 12 with brake-c rlinder 1 throuo'h al port 13 in the side of sai 1. This port 13'is so located that holds ack, and due in part to the fact that plied in the cars nearest the engine before t iey are applied on the rear cars. A similar une ual action in the recouplings between cars to draw-heads toJiull out clearance and the lost bra es in order to avoid breaking the train in rig g. two. he o eration of this form of device is as My invention avoids these difficulties b ollowsgllvhen an application of the brakes Slightly delaying the application of the full is made, air freely enters the brake-cylinder raking ower after the triple valve has and piston 2 quick] moves out to set the acted an also in delayin the full release of brakes.. When the grakes are set, however, the brakes after the trip e exhaust is o en. air passes back through pipe 12 and nearly Thus the brake-shoe is allowed to a just closes choking-valve 6, as shownin Fig. 4. itself to the Wheel-face before the full presl The How of air is then rest icted and the full sure comes on it, and the several cars of a IIO second of time or, perhaps, more or less. Un releasing the brakes the pressure comes ofi slowly until the piston 2 has )assed port 13, when valve 6 opens wide andl the remaining air is promptly discharged.

The advantages of this invention comprise the avoidance of the severe blow with which the brake-slices otherwise strike the wheels in emergency ap )lieations of' the brake and the eqnalizing ei'eet as to time of complete application and release on cars differently located in the train and differently adjusted as to piston travel. In the arrangement heretofore used when an emergency application is iliade piston 2 jumps out llke a shot fired from a gun with a force ol4 about ten thousand pounds or more. This slams the brake-slices up against the wheels like so many hammers. The brake-slice hits the wheel so sharply that the little projections which form its surface embed themselves in the surface of the wheel and lock it against movement, prcduein a skidding of the wheel on the rail. I ith my invention this action is avoided, and a much greater final brake-pressure can be employed without sliding the wheels. In the arrangement heretofore used also the brakes go on in- Stantly with full power in the first car, while in a fraction of a Second later they go on the second car, and so on down the train. As a car going a mile a minute travels eightyeight feet in a second, there may be ample time for the second car to run up on the first one with a sharp bump before the brake goes on in the second car, especially if the second car has three or four more inches of iston travel than the first car, and accordingll;Y gets about twenty per cent. less braking power. Vith my invention the full braking power will not be attained on car No. l until the initial braking action has begun down at car No. 20 or farther, and so during the interval all the cars have had time to adjust themselves as to their relative positions before the full effect of the brakes is felt, and there is no pulling and bumping. In releasing the brakes while `the train is moving slowly the reverse action takes place, and the tendency of the first cars to surge ahead away from the rear cars is so .far reduced that the train will not pull in two.

In the form of valve shown in Fig. 2 the choking action is afunction of the pressure. The spring 18 is raduated, so as to permit the plunger 19 toift at a given air-pressure, which might be fifty pounds to the square inch, if the purpose was simply to prevent slidin of the wheels, and ex )eriments proved that fty pounds could safely be ap lied t0 a given size cylinder without locking the Wheels. The whole system would then be adjusted to apply a maximum brake-cylinder pressure of seventy-five or one hundred www. .1

i' applicatidnotbrake-pressure is delayed for a pounds. U on makinf an emergency plication tien the ity-pounds prcssun would freely [low into the cylinder; but when that was exceeded the plunger 19 would rise and the choking-valve 20 nearly close, so wire-drawine the air that the maximum brake-cylindner pressure could only be more slowly reached. If' the purpose was to so delay ordinary heavy applications as to prevent surging of the cars, as above explained,

the spring 18 would be graduated to a pressure of twenty pounds or less. In Fig. 2 the valve is shown in full lines in choking position and in o en position in dotted lines.

It should e understood that the pur ose of my invention is not to delay the imtia action of the brakes or triple valves nor to impair the simultaneousness of the application on a series of ears. The quickestacting triple valve possible should be used. The purpose of my invention is to slightly extend the )eriod of time between the initial brake app ication and the attainment of the maximum brakeower for that a plication after the triple va ve has acted, t ns resulting in the benefits above set out.

It is evident that various forms of chokingvalves and other restricting means could be used to reduce the suddenness of the emergencyapplication and that other than pneumatic means mi ht be employed for timing the action of suc' choking means.

Having therefore described my invention, Iclaime.

1. In a fluidressure brake system, the combination Wit the brake-cylinder, auxiliary reservoir and tri le valve, of a connection between the tripi] restricted cross-section than the suppiy-passages through the tri le valve, dura portion of the period o brake application and release.

l2. In a fluidressure brake system, the combination witii the brake-cylinder, auxiliary reservoir and triple valve, of a connection between the triple valve and brake-cylinder provided with -apparatus arranged to produce a passage-way o more restricted cross-section than the supply-passages through the triple valve, toget er with means for so reducing the effective cross-section of said passage-way when the piston of the brake-cylinder is'near the end of its outstroke and maintainin such reduction during the initial portion o the return stroke.

3. In a iuidressure brake system, the combination wit the brake-cylinder, auxiliary reservoir and triple valve, of a connection between the triple valve and brake-cylinder provided with a passage-wa of more restricted cross-section than t e sup ly passages through the triple valve, togetlier with means for reducing the eiective cross-section of said passage-way when the piston of the IOO e valve and brake-cylinder provided with a passage-Way of moreV IIO sages through the of said passage-way when a pressure of prede termined amount has been attained in the brake-cylinder.

5. In a fluideombination wit i iary reservoir and tion between the trip rcssure brake system, the the brake-cylinder, auxiltri )le valve7 of a connecie valve and brake-cyl inder provided with a passageway of more restricted cross-section than the sup l)ly-passages through the triple valve, toget 1er with means for reducing the effective cross-section of said passage-way when a pressure of predetermined amount has been attained m the brake cylinder, said means comprising a pneumatically-operated valve.

6. In a Huidrcssure brake system, the combination wit i the brake-cylinder, auxiliary reservoir and triple valve, of a connection between the triple valve and brake-cylinder provided with a tissage-way of more restricted cross-section than the supply-pastriple valve, together with means for reducing the eil'ective cross-section of said passage-way when a pressure of predetermined amount has been attained in the brake cylinder, said means comprising a pneumatically-operated valve located in the connection from triple valve to brake-cylinder, and adapted to partially close itself automatically when such predetermined pressure of the air passing through the valve is attained.

7. The combination with the brake-cylinder, auxiliary reservoir and triple valve of means for choking down the How of air to and from the brake-cylinder in an emergency application ol the brake and release thereof.

8. The combination with the brake-cylinder, auxiliary reservoir and triple valve, of means for clicking down the How of air to the brake-cylinder before the maximum pressure is attained therein.

9. The combination with the brake-cylinder, auxiliary reservoir and triple valve, of means for choking down the flow of air to the brake-cylinder before the maximum ressure is attained therein, and choking own the flow of air from the brake-cylinder until a predetermined reduction of brake-cylinder pressure is attained.

N. Y.. this 28th day Signed at New York, of November, 1905.

WILLIAM HENRY SAUVAGE. Witnesses:

N. G. CRAWFORD, W. H. PUMPHREY.

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