US1989453A - Triple valve for direct acting automatic brakes - Google Patents

Description

Jan. 29, 1935. F. KAsANTzEFF 1,989,453

TRIPLE VALVE FOR DIRECT ACTING AUTOMATIC BRAKES Filed May 27, 1932 f 2.3 as

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Patented Jan. 29, 1935 UNITED STATES PATENT! OFFICE 1,989,453 TRIPLE VALVE Y FCR DIRECT vACTING r AUTOMATIC BRAKES o Florentin Kasantzeff, Berlin, Germany Appiication'May 27, 1932, serial N0.6'14,0o3

` '2 Claims. (C1. 303-35) This invention relates to a triple valve or distributor for pneumatic brakes of the direct-acting automatic type. l

In my copending application, Ser. No. 446,731,

I havedescribed a triple, Valve having a regulating chamber linserted between theY brake cylinder and the train pipe and fed with compressed air through narrowpassages which offer such a resistance tov the streaming air, that the brake ac- 0 tion is deferred for a certain time space, vand thereby even large alterations of pressure in the train pipe and even in long trains come into action sufliciently simultaneously on the brakes of the lsingle cars for obviating undue stresses in the car couplings and buiiers.

n The new invention concerns a further development of the said construction and consists therein, that the regulating chamber, which by its only slowly changeable air pressures governs the entrance and exhaust of air on the brake cylinder, receives a certain minimum initial air amount with an acceleration by aid of an initiating chamber adjoined to said regulating chamber through its air feeding valve by a large passage and fed through the above named narrow throttling passage from the auxiliary reservoir. The air-volume contained in said initiating chamber thereby streams quickly intol the regulating chamber, as soon as both said chambers are brought into connection with each other for braking, and thus the regulating chamber comes quickly on a certain initial pressure, which causes also in the brake cylinder a certain initial pressure to be quickly produced, so that the brake blocks become loosely applied to the running wheels. Thishas the advantage that the brake vblocks are instantly and softly applied, and the real braking action, which subsequently begins witha certain hesitation, becomes especially free from shocks and very uniform on all cars of the train.

A further valuable detail of the invention consists in a regulating valve inserted in the throttled feeding channeland in the exhaust channel of the regulating chamber in such Way that it allows of adjusting both said channels to different throttling actions or to close them fully. Thereby the time spaces needed for the full braking and brake releasinga'cti'ons can be regulated according to the requirements, and by fully closing said valve any given condition of braking or vbrake releasing can be maintained at will, for example for handling an uncoupled car. In the drawing Fig. 1 is a diagram showing the mode of action of the new triplev valve, and

Fig.'2 is a longitudinal section vof saidtriple valve. "V

The diagram-Fig. 1 shows the time as the 5 abscissa, and the braking Vpressures as the-ordinate, The line a corresponds to the action obtained according to the above named copending application'446,731, and line b shows the new action. Whereas according to line a the pressure in the regulating chamber and correspondingly also in the brake cylinder successively ascends from zero-to the maximum and on any point of said line the brake blocks become applied, novv, according-to line b a quick initial increase of pressure is obtained for applying the brake blocks, 'and thereafter the pressure is gradually increased up to the maximum.

The triple'valve according to Fig. 2 contains for this purpose three main parts (as in thementicned copending application) a regulating pressure producer 1, a regulating chamber 2 fed with the pressure from producer 1, and a brake cylinder-feeding device' B'governed by said regulating pressure. o

v'The regulating pressure producer 1 vcontains five chambers 4, 5, 6, 7, A8 separated from each other by an intermediate Wall 9, a diaphragm 10, a further intermediate wall 11 and second diaphragm 12. The rst diaphragm 10 is provided with a hub 13 extending with a close t through theintermediate wall 11 and perforated at 14. A double seat Valve 15|is arranged in an opening of the rst intermediate Wall 9 adapted to alternately close' and open both a passage through said wall also said perforation 14 inhub 13. The second ldiaphragm 12 is provided `with a casing 16 containing a spring 17 and an abutment, plate 18 pressed against a stop 16a on saiddiaphragm by said spring and holding said springunder a certain predetermined tensionV according to the desired maximum pressure in the regulating chambers 2, 5 and arranged Aopposite to the hub 13 so as to be engaged by the latter as soon as both diaphragms 10 and l2 approach each other.

The said uppermost chamber `8 is open to a constant pressure reservoir 23 (supplemental reservoir) which functions to load-the diaphragm 12 by van essentially constant pressure. 1 v t The next chamber '7 below said diaphragm y12 is connected through a passage 22 to the train pipe and serves to bring the variations of train pipe pressure into effect on'the Whole regulating pressure producer 1. Y l f Y The next chamber 6 is open to the atmosphere through a channel 21 and in cooperation with the said valve 15 and channel 14 serves for exhausting air from the chamber 5 and from the regulating pressure chamber 2 connected thereto.

Finally, the lowermost chamber 4 is connected to the auxiliary air reservoir through a channel 19 and a back pressure valve 48 having a small perforation 49. This chamber serves to feed air to the chamber 5 and to the regulating pressure chamber 2 connected thereto, in cooperation with the valve 15.

'I'he said channels 21 and 19 offer certain resistances to the streaming air for consuming a certain measured time in exhaustingV or feeding said chambers 5 and 2. For producing and .regulating such resistances, a cock having narrow throttling passages 60a and 60b is inserted into said channels 21 and 19. Saidcock also serves forl entirely closing said channels in case it is required that a certain pressure in chambers 5 and 2 shall be maintained for a long time, for instance a pressure of 0 atmosphere, when a car is to be shunted.

The said chamber 4 is of such size that the compressed air contained in it (for example having 5atmospheres) at the moment of opening of the valve l5, through the chamber 5 and the passage 20 fills the regulating chamber 2 up to a cer- .tain initial pressure (of for example 0.25 atmospheres) and thereafter the further filling up of chamber 2 proceeds more slowly according to the resistance of the narrow feed passage 60a in cock 60.-

For feeding compressed air to chamber 4, a feeding valve case 24, having a passage 24a, is provided, and said passage 24a is connected through a passage 45 to said train pipe passage 22. Said valve case 24 is closed on top by a diaphragm 25. A valve 25h, having a bore 25a, is connected to said diaphragm 25 and fits closely into said case 24. A spring 25e presses said valve 25h upwardly. A narrow bore 24h is arranged in said case 24 in such manner that it is closed by the head of valve 255 in the lowermost position of the latter. The space below said diaphragm 25 is connected to the atmosphere by a passage 26.

From the above said passage 45, a further passage 46 leads to a back pressure valve 47 and through a passage 47a. to the said back pressure valve 48, 49 and to the auxiliary air reservoir.

'I'he entire regulating pressure producer 1 and the feeding valve 24, 25 operate as follows.

In lling the train pipe, the air enters through passages 22, 45, 46, 47, 47a, 49 into the auxiliary reservoir and at once into the passage 19 and chamber 4. Further, the air enters through passage 24a into the valve case 24, and through the valve bore 25a to the constant pressure chambers 23a and 23. At once, a small amount of air escapes through the bore 24h to the space below diaphragm 25 and thence through passage 26 to the atmosphere. As soon as the constant pressure chamber 23 is filled up to a certain pressure depending upon the sizes of diaphragm 25 and of the spring 25e, said diaphragm 25 moves downwardly. The attached valve 25h then first closes the passage 24a,4so as to discontinue filling chamber 23. At once the entrance of air to the bore 24h ceases, and the passage 26 completely exhausts the space below diaphragm 25, so that the latter completely descends and closes said bore 24h. In this way the running position is attained, in which chamber 23 has full pressure, and chamber 2 is still without pressure.

In braking, a pressure reduction is produced in the train pipe and through passage 22 in chamber 7, so that diaphragm 12 (loaded from above by the full pressure existing in chamber 23) moves downwardly. Thereby valve 15 is lifted from its seat, and the air from chamber 4 streams through valve 15, chamber 5 and passage 20 to the regulating chamber 2, in which it suddenly produces a certain initiating pressure. Thereafter further air follows through the narrow passage 60a, so as to raise said initiating pressure more slowly. This rise is finished as soon as the rising pressure in chamber 5 suices for raising the diaphragm 10 so as to allow valve l5 to close.

` An excessive reduction of train pipe pressure, arising in braking by any mischief, would result in an excessively high pressure in chamber 2. This is obviated by the yielding effect of spring 17, which in such cases is compressed and allows the valve 15 to close.

In brake releasing, the effects are the same as in filling the brake, with the addition that the pressure existing in chambers 2 and 5 lifts the diaphragm 10 and thereby opens the channel 14 as long, until chambers 2, 5 have been exhausted through passage 14, chamber 6 and throttling cock-boring 60hto the atmosphere Thus, briefly stated, the regulating chamber 2, in running' state remains without pressure; in braking it receives at first an initial pressure of say 0.25 atmospheres and thereafter, slowly, a higher pressure up to say 1.2 atmospheres. In brake releasing said pressure is slowly diminished to atmospheric pressure. Any such pressure is automatically conserved as long as the corresponding train pipe pressure is conserved.

Now, it is only necessary to utilize the said various pressures for producing completely proportionate pressures in the brake cylinders. This is done by the brake cylinder feeder 3 as follows.

The brake cylinder feeder 3 contains four chambers 30, 31, 32 and 33, separated from the regulating chamber 2 and from each other by diaphragms 34, 35, 36 of different diameters and by an intermediate wall 3'7. The chamber 30 is open to the atmosphere through a channel 38. The next chamber 31 is connected by a channel 39 to a cock 40 having a groove 41 adapted to connect said channel to the atmosphere and a cross-bore 42 adapted to connect said channel 39 to a further channel 43 opening into the chamber 32 which is connected to the brake cylinder at 44. Said cock serves for either opening the chamber 31 to the atmosphere, so that the diaphragm 35 becomes ineffective (for loaded vehicles), or for connecting the chambers 31 and 32 to each other, so that the diaphragm 36 becomes ineffective (for empty vehicles), so as to produce in chamber 32 for instance a desired maximum brake cylinder pressure of 3.6 or 2 atmospheres respectively, if the regulating pressure in chamber 2 amounts to 1.2 atmospheres.

The chamber 33 is connected to the said train pipe through the passages 22, 45, 46, 47 and 47a. Said chamber 33 is further connected to the Yauxiliary reservoir through the said bore 49 of valve 48. Thereby the auxiliary reservoir is slowly filled through said bore 49v from the chamber 33 and from the train-pipe, but quickly delivers air through the valve 48 for filling the brake cylinder.

The diaphragms 34, 35, 36 are joined together by a hub 50 in which a channel 51 is so arranged that it leads from the atmospheric chamber 30 to the brake cylinder chamber 32 through a doubleseat valve 52 extending through the chamber 32 and through an opening of a valve casing 52a secured in the intermediate Wall 37. Both Valves 52 and 48 are held on their seats by a common spring 53.

The brake cylinder feeder 3 acts as follows. As long as atmospheric pressure is present in the regulating chamber 2 (during filling the brake system and while releasing the brakes) the diaphragms 34, 35, 36 remain in their middle position and the brake cylinder chamber 32 is open to the atmosphere. As soon as (for braking) a pressure reduction is produced in the train pipe and thereby an initiating pressure jerk and thereafter a slowly rising regulating pressure is produced in the regulating chamber 2, the diaphragms 34, 35, 36 go to the right under the action of the regulating pressure and by their hub 50 take along with them the double valve 52 at first quickly and thereafter slowly. Thereby air k from the chamber 33 through valve 52, 52a enters the chamber 32 and the brake cylinder, first in a certain large amount sufficient for quickly applying the brake blocks to the wheel rims, and thereafter more slowly for exerting the slowly rising braking pressure until equilibrium is restored. The brake cylinder pressure thus balanced against the regulating pressure depends upon the area proportions of the diaphragms 34 and 35 or 34 and 36in accordance with the position of the cock 40. This action of the brake cylinder feeder 3 follows very rapidly on all changes of the produced regulating pressure produced by feeding air to or exhausting it from the chamber 32, so that the time needed for adjusting any brake cylinder pressure, in applying as well as in releasing the brakes, precisely depends upon the time needed for adjusting the respective regulating pressures, as above described. Thereby it is possible to apply or release all the brakes of a train precisely at the same time and to any desired degree and without any unduly large braking forces being brought into action.

A temporary overloading of the brake remains innoxious, if for instance in the chamber 8 the pressure amounts to 5 atmospheres and in the chamber 7 to 3.8 atmospheres, and then for rapid release of the brake suddenly 7 atmospheres are produced in the chamber 7, the diaphragm 12 goes upwards, as the valve 24 closes the passage 24a before lling chambers 8, 23. to seven atmospheres, and the regulating pressure in the chambers 5 and 2 and in the brake cylinder chamber 32 begins to fall to the pressure of the atmosphere so as to release the brakes. The diaphragm 12 then returns to its middle position after the leader has again restored the usual pressure of 5 atmospheres in the train pipe. Even if valve 24, 2511 should jam during overloading and thereby seven atmospheres be produced in chambers 8 and 23, this remains still innoxious.

For, if thereafter, in order to apply the brakes, a pressure diminution is again produced in the train pipe and chamber 7, then notwithstanding the pressure of seven atmospheres now existing in chamber 8 and loading the diaphragm 12, the pressure arising in the regulating chambers 2 and 5 does not exceed the maximum desired pressure of 1.2 atmospheres, due to the yielding of the spring 17 which is previously placed under a tension according to the desired maximum regulating pressure of 1.2 atmospheres in chambers 2 and 5.

vConsequently also the brake cylinder pressure in the chamber 32 does not exceed the desired maximum pressure of, e. g. 3.6 or 2 atmospheres respectively.

If any regulating pressure in the regulating chamber 5, 2 and a corresponding braking pressure in chamber 32 and in the brake cylinder shall be maintained, for instance for a car being out of service, the valve 60 may be closed fully.

lWhen a car is to be shunted, the cock 60 is to be closed, before the pressure in chamber 7 is diminished below the maximum train pipe pressure. Thereby a pressure of Aatmosphere is maintained in the regulation chamber 5, 2 and the brakes are held in release position, when the train pipe is disconnected from the car which is to be shunted. Otherwise, if it is desired to adjust the throttling actions of the throttled passages of the channels 19 and 21, so as to diminish or increase the velocity of the pressure changes in the regulating chamber 2 and correspondingly in the brake cylinder chamber 32, the Valve 60 is closed partly, so as to obtain the desired effect.

I claim:

1. A triple valve for direct acting automatic air brakes, comprising a valve for feeding or exhausting air to the brake cylinder, a diaphragm member for governing said valve, a regulating chamber adjoinng said diaphragm member, an accelerating chamber of such a volume, that compressed air contained in the latter sufces for lling said regulating chamber up to an initial pressure y corresponding to the pressure needed for applying the brake blocks to the car wheels, means governed by the train pipe pressure for connecting or disconnecting saidv accelerating chamber to or from said regulating chamber, a throttled passage for feeding said accelerating chamber from the train pipe, means depending upon the train f pipe pressure for opening or closing said throttled passage, a further throttled passagefor exhausting said regulating chamber, and means depending upon the train pipe pressure for open-

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