US1490406A - Automatic control for air-brake systems - Google Patents

Description

1km-i! 15 1924,

J. E. STIEGLMEYER AUTOMATIC CONTROL .FOR AIR BRAKEv SYSTEMS Filed Feb. e,

f attorney,

Fatented Apr. l5, 1924.

JOI-IN EDWARD STIEGELMYER, OF INDIANAPOLIS, INDIANA, ASSIG-NOR TO AUTO- MA'IIC CONTROL COMPANY, OF INDIANAPOLIS, INDIANA, A CORPORATION OF IN- DIANA.

AUTOMATIC CONTROL .FOR AIB-BRAKE SYSTEMS.

Application filed February To all whom t may concern.'

Be it known that I, Jol-IN EDWARD STinenL- Marian, a citizen of the United States, residinc' at Indianapolis, in the county of Marion and State of Indiana, have invented a new and useful Automatic Control for Air-Brake Systems, of which the following is a specification.

In my Patent No. 1,306,504, issued June 10, 191), I show an apparatus which was designed to be placed at the rear end of a train brake system and was of such character that if, for any reason there was an improper reduction of train line pressure, such for instance as where the trainmenhad rendered a portion of the system temporarily ineffective and had failed to restore it to ell'ective condition, or where there were such leakagcs in the train line as .were not properly compensated by the pump, there would be an autonatic application of the brakes wholly independent of the engineer so that the trainmen would be notified of the improper condition of the system and therefore investigate as to the cause.

In the use of the above mentioned apparatus, it was found that there might be instances where the temporary ineffective portion of the system would be, say, only the caboose or one or two cars in front of the caboose and, of course, under such circumstances the apparatus would be wholly ineffective to meet improper conditions which might exist in the forward portion of the train.

It is, therefore, the object of my present invention to introduce into an ordinary train line brake system valve mechanisms, in large measure such as was disclosed in my above mentioned patent, one at the rear end of the system and the other in the forward end of the system, preferably between the engineers valve and the first set of brakes, this mechanism being so modified as to insure their co-operation with each other and with the entire brake system in such manner that, in the ordinary manipulation and control of the brakes through the engineers brake valve, there will be no functioning of my devices but, whenever there is a train line pressure reduction for any cause, in any part of the system, below a fixed minimum determined by the adjustments of my devices, there will be an automatic application of the s, 1922. sei-iai No. 534,363.

brakes, in the nature of an emergency application but at the reduced minimum pressure, which will be entirely automatic and independent of the engineer and the engincers valve, and equivalent, in that particular portion of the system in which the maximum train line pressure reduction has taken place, to a light service application.

The accompanying drawings illustrate my invention: Fig. l is a diagrammatic illustration of an ordinary train brake system and including my improved devices; Fig. 2, an axial section of my valve on line 2-2 of Fig. 3, and Fig. 3, a vertical section at right angles to the plane of Fig. 2 and on line 33 of Fig. 2.

In the drawings, M indicates the main reservoir, P the pump, E the equalizing reservoir, e the engineers brake valve, 'I the triple valve on each car, A the auxiliary reservoir on each car, B the brake cylinder on each car and t the train line connecting the various parts which have been mentioned, n the usual manner. In the train line t, there are the usual angle cocks a0, one at each end of each ear.

Thus far the mechanism is standard.

Located at the front end of the system, preferably between the locomotive and the tender, and at the extreme end of the system, are two of my devices indicated generally by S and, in general, these devices are the same as shown in my patent mentioned above, the construction being as follows:

.Ar chamber 10 communicates through passage 11 with the train line. @ne end of chamber 10 is enlarged te form a cylinder 12 in which piston'13 is mounted. The stem 14 of piston 13 engages a sliding D-valve 15 mounted in chamber 10 and co-operating with passages 16, 17 and 18. i

Communicating with cylinder 12 is a cylinder 19 which is of larger diameter than the cylinder 12 and partially separated from cylinder 12 by means of a ring 2O adapted to be engaged around its central perforation by the leather face of piston 13, so that said piston may serve to close communication between thc two cylinders 12 and 19.

Cylinder-19 is formed in a casing member 21 provided with an axial bore 22 which receives inits outer end a plug 23 having an axial bore 241. Plug 23 is packed by a packing gland 25 and at the outer end of plug 23 is the cap 26 which is screwed upon member 21 and forms a chamber 27 in communication with bore 24. A passage 28 forms a comn'iunication between chamber 27 and passage 18. l

Mounted in cylinder 19 is a piston 30 which is adapted to be engaged by the stem of piston 13. Leading from cylinder 19 between pistons 30 and 13 is a groove 31 to atmosphere. Associated with piston 30 is a valve 32 adapted to seat upon the inner end ot bore A compression spring 33 lies between piston 30 and valve 32, and said parts are shouldered at 34 in such manner that it the spring 33 should break, valve 32 may act upon piston 30 to drive it to its abnormal position. Spring 33 will be caused, by adjusting plug 23, to exert upon piston 30 a considerable pressure which, however, will be somewhat less per square inch than the pressure to which the train line pressure drops under ordinary brake application through the engineers valve, say forty pounds per square inch.y

Communicating with chamber 10 is a chamber 35 which communicates through passage 36 with chamber 37 which is in communication with atmosphere. Associated with passage 36 is a valve seat which is presented inwardly into chamber 35 and normally resting upon this valve seat is a check valve 38 normally held down by a spring 39. Formed below chamber 37 is a cylinder 40 in which is mounted a piston 41 having a piston rod 42 which is projected upwardly through the partition separating chamber 37 from cylinder 40 and engages kthe lower end of the stem ot check valve 38.

Passage 17 leads into a cylinder 45 in which is mounted piston 46. Piston 46 engages a. D-valve 47 which co-operates with passages 48 and 49. Valve 47 lies in a chamber 50 which is connected to supplementary reservoir 105.

At this point. attention is called to the fact that instead ot connecting chamber 50 to the supplemental reservoir at the end of the chamber in the manner set forth in my above mentioned patent I connect the end of the chamber with the trainV line through the pipe 100 and then provide a pipe 101, leading from the side of chamber 50, which connects with the supplemental reservoir 10F. Ithen connect the supplemental rreservoir with the train line by means of the pipe 103 and in this pipe I place a checlrvalve 104 which will permit flow from the supplemental reservoir to the 'train line but will not permit flow from the train line to the supplemental reservoir.

A bleed passage 51 forms a bleeding connection between cylinder 45, through chamber 50, and the train line, when piston valve 47 is in its normal position, shown in Fig. 2.

Passage 48 communicates with the lower end of cylinder 40 and passage 49 communi cates with atmosphere, these two passages being so arranged at their point of entry into chamber 50 that the valve 47 may connect them or may uncover passage 48 to the supplemental reservoir through chamber 50.

Chamber 50 is separated from the train line connection 10G by partition 107 having an outwardly opening valve seat 108. Valve 47 carries a valve stem 109 which passes loosely through partition 107 and carries a valve 110 which seats in seat 108 whenever valve 47 is shifted so as to connect passage 48 with the chamber 50 and the supplemental reservoir.

ln the connection 111l` between chamber 10 and the train line, l place a check valve 112 which permits flow from the train line to chamber 10 but will prevent tlow from chamber 10 back to train line.

The operation is as follows: Upon establishment of train line pressure, the parts will assume the positions indicated in the drawings, train line pressure entering chamber 10 and driving' piston 13 to the right, this piston coming into contact with ring 20 and closing communication between cylinders 12 and 19. The movement ot piston 13 to thc right drives pistou 30 to the right against the pressure ci spring 33. Valve 32 is normallyv seated so as to close the inner end oit bore 24. rllhis valve is of smaller diameter than the piston 30, so the train line pressure, established in chamber 27 through passages 18 and 28 from chamber 10, will not normally unseat it. rain line pressure also passes through passage 17 into cylinder 45 and drives piston 46 to the lett so as to shift the D-valve 47 to establish communication 'from the lower end of cylinder 40, through passages 48 and 49, with the atmosphere. rTrain line pressure bleeds from cylinder through passage 51 and chamber 50 to the supplemental reservoir and train line pressure also passes through pipe 106 past valve 110 through partition 10T into chamber 5u and from thence to the supplemental reservoir 105.

ln this connection one should not become confused by the fact that train line pressure may enter chamber 45 'from both ends because the bleeding from train line to chamber through partition 107 docs not begin until piston 4G has been started toward the left by the entry oi" train line pressure into chamber 45 through passage 17 and there is sufficient time interval to permit piston 48 to be moved to the limit of its movement toward the left before there is any equalization ot' pressures on the opposite sides of the piston.

Under normal application of the brakes through operation ot the engineers valve. the train line pressure in pipe 1.11 and chamber 10 will .not be reduced below the strength of spring 33 and there will, therefore, be no operation of my device under ordinary conditions either at the rear end of the system or at the front end because it will be noted that train line pressure, having once entered chamber 10, is trapped in said chamber by the check valve 112 except as leakage may occur through the bleeding passage 51 and, under normal conditions, this leakage is not sufficient to permit pressure reductions below the strength of spring 33.

As a consequence it is apparent that the pressure on the right hand side of piston 46 can not, so long as valve 15 fails to connect passage 17 with passage 16, become reduced below the pressure on the left hand side of piston 46 and consequently that there can be no accidental or improper operation of piston 46 to any reduction in train line pressure under service conditions through the engineers brake valve. For any movement of piston 46 to the right, there must be a reduction of pressure in chamber below the pressure of spring 33 and this reduction must be due to a reduction in train line` pressure below the strength of spring 33. Y i

If, however, for any reason, the train line pressure is reduced below the strength of spring 33, said spring immediately pushes piston to the left and pushes piston 13 in the same direction. This movement will shift the valve 15 so as to disconnect passage 17 from chamber 10 and connect it through passage 16 to atmosp-here, whereupon there is a sudden reduction of pressure in cylinder and the pressure in the supplemental reservoir serves to drive piston 46 to the right so as to disconnect passage 48 from atmosphere and connect it through chamber 50 with the supplemental reservoir pressure; whereupon, the supplemental rcservoir pressure, passing through passage 48, in the lower end of cylinder 40, shifts piston 41 upwardly so as to unseat check valve 38 and thereby establishing communication between the train line and atmosphere through passage 11, chamber 10, passages 35 and 36 and chamber 37, thereby setting the brakes in all of that portion of the system which has an open train line controlled by my apparatus. That is to say, if one of the angle cocks ac has been closed my apparatus at the rear end ofthe train or back of this angle cock will function as described and the one at the head end will remain inactive because train line pressure in front of the closed cock no is being maintained by the pump.

If, on the other hand, the pump is failing to function'for any cause, or if the engineer has allowed his valve to remain too long on lapped posiiton it will be apparent that there may be a drop in train line pressure Vbelow the strength of spring 33 and in that case my apparatus will function as described.l If all of the angle cocks ac are open, then both of my devices will function as soon as the reduction in pressure in their respective chambers 10 falls below the strength of spring 33, and if one of the angle cocks a@ is closed then my apparatus which lies in front of that cock will function if there is a pump failure or engineers lapped valve condition, and my rear device will function whenever the leakage from the system have been suflicient to bring the pressures below the strength of spring 33 whether that has been due to a closed angle cock or failure of maintenance of train line pressure from any other cause.

It will be apparent from what has been said that two of my devices, placed as indicated, will co-operate with the brake system as safety devices to automatically set some or all of the brakes as a warning to the engineer that the brake' system is not properly functioning and this warning will be givenwhenever and so long as the improper brake system condition exists.

Under some conditions, valve 15 may be moved to a position where it blanks passage 17 and there may b-e suf'cient leakages past valve 47 that?y the pressures in chambers 45 and 50 and the supplemental reservoir might be exhausted and there would then be a failure of piston 46 to function.

This, of course, would cause the whole apparatus to fail to function. It is for thatv reason that I have provided the connection between chamber 50 and the train line controlled by valve 110, this connection peri mitting a. maintenance of pressures in chambers 50 and 45, under normal conditions, which will insure at all times a sufficient pressure in chamber 50 to cause movement of piston 46 to the right whenever the pressures in chamber 45 are reduced through passage 17 by the proper movement of valve 15.

I claim as my invention:

1. The combination with-an air brake sys-- tem comprising means for maintaining train line pressure, a plurality of braking devices and associated control valves, and an engineers valve, of two control valve mechanisms, one located between the engineers valve and the braking unit and the other at the end of the braking unit, each of said control valve mechanism comprising a normally closed valve controlling communicationbetween the train line and atmosphere, a manipulating member for said valve normally held in inactive rposition by train line pressure, a spring for driving said manipulat ing member to active position upon reduction of train line pressure below a desired minimum, and connections for trapping train line pressure against said manipulating member so as not to be subjected to noriii) Cil

mal variations in train line pressure due to service manipulation of the engineers valve.

2. The combination with an air brake system comprising means for maintaining train line pressure, a plurality of braking devices and associated control valves, and an engineers valve, ot a control valve mechanism connected to said system and comprising a normally closed Valve controlling communication between the train line and atmosphere, a manipulating member for said valve, normally held in inactive position by train line pressure, a spring for driving said manipulating member to active position upon reduction ot train line pressurebelow the desired minimum, and connections for trapping train line pressure against said manipulatingmember so'as not to be subjected to normal variations in train line pressure due to service manipulation of an engineer-s valve.

3. An air brake applying safety valve, comprising a connection for train line, an exhaust port communicating with said train line connection, a check valve normally closing said exhaust port, pressure controlled means 'for liftingsaid check valve from its seat, train line pressure control means for controlling the application of opening Yforce to the check valve, a check valve arranged in the connection between said train line pressure controlled means and the train line for limiting flow in said connection to said pressure controlled means from the train line, a spring acting upon said train line -pressure controlled means in the direction kmental reservoir and train line. a check valve in said connection permitting flow only from the supplemental reservoir to the train line, a cylinder having a bleed passage connection with said secondary valve chamber, a piston mounted in said cylinder, a secondary valve mounted in the secondary valve chamber and connected with said last mentioned piston, a passage controlled by the primary valve for connecting the primary Valve chamber with the secondary cylinder, a check valve controlling outflow to atmosphere, a piston for acting upon the last mentioned check valve in opening direction,

a cylinder containing said piston, a passage connecting said last mentioned cylinder and the secondary valve chamber in a position to be controlled by the secondary valve, a piston acting upon the primary piston in the direction opposite to train line pressure, a passage connecting with the primary valve chamber, a cylinderl containing the last mentioned piston and communicating with said last mentioned passage, a valve closing said communication, a spring arranged between said last mentioned piston and valve to normally hold said valve closed and to act upon the piston in the direction opposite to the direction of train line pressure upon the primary pistou, a direct connection between the secondary valve chamber and train line, and a valve controlled by the piston in the secondary valve chamber for closing communication between said secondary valve chamber and the direct connection with train line when the secondary valve is shifted to open connmmication between the secondary valve chamber and the cylinder of the piston which controls the check valve leading to atmosphere.

5. The combination with an air brake sys` tem comprising means for maintaining train line pressure, a` plurality otl braking devices and associated control valves and an engineers Valve, of a control valve i'nechanism connected to said system and comprising a normally closed valve controllingcommunication between the train line and atmosphere, a manipulating member for said Valve normally held in inactive position by train line pressure, a spring for driving said Ymanipulating member to active position upon reduction of train line pressure below the desired minimum, and means for delaying the action of said manipulating member.

6. The combination with an air brake system comprising means 'for maintaining train line pressure, a plurality of braking devices and associated control valves and an enginecrs valve, of a control valve mechanism connected to said system and comprising a normally closed yalve controlling communication aetween the train line and atmosphere, a manipulating member tor said valve normally held in inactive position by train line pressure, a spring for driving said manipulating member to active position upon reduction oi' t `ain line pressure below the desired minimum, and means tor rendering said spring ineiiective while train line pressure is reduced by normal manipulation of the engineei"s valve.

7 The combination with an air brake system comprising means for maintaining train line pressure, a plurality of braking devices and associated control valves and an engineers valve, of a controlyalve mechanism connected to said system and comprising a normally closed valve controlling communication between the train line and atmosphere, pressure operated means for operating said valve, a normally closed valve for controlling the admission of pressure to said pressure operated means, a pressure balanced piston `for operating said valve, a normally closed valve controlling the pressure balance on said piston, a spring tending to open said valve, train line pressure o erated means for rendering said spring ine ective whereby the spring will become etfective upon the reduction ot the train line pressure below a desired minimum, and means for preventing the reduction of train line pressure on said train line pressure operated means by the normal manipulation of the engineers valve.

8. rlhe combination with an air brake system comprising means for maintaining train line pressure, a plurality of braking devices and associated control valves and an engineers valve, of a control valve mechanism connected to said system and comprising a normally closed valve controlling communication between the train line and atmosphere, pressure operated means for operating said valve, a valve for controlling the admission of pressure to said pressure operated means, a balanced piston subjected to train line pressure on both sides or operat-ing said valve, a second valve controlling the admission of train line pressure to one side of said piston which when opened permits a reduction of pressure on one side of said piston to cause the same to open its valve, a spring tending to open said second-mentioned valve, means subjected to train line pressure for balancing the eliectof said spring and maintaining said secondmentioned valve closed whereby when train line pressure drops below a predetermined minimum said second-mentioned valve will be opened to cause the operation of said pressure operated piston, and means for shutting od train line pressure on the opening side of said piston after the piston has operated its valve. Y

9. The combination with an air brake system comprising means for maintaining train line pressure, a plurality of braking devices and associated control valves and an engineers valve, of a control valve mechanism connected to said system and comprising a normally closed valve controlling communication between the train line and atmosphere, pressure operated means for operating said valve, a valve for controlling the admission o pressure to said pressure operated means, a balanced piston subjected on opposite sides to train line pressure for operating said valve, a second valve controlling the admission of train line pressure to one side of said piston, a spring tending to open said valve, means subjected to train .line pressure for rendering said spring ineffective whereby when the train line pressure falls below a predetermined minimum said spring will operate said second-mentioned valve to reduce the pressure on one side of the piston to permit the piston to operate its valve, and means for insuring suiiicient pressure for operating said pressure operated means for a short period in event the train line pressure is too low to operate the same.

10. The combination with an air brake system comprising means for maintaining train line pressure, a plurality of braking devices and associated control valves and an engineers valve, of a control valve mechanism connected to said system and comprising a normally closed valve controlling communication between the train line and atmosphere, pressure operated means for operating said valve, means for supplying train line pressure to said operating means, means controlling the admission of said train line pressure to said operating means, manipulating means for said means normally held in inactive position by train line pressure, a spring for Aoperating said manipulating means to active position upon reduction of train line pressure below the desired minimum, and means for automatically shutting off pressure to said pressure operated means after a predetermined period.v

1l. The combination with an air brake system comprising means for maintaining train line pressure, a plurality of braking devices and associated control valves and an engineers valve, of a control valve mechanism connected to said system and comprising a normally closed valve controlling communication between the train line and atmosphere, pressure operated means for said valve, means for supplying train line pressure to said p-ressure operated means for operating said valve, a supplementary pressure supply -i'or said pressure operated means, manipulating means for controlling the admission of pressure to said pressure operated means normally held in inactive position by train line pressure, a spring device for driving said manipulating means to active position upon reduction of train line pressure below the desired minimum, and means for preventing the admission of pressure to said pressure operating means longer than a predetermined period.

In witness whereof, l have hereunto set my hand at indianapolis, llndiana, this Aith day of February, A. D. one thousand nine hundred and twenty two.

JOHN EDWARD STIEGELMEYER.

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