US1840964A - Automatic air valve for sand traps - Google Patents

Description

R. A. LIGHT ET AL 1,840,964

Jan. 12, 1932.

AUTOMATIC AIR VALVE FOR SAND TRAPS Filed April 11, 1931 v 1 F ///////M um M a lNVfA/TORS 152% W. Price, 5 v

Patented Jan. 12, 1932 UNITED STATES PATENT OFFICE ALPII A. LIGHT, or CYNWYD, AND JOSEPH w. PRICE, JR, or PH ILADELPHIA, PEN

- sYLvANIA, ASSIGNORS TO THE. UNITED STATES METALLIC PACKING COMPANY, or IIHILALDELPHIA, PENNSYLVANIA, A CORPORATION or PENNSYLVANIA I AUTOMATIC AIR VALVE FOB. SAND rms Application filed April 11', 1931, Serial No. 529,462, and in Canada May 21, 1931.

Our invention relates to sandingmechanism such as isused in connection with locomotives and is intended for use in connection with sand traps provided with air nozzles, one

1; directed into the trap and operating to 'de-' liver'sand from the trap into the delivery pipe and the other directed into the delivery pipe-and operating to expel a blast of'air 'which will clean the delivery pipe'of ob- 1O structions whichma-y have accumulated in it.

The object of our invention is to provide an automatic air control valve operable by the admission of pressure air from the supply pipe of the system and operating in normal ltposition, that. is, when no'pressure air'is fiowin'g to-thetrap, to cut off all communication betweenrthe air supply pipe and the pipes leading from the-valve to the delivery and cleaner nozzles of the trap, and operating when air is admitted to the valve to first conmeet the airsupply pipe with an outlet passage leading to the cleaner nozzle,- then to close thisconnection and open the connection between the inlet pipe and the outlet port 25 leading to the sand deliverynozzle.

The purposeof this invention is to secure very shortly after the admissionof air to the valve a short blast of full pressure air through the cleaner nozzle followed by a continuous delivery'of air to'the deliverynozzle and also 1 when the supply of air under pressureis cut off to close the connection between the nozzles .of the trap andthe valve chamber. Further objects and features of ou r invention will be 35 explained in connection with the drawings, which illustrate a preferred construction of our automatic air delivery valve and is intended for use in connection with a sander system such as is shown for instancein our application, Serial No. 460,854, filed June 13, l930.' 1 I Y "In the drawings, 7 I;

Figure l'is atop view of our automatic filve.

Figure 2 is a section on the line 2-2 of Fig. l, and 7 Figure-.3 isawsecti Fig.',,;1. 4 =A isra cylindrical-chamber, closed at both in on the I line of 9 ends-by heads indicated-at B and Ganddivided by a movable wall, shown as a piston head G into a valve chamber A and a separate air containing chamber indicated at A Into the valve chamber A leads an admission port indicated at D, which is connected with the usual air supply pipe for air under pressure, indicated at D This port. D is shown as longitudinally elongated where it passes through the inner wall of the cylinder, as indicated at D so as to maintain registry with the air groove of the cylindrical valve working in the cylinder and to be de' scribed. Provision for the delivery of air from this chamber is made by ports indicated at F, F located on opposite sides of the cylins drical valve casing and radially disposed with regard to the port leading to the sand delivery nozzles at angles of 90 thereto. These ports F, F are connectible to the cleaner nozzles of a pair of sand traps and the construction s and disposition ofthese ports in connection with ports connectible with the delivery nozs zles of the traps is such as to provide for a convenient arrangement of the pipes leading to the traps. 75

At a difi'erent, and, as shown, a lower level there is formed through the wall of the valve chamber an outlet port indicated at E, which, as shown, and where, as is usually the case, the valve is to be connected to a pair of sand traps, is preferably made of a single port formed through the inner wall of the valve casing cylinder, said port connecting with bifurcated passages indicated at E E to which separate air pipes can be attached a; leading to the sand delivery nozzles of two traps. 'G is a piston valve fitting in the cylindrical valve casing A and having as shown a head G which forms a movable wall for the air containing chamber A separating it from the valve chamber A The body of the piston valve is circumferentia lly grooved as indicated at G said groove being so located and shaped that it willremain in registry with the air inlet portD in all positions of the valve, that it will be out of registry with all of the air delivery ports when the valve is in normally retracted position and that as the valve is actuated it will first register with and then pass out of registry with the air delivery ports F and F thus opening these ports for a brief period and will then register with and'remain in registry with the port E so that in the final position'assnrned by the moving valve this port will remain continuously open. An air passage, preferably of restricted area, must beprovided to deliver air to theair containingchamber A whenair is admitted to the inlet port and such apassage may conven-' iently be made through the piston valve between the groove G and the chamber-A--.- Such a passage is indicated at H. I indicates a spring seated on the' lower head of the casing and pressing against; the lower end of thepiston valve." f

The normal inoperative position of the valve is that indicated in" the drawings, the valve being held in this position by the" spring I and'the valve in this position while per: mitting the entrance of air to the groove Gr v closes all ofthe outlet ports in the valve cha1nber A When pressure air is admitted through theinletport'D it passes freely into the groove-G 'in the valve and passes thence through the restricted air passage I-I tothe chamber-A building up pressure in this chamber, which, acting on the piston head G will,whenit'attains sufficient pressure, overcome the pressure of thespring I, holding the valve in non-operative position and move the piston valve snowman so as, to bring the'groovl'iG first into registry with the cleaner' ports F and F delivering a full head of pressure air through these ports for'a brief interval, the further downward movement of the valveclosing these ports bringing itsgroove into 'registrywith the "delivery port E, so that thereafter all of the air passing through the valve is delivered to the sand delivery nozzles. IV hen the supply of air under pressure'isfcut off the air in the chamber A? will escape through the passage H and the releaseoi pressure on the movable Wall piston will then permit the spring I to restore the valve to normal inoperative position. w 7

It will be seen that by the use ofour valve weprovide for the delivery of all the air coming from the high pressure supply pipe to the outlet ports leading to the cleaner nozzles at high pressure for ai brief interval of time and then forthe cutting off of air to thesecleaneriports and the delivery of all the air thereafterthrough the ports connectedto' the sand delivery nozzles. It will also beobvious that by our construction the valve in normal inoperative position closes" all r con nection with the outletjports and thus pre- P g of any; particles of sand or dust into the valvecasingi 7 Anotheradvantageous feature of our con struction is that if the valve on admission of air does n tfor any reason operate no air,

will be lost, as both outlet ports will remain closed.

Having now described our invention, what We claim as new andv desire to secure by Letters'Patent, is-:

'1, An automatic air distributing valve adapted to be located in the air pipe system leading from a source of air under pressure tofa sand trap having air delivery nozzles,

ible respectively with the cleaner and deliv- V ery nozzles of a sand trap, valve mechanism located in said casing normally closing all connection between the inlet and outlet ports and shiftable in the casing to progressively open and close the cleaner port and'then to open the delivery port, resilient means opcrating to normallyhold the valve mechanism in position to-close the delivery ports and aconnection between the valve mecha nism' and the movable wall of the airzc'hambe'r whereby when'pressure airis admitted to said "chamber the valve is p'rogressively shifted to progressively open and close" the cleaner port "and then to open tl1e sand delivery ports." I V, I 1 V 2; In an automatic air controlled valve as called forin claim 1,'the construction of the'valve mechanism as apiston valve work ing in the valve casing chamber andgrooved to maintain'communication with" the inlet port in all positions of the valve, said groove being so formed that on'the movement of the piston-valve it communicates for a portion of the movement of the valve with the'outlet port leading'to the cleaner nozzle and then with the outlet port leading to the sand delivery nozzle. a

3. In an automatic air control valve as called for in claim 1, a piston valve having a cylindrical head which forms the movable wall of the air chamber and the cylindrical body fitting in the valve casing, saidc'ylin drical valve being formed With a groove so shaped as to maintain communicationwith the inlet-port in all-"positions of the valve, and as the valve is moved to progressively open and close the air port leading to; the cleaner nozzle of the trap and then toopen the air port leading to the sand delivery nozvbody fitting in the valve casing, said cylindri cal valve being formed with a groove so shaped as to maintain communication with the inlet port in all positions of the valve leading from a source of air under pressure to a sand trap having air delivery nozzles, one leading into the;trap to effect the delivcry of sand therefrom and the other directed into the'delivery pipe leading from the sand trap, said valve comprisin in combination a cylindrical casing divi ed into an air chamber and a valve chamber by a movable wall, said valve chamber having an inlet port leading into it, two outlet ports adapted to' be connected to the cleaner nozzles of two traps'and located on opposite sides of the valve casing, a bifurcated outlet port connectible with delivery nozzles of two traps and located at a point in the valve casing approximately midway between the outlet ports before mentioned, a piston valve working in the cylindrical casing provided with a groove so formed as to maintain communication with the inlet port in all positions of the valve, to close'all outlet ports when the valve is in normal inoperative position, to progressively open and close the outlet ports connectible with the cleaning nozzles as the valve moves from normal position and then to open the bifurcated outlet port connectible with the distributing nozzles, a movable wall separating the air transmitting and air containing chambers operatively connected with thepiston valve, an air conduit whereby air is admitted to the air chamber when pressure air is delivered a to the admission port of the valve casing and means operating to restore the valve and movable wall to normal inoperative position when pressure fluid is cut ofi from the valve casing. o RALPH A. LIGHT.

JOSEPH W. PRICE, JR.

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