Патент USA US2404924код для вставки
July 30; 1946- c.- R. SACCHINE 2,404,924 FLUID CONTROL APPARATUS Filed Jan. 29, 1.943 INVENTOR 28 Flq‘a' . I44 _ Cowmsus FE. SAccHam BY (500/ ><Q¥AORNEY 0W4. Patented July 30, 1946 2,404,924 UNITED STATES PATENT OFFICE 2,404,924 FLUID CONTROL APPARATUS ‘Columbus R. Sacchini, Euclid, Ohio, assignor to The Marquette Metal Products Company, Cleveland, Ohio, a corporation of Ohio Application January 29, 1943, Serial No. 473,911 3 Claims. (01. 277-45) 1 2 This invention vrelates to a safety stop valve mechanism or ?uid fuse arranged to be inter ?ow .of liquid from the pump to the damaged section of the'conduit and thereby prevents ex cessive loss of liquid from the system. Inac cordance with the illustrated embodiments, the posed in a ?uid pressure conduit between a source of ?uid supply and a ?uid operated trans» lating device and operable for controlling auto sliding valve member de?nes one wall of vair-an nular restricted metering ‘orifice of uniform width in response to therate of ?ow of the ?uid. More but of decreasing diameter in the direction of particularly'the invention relates to a ?uid fuse ?uid ?ow and the frictional force of the ?owing having means operable in response to the rate‘oi fluid on the valve member tends to move the ?ow of ?uid through the fuse to stop-the ?ow if 10 member to a'closed position against the bias of the rate‘of flow increases to a‘valueiindicative a calibrated spring. In event the rate of ?uid of abnormal ‘condition. ?ow increases above a value predetermined by In vaccordance with the illustrated vembodi the sizeof'the orifice'and the calibration of the ments of the invention herein disclosed, the spring, the frictional force of the ?uid on the means responsive to the rate of ?uid ?ow for movable valve member moves to a closed position effecting stoppage of '?uidv?ow comprises rela stopping further flow of ?uid through the fuse. matically the ?ow of ‘?uid through the conduit 'tively movable valve members which operate .to If the increased rate of ?ow of the liquid is a closed positionin- response to the;force of ?uid friction on' a wall oftan annularrestricted meter due to the breaking of ‘a conduit, the bro-ken conduit may be repaired ‘or isolated by suitable ing‘orifice having a, gradually varying diameter, 20 valves and :the fuse reset to open position for ire. a" tapered . annular ori?ce. resumption of'normal operation of the system The invention .is ' particularly ssuitable for use since the fuse prevents the loss of an excessive with ‘hydraulic systems wherein ‘a liquid under amount of liquid. ‘To reset the fuse it is merely pressure ;from a suitable ?uid .pressure appa~ necessary to stop the pump or otherwise relieve ratus such ;as ‘a pump or storage-tank is' utilized 25 the pressure‘against thefuse'forxan instant. An to effect ‘operation of a‘ mechanism at a consid auxiliary valve is vautomatically rendered op— erable :distancerfromthe source of ‘ ?uid pressure. erable upon apredeterminabledrop in this pres~ One application: ofithis'type of. hydraulic system sure to prevent'?ow of the liquidpast the fuse and one with vwhichithe present invention may until pressure is againapplie'd, so that, if the be .readilycombined togreataadvantageis in the 30 pressure against the fuse is reduced before the operation of-variousxmovable devices on'aircraft break is repaired, .no bleeding or additional loss such, .for example, as the retractable landing of the liquid results. gear. :In aircraft hydraulic ‘systems asuitable An object of the invention is to provide ‘an liquidysuchas oil, under high ‘pressure is sup improved automatic stop valve mechanism or plied ‘from a motor 'or engine ‘driven pump ?uid fuse. through conduits to servoemotors which operate Another object is to provide a ?uid fuse re the landing gear mechanism or 'otherdevices. sponsive only to the rate of ?uid ?ow for stop While the aircraft is in ?ight, one or moreof ping the ?ow. tne conduits may become broken, as by-a defect A correlative object is to provide a ?uid fuse or shell ?re, resulting ‘in a loss of much if not responsive only to the‘rate of ?uid ?ow, which all of the ?uid in the system.- This loss renders fuse is adapted to be readily inserted in the usual repairs during the ?ight impossible and,.since ?uid supply conduits of common hydraulic sys many essential control and navigational devices tems. maytderive their motivating force from the same Another object is to provide a ?uid fuse which hydraulic system, is apt to result in loss of the can bereset without dismantling or disturbing aircraft. the . adjustment. ‘Breaking or puncturing of a conduit in .such A correlative object is to providea ?uid fuse aircraft hydraulic systems immediately causes an whichcan be reset automatically from a point increase in the rate of ?ow ‘of the liquid therein, and, if the‘?uid fuse ‘of the present invention is 50 remotefrom the fuse but without opening a free ?uid path through the fuse. incorporated in the system between the pump and ‘A further correlative object is to provide a the pointof'leakage, the increase in the rate of ?uid fuse which can be ‘reset by relieving the flow causes an increase in ‘the force of ?uid fric pressure against the fuse without necessitating tion on-ia: sliding valve'memberiwhich thereupon moves'to. a closed'p‘osition :and'stops any-further 55 an auxiliary valve orother ‘means outside of the 2,404,924 3 4 fuse to prevent ?ow of ?uid through the fuse upon reduction of supply pressure. Still another object is to provide a ?uid fuse of the above indicated character which is small and compact, of rugged construction, and com simple to manufacture. Fig. 4), that is, an ori?ce of uniform width but of gradually decreasing diameter in the direction of ?uid ?ow. The plunger 30 has a generally cylindrical upstream stem portion 32 of reduced diameter and provided with ?uid venting “?ats,” said stem portion 32 being slidably received within a complementary longitudinal bore 34 in Another object is to provide a ?uid fuse oper able to a closed position due to friction of ?uid a cut-off valve plunger 35 (to be described later). A cylindrical downstream stem portion 36 of the prises a small number of parts each of which is 10 plunger 30 passes through a central opening in at a tapered annular metering ori?ce. an axially movable spring guide 39. Yet another object is to provide a ?uid fuse The spring guide 39 is slidably received within having means for readily adjusting its sensitivity the opening 2! downstream from the valve seat without disturbing the setting of its operating surface 29 and is of generally rectangular trans~ value. verse cross section. As indicated in Fig. 5 the Other objects and advantages will become ap parent from the following speci?cation, wherein cross section of the guide 39 deviates from a true rectangle in that the shorter sides are curved to reference is made to the drawing in which conform with the inner wall of the housing ID Fig. l is a diagrammatic representation of a to de?ne therewith a pair of circular segmental hydraulic control system incorporating the auto matic ?uid fuse of this invention; Fig. 2 is an ele 20 ori?ces 49. The guide 39 operatively abuts an annular shoulder 4| on the valve plunger 39 pro vational view of the automatic ?uid fuse; Fig. 3 vided by a portion 36' of increased diameter be is a longitudinal sectional view of the fuse of Fig. tween the stem portion 36 and the central por 2; Figs. 4, 5, 6 and 7 are sectional views taken tion 30'. generally along lines 4-4, 5—5, 6—6 and 'l—‘l, The valve plunger 39 is normally biased to fully respectively, of Fig. 3, and Fig. 8 is a fragmentary 25 open position by a helical spring 42 interposed longitudinal sectional view showing a modi?ca between the guide 39 and a spring support 44 tion. press ?tted or otherwise secured ?xedly in the Referring to the drawing, a unitary tubular counterbored portion 24 of the opening 2| against body or housing [9 of the hydraulic fuse ll of this invention has (e. g.) a hexagonal portion l2 30 the shoulder 26. The support 44 has a transverse cross section similar to that of the guide 39 as intermediate 9, pair of externally threaded cylin shown in Fig. 6 and de?nes with the inner wall drical end portions l4 and [5 which are adapted of the housing I0 a pair of circular segmental to be screwed respectively into complementary ori?ces 45. The ends of the spring 42 rest re tube couplings on spaced ends of suitable ?uid supply conduits I6 as shown more or less dia 35 spectively in shouldered recesses provided by op posing tubular end portions 39’ and 44' of the grammatically in Fig. 1. The ?uid in the con duits I6 normally ?ows freely through the fuses guide 39 and the support 44, respectively which end portions may be of circular section. II from a pump !8 arranged to force ?uid from The stem portion 36 of the valve plunger 39 a reservoir l9 to a plurality of hydraulic servo motors 20 such as commonly used to actuate var 40 extends slidably through the central opening in the support 44 and is threaded at its outer end to ious subservient devices, e. g. retractable landing receive an adjusting nut 46 which may be secured gear mechanisms. Upon the occurrence of an in adjusted position as by spot-Welding a washer abnormal rate of ?uid ?ow through one of the 48 to the stem portion 36. The adjusted position fuses H such as would occur upon the breaking of the nut 46 determines the size of ori?ce 33 of a conduit beyond the fuse, the fuse operates when the plunger 30 is in its normal open posi automatically to stop further ?uid ?ow and con sequent loss of ?uid. On military combat air tion and, as will be described hereinafter, thus determines the critical rate of ?uid ?ow which craft, because of the great likelihood of enemy causes the plunger 30 to move to its closed posi ?re severing the conduits I6 it is desirable that the fuses H be spaced at short intervals to pro 50 tion. The rate of ?uid flow for which the ad tect as completely as possible the ?uid system justment is made can be stamped on the housing from loss of ?uid. The protection afforded by In to indicate the protective point of the fuse l i. the fuses H when so arranged permits repairs to The cut-off valve plunger 35 has a central be made during ?ights, prevents total disability frusto-conical portion 49 intermediate oppositely of the hydraulic system by the breaking of a extending stem portions 50 and 5| and the pe~ ripheral surface 52 thereof is arranged to seat single conduit, and greatly reduces the ?re haz ard which would result from leaking oil. upon a complementary valve seat surface 54 pro The tubular housing H] of the fuse H has its vided at the inner end of a tubular cut-off valve central opening 2| (Fig. 3) counterbored at both seat member 55 slidably received Within the 1 ends as indicated at 22 and 24 to provide annular counterbored portion 22 of the opening 2| against shoulders 25 and 26, respectively. An inward pe the shoulder 25. The valve seat member 55 is ripheral projection 28 narrows the opening 2i in suitably retained in position as by spinning over termediate the ends of the housing I 9 and de?nes the tapered end of the threaded portion [4 of the a frusto-conical Valve seat surface 29 which housing [0 as indicated at 56. The downstream tapers inwardly or converges in the direction ‘of stem portion 50 is a cylinder of lesser diameter ?uid ?ow indicated by the arrows. A valve than the base of the frusto-conical portion 49 to plunger 39 is provided at an enlarged central por which it is joined by a cylindrical portion 50’ of tion 30' with a peripheral face portion 3| com intermediate diameter and has the longitudinal plementary to and adapted to seat upon the valve bore 34 in which the stem portion 32 of the valve seat surface 29 when the plunger 30 is moved to plunger 39 is slidably received. The upstream the right from the position in which shown. stem portion 5| (see Fig. 7) has a cross section When the plunger 39 is in its normal or open similar to that of the spring guide 39 and is slid-V position, shown in the drawing, the valve seat ably received within the circular opening in the surface 29 and the face portion 3| are spaced valve seat member 55 and de?nes with the walls apart to de?ne a tapered annular ori?ce 33 (see; 12,404,924 thereof a :pair :of :circular .isegmental orifices ‘58, Fig.‘ '7. A ihelical sspring $59 which is weaker than the spring ‘4-2 :is ‘interposed between Ithe 'valve rplungers :30 and 35 :and "normally biases Ithe valve'vplunger 35 tozits ‘fully :closed position on .the’valveseat member 555 as shown in vFig. 3. .Theiends of =the.'spring >159 rest respectively in annular shouldered recessesprovided :by the por ‘tapered gori?ce :33. If the pump .l.8 QShOUld :stop ‘The ‘operation of the ‘fluid ‘fuse will ‘be ex be done-after the broken conduit ‘has‘been =re for any reason, :the :trappedifluid pamrot :escape since :the :valve :plunger .35 returns :to :its closed vposition, :the spring 59 having-a su?icient'bias .ing force to iclose ivthe ‘plunger 35 :against :the hydraulic'headexisting‘when the pump l8iiS not operating. Closure ‘of the valve plunger 135 :of course permits opening of the ori?ce"*33 due "to the'bias' ofithe spring '42 on'theplungeris?. Thus tion 5.0’10'f the‘plunger 35~and~a similar portion ‘ the fuse l 1 maybe reset to normal position, after it has operated, merely by the pilot o‘flthe plane F32’ :between the stem portion ‘32 and 1the portion stopping the ‘pump 'for'an instant, which may 530' ofthe valve plunger' 30. plained by-considering-that a single'fuse II is inserted in the conduits‘ 16 "between the vpump _; 1| 8 and the “hydraulic-cylinders "'29, 'l the operation paired or' by-passed. ‘ It is thus seen that ‘no-manipulation-or 'dis mantling of the fuse aH is-required"for resetting, v'o‘f asystem lwith'moreithan one ‘fuse as illus this operation'being performed by hydraulically tratedin‘Fig. l'being apparent therefrom. ‘Fluid pressuredue "to operation of vthe pump :exerted acting means under the control of the ‘pilot. on itheIfrusto-conical'portion '4-9 of the cut-off 'valvelplunger 35 causes the ‘plunger 35 to move away from‘itsseate'd position on the seat mem ‘ber 5'55 against the bias of the spring 5-9 and thereby-e?ec‘ts opening of an annular ori?ce be tween tlie complementary surfaces 52 and 54. ‘FIuid‘is now free to flow from the pump l8 through the fuse I! to effect operation of any or all of ethe-servo-motors ~20. ‘It should be noted ‘The fuse ‘H may-therefore be mounted'in-"any position in "the system whether readily acces sible or'not. Besides permitting quick re-usepf the hydraulicsystem after-the breaking of'a'con duit while still-in flight, the semi-automaticre setting feature is extremely valuable ‘also ‘because of the'possi-bility ‘of surges‘in :the system ‘:being sufficiently :great 'to cause operation'of the fuse. In such .event all ‘that need be ‘done isto *stop or short circuit theipump ‘for an instant in order 'from'the drawing'that with the" plunger '35-0pen and-the-plunger 230 in-its normal position are 'stricted fbut =unobstructed ?uid path exists through the‘fuse I l '. Due to the inertia of the moving parts of the .to return the ‘fuse ,to its normal positionand then to restart or recondition the pump and the servo-motors 20 and-the-resistance of the mech anisms operated thereby, the rate of flow of the ‘ ?uid through the fuse II normally does not ex factured by varying ‘the degree of‘taperofthe ‘complementary surfaces '29 and "3|. ‘By making system is again ready foruse. _ ‘Fuses having various degrees .of sensitivity, that is various speeds of response, 'can'be manu the taper of these surfaces less gradual, the fuse becomes more sensitive in its operation. For use in systems subject to repeated surges, a fuse broken or punctured conduit between the fuse of low sensitivity is apt to be most suitable since II and the servo-motors, however, the rate of flow of ?uid through the fuse ll quickly exceeds 40 if the surge is not very great and ends before the ori?ce 33 is closed resetting of the fuse is the predetermined value. When the ?uid is ?ow not required. The sensitivity of the fuse is also ing through the tapered annular ori?ce 33 at a dependent upon the rate of the springs 42 and rate in excess of the predetermined Value, the 59: and thus a wide range of sensitivities is pos frictional force resulting from the action of the ceed a predetermined value. In event of a ?uid on the conical surface 3| causes the valve ‘ ‘7 sible by various combinations of taper and spring plunger 30 to move toward its closed position against the bias of the spring 42. As the plunger rate. The rates of the springs 42 and 55 depend upon the design of the respective? springs and thus 30 moves, the ori?ce 33 becomes smaller and the fuses of various sensitivities‘ can be manufac ?uid friction correspondingly increases resulting tured by choosing certain springs during assem in further movement of the plunger 35 and bly. Another method of predetermining sensi eventual seating of the surface 3| on the surface tivity during manufacture of the fuse is shown 39 with a snap action, closing the ori?ce 33 and by the modi?ed construction of Fig. 8. trapping all of the ?uid in the system between In Fig. 8, wherein similar parts are referred to the pump I8 and the fuse l i. As thus described, the fuse H has performed its main function of 55 by the same numerals as in the other ?gures plus 190, the counterbored portion I24 of the opening preventing excessive ?uid loss due to a broken £21 in the housing H5! is threaded and receives conduit. When two or more fuses are connected a complementary threaded spring support I44. in series in a conduit system, the sensitivity or The threaded connection between the housing I I0 setting of the fuses may be chosen so that the fuse closest to the broken conduit operates ?rst 00 and support Md provides a means for adjusting the sensitivity of the fuse by varying the length so that if possible a part only of the system may and consequently the rate of the spring I42. be shut off, much in the manner of overload When the support M4 is in the proper position protection commonly applied to electrical power for the desired sensitivity, it may be suitably se distribution systems. After the valve plunger 30 has moved to its 65 cured against further rotation as by a locking pin 65 inserted in a hole drilled through the coni closed position, the ?uid trapped between the cal end of the portion H5 and into the support pump l8 and the fuse H is under high pressure fill. If it should be desirable to provide for and, so long as the pump [8 continues to oper— ate, pressure on the portion 38' maintains the plunger 33 in its closed position. Extensive ex periments have shown that whereas the plunger 30 is retained in closed position due to ?uid pressure, ?uid pressure has no effect on its closing operation which is entirely dependent upon the friction force of the ?uid passing through the 75 variation of the sensitivity of the fuse after manu f acture, a suitable set screw may replace the look ing pin 65 and be arranged for screwing through a tapped opening in the portion H5 against the support I44. I claim: 1. In a ?uid fuse, a casing having a passage 2,404,924 7 extending therethrough from end to end, a valve means comprising a frusto-conical valve seat sur face in said passage intermediate its ends and a valve plunger slidably mounted in said passage for axial movement with respect to said casing, said plunger having a frusto-conical face portion complementary to and adapted to seat upon said seat surface and when so seated closing the pas sage through said casing, biasing means normally biasing said face portion and said valve seat sur face apart to de?ne a tapered annular ori?ce, the biasing force of said biasing means being less than the axial frictional force of said ?uid on said face portion when ?uid ?ows at a rate above a predetermined value through said tapered ori ?ce, whereby said ori?ce is closed by said fluid friction when the rate of ?ow of ?uid through 8 means normally urging said face portion and said valve seat apart to de?ne an annular ori?ce ta pered in the direction of ?uid ?ow, the biasing force of said biasing means being less than the axial frictional. force of said ?uid on said face portion when ?uid ?ows at a rate above a pre determined value through said tapered ori?ce, whereby said ori?ce is closed by said ?uid friction when the rate of ?ow of ?uid exceeds said pre determined value, and a second valve means con tained within said passage in series with said ?rst valve means between said ?rst valve means and said inlet, said second valve means being normally biased to a closed position and movable to an open position in response to ?uid pressure. 3. A ?uid fuse comprising a casing having a passage extending therethrough from inlet to outlet, a frusto-conical valve seat forming part said ori?ce exceeds said predetermined value, and of said passage located between said inlet and a second valve means contained within said pas sage in series with said ?rst mentioned valve 20 outlet and converging toward the outlet, a plung er guided for axial movement in the passage means, said second valve means being normally and having a frusto-conical head portion com biased to a closed position and movable to an plementary to said seat and surrounded thereby open position in response to ?uid pressure. normally spaced suf?ciently near the seat so that 2. In a ?uid fuse, a casing having a passage the head tends, to be moved against the seat by extending therethrough from end to end, one friction of ?uid en route through the passage to end being an inlet and the other end being an ward the outlet, a pair of springs of different outlet for ?uid ?owing through said passage, a valve means comprising a frusto-conical valve strength acting oppositely axially on the plunger, seat surface in said passage intermediate its ends and a valve vplunger slidably mounted in said passage for axial movement with respect to said casing, said plunger having a frusto-conical face portion complementary to and adapted to seat on the stronger of . the springs normally maintaining said valve seat surface and when so seated clos ing the passage through said casing, biasing the frusto-conical surfaces spaced apart as stated, and a valve in the inlet normally closed by the weaker of the two springs and opened by ?uid pressure at the‘mlet. ' COLUMBUS R. SACCHINI.