Патент USA US2408706код для вставки
Oct. 1, 1946. I K, w, 'T‘ODD' ' 2,408,705 MECHANICAL RELAY OF THE FLUID JET TYPE Filed Dec. 31, 1943. Mi”; 2d.‘ FIG. 3. l A I ' INVENTOR KEITH" WATSON Tom) ~ ATTORNEYS 2,408,705 Patented Oct. 1, 1946 ;IJ.UNITED_ STATES PATENT OFFICE . Keith Watson Todd, Warrington, England, as signor to Metropolitan-Vickers Electrical Com pany Limited, London, England, a company of Great Britain Application‘ December 31, 1943, Serial No. 516,595. In Great Britain May 28, 1940, and September 1 6, 1940 3 Claims. (01. 121-41) , This invention relates to mechanical relays of the fluid jet type. 2 According to the present invention, with a view to avoiding or, minimising pressure pulsa tions as above mentioned, in relays of the ‘type ‘A relay of the type referred to comprises a nozzle to which air or other ?uid is continuously referred to controlled otherwise than by a ma supplied, usually at constant pressure, and an 5 terial ‘vane, intercepting the stream ?ow, the transmitting nozzle and receiving ori?ce are ar ori?ce, which may be the opening to a second ranged so that in no control position do their nozzle, which ori?ce receives ?uid from the jet issuing from the aforesaid nozzle. The nozzle axes subtend with respect to one another an angle of less than 5° from coaxial alignment, and that ing an outlet port andsometimes provided with 10 inat least one control position the axis of the transmitting nozzle to which the pressure ?uid means whereby the pressure within the casing is supplied passes within the area of the receiv may be controlled, for instance maintained above ing ori?ce. ,In experimental use of one system or at or below atmospheric pressure. ' , of nozzles it was found desirable for the angle " The ?uid received in the receiving ori?ce may act upon a piston or bellows member for effect 15 between the axes to exceed 20°. Factors affecting the amplitude of the, received ing some indicating or control operation in ac pressure pulsations, and hence the angle neces cordance with the control imposed upon the re sitated between the axes of the nozzle and re lay, this control in the present instance being ceiving ori?ce for the removal wholly or mainly effected by Varying the degree of ‘impingement of‘ said pulsations, are the absolute and relative of the jet upon the’receiving ori?ce. Heretofore sizes vof the bores of the nozzle and receiving when this method of control has been employed ori?ce, the shape of the ori?ces, their distance the nozzle and receiving ori?ce have been main apart, the nature of the ?uid medium used, the tained as far as practicably possible in coaxial transmitting jet pressure and the pressure of the alignment when in one control position, the axis 7 ofthevreceiving ori?ce being taken, in this con 25 medium surrounding the jet. With a relayof the type referred to when the nection and in the following, as the axis of the ?uid used by the jets is a relatively highly com receiving nozzle if present (including a receiving pressible one, such as air, certain irregularities perforation if the length thereof permits the as appear to arise which it is believed are dependent signment of an axis) or the normal to the plane upon the air velocity being at least in the neigh4 face of the receiving ori?ce if no receiving nozzle is employed. I 7 bourhood of the velocity of the propagation of sound. It is known that under these conditions However, it has been found that-with this-ah the stream of fluid beyond the transmitting nozzle rangement, under certain conditions considerable may enter into a condition of standing waves, pulsations of the received pressure occur irre and that the length between nodes'will depend spectiveof the separation of nozzle and receiving upon the ratio of pressure of supply to that of ori?ce over a considerable range, even although the ?uid’ medium surrounding the jets, whilst precautions are taken to maintain uniformity of there is a complicated structure within this jet the pressure in the transmitting nozzle. These and certain regions of abrupt change known as pulsations may also vary in amplitude and be Riemann lines. It is also know that beyond the come considerable in parts of the separation Riemann line the jet conditions may change and range. . cease to be periodic, becoming somewhat inde In relays as above set forth the method of con terminate. Considerable experimental investi trol used may effect the said change in degree gation has been made on these jets by optical of impingement in any of various ways such as by methols along the lines of investigation made by de?ection of the one axis relatively to the other Julius Haitmanri-see Ingeniorvidenskabelige about any suitable centre and whether retain Slq'ifter 1939, Nr.- 4. These investigations have ing a coplanar relationship of the axes or not, tended to con?rm the aforesaid assumptions, and by movement apart of the two ori?ces along any have led to the present invention whereby one line but preferably along the axis of the ?rst and ori?ce are usually enclosed in a casing hav or outlet nozzle, or by de?ection of the jet by ' meansof a transverse jet, and the invention is essentially concerned with relays in which are employed such methods of control other than by means of a material vane arranged to ‘intercept’ the stream ?ow. source of irregularity in the receiving pressure of the relay can be avoided or minimised. Therefore, according to a subsidiary feature of thepresent invention the occurrence of the Rie mann, line isprevented or substantially prevented by the use of a convergent-divergent nozzle for 2,408,705 3 4 the transmitter of the relay. In the said experi mental investigations the shape of the receiving ing part of the frame 3 and at the other end is pivoted to a rod ID to which initiating movement will be imparted when the relay is intended to operate. Attached to the link 1]‘ of the frame ‘lb nozzle has not been altered; it has been very slightly convergent towards the entrance ori?ce. While the use of a convergent-divergent trans mitting nozzle has been found very effective it has been found that there are still certain pulsa tions in the receiving pressure to be dealt with‘ and according to a further subsidiary feature of the invention these smaller pulsations or dis l0 is a rod H which rests at its free end on a cam !2 which is attached to an extension of the pis ton rod 5b projecting beyond the supporting arm 3b. With the arrangement described, and assuming that the normal position of the jet from nozzle turbances are controlled by the introduction of 1 is such that said jet partially interferes with a wire or wires or a wire grid across the surface the under-side of the jet from nozzle l , then, when the rod Ill is for example depressed, pivot 9a for of the receiving nozzle. There may be a single the frame lb‘ will be lowered accordingly to de wire of diameter about one-tenth that of the ori ?ce placed diametrically across the latter. Alter 15 press nozzle 1 and correspondingly reduce the ex tent to which the jet from nozzle I is interfered natively a series of parallel wires may be used. with by the control ?uid jet from nozzle 1, so It will be appreciated that the presence of several that the pressure in the receiving nozzle 2 is wires unavoidably reduces the available receiv raised and the pressure in the trapped space 5b ing pressure. The invention will now be described with ref 20 of the working cylinder 5 correspondingly in creased relatively to the constant opposing pres erence to the accompanying somewhat diagram sure, in the trapped space 5a, with the result that matic drawing in which: Fig. 1 is a perspective view of a ?uid jet rela the piston 6 will be moved to the left in the draw ing. With such movement of piston 6,, the at. in accordance with the invention, Fig. 2 being an enlarged sectional view of part 25 tached piston rod 6a is moved outwardly from the working cylinder 5 accordingly to operate mecha of the transmitting nozzle of the relay, and Fig. 3 being an enlarged perspective view, part nism with which the relay will be associated, and at the same time, the piston rod 81) is moved ac ly in section, of the receiving nozzle with ?tted cordingly, thereby retracting the cam I2 and per mesh diffuser. ' In Figure 1, l and 2 are nozzles respectively 30 mitting downward movement of the rod H, and causing the frame 111 to swing about. pivot 9a. in supported on arms 3a and 32)‘ forming parts of a ?xed frame mounting 3. The nozzle I has at the direction to raise the nozzle 1 to its normal position aforesaid, and so restoring the jet from. tached to it, at its rear or anchored end, a nip said nozzle 1 to the position in which it partially ple 4 to which will be connected a pipe for con interferes with the under-side of the jet from veying working fluid, for example air, under nozzle l. Similarly, for an upward movement of constant pressure to the interior of the nozzle. the rod Iii, piston 6 will be moved to the right in This nozzle constitutes the transmitting nozzle the drawing accordingly, through piston, rod 60., and has a through bore la which, at the outlet end, is of convergent-divergent form as illus to operate the mechanism associated with the re—~ trated more clearly in Fig. 2. The nozzle 2, in 40 lay, and, through the rod 6b, to operate the cam l2 and rod H to rock the frame Tb about pivot tended to receive the fluid ejected under pres sure from the transmitting nozzle I and herein Ea for restoring the nozzle 1, and thus the con referred to as the receiving nozzle, has a through trol jet therefrom, to its normal position afore bore comprising a cylindrical part 2a and a re said. duced cylindrical part 21). Supported in the frame 3 is a cylinder 5 in which is disposed a piston 6 attached at its front face to a rod 60. and at the rear face to rod 6b; If it were desired-that mechanism similar to that illustrated should respond when a control ?uid jet ejected from nozzle 1 is moved from a normal position in which said jet interferes with the rods 6a and Eli extend through substantially the upper-side of the jet from nozzle I, then the‘ pressure-tight sealing glands mounted in the 50, only change which would be required in the mech closed opposite ends of the cylinder "5. The bore anism to ensure restoration of the control jet from Id. of the transmitting nozzle I registers with a nozzle 1 to its normal position in relation to the duct 3a’ in the supporting arm 3a whereby, when jet from, nozzle 1 would be for the cam 12 to be pressure ?uid is supplied to the transmitting noz reversed, namely, so that its inclined surface is zle- I, pressure fluid is also supplied to the trapped 55 directed upwardly from the left to- right in the drawing. > space 5a of cylinder 5 accordingly‘ to act upon It is preferable that the transmitting nozzle l the piston 6. The bore 2a of the receiving noz and the receiving nozzle 2 are arranged so that zle registers with a duct 3b’ in the supporting arm 31) whereby pressure ?uid received by the the maximum pressure receivable through nozzle nozzle 2 from the transmitting nozzle 1 is fed 60 2 in the trapped space 522 is approximately half into the trapped space 5b in cylinder 5 accord the normal constant pressure in the trapped space ingly to act upon the piston 6. 5a and that the amount of interference of the At 1 is shown a third nozzle which, in the ex control jet from nozzle 1 on the jet from nozzle ample illustrated, is supported by a bracket ‘la l is such that the normal received pressure in attached to a frame lb and is, in turn, supplied trapped space 5b is about half the maximum with fluid under constant pressure through pipe available pressure, that is, about a ‘quarter of the 8, thereby to provide a ?uid jet acting substan normal constant pressure in the trapped space 5a. tially at right angles to the fluid jet passing be Despite this dissimilarity in pressure on. either. tween the nozzles l and 2, The frame 11) to which the nozzle 1 is attached comprises‘ a pair of par 70 side of the piston 6, the differential areas are such that a balance condition is maintained. allel levers 1c and 7d pivotally connected at their Advantageously, the design of. the ori?ce in respective ends to a link ‘Fe extending from the the control jet nozzle 1 is such that it is not possi bracket ‘la and to a link ‘if, and is supported on ble for over-movement of the rod. H). to result a knife edge 9a intermediately of a beam 9 which, in such movement of the control jet from nozzle at one. end, is supported on a knife edge 3c form 2,408,705 5 1 that its in?uence upon the jet from nozzle I is entirely removed. _ As shown in Fig. 3, the receiving nozzle 2 is ?tted at its outer end with a cylindrical part 20 having an attached'circumferential ?ange 2d for supporting a wire grid 26 of relatively ?ne mesh in a plane substantially at right angles to the axis of the nozzle, to act as a di?user for said re ceiving nozzle for the purpose hereinbefore de scribed. ~ ' nozzle adapted to be supplied with ?uid at con stant pressure and a receiving nozzle arranged with the axis of the transmitting nozzle passing through the area of the receiving nozzle and in clined to the axis of the receiving nozzle so as to subtend therewith an angle of at least ?ve degrees from coaxial alignment, a control nozzle for di recting ?uid at constant pressure transversely of the jet from the transmitting nozzle, means re 10 sponsively operable to a control in?uence .for As represented in Fig. 1, the transmitting and varying the inclination of incidence of the trans receiving nozzles I and 2 respectively are mount ed so that their axes are not in linear alignment verse jet With the jet from the transmitting noz but are inclined to one another at an angle or, with means for supplying ?uid at the pressure zle, a pressure-responsive servo-piston, together which angle, for all working positions, has a value 15 in the transmitting nozzle , to one face of said servo-piston and means for supplying pressure which exceeds 5° and which willgenerally be in 1 ?uid received in the receiving nozzle to the op excess of 20°. Moreover, as represented in the posite face of said servo piston. drawing, the axis of the transmitting nozzle I 3. A ?uid jet relay comprising a transmitting will generally pass within the area of the inlet 20 nozzle adapted to be supplied with ?uid at con~ end of the receiving nozzle 2. stant pressure, a, nozzle for receiving ?uid emitted I claim: from the transmitting nozzle, a controlling nozzle 1. A ?uid-jet relay comprising a transmitting for directing ?uid at constant pressure trans nozzle adapted to be supplied with pressure ?uid, versely of the emission from the transmitting an orifice for receiving the ?uid jet from the nozzle, means responsively operable to a variable 25 transmitting nozzle, a controlling nozzle for di control in?uence for correspondingly varying the recting pressure ?uid transversely of the jet from angle of incidence between the transverse ?uid the transmitting nozzle, means responsively 0p emission and the ?uid emission from the trans erable to a control in?uence for varying the in mitting nozzle, means continuously responsive to clination of incidence of the transverse jet with 30 the difference between the pressure in the trans the jet from the transmitting nozzle, means re mitting nozzle and the pressure in the receiving sponsive to pressure ?uid received by the receiv nozzle for rendering available an in?uence which ing ori?ce for rendering available an in?uence is at all times substantially representative in representative of said control influence, said magnitude of said control in?uence, said trans transmitting nozzle and receiving nozzle being mitting nozzle and receiving nozzle being ar arranged with the axis of the transmitting noz ranged so that the axis of the transmitting noz~ zle passing through the area of the receiving noz zle‘passes through the area of the receiving nozzle zle and inclined to the axis of the receiving ori?ce and is inclined to the axis of the receiving nozzle so as to subtend therewith an angle of at least so as to subtend therewith an angle of at least ?ve degrees from coaxial alignment. ?ve degrees from coaxial alignment. 2. A ?uid-jet relay comprisinga transmitting KEITH WATSON TODD.