US 2140559 A
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Dec. 20, 1938. F. P. SCULLY El AL AUDIBLE SIGNAL DEVICE Filed Oct. 7, 1936 2 Sheets-Sheet l Dec. 20, 1938. F.'P. SCULLY Er AL AUDIBLE SIGNAL DEVICE Filed Oct. 7, 1936 2 Sheets-Sheet REISSUEB Patented Dec. 20, 1938 UNITED STATES id Ug g.
PATENT OFFICE AUDIBLE SIGNAL DEVICE Frank P. Scully, Cambridge, and Alcide E. Mather, Auburndale, Mass., assignors to Scully Signal Company, Cambridge, Man, a corporation of Massachusetts Application October '2, 1936, Serial No. 104.488 4Claims. (01. 110-109) a predetermined height and thereafter discontinue upon attainment of the indicated level.
In pursuance of this and other objects, we have developed an audible vent alarm for closed containers which consists essentially of a venting conduit-from the container to atmosphere with an audible signal device in series with the conduit. The conduit is essentially provided with an open lower end, the. position of which J determines approximately the level at which the =audible signal is to be discontinued. Associated with the conduit are means which permit continued venting through the signal device without causing audible operation thereof. This is accomplished by varying the characteristics of the conduit from the lower end will cause actuationof the whistle. If, in addition," we provide one or 35 more openings presumably in the side of the conduit in reasonable proximity to the whistle, then an air stream entering the conduit through these openings will not audibly sound the whistle. We do not attemptto account exactly for this mode of operation except that we believe that an air stream entering the 'side' of the conduitor at an angle thereto or in such a manner as to unbalance a generally uniform flow of air throughout the cross-section of the conduit and 5 in the direction of its length interferes sufficientlywith the functioning. of the whistle to avoid audiblesounding. In this connection, we have found that an orifice in theside of theconduit' located slightly below the whistle and either circular, oval orrectangular, will accomplish the purpose and that a reduction of the lower end of .the conduit'in half 'with'an' upper opening lengthwise of'the conduit willalso accomplish the'desired result. In all cases, the signal au'dibly sounds so long as an air stream can enter the conduit from the lower open end and pass lengthwise thereof. In this case, the presence of the openings does not interfere with the sounding of the signal. When the rising liquid level blocks the open lower end, continued venting is compelled through side orifices or their equivalent, and the signal fails to sound even though the same essential volume of gas or vapor may be passing therethrough. This type of construction provides an extremely simple and eflicient method of audibly indicating the attainment of predetermined levels in all cases where venting from the closed container may be satisfactorily accomplished by the single vent in which the signal is located or, in other words, where the orifice of the signal itself creates sufflcient venting capacity. 'Inthose cases where the signal orifice itself is insuflicient or cannot practically be made large enough to be sufficient,
then continued venting after the predetermined 2o level has been reached mustbe accomplished by by-passing gases or vapors in some fashion about the signal device.
In the accompanying drawings illustrating the preferred form of the invention, Fig. 1 illustrates a cross-sectional elevation of an audible venting device-introduced into the filler pipe of a motor vehicle fuel tank; Fig. 2 is a similar cross-sectional view with a different form of filler pipe; Fig. 3 is a third type in which the filler and vent are separate; Figs. 4,- 5 and 6 are sections in elevation illustrating alternative methods of varying theair stream to provide operation of the audible signal; and Figs. 7, 8 and 9 are end views .respectively of the constructions shown in each the usual fuel tank of a motor vehicle is indi-- cated at It and is provided with a fuel pipe I! entering the side of the tank adjacent the top. This fuel pi-pe extends outwardly into a position conveniently accessible to the operator. It may be attached to the side of the tank through a sleeve coupling ll welded to the side of the tank and threadedly connected with a complementary member I, the two members of the coupling serving to clamp between them an outturned flange I. on the fuel pipe, together with suitable packing rings 20. In order to determine when the contents of the fuel tankhave reached a to predetermined level, without resorting to gages or similardevices, we provide a vent pipe 22. within the fuel pipe and having a downturned end 24 within the tank which, as shown in Fig. 1, terminates at approximately the level of the bottom of the feed pipe. This downturned open end 24 predetermines the liquid level at which audible indication ceases, as will be hereinafter more fully described. As indicated, the vent is provided above the open end' with an oriflced whistle indicated at 26 and openings 28 in the sideof the vent and in proximity to the whistle. The entering passage through the fuel pipe I2 is partially restricted by an inclined baille 30 which tends to divert incomingliquid from the lower end of the vent pipe and also restrict the passage in the feed pipe to insure substantially against venting of gas or air therethrough.
Fig. 2 illustrates a slightly modified form of construction in which the tank I is provided with an inclined feed pipe 32 entering the top of the tank through a fitting 34. The vent pipe 36 extends lengthwise of the feed pipe and projects at its lowerend into the tank a predetermined distance, the open lower end 38 of the vent serving to indicate a predetermined liquid level as in'the case of the construction shown in Fig. 1. A baflie 40 extends across the feed pipe to partially restrict the entering passage and insure escape through the vent pipe, as previously described.
In the construction shown in Fig. 3, the tank It) is provided with'a feed pipe'42 entering the top thereof through a connection 44. This feed pipe extends through the tank to a-point adjacent the bottom so that the lower end of the feed pipe is always trapped against escape ofgas or air so long as .fuel remains in the tank. A separate vent 46 enters the tank and has an open lower end located at 48. Thisvent, similar to those shown in Figs. 1 and 2, is provided with an audible whistle 26 and with side orifices 52.
All of the constructions shown in Figs. 1 to 3 inclusive have a common mode of operation, namely, the liquid delivered to the tank through the feed pipe causes escape of air and gas through the open lower end of the vent as the liquid level within the tank rises. This escaping stream of air passing through the vent pipe from the open lower end causes actuation of the audible whistle which continues until the rising liquid level contacts with and blocks the open lower end of the vent pipe against further escape of gas or air therethrough. Continued delivery of liquid with a consequent rising level will cause venting of air or gas through the side openings 28, as shown in Fig. 1, this air also passing through the audible whistle. Although these openings provide for continued venting and avoid excessive pressure increase if the tank is filled beyond the lower ehd of the vent pipe, nevertheless no actuation of the audible signal takes place after the lower end of the vent pipe has been blocked. Neither do these openings, if properly constructed, interfere with the actuation of the audible signal on account of the air stream entering through the lower end of the vent.
Illustrated in Figs. 4 to 9, inclusive, are a series of alternative constructions, all of which serve as combined vents'and audible signal devices to permit continuous venting through the same conduit so long as filling continues, but to discontinue audiblesignalling when the filling level reaches the open lower end of the vent pipe. Indicated'in Figs. 4 and '7, is an enlarged viewof the construction shown in -Figs. 1 to 3, inclusive. In this view, the lower end of the vent pipe is indicated at 24 and is provided with an orificed whistle 26 of conventional form fitting closely in the vent and with supplementary vent openings 28 in the side of the vent pipe below the whistle and in proximity thereto. So long as the air stream enters the vent pipe through the open lower end 50, actuation of the whistle takes place. When this open lower end is blocked by rising liquid, continued venting may take place through one or more openings 28 without, however, causing actuation of the signal if the openings are located'in sufficiently close proximity to the whistle device to avoid straightening out of the air stream before it reaches the whistle. In addition, the supplementary vent openings should be smaller in their combined area than the area available for venting through the open lower end in order that the venting of air through the open lower end until this portion is trapped shall constitute the path of least resistance for the flow of air theret-h-rough.
In Figs. and 8 is illustrated a similar but not identical construction which has an equivalent mode of operation. In this construction, the vent pipe 24 is provided with the same whistle 26 and the open lower end 50 but the circular or round vent openings have substituted therefor an elongated and comparatively narrow slot 52 in the side of the vent tube below the whistle.
In Figs. 6 and 9 is illustrated a third form in which a vent tube 54 is reduced at its lower end 56 through the employment of a lengthwise partition 58 extending transversely of the tube, as indicated in Fig. 9. This partition extends into proximity to the whistle 26 and at the opposite side thereof is provided a supplemental vent 60 produced by cutting away a portion of the tube, as will be clearly evident. With this construction, so long as the open lower end. of the vent is above the liquid level and gas can be freely vented through the tube on both sides of the partition, actuation of the whistle is produced. When the open lower end is blocked, however, further venting would occur through the supplementary vent 50 without, however, actuating the whistle. Al though the flow produced by this device may be somewhat difierent from that produced by the openings in the wall of the tube, nevertheless the resultant effect, namely, sounding of the audible signal with cessation when the lower end of the tube is blocked, is the same in all cases.
The foregoing constructions illustrate in part the variations which may be-made in the actual devices without departing from the scope of the invention. As stated previously, althoughl the exact theory upon which these constructions operate 1 is not fully and completely understood, nevertheless it is quite evident that an air stream entering the tube below the whistle through an orifice of ample capacity will satisfactorily actuate the whistle and that additional openings prethe whistle to avoid operation as the utilization of supplementary openings in a long tube with the openings sufficiently removed from the whistle by a length of tube would permit smoothing out of the air stream and would defeat the result sought for. Generally speaking, supplementary openings or passages located in sufllciently close proximity to the whistle to cause turbulence oi the air stream impinging on the whistle will avoid sounding thereof and these same openings or pasentering in this manner.
What is claimed is:
l. The combination with a closed container, of a conduit extending into the container below the top thereof andopen at its lower end, an audible signal in series with the conduit and normally actuated by a stream of gas or vapor entering the conduit from the open end when the rising liquid. level is below the lowermost portion of the conduit, and means-associated with the conduit so constructed and arranged relative thereto and to the audible signal as to vary the characteristics of the air stream, after entrance to the lowermost portion oi the conduit has been sealed by rising liquid level, to avoid actuation of said signal while still permitting continued virliting 01' gas or vapor through the audible sign 2. The combination with a liquidtank, of a conduit having an open lower end below the top 01 the tank and serving as a vent without the tank, an audible signal in serieswith the conduit and normally actuated bya stream of gas or vapor entering the conduit through the open lower end when the rising liquid level is. below this end of the conduit, and a supplementary open-- ingdelivering air or gas at the sideoi the conduit at such a location relative to the signal and in such a manner, when the open lower end is sealed and venting continues through the conduit and the signal, as to avoid actuation of the signal.
3. The combination with a liquid tank, of a conduit having an open lower end below the top of the tank and serving as a vent without the tank, an audible signalvin series with the conduit and normally actuated by a stream of gas or vapor entering the conduit through the openlower end when'the rising liquid level is below'this end of the conduit, and a supplementary opening in the side of the conduit in such close proximity to the signal and of less area than the opening at the lower end of the conduit and so constructed as to vent air or gas through the signal device after the lower end of the conduit has been sealed in such a turbulent manner as to avoid actuation of the signal device.
4. The combination with a liquid tank. of a conduit having an 'open lower end below the top of the tank and serving as a vent without the tank, an audible signal in series with the conduit and normally actuated by a stream of gas or vapor entering the conduit through the open lower end when the rising liquid level is below this end oi the conduit, and a circumierentially extending series of openings formed in the side' 01' the conduit 'in such close proximity to the signal, and being of less total area than the opening at the lower end. of the conduit, to vent air or gas through the signal device after the lower end of the conduit has been sealed in such a turbulent manner as to avoid actuation of the signal device.