US2143492A - Tank alarm - Google Patents

Description

L. H; MORSE Jan. .10, 1939.

TANK ALARM Fild April 14, 1936 EJ/arsu;

Patented Jan. 10, 1939 v I D UNITED STATES PATENT OFFICE TANKALABM Lynn H. Morse, Natick, Mass., assignor to Scully Signal Company, Cambridge, Mass, a corporatlon of Massachusetts Application April 14, 1936, SerlalNo. 74,295

2 Claims. (01.137-111) v This invention pertains to tank alarms de-. stalled without necessitating any change in the signed to indicate when a tank or other closed size of the usual openings in the tank. Since container has been filled to the desired level. audible signal devices operating upon the gen- Such alarms are particularly useful in associaeral principle above referred to are usually in- 5 tion with fuel supply tanks for oil burners such stalled within or in association with the over- 5 as are now commonly used for house heating, flow or vent pipe of the tank, and since as above etc. In such oil heating systems the supply tank noted, the minimum size of the vent opening is is customarily located in the basement and fllled fixed by law in some communities, the signal dethrough'a pipe leading from the ground level. vice must be of such form and dimensions as not 10, When the tank is thus located, it is diflicult for to restrict.the overflow or vent opening below the'person' filling the tank to determine the that required by law. Furthermore, the signal height of the liquid in the tank at any given time device must be of such character that it will not and thus. itfrequently happens that the tank is be permanently silenced if temporarily flooded overfilled and the surplus oil escapes frequently with oil; it must emit a sufliciently loud sound,

causing damage to the surroundings and conwhen actuated by the relatively low pressure 15 stitutinga serious fire hazard. By providing the available, to produce a readily audible and distank with an alarm or signal device which autinctive signal; it must be durable and capable tomatically gives a signal when the liquid level of functioning at intermittent intervals over long reaches a predetermined height, the person fillperiods of time, and under the somewhat adverse ing the tankis warned to cease at the proper conditions incident to its environment; and it 20 time. Since it is desirable to keep installations must be cheap to construct and easy to install of this type as simple as possible, complicated and shouldnot require an undue amount of head signals such as those necessitating, the installaroom above the tank. Preferably, the signal detion of electrical wiring or the like,; are not fa- 'vice should be of the type which begins to sound 2 vored, and recourse has been had to audible sigas soon as the pre ur h nk rises to ny nal devices which respond automatically t a, substantial extent and which ceases when the predetermined rise in pressure in the air or vapor fluid level has reached the predete e e above the liquid in the tank as the level of the since a signal of this kind will also respond, and liquid moves up during filling, the present inserve as an alarm, when for any reason (for ex vention relating more especially to alarms of this p al n ease in temperature) the 30 kind- I am aware that this general principle of pressure in the tank rises above the normal. The operation has been familiar to the public for present invention has for its principal object the a y years, as instanced, for example, in the provision of a signal or alarm device possessing patents to Pickering No, 29,309, dated Jul 24, all of the above desirable characteristics to- 5 1860; Phillips No. 96,833, dated N vemb r 16, ,gether with other features of improvement'and 1869; Maul No. 753,600, dated March 1, 1904; and dvan a as w be r fully described inth Seltzer No. 1,116,934, dated November 10, 1914, following detailed description and by reference to and I do not propose herein to lay claims broadthe annexed drawin in Which ly to this principle of operation, but only to cer- Fi 1 is a p p e w t small scale s w- 40 tain specific improvements in apparatus in which ing a fuel ta q pp With the p d 40 this principle is employed. nal device of the present invention; In modern oil burner installations it has be- Fig. 2 is a side elevation of the si dev e come common custom to use pipe fittings etc. of removed from the tank and to larger scale; standard size, while in some communities laws Fig. 3 is a fragmentary vertical section, partly have been passed requiring that tanks be furin elevation, showing the signal device installed 45 nished with vents or overflows of a predetermined in a tank and showing t Parts in the Position cross-sectional area usually corresponding to the which they normally occupy during filling of the area of some standard cast iron pipe fitting. tank; v

Thus most tanks, whether new or in present in- Fig. 4 is a view similar to Fig. 3 showing the stallations, are furnished with internally threadparts in the position which they may occupy after ed openings, for the reception of inlet and overthe fluid has attained the predetermined level in flow pipes of standard pipe dimensions. Acthe tank; and cordingly, any signal device to be applicable to Fig. 5 is a bottom plan view of the device such a tank must, for practical reasons. be so shown in Fig. 2.

designed and constructed that it may be in- Referring to the drawing the numeral 1 desig- 55 boss 1 projecting from the tank wall, is provided for the reception of the combined vent and signal device 8 forming the immediate subject matter of the present invention.

Referring more particularly to Figs. 2, 3 and 4 this improved signal and vent device 8 preferably comprises an open ended casing 9 desirably made from pressed metal and having a body portion providedwith a downwardly directed nipple ID externally'screw threaded at II with a standard pipe thread for engagement with the opening in the-boss 1 on the tank. Preferably the casing is also provided with an upwardly extending nipple l2 which may be internally screw threaded at I 3, if desired, with a standard pipe thread for the receptiomof an overflow or vent pipe l3 (Fig. 1) leading to any desired point. 1

The casing is preferably of one piece construction and comprises a spider having downwardly convergent spaced arms l4 whose upper ends are integrally joined to the lower edge portion of the nipple l and whose lower ends are integrally merged with an annular tube holder is. In this tube holder is mounted atube it which is fixed to the holder l5, for example, by solder or brazing and which is coaxial with the nipple Hi. This tube extends downwardly to a predetermined distance below the holder 15 and is permanently open at its lower end as indicated at H, while at its upper end, which is conveniently located within the body portion of the casing, the tube is furnished with the signal device it such, for example, as a disk whistle of a common and well known type so arranged that gaseous fluid escaping upwardly through the tube l6 will cause the whistle to sound. Preferably the internal diameter of the tube It and the passage through the whistle is such that under normal conditions of filling the tank, that is to say, when the fuel is delivered to the tank at a rate not exceeding twenty-five gallons per minute, for example, the air confined in the upper part or the tank may all escape through the tube It and through the whistle device without unduly increasing the pressure within the-tank, that is to say, without increasing it substantially above two ounces per square inch, for example.

At the Junction of the body portion 9 0! the casing with the downwardly extending nipple Ill a substantially horizontal internal shoulder l9 is formed, constituting an annular valve seat with which at times cooperates an annular valve disk l 9 arranged to slide freely on the upper part of the tube i8, being limited in its upward movement by the whistle device i8. While the external diameter is such that the screw threads at H are of standard pipe size corresponding to an ordinary cast fitting oi the same nominal diameter, the metal of the casing is so much thinner than the ordinary cast iron fitting orthe same diameter that the annular space-or passage between the inner surface of the nipple I 0 and the external surtace oi the tube It is or a transverse area at 01' the nipple i0 used least as great as the minimum vent area required by law. For example, if the legal requirement is that the vent pipe shall-be lil inches in diameter, this annular space will be atleast as great in cross-sectional area as the internal area of a standard 1% inch pipe nipple.

Likewise the internal diameter of the body portion 9 of the. casing is such that the annular space or passage between its inner surface and the outer periphery of the valve I9 is also at least as great as the minimum vent area required by law.

Further, it is to be noted that by arranging the legs is of the spider to converge downwardly, with the tube holder i at a substantial distance below the plane of the lower edge of the nipple, the aggregate of the spaces between the legs l4 may readily be made sufflcient to provide an entrance area to the lower end of the nipple at least as great as the minimum vent area required by law.

The tube l6, as illustrated in Fig. 2, is preierably furnished with a peripheral groove at the point 2!). The length of the tube it, from the holder l5 to its lower end is that which has been found desirable for use in a tank disposed vertically as illustrated in Fig. 1. However, if the vent and signal device is to be used in the tank disposed horizontally, the tube I 5 may readily be cut oif at the location of the groove 20, thus providing a shorter length between the holder i5 and the lower end of the remaining ortion ofthe tube is to provide for proper filling of the horizontally disposed tank before the signal is given to cease filling.

In the ordinary operation of the device the parts are disposed as in Fig. 3, the valve 19 being seated and the lower end of the tube I! being open. As the level of the liquid L in thetank rises, the air above the liquid is driven out from the tube l 6, causing the whistle to begin to sound almost as soon as filling commences, such sounding of the whistle continuing. until the level of the liquid L rises above the level of the lower.

end of tube it as shown for example in Fig. 4.

As soon as the level of the liquid reaches the low-- er end of the pipe it, the air is prevented from entering the tube is and thus the whistling sound stops, notifying the person filling the tank that the tank has been suillciently filled. However, if the filling should not be stopped in response to this signal, or if the filling should be done with undue rapidity, so that the pressure in the tank rises abnormally, the valve l5 lifts from its seat, providing a free venting of the tank through the open ended casing 9 in the same way as though'the whistle device were not employed. It

is further to be noted, that it with the parts inf.

the position of Fig. 3, the pressure in the tank" should rise from some other cause than filling,

for example, by reason of dangerous rise in tem-v 'perature, the alarm will automatically sound. I

While I have herein disclosed my desirable embodiment of the invention by way of example, I wish it to be understood that the invention or construction here disclosed nor to thematerials employed nor to the exact dimensions suggested herein by way of example, but is to be re- .65 is not necessarily limited to the precise-details garded as broadly inclusive 01' all equivalents J0 which fall within the-scope oi the appended clalms. I claim:

l. A tank alarm including a casing having a downwardly directed externally screw=threaded 15 the tube and easing.

nipple portion and an upwardly directed internally screw-threaded nipple portion, the external and internal screw threads thereof being of a standard pipe size, the body portion of the casing being of larger internal diameter than the nipple portions, a tube holder, a tube fixed in the holder in coaxial relation to the lower nipple, the upper end of the tube being within the body portion of the casing and its lower end being at a predetermined distance below the holder, a whistle mounted at the upper end of the tube member at a point within the casing, and mannular valve arranged to slide on the tube; said valve normally closing the annular space between 2. A tank alarm including a casing having a downwardly directed externally screw-threaded nipple portion, the external screw threads thereof being of a standard pipe size, the body portion of the casing being of larger internal diameter than the nipple portion, the casing having an internal annular valve seat substantially at the junction of the body portion of the casin with the nipple, a tube fixedly supported coaxially with said nipple with its upper end within the body portion of the casing, an annular valve arranged to slide along the tube toward and from said annular seat, and a whistle mounted upon the upper end of the tube, said whistle constituting a limiting stop for the valve.

' 1mm 5. MORSE.

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