US2590386A - Vacuum breaker - Google Patents

Description

March 25, 1952 c, DOBRlCK 2,590,386

VACUUM BREAKER Filed May 29, 1947 30 I H K 7 fill/81425) fl wif 50/0 am.

a, fizzy/7261,95,

Patented Mar. 25, 1952 VACUUM BREAKER August 0. Dobrick, Chicago,- Ill., assi'gnor to The Imperial Brass Manufacturing Company, Chicago, 111., a corporation of Illinois Application May 29, 1947, Serial No. 751,255

3 Claims.

The invention relates to a vacuum breaker and has as a general object to provide a vacuum breaker of new and improved construction which assures proper operation under all conditions.

Many vacuum breakers in the past have been so constructed that there was some noise incidentto their operation. The construction of the vacuum breakers, moreover, was such that the element which was the cause of the noise could be removed without giving outward evidence of such removal. As a result, all too frequently the above referred to part Was accidentally omitted or deliberately removed, with the result that though the vacuum breaker served to prevent outflow of fiuid' it did not function as a vacuum breaker.

It is, therefore, one of the objects of this in vention to perfect a vacuum breaker of such cone struction that the one movable part therein may not be removed without total destruction of the functioning of the vacuum breaker and without immediate outward. evidence of the removal of that part when the vacuum breaker is installed.

Another object of the invention isto perfect avacuum breaker in which the area of'tlie passage for the inflow of atmospheric air is greater than the areaof the fluid outlet passage so as to assure ample inflow of air to break any syphoning action in the event of a vacuum tending to cause a syphoned backflow.

Still another object is to provide a vacuum breaker having a float valve designed to have minimum frictional resistance so as to assure quick. opening movement upon the creation of a vacuum.

A further object is to provide a vacuum breaker with a float valve having guide means formed thereon and located so as to come into play as thevalve approaches seated position cooperating with the valve seat to center the valve and assure proper seating. I

Other objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawing, in which:

Fig. 1' is. a side elevational view of a vacuum breaker embodying the features of this invention.

Fig. 2 is an enlarged longitudinal sectional view of the breaker of'Fig. 1 taken on a diameter of the breaker intersecting the outlet of the breaker.

Fig. 3 is a transverse sectional view taken approximately along the line 33 of Fig. 2.

Fig. 4 is a closed end view of a modified form of 'float valveemployable in the vacuum breaker of;Figs. 1 1:03.

Fig. 5 is a' diametrical sectional view taken on tlie -Iine 5 -5 of Fig; 4.

While the invention is susceptible of various modifications and alternative constructions, it is shown in the'drawing and will hereinafter be described in a preferred embodiment and one modification. It is not intended, however, that the invention is to be limited thereby to the specific disclosures shown. On the contrary, it is intended to cover all modifications and. alternative constructions falling within the spirit and scope of the invention as defined in the appended claims.

As shown in Figs. 1 to 3 of the drawing, for purposes of illustration, the vacuum breakercomprises a casing or housing, generally designated l0, having a liquid inlet II, a liquid outlet l2, and communication with atmosphere at 13. Within. the housingis a valve, generally designated I4, which is ofthe float type so arrangedthat during the flow ofliquid from. the inlet. to the outlet and also during static presence of liquid under pressure from the inlet the valve opens. a-

the outlet and tightly seals the breaker against communication with atmosphere to prevent leakage of liquid, but instantly upon any tendency of syphoned backflow the valve opens wide the communication with atmosphere and interrupts the communication between the outlet and the inlet.

The casing l0 herein comprises a hollow main body portion l5 and a closure portion I6. Save for a lateral tubular projection l1 forming the outlet I2, the main body portion l5 is cylindrical with three sections or portions l8, l9 and 200i progressively slightly. reduced diameter; The smallest portion 20 forms the inlet ll and to thatend is formed internally with threads 21 for thethreaded reception ofa conduit. Internally at about thejuncture of the portions Hand 20 the-main body portion [5 is formed'with an in"- wardly extending annular flange 22. Supported in this flange'and extending longitudinallvtdward the enlarged end of the main body portion is a tube 23 terminating about midway of "the largest portion or section IS. The tube 23' may besecured in the flange 22 by brazing or soldering but is preferably constructed to have an external diameter larger than the internal diameterof the flange 22 and tohave at one end an inwardly oifset portion 24 with an external di ameter just large enough to be received with a snug fit in the flange 22. With this construction, the tube 23 may be inserted through-the upper enlarged end of the main bodyportion'whilethe cap H5 is removed until the annular shoulder'25 formed by the inward ofiset of the tuberests" on the flange 22. The end of the ofiset-portion 24 proj ecting beyond the flange 22 is" then" given an outward flare 26 tightly and permanently to secure the tube in the flange.

The tubular projection II forming the outlet I2 projects from the intermediate portion I9 and, like the portion 26, is ctormed with an internal thread 21 forthreaded connection with a conduit or pipe.- The wall of the portion I9 is cut away at '28 to' provide communication between the outlet I2 and the annular space 29 formed between the tube 23 and the walls of the portions I9 and i8.

As stated, the housing is completed by a closure I6 in the nature of a plug threaded externally for threaded engagement with internal threads 30 formed at the upper end of the main body portion I5. Extending axially through the closure is a passage 3I and surrounding this passage at its inner end is an annular axially extending flange 32 forming a. valve seat 33. Completing the closure I6 is a cap 34 disposed over but spaced from the plug portion of the closure so as to prevent foreign material from dropping into the passage 3| while at the same time providing ample communication between the passage 3| and atmosphere. The cap 34 and the plug portion of the closure'are connected by web means 35. It is to be noted that the passage 3I has a diameter larger than the diameter or the opening 28 so as to assure greater ease and Volume of air flow through the passage 3| than flow of liquid through the opening '28.

v The valve I4, as stated, is of the float type and herein takes the form of an inverted cup 36. The cup j has an external diameter substantially smaller than the internal diameter of the portion I8, and has an internal diameter substantially larger than the external diameter of the tube 23 so as to be receivable over the portion of the tube 23 projecting into the section I8. The valve is, as a matter of fact, adapted and intended in one position to rest on the end of the tube 23, the end ofthe tube forming in effect a valve seat with which the cup cooperates to break communication between the outlet and the inlet of the vacuum breaker. It is not essential that the valve and the tube 23 form a fluid-tight seal when the cup is resting on the tube. As a matter of fact, it is desirable that there be slight leakage for such leakage, as will hereinafter be made more apparent, serves to dissipate the vacuum which caused the seating of the valve on the tube as an incident to attempted backflow of the liquid induced by syphoning action. The valve must, however, form a fluid-tight seal against outflow of liquid through the passage 3I under the substantial pressures that exist within the casing during normal operation of the system in which the vacuum breaker is incorporated. To that end, the cup 36 has mounted thereon a disk 31, of a diameter larger than the annular valve seat 33, of some resiliently yieldable material commonly employed in valves, such as natural or synthetic rubber, certain plastics, or combinations thereof.

It is believed readily apparent from the foregoing and well known to those skilled in the art that during flow of liquid through the vacuum breaker from the inlet II to the outlet I2 the valve I4 wi1l by the pressure of the fluid be lifted off of the tube 23 and forced into tight sealing engagement with the valve seat 33 preventing the escape of liquid through the passage 3| while permitting the flow of liquid from the inlet II, upwardly through the tube 23, thence downwardly betweenthe tube and the side walls or skirt of the cup 36, annular space 29 and opening 28 to the outlet I2. Similarly, under normal static conditions, the valve will by the pressure of the liquid be lifted and held in tight sealing engagement with the valve seat 33. Thus the broken line position of the valve shown in Fig. 2 is the normal position. In the event that a drop in pressure occurs in the system in which the vacuum breaker is incorporated with its resultant tendency to create backflow through the vacuum breaker, the valve I4 must quickly move from engagement with the valve seat 33 to engagement with the tube 23. With the valve I4 thus shifted back and forth, provision must be made for guiding the valve during its movements. Accordingly, the valve is provided with a pluraltty, herein four, of radially outwardly projecting ribs 38 which approximate but still do not equal the internal diameter of the portion I8. This slight clearance between the ribs and the wall of the section 18 is provided in order to reduce to the maximum extent possible any frictional resistance or retardation to movement of the valve while at the same time guiding the valve sufficiently to prevent it from becoming tilted and to retain it .approximately centered with respect to the tube 23 and the valve seat 33. To assure the more precise positioning of the valve relative to the seat 33 without adding to the frictional resistance to rapid seating of the valve on the tube 23, which is the critical direction of movement of the valve, guide means is provided which comes into play only as the valve approaches engagement with the valve seat 33. This means herein takes the form of a metallic disk 39 positioned over the composition disk 31 and having a beveled peripheral edge 40. The maximum diameter of the disk 33 is just slightly less than that or the passage 3I and hence of the internal diameter of the seat 33. The beveled peripheral edge 46 01f the disk thus serves as a cam functioning upon engagement with the flange 32 to effect the final and. precise centering of the valve I4 essential to assure proper seating on the valve seat 33. The disk 39 serves the additional function of holding the composition disk 31 against curling and warping. Both the disk 31 and the disk 39 are removably retained on the cup 36 of the valve through a screw M which herein is shown as constituting an integral part of the disk 39.

It is believed apparent from the foregoing that I have perfected a very simple yet properly functioning vacuum breaker. The breaker has but one movable part, namely, the valve I4. In the form of the invention shown in Figs. 1 to 3, the cup 36 forming the major portion of the valve is molded from one of the plastics giv ing it the advantage that it is silent in operation, does not corrode, and so forth. A very significant feature is that should this one removable part be accidentally or intentionally removed, the vacuum breaker is rendered completely inoperative and thus there is absolutely no possibility that, as in the past, the vacuum breaker may function to prevent outflow of fluid through the opening to atmosphere while being wholly incapable of performing the principal function for which it was designed and for which it is incorporated in liquid supply systems. Further, while my valve is loosely guided so as to be free to shift quickly from normal position to emergency position in the event of attempted form of valve M.

ment with the valve seat 33 Where the seal must be fluid-tight and capable of withstanding substantial pressures.

Turning now to the construction disclosed in Figs. 4 and 5, there is there shown'a modified The valve 14 is in the main the same as the valve 14, being of the float type and composed in the main of an inverted cuplike member 36. On its closed end, the member 36 again carries a disk 31 of suitable composition and a second disk 39' preferably of metal and having a beveled circumference 43'. In this form, the member 36' instead of being molded of one of the plastics is of metal and in place of ribs 38 is formed with circumferentially spaced, radially outwardly projecting ears 45 at both the top and bottom of the cup-like member 36'. For convenience in manufacture, the member has its closed end formed by a plain metal stamping 46. The skirt 4'! of the inverted cup-like member is formed as a cylinder having the cars at one end thereof. The parts are then welded or brazed together with the ears in longitudinal alignment. This modified form of valve, of course, functions in precisely the same manner as the valve disclosed in Figs. 1 to 3. It has, however, the additional advantage that the possible frictional resistance to movement of the valve is further reduced by the employment of the ears as distinguished from the ribs 38. With proper selection of the metal composing the valve, there is little objectionable corrosion and there is no swelling or warping of the valve.

I claim as my invention:

1. A vacuum breaker comprising a casing having a hollow generally cylindrical single main part and a single-piece closure receivable in one end of said main part, said main part having a liquid inlet formed in the end thereof opposite said closure and a liquid outlet opening through the side near the inlet end, a tube extending longitudinally within said casing communicating at one end with the inlet and terminating at the other end beyond the outlet, said tube having a diameter smaller than the internal diameter of said casing to provide an annular passage around said tube, said closure having a longitudinal passage communicating at its outer end with atmosphere and terminating at its inner end in an annular valve seat disposed opposite and spaced axially from the inher end of said tube, and a valve of the float type comprising an inverted relatively deep cuplike member operable in one position to project over the inner end of said tube and seat on the end of said tube to break communication between the outlet and the inlet, circumferentially spaced, radially outwardly projecting elements on said cup-like member forming means for loosely guiding said valve in its movements, a composition disk carried by the closed end of said cup-like member for seating on the valve seat formed by said closure, and a second disk overlying said first mentioned disk including means for retaining both disks on said cuplike member, said second disk having a maximum diameter smaller than the internal diameter of the valve seat formed on said closure to be receivable therein and having a beveled peripheral edge serving as cam means operable in the event said valve is not precisely centered to engage said valve seat formed on said closure to efiect proper positioning of said valve, said projecting elements and the beveled peripheral edge cooperating to prevent tilting of the valve and to accurately guide and seat said valve.

2. A vacuum breaker comprising an elongated generally cylindrical casing composed of a main body portion and a closure threadedly receivable in one end thereof, said main body portion having three sections of progressively reduced diameter giving the main body portion a stepped appearance, a fluid inlet opening formed in the end of said main body portion opposite said closure and an outlet communicating with the interior of said main body portion through an opening formed in the side wall of said main body portion near the inlet end of said casing, a radially inwardly extending annular flange formed in said main body portion intermediate said inlet and said outlet, and a tube having a diameter in the main greater than the internal diameter of said flange and offset inwardly at one end to be receivable with a tight lit in said flange and flared outwardly to be firmly secured in position, said tube terminating above the outlet, said closure having formed therein an axial passage communicating at one end with atmosphere and terminating at the other end in an annular valve seat and a relatively deep cup-like valve of the float type operable to seat in one position on the inner end of said tube and in another position on the valve seat formed on said closure, and a plurality of longitudinally extending radially outwardly projecting ribs carried by the valve and extending longitudinally the full depth of the valve, and a beveled edge disc carried by the closed end of the valve, said beveled edge and ribs cooperating to prevent tilting of the valve and to accurately guide and seat said valve for guiding the same in its movements from one position to another.

3. A vacuum breaker according to claim 1, in which the circumferentially spaced, radially outwardly projecting elements are ears at each end of said cup-like member.

AUGUST C. DC'BRICK.

CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 847,146 Aller Mar. 12, 1907 1,247,326 Porter Nov. 20, 1917 1,689,095 Wray Oct. 23, 1928 2,153,904 Wilson Apr. 11, 1939 2,282,188 Horne May 5, 1942 2,283,973 Criss May 26, 1942 2,303,037 Fredrickson Nov. 24, 1942 2,324,084 Horner July 13, 1943 2,325,955 Holtman Aug. 3, 1943 2,412,760 Svirsky Dec. 17, 1946 FOREIGN PATENTS Number Country Date 211,511 Germany July 3, 1909

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