US2282188A - Vacuum breaker - Google Patents

Description

B. E. HORNE CUUM BREAKER May 5, 1942.

Filed June 26, 1939 INVENTOR. flaw/245526. Way/x ATTORNEYS Patented May 5, 19 42 VACUUIVI BREAKER Bun-chard E. Horne, Andover, Mass., assignor to Watts Regulator Company, Lawrence, Mass.,

a corporation oi Massachusetts Application June 26, 1939, Serial No.-281,114

2 Claims.

My invention belongs to that class of devices utilized for venting a pipe line or the like to atmosphere, when the pressure in the line drops to atmospheric, to prevent the creation of a vac uum in the line.

An object of my invention is to provide a vacuum breaker which shall be positive and dependable in operation.

Another object is to provide such a vacuum breaker which will not leak from the vent when subjected to fuctuations or rapid variation in line pressure.

A further object is to provide in a vacuum breaker a vent which is surroundedand protected in a manner to prevent the entry of dirt or other foreign matter which might injure or clog the valve surfaces.

Another object is to provide such a device in which the valve is guided on to its seat to assure a secure closure even under conditions of severe hydraulic or mechanical disturbance.

Another object is to provide a modified form of vacuum breaker in which the guide is of slotted tubular form to improve the operation of the breaker under certain conditions.

Another object is to provide such a device embodying a restricted orifice between the main valve chamber and the outlet passage.

With these and other objects in view, my in- 'polnted out in my claims and illustrated in the accompanying drawing, whereinr Figure 1 is a vertical sectional view of a vacuum breaker embodying my invention.

Figure 2 is a horizontal sectional view taken on the line 2-2 of Figure 1.

Figure 3 is a vertical elevational view partly in section similar to Figure 1 showing a modified form of my invention.

Figure 4 is a horizontal sectional view taken on the line 44 of Figure 3.

Figure 5 is a vertical elevational view partly in section similar to Figure'3, and showing another modified form of my invention.

Figure 6 is a horizontal sectional view taken on the line 6-6 of Figure 5.

In the accompanying drawing I have used the reference numeral In to indicate generally a casing which may be of brass or any other suitable material and may be cast, forged or made up from rolled stock as best fits the requirements of particular cases.

' 42 constitutes a guide'for the head of the bolt At its lower end the casing II is threaded to receive a standard pipe or pipe fitting l2. A

portion of my device is formed as an internally threaded hub l4 which may be either a separate piece .threadedly engagingthe body III, as in Figure 1, or may be formed integrally with the body III, as I have shown it in Figures 3 and 5.

The hub I4 receives a threaded pipe or pipe fitting l6.

In the interior of the body I. I form a chamber l8. At the bottom of the chamber l8 th material of the body It is formed in a restricted aperture constituting a port 24 surrounding which I may form an upstanding annular rim 22. A valve member indicated generally as V includes a bolt 24 preferably having a square head as I have shown it in Figure 1. On the bolt 24 I secure a composition washer 26 and the metal washer 28 by means of the nut 30 threadably engaging the lower end of the bolt 24. In the lower end of the nut 30, I preferably form a recess 32.

To close the top of the chamber I8 I provide a plug 34 having a threaded engagement with the body It at 36 and having a portion 38 of enlarged diameter which is preferably knurled as in Figure 3 to facilitate its removal without tools. Between the portion 38 and the body III I preferably employ a gasket 40 to effect a leak-proo seal.

The plug 34 has a downwardly extending tubular portion 42 having an internal diameter slight 1y greater than the greatest distance across the sharps of the head of the bolt 24. The portion 24 as can be plainly seen in Figure 1.

In the plug 34 I provide a passage 44 constituting a vent between the inside of the tubular portion 42 and the external atmosphere. A number of such passages 44 may be provided if desired. Also, in the top of plug 34 I provide for the threaded engagement of a screw 46 which has afllxed to it by soldering or by other suitable means, a cap or bonnet 48. This cap prevents the entry of dirt or other foreign material into the passages 44 which might injure or foul the valve surfaces or which might obstruct the nected to the source. The pipe Ii will be con nected to the fixture. My vacuum breaker should be installed in the supply system at a level above -tainly annoying and distressing the outlet of the fixture which it serves, pref erably at least six inches or more above that out-. let.

Under normal operating conditions when the proper supply pressure exists in pipe H the supply line pressure will exist in the chamber I B and the valve assembly V will be held in raised position with the composition disc 26 in engagement with the lower end of the tubular portion 42. This position of the valve, which I will call the inoperative position, is shown in dotted lines in Figure 3.

However, should the pressure in the supply line l2 fall for any reason, the valve assembly V will drop as soon as the supply line pressure is reduced to atmospheric. At that point the valve assembly V will move downwardly, guided by the coaction of the head of the bolt 24 with the inside of the tubular portion 42 and also by the coactionof the nut 30 with the port 20. The pipe I6 is then vented to atmosphere through the opening 50, the chamber I8 and the vent passage M. This venting function assures in the pipe I: will not be communicated to the pipe 16, and hence the danger that foreign macause the manner in which it seats is the same every time.

Various methods of guiding the valve V may be provided and come within the scope of my invention. In Figure 1 the nut 30 is substantially square with rounded corners as appears more plainly in Figure 2. The head of the bolt I 24 is of similar shape. However, I do not limit myself to square formation either in the nut 30 or the head of the bolt 24 but I may, for example, use a triangular shape as shown in Figures 5 and 6, in which I have designated the parts by the reference numerals 24a and 30a.

The triangular shape permits somewhat greater room for passage of fluid between the "flats" of the nut 30A and the walls of the port 20. This will be apparent by comparison of that any condition of vacuum which might occur terials or dirty water might be drawninto the system by reverse fiow from the outlet of the fixture which may be connected to pipe I6 is eliminated.

It will be observed also that the engagement of the washer 28 with the annular seat portion 22 forms a check valve arrangement which substantially prevents the entry of air into the pipe I! when a vacuum exists therein.

In'the abnormal situation where the supply pressure fails and a vacuum occurs in the supply line (as for example when a fixture is opened on a lower fioor), my vacuum breaker accomplishes in a'very eilicient manner two desirable functions, to-wit:

a. It vents the fixture line It to atmosphere as soon as the supply line pressure drops to at-- mospheric;

b. It serves as a check valve entry of air into the portions of the supply sys- "tem ahead of the 'vacuum breaker.

The first function is desirable as pointed out above to prevent contamination of the supply preventing the faucet may be below the water level and my device prevents back siphonage in case of failure of the supply pressure.

With regard to the function I),

the system (except for the vented portion between the-vacuum breaker and the fixture, repreit is desirable so far as possible to prevent entry of air into sented by the pipe it) because when pressure is re-established and the faucet or other fixture is opened the imprisoned air usually issuesfrom the fixture in almost explosive bursts which may be' injurious to fixtures and piping and is cerstant and dependable operation of the valve be- Figures 2 and 6, taking into consideration that the figures are not to the same scale. Any other forms, such as hexagonal, may be employed, if desired.

In Figure 1 the valve assembly V is shown in what will be called the operative position, which is the position taken when the pressure in the pipe I2 is equal to or less than the atmospheric pressure outside. the device. when the pressure is restored in pipe i2, it will exert a force against the underside of the nut 30 tending to move the valve assembly V upwardly, It will be seen, however, that as soon as the valve assembly is lifted, water will flow into chamber l8, building up .somepressure there, and the resulting flow will .have the effect of reducing the net lifting force Furthermore, for installations where the de guide member 58. The composition washer 26 is retained'against the disk-like portion 54 of the unit 52 by a nut 62 threaded on to the stud 56.

The tubular member 58 is provided with longitudinally extending slots '60. These slots are shown as open at the lower end of the member 5. but, if desired, the tubing may be circumferentially complete at the lower ends, thus closing the ends of the slots and giving greater strength.

As will be seen in Figure 4, I have provided four of the slots, spaced equi-distant. It is obvious, however, that any suitable number may be used. 1

' The tubular guide SI has an external diameter slightly less than the internal diameter of the port 2| and hence serves to guide the unit 52 and the parts associated with it in their vertical movement when the valve functions.

An important detail or the tubular guide portion 58 is the tapered shape of the upper ends of the slots 60, as indicated at 64 in Figure 3. After the valve assembly V' has been in operative position (full lines Figure 3) and the pressure in pipe I2 is subsequently restored, the assembly V will move upward, but since only the apex of the tapered portions 84 will at first project above the top or the port 20. the water flow in the chamber I8 will be held to a small amount until the valve has traversed a substantial part of its movement on the way to its inoperative position (dotted lines Figure 3). In other words, the cycle of movement 01 the valve assembly is well under way before there is enough build-up of pressure in the chamber It to efiect any substantial reduction of the net lifting force on the valve. Positive, trouble-free operation is the result.

Some changes may be made in the construction and arrangement of the parts of my device without departing from the real spirit and purpose 0! my invention, and it is my intention to cover by my claims any modified forms 01' structure or use or mechanical equivalents which may be reasonably included within their scope without sacrificing any of the advantages thereof.

I claim as my invention:

1. In a vacuum breaker, a casing, an inlet passage to said casing, a plurality of outlet passages from said casing, and a valve assembly comprising a headed bolt, a metal washer, a composition washer, and a nut retaining said washers on said bolt, the head of said bolt engaging the wall of one of said outlet passages and being guided thereby and said nut engaging the wall of said inlet and being guided thereby.

2. In a vacuum breaker, a casing, a chamber therein, an inlet passage to said chamber for connection with a pressure supply line, a plug closing one end of said chamber, a tubular extension of said plug projecting into said chamber, a passage through said plug from the outside thereof to the inside of said tubular extension, and a valve assembly comprising a headed belt, a metal washer, a composition washer, and a nut retaining said washers on said bolt, the head of said bolt engaging the inside wall of said tubular extension and being guided thereby and said nut engaging the wall of said inlet and being guided thereby.

BURCHARD E. HORNE.

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