US1238779A - Blow-off valve. - Google Patents

Description

A. H. JOHNSON.

BLOW-OFF VALVE.

. APPUCATION FILED MAYS. 1915.

Fly. L 2'.

Q Hozne 1 Patented Sept. 4, 1917.

ALBERT H. JOHNSON, 0F GLEN 'S FALLS, NEW YORK.

BLOW-OFF VALVE.

To. all whom it may concern:

Be it known that I, ALLBERT H. JOHNSON, a citizen of the United States, residing at Glens Falls, in the county of Warren and State of New York, have invented certain new and useful Improvements in Blow-Off Valves, of which the following is a specification.

This invention relates to a safetyor blowoff valve adapted to be used in conjunction with a boiler or other container for fluids under pressure and contemplates as its principal object the provision of a valve which shall offer a predetermined resistance to the action of the pressure fluid and which will permit such fluid to escape after such resistance is overcome.

A more specific object, but of equal importance with the foregoing is to provide a hollovx valve stem which is anchored to the boiler or other container and which carries a slidable valve head or casing through which a pressure fluid from the container may escape to the outer atmosphere, and to employ in conjunction with such valve casing spring means offering a predetermined resistance to the escape of the pressure fluid.

The above and additional objects which will become apparent as this explanatory de scription proceeds, are accomplished by such means as are illustrated in the accompanying drawings, described in the following specification and then more particularly pointed out in the claim which is appended hereto and forms a part of this application.

With reference to the drawings, wherein there is illustrated the preferred embodiment of this invention as it is reduced to practice, and throughout the several views of which like characters of reference designate similar parts:

Figure 1 is a vertical sectional view taken through the valve of this invention, as anchored to a boiler and before the resistance of the spring has been overcome,

Fig. 2 is a similar view, showing the relation of the parts when assuming that position where the fluid of pressure may escape, and

Fig. 3 is a central horizontal section taken Specification 'of Letters Patent.

Patented Sept. d, 1917.

Application filed May 6, 1915. Serial No. 26,376.

of which carries the spacing disk 9 that forms a pistonand whichcontacts with the inner surface of the cylindrical valve casing 10 for maintaining the stem 8 in alinement therewith.

The casing 10 is provided with the integral closed top 11 and is adapted to have a bottom cap 12 threadingly received upon its lower extremity, such bottom being apertured to slidably receive the stem 8. Packing means 13 is interposed between this bottom cap and a retaining plate 14: which is also apertured to slidably accommodate the valve stem, being threadingly retained in position by the valve casing 10. Suitable apertures 15 are formed in the valve casing walls to establish communication therebetween and the external atmosphere, such apertures being of any desired size and number and being positioned at substantially the center of the valve. A. contractile coiled spring 16 surrounds the body of the stem 8 and has its ends respectively secured Within the cap 13 and anchored to the plate 6 as denoted by the numerals l7 and 18. This spring is calibrated to withstand a desired pressure and will, of course, vary with different installations of the valve of this in vention.

In operation, it will be seen that the spring 16 normally holds the casing top 11 in contact with the disk 9 so that no escape is permitted for the fluids of pressure. Should however the pressure in the boiler 5 rise beyond that pressure for which the spring 16 has been calibrated the upward force of the confined fluid against the casing top 11 will overcome the spring resistance and force the valve casing bodily upward until the apertures 15 are uncovered by passage of the disk 9. These apertures will offer an avenue of escape for the fluid and the latter will continue to pass from the boiler 5 outwardly through such apertures until the pressure, within. the boiler is so lowered as to permit the spring 16 to again draw the valve casing downwardly about the stem 8 into the position illustrated in Fig. 1. When employing the blow-01f valve of this invention as a damper regulator, a function for which it is also eminently fitted, the apertures 15 are dispensed with in balancing the pressure between the spring 16 and the steam within the valve casing.

It will be apparent that in the above is disclosed an embodiment of this invention capable of attaining the previously presented objects thereof, so that this invention may therefore be claimed as possessingthe advantages and desirability set forth in such objects.

What is claimed is:

In a blow-off valve, a hollow stem connected at one end to a container for fluids under pressure, a piston disk screwed on the other end of said stem, a cylindrical casing having a removable head sliding on said stem and having fluid-tight connection therewith, said casing having fluid-tight connection with said piston disk, outlet apertures being formed in the casing a predetermined distance below its upper closed end, and 21 Copies of this patent may be obtained for calibrated contractile spring surrounding said stern and connected at one end to said casing and at its'other end to the container and normally holding said casing downwardly with its piston disk, in contact with its closed upper end but yielding under pressure within the container to allow the fluid to escape through the hollow stem and apertures. y

In testimony whereof I afiix my'sig' ature in 'presenceof two witnesses.

ALBERT H. JOHNSON.

Witnesses I THos. E. HILL,

S; F. HIGLEY.

five cents eachflay addressingthe Commissioner of-Patents, Washingtomhfl. l .7

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