US666109A - Safety-valve. - Google Patents

Description

No. 666,l09. Patentedlan, I5, l90l.

, J. E. OSMER.

SAFETY VALVE.

(Application filed July 20, 1900.) (No Model.) 2 Sheets-Sheet :l.

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5 HEP-Z I UNITED STATES PATENT OFFICE.

JOHN EDGAR OSMER, OF GIIINTON, IOWA.

SAFETY-VALVE.

SPECIFICATION forming part of Letters Patent N 0. 666,109, dated January 15, 1901.

Application filed July 20, 1900. Serial N0.24,311. (N0 model-J To 00% whom it may concern Be it known that I, JOHN EDGAR Osman, a citizen of the United States, residing at Clinton, in the county of Clinton and State of Iowa, have invented certain new and useful Improvements in Safety-Valves; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in safety-valves for use on steam-boilers, and has for its object to provide a safety pop-valve which is simple of construction, balanced in an effective manner to secure the requisite degree of sensitiveness Without chattering, and adapted to relieve the excess pressure on the boiler quickly and promptly and without the loud and prolonged noise produced by safety-valves of ordinary construction.

With this and other minor objects inview the invention consists of certain novel features of construction, combination, and arrangement of parts, as will be hereinafter more fully described, and particularly pointed out in the appended claims.

In the drawings hereto annexed and forming a part of this specification, Figure 1 is a side elevational view of a safety-valve constructed in accordance with my invention. Fig. 2 is a top plan view of the same. Fig. 3 is a vertical longitudinal section showing the parts of the valve in their normal or closed positions. Fig. 4 is a similar view showing the valves open to equalize the pressure and exhaust the excess steam. Fig. 5 is a sectional view on line 5 5 of Fig. 3. Fig. 6 is a perspective view of the internal cylin der, duplex valves, and cooperating parts. Fig. 7 is a similar View of the pressure-spring and coacting parts.

Referring now more particularly to the drawings, in which like reference characters designate corresponding parts throughout the several views, the numeral 1 represents the cylindrical valve-casing, comprising a base or main section 2 and a dome or cap section 3, said base-section being formed or provided at its outer end with an internally-threadedextension 4 for connection with a steam-escape pipe leading from the boiler and at its inner end with an annular shoulder or enlargement 5, formed with a valve-seat 6 and external threads to receive the threaded inner or lower end of said dome-section 3,whereby the sections are coupled together. dome-section is provided with a hexagonal head 7 for application of a wrench or analogous tool thereto in applying and removing it, two annular series of escape-ports 8 and 9, one opening to the atmosphere through said head and the other through the top of the dome at the base of the head, and a central screw-threaded opening 10, in which works an adjusting-screw 11, held in fixed position by a lock-nut 12. This screw is provided with a rectangular outer head 13, to which a wrench may be applied for adjusting it, and a tapered or hemispherical inner end 14, designed for a purpose hereinafter set forth. The base-section 2 has arranged therein a guide-chamber 15, provided at its upper open end with a valve-seat 16. This guide-chamber, in conjunction with webs 17, which support it, divides the interior of the base-section into a lower steam-inlet chamber 18 and upper balancing-chamber 19, said chambers being in communication through ports or passages 20, formed by the spaces between said webs. The guide-chamber and webs are preferably cast integrally with the said base-section 2. The interior of the dome-section 3 forms an equalizing-chamber 21, into which the excess steam passes before exhausting to the atmosphere.

Mounted to slide vertically in the casing is a duplex valve device comprising an internal cylinder or hollow carrier 22, open at each end and fitted to slide at its upper end in an annular guide 23, projecting from the under side of the top of the dome. This cylinder or carrier has formed therewith or attached thereto two valves 2 & and 25 of different areas, the upper and larger valve 24 being designed to rest upon the seat 6 and the smaller and lower valve 25 upon the seat 16, and is provided above said upper valve 24 with a series of equalizing-ports 26, communicatipg with the said equalizing-chamber 21. A hollow extension or spider 27 hangs pendent from the under side of the lower valve 25 and is attached thereto by an annular Web or flange 28 of less thickness than the valve and extension 27 and forming an annular steaminlet space 29. With this space communicate a series of vertical regulating-ports 30, extending through the piston and opening into The the guide-chamber 15. The extension 27 is mounted to slidevertically within the guidechamber, and the latter is in communication through said extension 27 with the internal cylinder or valve-carrier 22. Instead of vemploying an extension of the construction shown I may employ a spider in which the ports 30 are formed by the spaces between the arms of the spider, as will be readily understood.

The valves 24 and are normally held closed against their seats tiand 16 by a coiled or a spiral pressure-spring 31, bearing at its lower end against a flanged washer 32, bearing upon a shoulder 33 at the base of the internal cylinder or carrier. 22 and at its upper end against a flanged cap 34, provided with ports 35 for the passage of steam from said cylinder to the escape-ports 8. This spring serves as a common tension device to hold the valves 24 and 25 seated and the extension 27 down to its lowermost position in the dashpot 15, in which position the ports 30 are out of communication with the balancing-chamber 19,wit-h which the dash-pot communicates when the valve 25 is open. The tapered or hemispherical endv 14 of the adjusting-screw 11 turns within a seatordepression 36, formed in the cap 34, and by turning this screw in one direction or the other the tension of the spring may be regulated to adapt the valves to open at any pressure desired.

The operation of'the valve is as follows: The normal position of the ports When the steam in the boiler and chamber 19 is at or below safety-pressure is shown in Fig. 2. \Vhen the pressure in the balancing-chamber 19 is sufficient to overcome the tension of the spring, the carrier 22, valves 24 and 25, and extension 27 rise, thereby bringing the charm ber 19 into communication with the equalizing-chamber 21 and guide-chamber 15, and the steam passes upward and out to the atmosphere through the ports 9 and also down through the ports 30 into the guide-chamber 15, thence upward through the internal cylinder or valve-carrier 22, and out to the atmosphere through the ports 35 and 8. Owing to the fact that the-valve 25 is of less area-- that is, has less surface exposed-than the the valve 25 with somewhat less force than upon the under side of valve 24. Hence the valves are prevented from opening with violence and from chattering and are balanced in a simple and effective manner. At the point of popping or blowing off if the volume of the steam is not of great force the valves will open to allow the excesssteam to pass out and then immediately seat, for the reason that-the regulating-ports 3O will'discharge the steam from the under side of valve 25 and prevent an upward pressure thereon; but if the pressure comes with great force or volume and the steam cannot pass downward through the ports 30 fast enough it will exert an upward pressure on the under-side of valve 25, which adds the area of said valve 25 to that of the valve 24, and in consequence the valves will rise to a greater extent and discharge a much greater volume of steam to the atmosphere. v The relative areas of the valves 24 25 are therefore of great importance in order to secure an effective sensitive balancing action and prevent extreme sensitiveness and chattering of thevalves and the discharge of too much steam. The ports may be so proportioned that the steamgage employed on the boiler will indicate the opening and closing of the valves at the same point of pressure.

The construction of the valve herein shown and described is deemed preferable; but it will of course be understood that modifications withinvthe scope of the inventionas defined by the appended claims may be made without departing from the spirit thereof.

Havingthus fully described my invention, what I claim as new and useful, and desire to secure by Letters Patent of the United States,

1. In a double-seated safety-valve for steamboilers, the combination of a valve-casingcomprising separable base and dome sections and having an inlet-port in its bottom, two sets of discharge-ports in its top, a lower-valve guide having a valve-seat, an upper-valve guide between the said sets of discharge'ports, and a valve-seat between said guides, together with a hollow valve device inclosed within said casing and having valve members cooperating with said seats and forming upper and lower chambers, inlet-ports opened and closed by the lower-valve member and establishing communication between the interior of the valve and said lower chamber, equalizingports establishing communication between the interior of the valve and said upper chamber, and a pressure-spring inclosed within the valve and adapted to hold said valve members to their seats, substantially as set forth.

2. In a double-seated safety-valvefor steamboilers, the combination of a casing having an inlet-port in its bottom, two sets of discharge-ports in its top, a lower-valve guide having a valve-seat, an upper-valve guide between the said sets of discharge-ports, and a valve-seat between said guides, and a hollow valve device having valve memberscooperating with said seats, an internal shoulder, relief-ports above the upper-valve member, a coiled pressure-spring on the interior of the valve device and bearing at its lower end on said shoulder, a perforated cap bearing upon the upper end of the spring, and an adjusting device acting on said cap, substantially as set .forth.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

- J NO. EDGAR OSMER.

Witnesses: S. S. PUTMAN, ALEXR. S. SPALDING.

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