US472233A - Valve for safety-plugs for steam-boilers - Google Patents

Description

(No Model.)

L. SLENO. I VALVE FOR SAFETY PLUGS FORfiTEAM BOILERS Patented Apr. 5, 1892.

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LEONARD SLENO, OF WEST BAY CITY, ASSIGNOR OF TWVO-TI-IIRDS TO JOHN H. DAVIS AND WILLIAM BURNETT, OF BAY CITY, AND ALFRED FOR- REST, OF NEST BAY CITY, MICHIGAN.

VALVE FOR SAFETY-PLUGS FO'R STEAM-BOILERS.

SPECIFICATION forming part of Letters Patent No. 472,233, dated April 5, 1892.

Application filed September 25, 1891. Serial No. 406,831. (No model.)

To all whom; it may concern.-

Be it known that I, LEONARD SLENO, a citizen of the United States, residing at West Bay City, in the county of Bay and State of Michigan, have invented certain new and useful Improvements in Valves for Safety-Plugs for Steam-Boilers; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable those skilled in IO the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to improvements in valves for fusible plugs, pertains to that class of valves or devices which are adapted for closing the opening in a steam-boiler caused by the fusion of a metallic plugof metal which melts at a low heat. It is well known that it is common to insert in the crown sheet of a boiler a plug of metal fusible at a slightlyhigher temperature than the temperature of the water in a boiler, so that should the water 2 5 in the boiler become reduced in quantity, so as to leave the crown-sheet wholly or partially bare, the plug will fuse and leave the opening occupied thereby free for the exit of steam, which, rushing out, extinguishes the fire.

The object of this invention is to provide a means for closing the opening thus formed temporarily, so as to permit the water in the boiler to be replenished, and thereby prevent the entire loss of the water and a possible loss 3 5 of time inrefilling the boiler and raising the temperature of cold water to provide steampressure.

Another object of the invention is to provide devices whereby theopening in the crown- 4o sheet of a boiler formed by fusing the metal plug therein can be closed temporarily, but which cannot be operated or tampered with without the knowledge and information of the engineer or inspector of the boiler.

My invention consists in a steam-boiler provided in its crown-sheet with a plug of fusible metal and a valve for covering the inner portion thereof, a rod provided with means on its inner end within the boiler for operating the valve and with an adjustable joint and having its outer end portion passed through the boiler-head and provided with means for operating the rod and devices forlocking the operating-rod in position against turning.

My improvement is illustrated in the accom- 5 5 panying drawings, in which similar letters of reference are used to indicate like parts throughout the several views.

Figure 1 is a longitudinal vertical section of a portion of a steam-boiler having my improvement attached thereto. Fig. 2 is a view of the rear end of the same, partly sectional. Fig. 3 is a plan view of the same, partly in section. I

a represents the shell of a steam-boiler, and b is a smoke-flue, while 0 is the crown-sheet, arranged in the ordinary way, and through the crown-sheet is passed a screw-threaded bushing cl, with its inner end portion e projecting above the sheet, and this bushing is provided with a longitudinal central opening f, which isclosed bya plug g of a metal fusible at a low temperature.

Upon the inner end portion e of the bushing is attached a valve-casing h, provided with a 5 valve-seat "L, and j is a valve fitted upon the seat '5, and is preferably arranged to slide to and fro upon the seat for closing the opening f against exposure to the water in the boiler or for opening or uncovering the same when the plug is in position.

The valve-casing is provided with a threaded opening Z, and m is a section of threaded valverod passed through the opening Z, and is ar ranged with its inner end attached to the valve j in such a manner that the rod may turn,and the outer portion of the rod-section m is attached to the inner end of a rod-section n by a universal joint 0, the section at being passed through the head 19 of the boiler, an opening (1 being arranged in the head, and the outer end of the section n is provided with a handle z for turning the rod.

1 is a packing-box having a central opening for the rod 02, and is provided with a screwthreaded inner end which is passed into the threaded opening q, and the lateral sides of the box are provided with a flange s,over1apping the head around the opening q, and from this flange project the cheek-pieces t, between I00 7 which is placed and pivotally secured by a pin 0', passed through the cheek-pieces and lever, the inner end of a lever 16, while the op posite or outer end of the lever is bent at a right angle toward the stem 91, and this bent portion is provided with a central longitudinal slot 1;, with arms to on each side of the slot, which when the lever to is oscillated toward the stem passes on opposite sides of the stem, and the stem may be provided with a flattened surface p on each side to receive the arms to, which prevent the stem from turnin g, or the arms in contact with the inner side of the handle will attain the same result, and the outer ends of these arms are provided with transverse openings, through which and across the open ends of the slot 17 is passed the staple a of a padlock b, which retains the arms in position and prevents the valvestem from being turned without first unlocking the lock and removing the staple. The pin 0' is provided on one end with a suitable l1ead,and on the opposite end, which projects beyond the cheek-piece, is provided with an opening c, through which is passed a staple f of a padlock g, which prevents the removal of the pin without the knowledge of the person retaining possession of the key thereof.

In operation the valve is withdrawn, so as to leave the metal plug exposed to contact with the water in the boiler, and the plug then remains in a solid state so long as the water is of suificient quantity in the boiler to cover the plug; but should the surface of the water become lowered so as to expose the plug to the steam, then the action of the fire below the crown-sheet raises the temperature of the plug to a meltingpoint, and the metal thus softened by the action of the steam-pressure within is blown out, and then the steam and water at once rush through the opening thus formed and operate to extinguish the fire, and the fireman or engineer 011 hearing the sound of the rushing steam at once unlocks the arms to and oscillates the lever back from engagement with the stem at, which he then turns and moves the valve inwardly over the opening, closing it against the exit of steam, and the fire having by this time become deadened by the steam the water in the boiler can be replenished with safety and dispatch, only a small amount being needed, and then a few minutes heavy firing brings the steam to its original pressure without great loss of time, and the vessel can then be run into port and the plug replaced; and this is a great advantage, as with the ordinary appliances the plug once blown out permits all of the water to leave the boiler before the plug can be renewed, and in most cases the boiler must be cooled for permitting a workman to enter the smoke-box to replace the plug, which requires a long time, and should the plug blow out when the vessel is at sea in stormy weather the vessel is liable to be driven ashore or into a collision before the plug can be replaced, while with my improvement the water is nearly all retained in the boiler with all of its heat, and it requires buta few minutes work to place the boiler in full working trim.

In order to prevent the device from being operated without the cognizance of the party in charge of the boiler, the locking devices are applied, as shown, and then the device must either be unlocked or broken to allow the valve to be closed over the opening, and any tampering with the valve would of course reveal itself to the inspector, so that the cause could be ascertained and the proper remedy appplied, and this is very important, as by closing the valve for a few minutes will cause the plug to fuse, and then the opening must be kept closed by the valve until the vessel is brought into port or parts are allowed to cool to replace the plug; but by use of the locking devices the arrangement is such that the valve will not be liable to be moved unless by some person having a key and a proper reason for manipulating the valve.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is

The combination, with the steam-boiler, a bushing passed through the crown-sheet and provided with a central opening closed by a plug of fusible metal, a valve-casing secured to the inner end of the said bushing and carrying a valve, as described, and a stem passed through the back head of the boiler and provided on its outer end with a handle for operating the valve, of a packing-box surrounding the rod and secured to the boiler and provided on one side with projecting earpieces, a lever pivoted between the ear-pieces and with its outer end turned toward the valve-stem and provided with arms reaching over opposite sides of the stem, and a padlock having its staple passed through transverse openings in the outer ends of the said arms, for the purpose set forth,'substantially as described.

In testimony whereof I aflix my signature in presence of two witnesses.

LEONARD SLENO.

\Vitnesses:

GEO. P. THOMAS, J AS. E. THOMAS.

IIO

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