US1614754A - Boiler plug - Google Patents

Description

Jan. 18, 1927. 1.614.154

F. K. MURPHY ET AL BOILER PLUG Filed May 5, 1924 A L/ I;

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Patented Jan. 18, 1927.

. UNITED STATES PATENT OFFICE.

FRED K. MURPHY, DANIEL J. MULLEN, AND RAYMOND W. RETTEREB, OF. INDIANAPOLIS, INDIANA.

BOILER PLUG.

Application filed May 3, 1924. Serial No. 710,856.

This invention pertains to a clean-out for boilers and the like.

Whereas the usual clean-out plug used on boilers is adapted to screw tightly therein, the threads become corroded and rusted making it difficult to unscrew the plug, or replace it. Furthermore the screw threads in the boiler become worn and broken so that eventually it is necessary to retap the boiler and use a larger plug.

It is the object of this invention to provide a plug having a removable core so that the plug can remain screwed into the boiler permanently, access to the interior of 5 the boiler being had through an opening in the plug which is closed by a core held in place by suitable screw thread segments with plug respect to the plug, said screw threads being protected from corrosion by the water by a ground ball joint and beveled seat.

Other features of the invention with respect to the locking and wedging construction as well as a means for preventing the movement of the core from the closed position will be herein after more fully set forth and described. I

The value of this invention resides in the fact that it eliminates the danger of a plug blowing out causing damage and often per- 140 sonal injury. This has been occasioned heretofore, where in screwing the plug in place after having been removed, the threads are crossed, causing some threads to be stripped so as to weaken them and permit the high pressure of the boiler to cause the blowout with the consequent danger and damage. This invention eliminates that danger by reason of the fact that the screw threaded plug remains permanently in the boiler, access being had only through the removable core.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims.

Fig. 1 is a plan view of theplug with the core in unlocked position. Fig.2 is the same as Fig. 1, showing the plug with the core in locked position thereon and provided with a retaining key. 'Fig. 3 is a section taken on the line 33 of Fig. 2. Fig. 4 is aside elevation of the closing core. Fig. 5 is a central vertical section through the plug taken on the line 55 of Fig. 1 with the core removed.

In the drawing there is shown a plug for a boiler or the like having a threaded portion 10 adapted to screw into a tapped opening in the boiler, said threaded portion being surmounted with an annular outwardly extending head 11. The plug is in the form of a shell having a relatively large opening 12 which is adapted to be closed by the core 13. Adjacent said opening and contained within the head 11 there is provided a beveled seat 14 adapted to receive a correspondingly ball portion 15 on the cap so as to permit a ground fit to be had therebetween.

The head of the plug is provided with oppositely disposed and inwardly extending thread segments 16, each of which extends a quarter of the distance about the innerperipheryof the head. Said thread seg ments are tapered as best shown in Fig. 5, to give a substantial pitch. As shown herein, they are formed with a half inch pitch.

The core is provided with corresponding outwardly extending thread segments 17 formed about the periphery thereof and diametrically opposed to each other. Said thread segments 17 likewise extend a quarter distance about the periphery, and lie adjacent the bevel sealing portion 14, the same having anopposite and corresponding pitch as shown in Fig. 4. This arrangement is such that the core may be inserted in the head of the plug so as to be seated upon the beveled portion 14 thereof, the thread segments 17 dropping intoposition between the ends of the thread segments 16 on the plug. Therefore, upon turning the core within the plug head the segments 17 and 16 will interlock as shown in Figs. 1 and 2, and by reason of their respective pitches will screw together so that the tighter the cap is turned 95 the more firmly they will be screwed into position, causing the ground bevel portion 14. and ball 15 to be more firmly and securely sealed to withstand leakage and pressure.

The core is further provided with a head 18 having a centrally disposed hexagonal recess 19 for receiving a suitable wrench. It will be obvious therefore that on applying the wrench thereto and turning the core a quarter turn in one direction it will be interlocked in the plug so as to close the opening' therein, and the greater the pressure exerted in turning the core the more firmly it will become seated for withstanding leakage.

On the other hand by turning the core a quarter turn in the opposite direction it will become freed and can be readily removed from the plug so that access may be had to the interior of the boiler.

A suitable means may be employed" for limiting the turning movement of the core in closing position, which is herein shown as comprising the. pin which extends through the ends of the segments 16 away from the receiving. ends thereof so that it will be impossible to turn'the core beyond the locking engagement of screw threads. l'lowever the thread segments are so'formed' as to cause them to screw together when the cap is nartially turned to locking engagement so that there will be sufficient latitude permitted'for further turning it to compensate for wear. f

For retaining the .core in locked position, or rather for preventing it. from being turned so as to be released from the plug, there is provided a tapered locking key pin 21 having a head 22 adapted to be inserted through a taperedtangential opening 23 in the head 11. After the core is turned into locking engagementwith the head the pin maybe freely passed through said opening and locked therein by the end piece 24, which falls into locking position by gravity because of its elf center pivoted connection 25.

- iVith respect'to the locking pin, it will be observed that it is so positioned with respect .to the core as to permit the core to be tightened but prevent its becoming loosened.

The invention claimed is: V 1. A plug for boilers or the like having an opening therethrough, a bevel seat adjacent said opening, a core having a ball portion adapted to rest on sald seatand havmga ground -,tit v therewith, inwardly formed -,grooves having their open ends spaced apart "within said plugexternally of said opening and increasing in thickness from one end to the other so as to have a suitable pitch, and corresponding oppositely disposed thread segments formed onsaid core externally of.

said ball portion and tapering in thickness from one end to the other so as to havc a corresponding pitch, said segments being so arranged that said core maybe inserted {in said plug for closing said 1 opening and turned therein so thatthe segments will engage'and wedge 1n saidgrooves into locking position.

- 2. A plug construction, comprising a tubul'ar. body having one end suitably formed -for boiler mounting .and a central opening.

therethrough, a laterally directed flange opposite the mountable end of the body and including a circular valve seat at the junction thereof, a plurality of inwardly and radially extending overhanging portions integral with thefiange and circularlyconnectedi together for forming :protected and enclosed segmental thread grooves with theflange face, each of said overhanging portions having an inclined face and arranged in spaced relation with each other, and a cap having acircular valve forming portionat the bottom thereof, a tool engageable portion at the top thereof, and a plurality of outwardly and radially extending thread forming segments in spaced relation with each other and intermediate the top and bottom, each thread forming segment having an outer inclined face for wedging engagement with the inclined face of the groove, said overhanging portions being spaced apart sufficient to permit longitudinal axial seating of the thread forming segments and valve seating prior to rotational locking. i

3. A ,device of the character defined by claim 2, characterized by the sealing cap being so arranged that no portion of it projects laterally or longitudinally beyond the plug body when seated.

defined by claim 2, characterizedby the valve and valve seat being complementarily formed, one. being a bevelled surface and the other a ball surface.

5. A plug for boilers or the like having an opening therethrough, abevel seat externally ofand adjacent said opening, a core having a ball portion adapted to restin said seat and having. a ground fit therewith, inwardly formed groovcsin said plug externally of said 1 opening I width from one end to the other so as to have a suitable pitch, corresponding and oppositely disposed thread segments formed vonsaid. core tapering in thickness from one end to the other so as to have a correspondingpitch, said segments being so arranged that saidcore may be insertedin said plugfor closing said opening and turned thereinso as to engage within said grooves and wedge into locking posi tion, a key men'iberadaptedto be engaged in said plug upon said core being locked in position therein so .as to prevent it being turned to unlocking position, and a lug pivotally mounted off centeron one end of Said member soas toibe capable of dropping cluding a substantially tangentially arranged recess communicating with the locking groove, and the addition of a key receivable'by said groove and tangentiallyengaging said cap for preventing the unthread- .ingmovementofthesame.

8. A plug construction, comprising-atria bular body having an exter orally threaded portion at one end, a lateral enlargement at the opposite end including a circular valve seat concentric with the tubular body at the junction therewith, and a plurality of overhanging inwardly and radially extending spaced portions circularly connected together, each of said portions forming with the face of the lateral enlargement a plurality of arcuate and protected grooves, each of said arcuate grooves having pairs of walls relatively inclined to each other, and a cap having its top formed for tubular engagement and its bottom provided with a circular valve for seating engagement with the valve seat, said valve and valve seat being cooperatively formed to rovide a fluid and pressure tight joint, an a similar number of similarly spaced radially extending thread forming sections on the cap each having a pair of relatively inclined faces whereby partial relative rotation between the cap and body wedgingly secures the cap and body together in fluid and pressure tight relation. In witness whereof, we have hereunto affixed our signatures. Y

FRED K. MURPHY.

DANIEL J. MULLEN.

RAYMOND W. RETTERER.

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