Method of plugging holes in plates

2,010,569

Aug. 6, 1935.

T. B. S1TZLER

METHOD OF PLUGGING HOLES IN PLATES Filed March 28, 1934

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'ATTORNEYS.

Patented Aug. 6, 1935

2,010,569

UNITED STATES PATENT OFFICE

2,010,569

METHOD OF PLUGGING HOLES IN PLATES

Thomas B. Sitzler, Florence, N. J., assignor, by mesne assignments, to Florence Pipe Foundry &amp; Machine Company, Florence, N. J., a corporation of New Jersey

Application March 28, 1934, Serial No. 717,869

Claims.

My invention relates generally to a method of plugging holes in plates, and has particular utility as applied to plugging the ends of passages in steam platens.

Heretofore various methods have been proposed for drilling and plugging holes in metal plates. For example, in lieu of the customary screw threaded plugs employed for closing the ends of the interior passages of steam platens, 10 it has been proposed to employ plugs of special shape which are driven with a forced fit to effect a tight seal between the end of the passage and the plug. Such methods have not proved altogether satisfactory, either because the opera15 tions involved are too elaborate and expensive, or because the plug does not effectively seal the passage against the internal fluid pressure.

Accordingly, the object of the present invention is to provide a method of plugging holes in 20 metal plates which involves only simple and inexpensive operations, and which results in effectively sealing the holes. More particularly, the method of this invention is characterized by the formation of a novel interlocking joint be25 tween the plug and the mouth of the passage to be plugged, which joint is capable of withstanding high internal pressure without danger of failure. It will be understood that the invention is adapted for many other uses than the plug30 ging of holes in steam platens, and that it possesses other more specific objects and advantages which will become apparent from the description hereinafter set forth of several examples of the practice thereof, having reference to the accom35 panying drawing. Of the drawing:

Fig. I represents a side elevation of a plug ready for insertion in a steam platen, a portion of the platen surrounding the hole to be plugged being shown in cross section.

Fig. Π represents the platen and plug in cross section, with the plug inserted in the hole and ready to be driven home.

Fig. m is a similar view showing the same parts with the plug driven home.

Fig. IV is a perspective view of the plug.

Fig. V is a view similar to Fig. HI, but illustrating a modified method in which a soft metal disc is interposed between the plug and the shoulder at the hole in the steam platen.

Fig. VI is a perspective view of the soft metal disc.

Fig. VH is a view similar to Fig. ΙΠ, but showing a modification of the above method in which a soft metal ferrule is interposed between the 55 plug and the wall of the hole in the steam platen, (Cl. 29—148) the figure also showing in dot-and-dash lines how the ferrule is applied to the plug before the plug is driven; and,

Fig. vm is a perspective view of the soft metal ferrule. 5

In Figs; I, Π and IH of the drawing, a portion of a steam platen is represented at I, with a hole or passage to be stopped shown at 2, and with the special form of plug shown at 3. The plug 3 has a cylindrical body portion 4 and a 10 centrally depending projection 5 concentric with the body portion. The projection 5 gradually increases in diameter from its upper end towards its lower end, and preferably terminates in a cylindrical base 6 of a diameter such that 15 it will fit snugly within the hole 2 of the steam platen i. Thus the projection 5 assumes a substantially conical shape with its tapered wall . sloping upwardly and inwardly toward the body portion. 20

In carrying Out the practice of my invention, the steam platen I is formed with an enlarged hole or counterbore 7, concentric with the steam passage 2 at the mouth thereof, and extending to a depth substantially equal to the thickness 25 of the body of the plug 3. When the steam platen I is thus counterbored at the passage 2, there is incidentally formed a sharply pointed shoulder 8 at the base of the counterbore, the top surface of the shoulder being inclined upwardly 30 and inwardly.

In Fig. I the parts are shown in readiness for assembly. In Fig. H the plug 3 is shown seated in its initial position within the steam passage 2. It will be noted that the body portion 4 fits snugly 35 within the counterbore 7, and that the depending conical projection 5 fits snugly within the passage 2, with the cylindrically formed base 6 of the projection serving to center the plug. Moreover, it will be observed that the cavity or void defined 40 at the base of the counterbore between the flat undersurface 9 of the body portion 4 of the plug 3 and the sloping surface of the sharply pointed shoulder 8 is substantially equal in volume to the cavity or void defined between the vertical wall 45 of the passage 2 and the tapered wall of the conical plug projection 5.

After the parts have been thus assembled, the plug 3 is driven home within the steam platen I. The driving of the plug 3 . against the sharply 50 pointed shoulder 8 forces the metal of the shoulder into intimate locking engagement with the conical plug projection 5, so that when the top surface of the plug is flush with the edge of the steam platen I, the shoulder 8 is distorted to the 55

2,010,569 fitting the counterbore and having a depending conical projection with its enlarged bottom end fitting said hole, and driving the body of the plug against said, sharply pointed shoulder thereby forcing the point of said shoulder into locking en- 5 gagement with the conical projection aforesaid.

2. A method of plugging a hole in a metal plate of the character described which consists in forming a counterbore in the plate concentric with the hole therein, with incidental formation of a 10 shoulder with an acute angled point at the base of the counterbore, inserting in said hole and counterbore a plug having a flat-bottomed discshaped body of a diameter fitting the counterbore, and having a concentric projection of conical 15 formation depending therefrom with its enlarged bottom end fitting said hole, and driving the body of the plug against said acute angled shoulder, thereby forcing the shoulder into locking engagement with.the conical projection aforesaid. ²⁰

3. A method of plugging a hole in a metal plate of the character described which consists in counterboring the plate at the hole with incidental formation of a shoulder at the base of the counterbore, providing a plug having a body por- ²⁵tion substantially fitting the counterbore and having a depending projection of gradually increasing diameter towards its lower end and terminating in a cylindrical base of a diameter substantially equal to that of the hole, inserting the 30 plug within said hole and counterbore with the cylindrical base of its depending projection, guiding the body of the plug into seating engagement with said shoulder, apd driving the body of the plug against said shoulder to displace the same 35 and force it into locking engagement with the projection aforesaid.

4. A method of plugging a hole in a metal plate of the character described which consists in counterboring the plate at the hole with incidental 40 formation of a shoulder at the base of the counterbore, applying to said hole and counterbore a plug having a body portion substantially fitting the counterbore and having a depending conical projection with an enlarged end fitting said hole, 45 with interposition of a soft metal ferrule between said projection and the wall of said hole, and driving the body of the plug against said shoulder to displace the metal thereof, thereby compressing the ferrule and forcing the same into engagement 50 with the conical projection.

5. A method of plugging a hole in a metal plate of the character described which consists in counterboring the plate at the hole with incidental formation of a sharply pointed shoulder at the 55 base of the counterbore, inserting in said hole and counterbore a plug having a body portion fitting the counterbore and having a centrally depending conical projection with its enlarged bottom end fitting said hole, said shoulder and plug being so 60 designed that when the plug is thus seated in its initial position an annular cavity is defined at each side of said sharply pointed shoulder, and said cavities are of substantially equal volume, and driving the body of the plug against said 65 shoulder, thereby forcing the point of said shoulder into locking engagement with the conical projection aforesaid.

THOMAS B. STTZLER. 70 shape represented in Fig. TH. When thus driven home, the plug 3 is not only secured against dislodgment, but also the mouth of the steam passage 2 is effectively sealed. By properly design5 ing the sharply pointed shoulder 8 at the base of the counterbore, the shoulder 8, incident to the driving of the plug 3, may be caused to assume a shape substantially complementary to that of the plug, as represented in Fig. ΠΙ.

While good results may be obtained with the method described above, there is represented in Figs. V and VI, an alternative method which furnishes a very effective fluid tight seal at the plug. According to this method the counterbore

IS 7α in the steam platen fa is made to a greater depth than the previously described counterbore 7, and a soft metal ring 10 is interposed between the shoulder 8α of the steam platen la and the flat surface 9 of the plug 3. Accordingly, when ²⁰ the plug 3 is driven home, the metal of the ring 10, as well as the metal of the shoulder 8α, is forced into intimate engagement with the conical projection 5 of the plug. The soft metal ring 10 assures the formation of a fluid tight seal ²⁵ in the vicinity of the shoulder 8α.

A further example of the practice of my invention is represented in Figs. VII and VIII. According to the method there illustrated, a soft metal ferrule 11 is inserted around the conical projec30 tion 5 of the plug 3 before the plug is applied to the steam platen lb. Either the ferrule II may be made to fit closely over the conical projection 5, as illustrated by the representation of the plug and ferrule in broken lines, or obviously the 35 ferrule 11 may be split and sprung over the conical projection 5 of the plug 3. When the plug . 3 is driven home, the shoulder 8b at the base of the counterbore 7b is distorted with the metal thereof displaced, which in turn compresses the 40 soft metal ferrule 11 and forces the same into intimate engagement with the conical projection 5 of the plug 3. This method likewise insures the formation of a fluid tight seal in the vicinity of the shoulder 8b.

According to the several methods outlined above, it will be noted that in each example the parts are so designed that with the insertion of the plug, an annular void is defined at each side of the shoulder at the base of the counterbore, 50 the two voids being of triangular cross section and substantially equal in volume. Accordingly, when the plug is forced home, the metal of the shoulder is free to assume the new shape desired for it.

While I have described several examples of the 55 practice of my invention, showing certain specific shapes for the plug and the mouth of the passage in the plate, it will be apparent that various changes may be made in the shape of the parts without departing from the spirit of 60 my invention, and it will also be apparent that the method herein described has utility in many other fields than for the plugging of holes in steam platens.