US3414158A

US3414158A - Expansion plug and installation means and method

Info

Publication number: US3414158A
Application number: US571941A
Authority: US
Inventors: Paul J Hunckler; George M Keefer
Original assignee: Hunckler Products Inc
Current assignee: Hunckler Products Inc
Priority date: 1966-08-11
Filing date: 1966-08-11
Publication date: 1968-12-03
Anticipated expiration: 1985-12-03

Description

Dec. 3, 1968 P. .1. HUNCKLER ET AL EXPANSION PLUG AND INSTALLATION MEANS AND METHOD Filed Aug. 1l, 1966 DeC- 3, 1958 P. J. HUNCKLER ET AL EXPANSION PLUG AND NsTALLATIoN MEANS `AND METHOD Filed Aug. ll, 1966 2 Sheets-Sheet 2 INVENTOR 75 9m J /fuNcK/.ER ml GEORGE M /'e-Fs United States Patent G 3,414,158 EXPANSION PLUG AND INSTALLATION MEANS AND METHOD Paul J. Huuckler and AGeorge M. Keefe, Huntington, Ind., assignors to Hunckler Products, Inc., Huntington, Ind., a corporation of Indiana Continuation-in-part of application Ser. No. 558,759, June 20, 1966. This application Aug. 11, 1966, Ser. No. 571,941

22 Claims. (Cl. 220-24.5)

ABSTRACT F THE DISCLOSURE An aperture sealing plug, typically for engine blocks, and including a radially expandable axially extending flange, with a mechanically-operated dish shaped disc, or thermally operated expansive or explosive chemical component to effect the expansion in the aperture after placement therein by a finger-operated installation tool.

Background of the invention This invention relates generally to plugs employed in engine blocks and the like, and more particularly to an expansion plug and method for the closure of openings in such blocks. This application is a continuation-in-part of our copending application Ser. No. 558,759 filed June 20, 1966.

In the manufacture of castings for engine blocks and for other purposes, it is common practice to provide openings at a number of locations to facilitate removal of cores and core material used in the casting process. Typically these openings or holes are circular and many of them are employed in cylinder blocks for internal combustion engines.

Conventional practice is to seal such core holes or openings with steel plugs which are driven into the holes and expanded into place by hammering on them. It happens that after a period of use of the engine, one or more of such plugs become rusty and leaks develop, whereupon the coolant from Water passages leaks from the engine cooling system. This necessitates replacement of the leaking plugs.

In many instances, because of crowded conditions in engine compartments, the installation of a replacement plug is extremely diflicult and time consuming.

It is therefore a general object of the present invention to provide improved expansion plugs and methods of installation thereof.

A further object is to provide plugs adapted to installation by various techniques which are easily employed.

Described briefly a typical embodiment of the present invention employs a generally cup-shaped first member including a dished central disc portion and an axially extending flange integral therewith. The cup member receives and retains a second dished disc, the convex faces of the disc portions facing each other. Expander means are provided between the nearest points of the facing convex surfaces and are expanded after installation of the assembly in the opening to be sealed, to achieve radial expansion of the flange.

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

FIGURE l is a reduced scale sectional view through a liquid-containing block having an aperture therein with a plug sealing the aperture according to one embodiment of the invention.

FIGURE 2 is an enlarged fragmentary section through the block showing one embodiment of the invention before expansion.

Patented Dec. 3, 1968 rice FIGURE 3 is like FIGURE 2 showing the plug assembly expanded in the opening.

FIGURE 4 is a fragmentary section of another embodiment of the invention.

FIGURE 5 is an enlarged fragmentary section through the block showing still another embodiment of the invention with an installation tool locating the same according to the invention.

FIGURE 6 illustrates the embodiment of FIGURE 5 after installation is completed.

FIGURE 7 is a section through a still further embodiment employing an explosive cord.

FIGURE 8 is another embodiment of the invention i11- corporating a chemically reactable packed compound.

FIGURE 9 is another embodiment of the invention employing an electric initiator. f

FIGURE l0 is a view of the installation tool on a scale considerably reduced from that of FIGURE 5, and viewing the tool looking in, the direction of the arrow 81 in FIGURE 5.

FIGURE 11 is another view of the tool looking in the direction opposite the arrow 81 in FIGURE 5.

Referring now to the drawings in detail, an application of a typical embodiment of the present invention is illustrated in FIGURIE l with a block 11 shown sche-matically containing a liquid 12 and having an aperture 13 in the wall 14 thereof. lt is desirable to seal up the aperture or opening 13, in order to prevent escape of the liquid 12 from the block. The pressure on the liquid may be greater than, equal to, or less than atmospheric pressure, as desired,r as the present invention is useful in any event.

One embodiment of the plug of the present invention as illustrated in FIGURES 2 and 3 includes a generally cup-shaped member 16 having a concavo-convex circular disc 17 with an axially extending cylindrical flange 18 extending from the perimeter of the disc. The unit is .symmetrical with respect to the axis 19. A second concavo-convex circular disc 21 is received within the flange 18 and the outer marginal edge 22 thereof is fittingly received in the inner wall 23 ofthe flange, with the edge 24 of the flange inwardly turned to retain the disc 21 within the flange. So the convex faces 26 and 27 of the

discs

21 and 17, respectively, face each other.

Further according to certain embodiments of the present invention, it is desirable to apply a separating force in a direction parallel to the axis 19 and against these facing

surfaces

26 and 27 to expand the flange 18 radially outward and into tight fitting and sealing engagement with the cylindrical wall 28 of the opening 13. For this purpose, according to one embodiment of the invention, an explosive charge 29 is received in a capsule 31 centrally located in the cavity 32 defined by the discs and flange of the plug assembly. The capsule may be formed of a material having a greater wall thickness in its wall 33 than in its end walls 34, Iwall 33 being cylindrical, for example. Furthermore, the wall 34 has its outer face 36 preferably in contact with the face 26 of disc 21 throughout the entire area of the capsule face 36 to enable attainment of good thermal conductivity between the explosive chemical charge and the outer surface of disc 21 at 37. The capsule may be centrally located in the cavity 32 by a circular disc 38 of any `suitable material such as heavy paperboard or cardboard, which is both sufiicient to locate t-he capsule in the center and yet minimizes any heat transfer from the capsule to the flange 18 or vice versa, the perimeter 39 of the disc being located by the inner flange Wall 23 and the central aperture 41 of the locator disc 38 fitting the outer surface of the wall 33 of the capsule. Alternatively or supplementarily the capsule can be attached by `glue 42 or other means to the face 27 of the disc 17 and it may be found desirable to apply insulator means at 42 in the form of glue or anot'her insulating material to minimize heat transfer between the capsule and the disc 17. In any event, it is desirable in this embodiment of t-he invention to have good thermal conduct-ivity between the front face of the disc 21 at 37 and the chemical charge 29 and this can be accomplished by using metals, and soft brass .050 inch can be used for disc 21, if desired. This material can also be used for the member 16, if desired.

By employing the construction described, the unit can be installed in the opening 13 and the charge 29 can be exploded. by applying heat thereto. This may be done by placing a heated iron 43 against the disc 21 at a point thereon near the charge which explodes the charge and causes expansion of the capsule in an axial direction, the thicker wall 33 preventingr expansion in any direction other than the axial direction. Thus the ends of the capsule are forced away from each other by the explosive charge and push the central portions of the

discs

17 and 21 away from each other. This results in radial expansion of the marginal edge 22 of the disc 21 and radial expansion of the disc 17 at its perimeter 44. This causes the flange peri-meter to expand at 44 into sealing engagement with the aperture wall 28. Radial expansion of the disc 21 forces the flange to expand at 46 also around its perimeter to effect a sealing engagement with the aperture wall Z3 here as well. Thus, there are at least two complete circular seals provided in the opening to prevent leakage of any liquid from the block to the exterior thereof.

Thus it is seen from the description above, that in the illustrated example, a line drawn between points on the

discs

21 and 17 which are nearest each other would be a line on the axis of the assembly and the capsule is constructed to permit expansion of the explosive charge in the direction of the axis and prevent expansion in other directions.

The embodiment of the invention shown in FIGURE 4 includes a member 16 constructed much like the member of the previously described embodiment but in this example a reinforcing piece 47 may be added with a slight piloting depression 48 at the center thereof. A disc 49 similar to disc 21 is also provided but includes an internally threaded member 51 on the outer surface thereof which may be welded or brazed thereto. A central aperture 52 is provided in the disc 49 to permit passage of thescrew 53 therethrough, this screw being threadedly received in the member 51, and the screw may have an hexagonal head thereon, for example.

In the use of this embodiment of the invention, the assembly, including

members

49, 16 and 53, is installed as a unit in the opening 13 in the same manner as the other embodiment. It may be held in place and prevented from rotation by application of an end wrench or other tool to the surface of the member 51, which can be a hexagonal nut brazed to the disc 49. The screw S3 is then turned by applying another wrench thereto while the first wrench is held stationary, whereby the portion of the screw in the cavity 32 increases and the screw end bearing on the surface 48 increases the axial distance between the central portions of the discs while the axial distance between their perimeters remains constant. This causes the radial expansion thereof in the manner described above with reference to the other embodiment of the invention. Once suicient expansion has been accom4 plished to prevent turning of the member 16 in the opening 13, the wrench can be removed from the nut 51 and turning of the screw can continue with the other wrench applied to the head 54 thereof. Naturally, other forms of wrench receiving surfaces can be provided on the screw and on the threaded screw receiver, if desired. Although it is not essential in manufacture of the assembly and before installation in an opening, it may be preferable to provide sufficient gripping between the inwardly turned portion 24 of the flange 18 and the disc 49 to prevent CII member 16 from turning lin the opening during the initial expansion or turning of the screw 53. In any event, so long as the screw can be advanced in such manner as to effect spreading of the central portions of the discs while the portions thereof near the perimeter thereof remain at essentially the same axial spacing, proper sealing engagement in the opening can be accomplished.

From the foregoing description, it should be apparent that a variety of materials can be used in the capsule, so long as they can be activated at a desired level of temperature to cause the axial expansion and force application to one or both of the discs sufficient to obtain the radial expansion necessary to provide a proper seal and mechanical attachment of the assembly in the opening. It is also desirable that the materials used in the disc and flange be permanently and plastically deformed, as distinguished from elastic deformation, so that the axial force separating the centers thereof need not be maintained. This would permit the use of truly explosive types of mixtures as distinguished from a chemical composition which would expand substantially and remain permanently expanded upon application of heat above a predetermined level. Also, it should be clear that if the charge used in the capsule is of a type which is expandable rather than explosive, the rate of expansion with temperature change should greatly exceed the rate of expansion of the materials of the discs and flanges themselves and lcapsule wall 33 in order to assure that the flange 18, for example, would not expand axially at the same rate as the charge Within the capsule.

A variety of chemical charges could be employed, including the explosive type and the expansion type. The specific one selected might be one in which a chemical reaction can be initiated by application of an electric soldering iron to disc 21 at point 37, for example.

Although the dished form of each of the

discs

17, 21 and 49 is achieved by the concavo-convex configuration in the described embodiments, the dished form might be conical or it might be a combination of shapes, so long as by being dished it is capable of radial expansion by axial loading.

The dished construction may also be used conveniently in additional embodiments of the invention wherein the radial expansion of the dished portion is not essential to proper functioning of the apparatus. This is represented in FIGURES 5 through 9 wherein a chemically expandable material, which can include explosives, is applied in the sealing unit so that the force of the chemical reaction is applied directly outward against the axially extending ange. In the embodiment of FIGURE 5, for example, the plug assembly 56 includes the outer member having the cylindrical flange 57 extending axially from the concavo-convex center portion 58 with another concavo-convex disc 59 received within the flange and retained therein by the radially extending circular flange 61 at the rear end of the outer member. Sandwiched between the inner member 59 and portion 58 of the outer member are another concavo-convex disc 62 and a sheet 63 of explosive material. A material which may be used for the sheet 63 is flexible high explosive marketed under the trademark Detasheet by E. I. du Pont de Nemours & Company (Inc.) of Wilmington, Del. The composition of such material may be as disclosed in United States Patents Nos. 2,992,087 and 2,999,793. Once this assembly is placed in the opening in the manner which will be described hereinafter, the heated tip of an iron is to be applied to the disc 59 near the region of contact at 64 between the sheet and the disc to explode the sheet and cause a direct radial expansion of the flange 57 around its entire circumference. This will produce a tight press fit in the block opening 13 throughout the circumference of the opening and for an area generally extending between the lines 66 in FIGURE 6. In this embodiment there may be some axial separation and consequent radial expansion of the discs, also tending to expand the fiange.

However, the radial expansion of the axially extending flange as a result of the direct gas pressure applied thereto by explosion of the explosive material is emphasized in this embodiment.

Upon referring again to FIGURES 5 and 6, it will be observed that the length of the flange and the over-all length of the plug unit from the front to the rear is less than the thickness of the block wall at the opening 13 between the outer surface 68 thereof and the inner surface 69 thereof. This makes it comparatively easy to insert the unit without the hazard of pushing it entirely through the wall and into the interior at 71. However, to facilitate insertion and retention of the sealing unit properly in the opening until it is permanently secured therein according to the invention, a spring clip installation tool 72 of FIG- URES 5, l and ll is employed. This incorporates a single formed spring metal strip having two inwardly punched tabs 74 and a loop 76 therein. These tabs 74 proje-ct away from the tool faces 73 and the outer tips of the tabs point away from each other and away from the space between the ends of the loop. The ltabs are resiliently movable toward each other from their normal spacing by compression of the loop 76 between the thumb and lingers 77 and 78 of the hand of the workman. By so doing, the tips of the tabs can be inserted in the circular notch 79 formed by the inturned flange 61 of the outer member, and the disc 59. When the thumb and fingers are then released, the Spring load generated in the loop by its compression urges the tab tips securely into the notch and the spring clip installing tool becomes a locator so that inward movement of the assembly into the block in the direction of the arrow 81 is halted upon abutting engagement of the tool faces 73 with the block face 68. The installing tool can be left in this position until the sealing unit has been exploded in place. Then the tool can be removed easily by merely squeezing the loop and thus retracting the tabs 74 from the notch in the sealing unit. So the loop serves both as a spring and a handle.

Another embodiment of the invention is illustrated in FIGURE 7 wherein a construction like that in FIGURE is employed except that the explosive is in the form of a cord 82 wound in a circle around the converging portions of the

discs

59 and 62 and symmetrical with respect to the cylindrical axis of the cup.

In FIGURE 8, the chemically expandable material 83 is packed in the space between the

discs

59 and 62 and can be an explosive material or can be merely a chemically expandable material so that by application of heat thereto a chemical reaction will be caused toexpand the ange radially outward as indicated in FIGURE 6 and without reliance upon axial separation between the disc 59 and disc 62 or central portion 58 of the outer member. In this example, an aperture 84 is provided in the disc 59 and has a varnish seal at 86 therein to prevent admission of moisture or contaminants during storage. However, upon application of a torch 87 thereto the flame 88 can readily melt or burn out the varnish and initiate the chemical reaction in the compound 83.

Another embodiment of the invention is illustrated in FIGURE 9 wherein the outer cup shaped member is formed much like that of the other embodiments but a flat disc 89 is provided within the inwardly turned flange 61 and may be spaced from portion 58 by a washer 91 centered on the convex surface of the inner portion 58 of the outer member. A washer 92 of explosive material can be incorporated in the space 93 between the -disc portions 89 and 5S and can have a detonator cap 94 mounted therein and extending into the aperture provided in the disc 89. Two

terminals

96 and 97 are available for the electrical supply to detonate the cap and explode the charge to lock and seal the member in the block.

From the foregoing description, it will be recognized that various types and thicknesses of materials can be used and various types of chemical charges can be employed `to obtain the degree of expansion desired and the desired response to the type of initiator applied, whether it be by a heated iron or electrical supply or direct llame. Moreover, because of the convenient installation tool and the fact that the embodiments illustrated are of less overall length than the thickness of the wall at the opening where they are to be used, there is no danger of the unit being accidentally pushed into the block so far `that it falls out of sight Where it might become a problem to proper tlow of coolant in the case of an engine block, for example.

While the invention has been disclosed and described in some detail in the drawings and foregoing description, they are to be considered as illustrative and not restrictive in character, as other modifications may readily suggest themselves to persons skilled in this art and within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

1. A plug combination comprising:

a first member receivable in an opening to be sealed, said first member having an outer portion outwardly expandable to tightly engage the wall of the opening to be sealed and said first member having an inner portion;

a second member received within said outer portion;

and expander means disposed between inner portions of said members and operable, when actuated, to expand said outer portion.

2. The combination of claim 1 wherein said expander means includes a compound chemically responsive to application of heat to cause a rapid expansion.

3. The combination of claim 2 wherein the inner portion of one of said members has a region of high thermal conductivity, said compound being in good heat transfer relationship with said region to facilitate setting olf said explosive by application of heat externally to said region by a tool.

4. The combination of claim 2 wherein said outer portion of said rst member is an axially extending flange and said compound is arranged to apply direct radial explosive force to said flange.

5. The plug combination of claim 1 wherein:

said first member is a disc having a ange extending axially from the perimeter of the disc, a portion of said flange being the said outwardly expandable outer portion of said first member;

and said second member is a disc.

6. The combination of claim 1 wherein said outer portion of said rst member is an axiallyextending flange and said expander means includes a sheet explosive disposed within said flange.

7. The plug combination of claim 1 and further comprising:

a fluid containing block having an opening in a wall thereof, said rst member being received in said opening, with the outer perimeter of said outwardly expandable outer portion being disposed in contact with the perimeter of said opening, said perimeter being in plug retaining and sealing engagement in response to actuation of said expander means whereby said plug is permanently secured in said opening and is sealed to said opening around the perimeter of said rst member to prevent passage of liuid from within said block through said opening to the exterior of said block.

8. The combination of claim 7 wherein said outer portion is an axially extending circular flange the length of extension of said ange being less than the thickness of said block wall at said opening.

9. Aperture sealing means comprising:

a iirst generally cup shaped member having a closed end insertable into an aperture and having perimetral flange means extending axially from said end;

expansion means behind said end and within said flange and operable upon expansion thereof to move said ange radially outward throughout its perimeter into sealing engagement with the aperture wall;

said expansion means being responsive to application of heat thereto to effect an expansion at a rate much greater than the rate of thermal expansion of the material of said iirst member;

and a second member mounted to said iirst member and confining the said expansion means within said flange. 10. An expansion plug installing tool comprising: seating means adapted to rest on an outer surface of a wall of a block having an aperture through the wall;

rst and second tabs mounted on said seating means, said tabs projecting generally away from each other and projecting in the same direction with respect to said seating means;

resilient means establishing a normal unloaded spacing between said tabs:

and handle means mounted to said seating means to facilitate positioning a plug in an aperture while the plug is supported on said tabs.

1.1. The expansion plug installing tool of claim 10 wherein:

said seating means are rst and second spaced portions having faces adapted to abuttingly rest on said outer wall surface in co-planar relationship thereto and to each other;

said tabs project to one side of the plane of said faces;

said tabs are disposed inwardly of the abutting portion of said faces;

said resilient means comprise a spring loop projecting to the side of said plane opposite that to which said tabs project, said spring loop also serving as said handle means and facilitating manipulation of the plug in the aperture.

12. The method of closing and sealing an opening in a wall of a uid container, said method comprising the steps of:

placing iirst and second members as a unit in said opening;

applying an internally expanding force between said members and thereby expanding at least one of them into locking and sealing engagement with the wall portion of the container dening said opening.

13. The method of closing and sealing an opening in a Wall of a fluid container, said method comprising the steps of:

setting a spring clip into a sealing unit:

placing said sealing unit in said opening;

properly positioning said unit in said opening by moving said spring clip;

producing a chemical reaction in said sealing unit and thereby expanding said sealing unit into sealing engagement with the portion of said wall defining said opening and thereby sealing said opening;

and removing said spring clip from said unit.

14. The plug combination of claim 1 wherein said expander means include a thermally expansible material having a substantially greater rate of thermal expansion than the rate of expansion of the material of said iirst member through a predetermined range of temperature.

15. The plug combination of claim 1 wherein the inner portion of one of said members is normally dished.

16. The plug combination of claim 15 wherein said expander means include a screw threadedly connected to one of said members and bearing on the other member and having a portion extending through Said `one member and accessible for rotation by a tool receivable thereon to urge the inner portion of one member toward a lesser degree of dishing for expanding the perimeter of the one member.

17. The plug combination of claim 5 wherein said discs are circular, said flange is cylindrical and both of said discs are dished, said second disc being confined at its circumference to prevent increases in axial separation from said first disc at its circumference.

18. The plug combination of claim 17 wherein the convex faces of said discs face each other.

19. The plug combination of claim 1 wherein:

said expander means include a body having a chemical charge therein, said charge being responsive to a temperature above a predetermined level t0 forceably expand, said body being constructed to permit expansion of the charge in one direction and prevent expansion in other directions, and said body being oriented so that said one direction is generally parallel to a line drawn between points of said inner portions which are nearest to each other.

20. The plug combination of claim 19 wherein:

said body has a thermally conductive face portion engaging the inner portion of that one of said members which will be exposed to the exterior of the object having the opening to be sealed by said plug when said plug is installed therein, to facilitate attainment of said temperature at said charge and initiate a chemical reaction therein by application of a heated iron to an exposed face of the inner portion of said that one member.

21. The plug combination of claim 20 wherein said chemical charge is explosive and said inner portions are concavoaconvex, with the convex face of one inner portion facing the convex face of the other inner portion, and both of said inner portions being plastically deformed and increasingly separated from each other upon explosion of said charge to obtain and maintain a radially expanded condition of said iirst and second members.

22. The method of claim 12 and further comprising the step of directing said internally expanding force generally parallel to an axis of symmetry of one of said members.

References Cited UNITED STATES PATENTS JAMES B. MARBERT, Primary Examiner.