Oct.29, 1946. a ' ' ATOWNHILL I ‘2,410,190 METHOD OF MAKING PLUG TYPE ‘HOLLOW POPPET VALVES Filed Feb. 4, 1944 ' I / n4. ' _E5'- 1 ' //7?/ _ //4. /////////// / .I ‘ . — /// ‘/2_7 i275 . 2/ ' ' 23 ' ‘£5 / 2,410,190 Patented Oct. 29, _ 1946 METHOD OF f Arthur‘ Townhill, Cleveland, ‘ohiopassignorv to j Thompson‘. Products, Inc., Cleveland, Ohio, at " " corporation of Ohio Application February 4, 1944, Serial No. 521,115 1 Claim.‘ 7 (ol. 29—156.7-) i 2 . . plug in the end ?ller opening of the head of a 7 ‘This invention relates to a method of ‘making a' hollow poppet type valve and a closure plug for hollow poppet valve whereby the force of insert ing the plug in the ‘opening is employed to estab the head thereof, and more particularly to the lish- a seal between the inner extremity'of the plug and the ?ller opening in the head of the manner in which the plug is ‘inserted and at tached to the head of the valve. 1_It is important'in the fabrication‘ of poppet valve.‘ , _ ‘ Other objectsand features'of this invention will more fully appear from the following detail description; taken'in connection with the accom valves having on the interior thereof a heat dissi pating coolant" that every precaution be taken against leakagerof ?uid into the interior of the valve so.‘ as to preventoxidation orother dele 10 panying drawing which illustrates a single modi ?cation of the invention, and in which terious effectszon the coolant. This problem be-' Figure 1 is a crossgsectional view through a comes of considerable moment at the plugged semi-?nished valve embodying the’ features of ?ller opening of a' valve since,vfor example,_ where this invention; _‘ f f . metallic sodium is employed as the heat-'dissie pating ?ller,‘ any‘ leakage of air around the 15 ‘Figure 2 is an enlarged cross-sectional view taken through the plug of my’ invention prior to threads of‘the pluginto the interior of the valve the insertion of the ‘plug in the ?ller opening of will result intoxidation of the; coolant, thereby detracting from its efficiency. p ' _ the poppet valve; v 7 _ Figure 3 is an end View ofv the plug shown in object, thereforavof this invention is to pro; vide a method of making a‘popp'et valve con 20 Figure 2 looking at it from the left-hand side of struction including a closure plug for the ?ller Figure 4 is an enlarged fragmentary cross-sec opening with a‘ simple but ef?cient improvement theplug; ' > tional view of the headportionv of the valve shown which will obviate the occurrence of leakage of the above-mentioned character. ‘ in Figure 1 but Withthe plug removed‘ therefrom a _ Another. object of this invention is to provide 25 so as to show’ clearly the contour of the end opening in the valve head portion; ' . a novel but simple way of securing a plug in a , ‘ Figure 5'is a cross-sectional view of the'valve ?ller opening of a, hollow valve whereby the plug leakage of fluid pastthe threads of the plug and structure of Figure l butshowing the valve in its ?nished condition after the plug vhas been ?nallyinserted and .cut and after the valve ‘has into theinterior of the valve.~ been shaped to the desired form; not only ‘serves its usual function of ?lling the opening,'but in addition establishes a seal against ' V Figure 6 is an enlarged fragmentary sectional view corresponding to the left-hand end of Fig provision of‘ an inexpensive, and simple type of ure 5 showing in detail the construction of the plug which may be readily used for the purpose of establishing a seal in the filler hole of a hollow 35 head of the valve after the plug has been ?nally lA‘further object of theinvention relates to the poppet type valve._ ‘ secured therein; , and .' ' I 7 I , ‘ Figure 7 is‘an enlarged fragmentary cross-sec ' In accordance with the general features of this tional view corresponding toa portion of Figure inventionthere is provided a method of making 6‘ showing more in detail the manner in which a ‘valve,havingjatleast the head portion‘thereof formedhollow and ‘?lled with a heat-dissipating 40 the inner lip or skirt on the plug is deflected along the inclined'surface of the flange at the inner coolant ‘previously, ' introduced in the valve extremity of the ?ller or plug opening in the through'the end opening and also having a plug secured in the ‘opening andvhaving an inner por head end of the valve. tion‘thereof ‘deflected into a metal-to-metal seal , , ingcontact with a shoulder at the inner extrem ity of the opening to form a seal at that point. Still another feature of the invention're'lates tonthesecuring of the plug to the valve head portion partly by a threaded ?t in the ?ller open-7' ingvrand partly by being welded to the valve head portion, whereby said welded attachment will assist in maintaining the seal established at the inner extremity of the plug.v ‘ _ '_‘_Yet vanother ‘feature of the’ invention relates to the provision of anew method of sealingth'e 45 As shown on the drawing :, ' ' > v , ‘ _ “ The valve of my invention is illustrated in both Figures land 5, it being shown in a semi-?nished condition in Figure 1 and in its ?nished form in Figure 5. For this reason, the samereference v numerals‘ are being used .in both of these ?gures toiiden'tify iThereference, corresponding character parts Ill designates or portions. general 13; the vhollow poppet type of valve embodying the features of this invention ‘and which is especially adapted for use in internal combustion engines and the like. This type of valve, as is well known 2,410,190 4 3 in the art, embodies a stem or shank portion H and a head portion l2. In order to cool properly the valve, it is desirable to form at least the head portion thereof hollow, although as I have illus trated it, the stem is also formed hollow, as indi cated at I3. This hollow portion |3 may be ?lled After the plug 2| has thus been properly seated in the head of the valve, the valve is axially sup ported in suitable mechanism and is shaped to with any suitable heat dissipating coolant such, the contour shown in the-?nished state of the valve illustrated in Figure 5. It will be clear from Figure 1 that the plug 2| has a center hole 26 and likewise the valve stem portion H has a for example, as metallic sodium which has been successfully used to withstand the tremendous center hole 21, which two center holes are in sub stantial axial alignment. These center holes may heat to which the valve is subjected in operation, 10 be used in mounting the valve in suitable equip I have ment for shaping the same into the ?nished con designated the coolant generally ‘by the reference , dition. In this ?nishing of the valve, it is brought character I4. down to the size desired and it is formed with The semi-finished valve piece as shown in Fig the usual spring seat retainer groove 28. There ure 1 may be fabricated in any suitable manner 15 after, the projecting end of the plug is cut off and any suitable material may be employed for so that the outer end of the plug is formed flush the same. For illustration, the valve piece may with the curved surface it of the valve head comprise a single steel casting. It should also be portion. In fact, the cutting of the plug is such noted at this time that the plug, which I shall de- , that its cut surface is symmetric with the curved top surface l5 of the valve head, as designated scribe hereinafter, may be made of the same type at 30 in Figures 5 and 6. of material as is employed in the single piece cast valve. From the foregoing it is clear that prior to the As best shown in Figure 4, the head portion l2 insertion of the plug in the head of the valve the as where it is used as an exhaust valve. of the valve is provided with a curved outer face hollow interior of the valve is ?lled with a suit which, at its center has a tapped threaded central opening I‘! extending through a thickened in able heat-dissipating coolant, such, for example, wardly offset portion I5 formed integral with the head portion of the valve. The tapped hole may as metallic sodium. I have found that excellent be supplied with any suitable form of thread al though I have found that V-type pipethread may results may be obtained by ?lling the cavity in the valve to the extent of 65% of its volume with solid metallic sodium. After the ?lling of the valve, the plug is in be advantageously used. The thread I‘! at its inner extremity terminates serted therein as described before so that it is held in tight sealed engagement by reason of its in a ?ange or shoulder'lt which extends radially inner lip portion 24 being de?ected radially in wardly along and in tight engagement with the inward of the thread and has a smaller size or re stricted opening l9 coaxial with the threaded 35 inclined surface 2!] of the inward offset "Son the opening II. This opening Ii} communicates with head portion of the valve, This sealing of the the hollow interior of the valve stem. plug in position is highly desirous in that it aids The lowermost thread of those in the open in preventing leakage of ?uid or air into the in ing |'| terminates inva shouldered. surface which terior of the valve; such leakage having been in turn terminates in an inclined or slanting sur face 20 which extends clear to the opening I9. I propose to utilize this inclined surface 20 in the sealingr of my plug 2| in the valve head. 40 found to be very undesirable for the reason that the metallic sodium is readilyoxidizable and, when oxidized, it loses its efficiency as a heat dissipating coolant. Moreover, the oxidation of The valve plug is designated generally by the the metallic sodium has deleterious effects on the reference character 2| and is shown in Figure 2 45 interior walls of the valve. in a position preparatory to its insertion in the It is also desirable to ?rmly hold the plug in threaded hole H in the valve head portion |2 of its sealed and retained position, and this may be the valve. This plug 2| includes a squared accomplished after the cutting off of the plug end Wrench-gripping portion 22 (Figures 2 and 3), bywelding the plug to the head portion |2 as an intermediate threaded portion 23, and a re indicated at Si in Figures 5 and 6. duced lip or skirt-like portion 24 which is of a It has been observed that during the welding diameter such that it can engage and‘ cooper» of the plug due to the heating up of the valve ate with the inclined surface 20 of the valve head and the threads, air leaking through the threads upon the screwing of the plug into the tapped tends to readily oxidize the sodium. In other hole H. words, the oxidation of the sodium occurs very In the assembly of the valve the plug 2| is readily when the same is subject to high tem screwed into the tapped hole I'| until it is brought peratures. By using the seal of my invention into the position shown in Figure 1. In this po previously described, the plug may be welded to sition the threads on the plug are in tight co the head of the valve Without the occurrence of operation with the threads of the threaded hole 60 such oxidation since any air is prevented from H, and the annular lip on the skirt portion 24 coming into contact with the sodium ?ller. is de?ected radially inwardly along the inclined The above description makes it clear that I surface 20 in the thickened center portion l8 of have not only provided a novel valve of the hol the head portion of the valve. 10w poppet type, but in addition I have provided As best shown in Figure '7, it will be perceived 6,5 a novel plug for closing the ?ller hole of the valve, that the thin edge of the lip portion 26 is caused and which plug ‘is so formed as to establish a seal at 25 to be turned radially inwardlyalong. the when it is inserted in a hole in the head of the inclined surface 20 as the plugv is progressively valve. My novel method of accomplishing this threaded into tight engagement with the hole in sealing operation is believed to be fully evident the head of the valve. This de?ected lip 25 thus 70 from the foregoing detailed description and a by reason of its wedged tight engagement with repetition of the steps involved is not thought to the inclined surface 20, establishes a tight metal be necessary. to-metal contact which results in the forming I claim as my invention: of a seal at the inner extremity of the holev in The method of sealing a coolant-?lled. hollow the head of the Valli/B. 75 poppet valve body having an internally threaded 2,410,190 5 plug-receiving ?ller aperture equipped with an annular axially tapered shoulder adjacent its inner end and so disposed as to block the advance of an externally threaded aperture-?lling plug having a continuous annular skirt on the inner end disposed to engage the taper of the shoulder when the plug is advanced into initial shoulder engaging position, which comprises screwing the plug into the aperture beyond the point where said skirt initially engages the shoulder to de?ect 10 6 the skirt by means of the taper of the shoulder as the skirt is rotated relative thereto and effect metal-to-metal contact with a substantial an nular area of said shoulder and establishing a seal between the coacting skirt and shoulder sur faces throughout said annular area, and welding the plug to the valve body externally of said annular area and the hollow sealed by it. ARTHUR TOWNHIIL.