US2422052A - Method of making collapsible tubes - Google Patents

Description

jm@ w @4W I G. W. TEMPLE I 2,422m5 METHOD OF MAKING COLLAPSIBLE TUBES Original'Filed July 5, 1941 e/ 22AM* /f za 1 /4 Hl l// a .A

/9 y /z /a Wiley Patented June 10, 1947 'r NoifFlcI-j MetalY Products Corporation, corporation oNe'w York' I Brooklyn, N. Y., a

Original Y application .lilly 5, 19471,` Serial No.

1944, Serial No. 537,818

This invention Ais a division of my prior` patent No. 2,352,456 and relates to the methodof Amaking collapsible tubes of 'metall'suchas lead `which mignt'contaminate or'o'tnerwisevinjurouslyjarect the contents,A or which 4.might"beb'cn'i"affected thereby. Collapsible tubes are customarily"'extrudedfin Aa press. from `such Valuniriuiri A.non-ferrous t metals' Aas tin, and Zinc or alloys th`ereol:"...,In Acertain ca'ses,^leadrfhasbeen used foi" the tubfw'he fthe contents` might affect or belvaflected uby'ffother metals. Lead is more abundant and cheaper than the other jmeta'lfssmentioned, but owing to the chemical action upon lead of many ingredients of the pharmaceuticals inserted into circumstances referred to.

Even if the tube-were extruded bywell known processes from a tin-plated or coated slug of lead, finishing operations upon the pressextruded tube, such as trimming andtthreading theneck of the tubawould out away` thin coatinetand undesirably expose the underlying lead.

I have found, however, that a lead tube can be extruded from a tin-coated slug in such a manner that all surfaces of the sandwiched lead are covered with tin. By forming on the neck of the tube at its discharge opening a projecting thin tin-coated cup provided with an end at closure wall and with a substantially cylindrical wall and then trimming off the end wall to expose the discharge opening, the cylindrical wall with its thin exposed lead edge may be rolled over to carry said exposed edge against the exterior surface of the tube, thereby inexpensively providing a tincoated lead tube having no exposed lead surfaces.

My invention therefore contemplates th-provision of a simple and inexpensive method of making a tin-coated lead or the like collapsible tube provided with a downwardly and outwardly rolled bead, lip or wall arranged outwardly of the discharge opening, and with rolled external screw threads whereby the tube may be extruded, trimmed and finished largely by the usual methods and machinery except for the rolling of the lip and threads which rolling may be accomplished by the use of suitable simple tools rapidly and automatically.

The various objects of the invention will be clear from the description which follows and from the drawing, in which,

Fig. 1 is a fragmentary front elevation, partly in section, of the tube as it appears before the collap- I5 ,sible tubes and` sold therein,A it has not been extensively used' "for such tubes "except under the Divided and this application May 29,

projecting cup thereofhas" been trrnmedland rolled over; 'u t f i j' Fig. 2 is a similarlview of the tube as-'it appears with'the thinwall rolled into a bead. 1, ,t

In Athe practical embodiment of thin'vention which I havevshownby way of example, the` tube is'extruded in a pressof the usual typeby means of suitable dies. Preferably,af"ltin coated flead slug is `used from which to extrude the tube. Since the extruding operation iswell known, no further description thereof :is deemed necessary. Itwill be understoodyhowever, that the terms `Lead and tin in" thisspecificationf means those specific metals asl well asany other` metals suitable for, extrusion from aV coatedslug into fa tube, and that `said terms refer tofdiflierentlsuitable metals, one adapted to be coated by or sand- `wiched `betweenflayers of the other.

As a result of the extruding operation, the partly finished tube l0 (Fig. 1) is formed, having a thin cylindrical body II, the thicker tapered conical shoulder I2, the comparatively thick'neck I3,j (with orwithout the externalscrew threads I4` thereon) and the discharge passage I5 closed by the cup-like and very thin projection I6. The formation of said projection is an important intermediate step in the manufacture of my improved tube from two different metals, one metal coating the other. The projection has a preferably at end wall Il and a substantially cylindrical Wall I8 extending integrally from the end wall to the neck I3 and surrounding the opening or discharge passage I5. The tin coating I9 however covers all surfaces of the tube, both interior and exterior with the heavier lead layer 20 sandwiched therebetween.

After the tube I0 has been extruded in the press, it is mounted on the mandrel of a trimming and finishing machine, where the open end of the tube is trimmed ofi to cut the tube to the required length, and the threads I4 are rolled in by suitable pressure tools (if the threads have not been previously formed) without breaking the tin coating.

The neck end of the tube is also trimmed and finished. This is done by rst trimming off the end wall Il of the cup-like projection I6 on the line marked cut in Fig. 1. Such trimming exposes a lead edge on the wall I8, which of course is undesirable and cannot be left in that condition, owing to the possibility of contact therewith by the tube contents. Consequently, the wall I8 is bent on itself to form a bead and then partly flattened into the position thereof shown in Fig. 2 wherein the extreme end edge 22 thereof is ar- 3 ranged in contact with the exterior surface of the prising extruding the body and the neck simulwall I8 and is protected by the bent part of the taneously from a tin-coated lead slug while at wall. The bending of the wall I8 may be accomthe same time forming a temporary cup-like plished by a rolling operation by means of a suitprojection on the neck, then trimming off part able tool entering the exposed discharge opening of the projection to leave a Wall having an edge remaining afterthe end wall I1 has been trimmed in which part of the lead is exposed, and finally off. Suchtoo'lslmaybe arrangedlonthe turret bending the wall suicientlyto carrylthe edge of the trimming machine. rintoiirm contact with'a surface of the tube and The doubled Wall or bead 2| resulting from thereby to protect said edge against Contact with the above-described trimming and rolling opera- 10 the tube contents. tions is forced against the'ftop-walloredgel23 '3-'f-'Ihe-meth0d o'f making a tin-coated lead of the tube neck and someWfhat-,attened and `collapsible tube comprising extruding the tube does not interfere with the threads |.4,;nor`with "Sdtha't it remains tin-coated on all of its surthe cap which 'may be screwed on the threads. faces and with .a tin-coated cup at one end, It will be understood that if desired and found ,15 trimming off the end part of the cup t0 leave a convenient, the wall I8 may befrolledlinwardly f wallfhaving an'edgefin which part of the lead is instead of outwardly in an obvious'manner. After texposed;railing the well over suiciently to form the tube has been thus finished, it may be subahead land tocarry said edge into the interior jected to the usual enamelling and capping.op surfacey of the bead, and rolling threads on the erations in a, manner well known in the art` tube While maintaining the tin coating thereof nIt -will ibevseen .from the above that I have prounbroken.

vided a simple method of making tin-coated lea'd 4iii The 4method of making a collapsible tube .tubes and particularly forrnishing such .tubes fheving an'open hollow neck, COmDlSing-lst eX- Without exposing .any leadsurfacethereon. "t'lldng'fhe'tube 'and the neek`the1e0f'f1'0m a 1 .Q1aim; 51m-'coated metal Vslug so that it 'remains tin- .1 The method Vof 4Vmaking a collapsible mbe 'coated on all of its surfaces While simultaneously .having-aneck-of.angivenmetal coated with a, eXtruding a closing wall on the extreme outer- (-difrent metal 4(njrnprisilflg ,performing ,an gxmOSt 'I1d'0f`the neck, then IemOVing the Outertruding-operation upon .a slug ofthe vgiven metal most end'palf' '0f 'the 'neck and the' Closing Wall .coated with Ysaid 4different .metal .to extrude .a 30simultaneeusly'toopen the neck, and then'bendtube-havinga.bodyandaneck-with acomparan'gpl't 0f the neck '00 VCerri the "eXDOSed'end ftivelythin `cupeshaped projection extending be- "edge thefeofa'g'fnst a *Smfafe 0f the neckyond andcovering the dischargefopening of the meek, trimming off the end surfaceof the .cup- Av'shaped vprojection to expose the .discharge openg55 ingr. and to for-m asubstantially cylindrical thin REFERENCES CITED wall. surrounding said opening, rolling the wall The'following references are of record inthe downwardly tofarrange the otherwise exposed ""le of this patent:

vedgeof the Wall against a Surface of the tube neck,l and rolling external threads by pressure m40 UNITED STATES PATENTS TGEORIGE AW.

=.into the outer'surface of the neck whilemaintain- Number Name Date ingthe coating unbroken- 2,122g325 'Rumball June A28, 1938 v Y2. The vvmethod of making a tin-coated mad V2,320,498 'Wheeler 'June 1,'1943 lcollapsibletube having a body and a neck com- 2,352,456 lTemple June'Z', 1944

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