US2203376A

US2203376A - Blank for forming collapsible tubes

Info

Publication number: US2203376A
Application number: US282052A
Authority: US
Inventors: Witte Paul
Original assignee: WHITE METAL Manufacturing Co
Current assignee: WHITE METAL Manufacturing Co
Priority date: 1938-03-16
Filing date: 1939-06-30
Publication date: 1940-06-04
Anticipated expiration: 1957-06-04

Description

June 4, 1940. P wlTTE 2,203,376

BLANK FOR FORMING ooLLAPslBLE TUBES original Fifled March 16, 193s j, fe f@ W vu MM 5? BAUL M'TTE.

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4Patented June 4, 1940 vraul witte, New Minoru Metal Manufacturing `N. J., assignor to White Company, Hoboken,

N. J., a corporation of New Jersey Original application March 16, 1938, Serial No.

198,163, now Patent No. 2,172,745, dated September 12, 1939.

Divided and this application June 30, 1939, Serial No. 282,052 l 2 Claims. (Cl. 29-148) The present application is a division of my application Serial No. 196,163, filed March 16, 41938 now Patent No. 2,172,745, 'September 12,

My present applicationrelates tp `a blank or slug of soft' ductile material suitable for forming into a collapsible tube byV extrusion under pressure.

Collapsible tubes for containing pastes, such as lo tooth paste, shaving cream and similar materials, are formed of very soft ductile metals, such as tin and lead, or alloys of suclf metals. Informing a collapsible tube, a slug or blank of a soft metal or alloy is placed in a hollow die of the outside l diameter of the tube to be formedand recessed to the dimensions`I and shape of the neck and v shoulder of the tube. Thereupon, an inner plunger, or inner die, of the internal shape and dimensions of the tube to be formed, is forced 20- against the blank or slug and into the hollow die. As the inner die member is forced into the hollow die, it compresses the slug'flrst into the space between the dies and then, upon further movement of the inner die, causes some of the metal 251:0 flow through a narrow space or slot between the dies and thence over the inner die in athin, seamless sheet to form'the tube-like body, some of the metal being left in the die to form the shoulder and neck. The body of the tube thus V30 formed is very thin, being only a few thousandths.

of an inch in thickness, andthe shoulder and neck portions are somewhat thicker..

Blanks for forming. such tubes have heretofore for the neck and shoulders of the tube, but for the thin seamless tube-like body that is forced or extrudedfrom the die, and inasmuch as there is some variation in a cast slugor blank, some 40 excess thickness must be permitted in orderto ensure a tube of suiiicient length. When ,a solid disc or blank is used, it is contacted ilrst by a projecting tip of the inner die which forms the inner opening of the neck. The effect of 45 vthis is to displace a corresponding amount of \the metal of the disc while it remains unconflned in the die and thus further to distort the blank or I disc and render it of uneven or unregulated thickness. I f' 50` In my Apresent inve tion I provide a 'disc havingla central opening 7or recess of approximately the diameter of the neck part of the inner die so as to avoid any substantial extrusion of the metal as this part of the inner die enters ,the .I outer or recessed die and before the metal is been cast in the form of discs, the thickness of 35 the disc being sufficient to 'provide metal not only confined within the two dies. Moreover. I provide a blank thatis machined to an accurate thickness and independent of any inaccuracies in casting, and which has a face to fit accurately into the bottom or bottom edges of the outer die. '5

The various features of my invention are illustrated by way of example in the accompanying drawing, in which Fig. 1 is a section taken on a diameter of the disc. i0 Fig- 2 is a vertical section of a casting mold in which the metaLto form the blahk is cast.

Fig. 3 is a view similar to Fig. 2 showing the blank being machined to an accurate predetermined thickness.

Fig`. 4 is a view showingthe expulsion or removal of the blank from the mold, and

Fig. 5 is a view on a smaller scale showing the blank in position in the outer or recessed die of an extrusion machine immediately before being extruded and formed into a tu v In the example of the invention shown in the accompanying drawing, the blank III is formed -in the shape of a thin circular disc having a central opening II, and a lower face ,I2 the perlph- 25 eral edge ,of whicnis inclined or rounded up" wardly as at I3 tothe peripheral face Il. -Each of .the faces II, I2, I3 and Il is formed by casting the metal into a smooth surfaced, accurately dimensioned mold. An upper face Il, parallel to the face I2, is formed by machining the upper part of the blank to remove any unevenness fromthesurface of the blankv and to reduce it to a predetermined and accurately gauged thickness. This is obtained by one or more machinings in which thecast metal is lifted from its mold to a predetermined height relative to the cutting edge of a tool that planes 4away the excess metal as described in my Patent 2,172,745.'

The resulting -blank is one of accurately gauged 40 -thickness with the edges atathe periphery and at the central opening sharply and accurately shaped except for the rounded edge `I3 which is tol lit, against the inner surface of an extrusion die.

'I'he manner of forming the blank is illustrated in Figs. 2, 3 and 4 in which F1g.2 shows the blank I0 cast into a mold comprising an outerwall.

I6 having a cylindrical ope ng in whichv ts a plunger I1. The plunger I forms the bottom 50 of thel mold of which I6 forms the peripheral wall A post station I8 stationary with respect to the wall I6 and of no greater height, is positioned centrally of the-plunger I1. I There is thus formed an annular recess into which the molten ASIS after the plunger I'I is lifted or raised, pushing the blank I0 upwardly so that its upper surface 'is above the upper surface of the wall I6 and post I8. Thereupon a cutting blade I9 passes over the disc, trimming away the upper surface portion 26 of the cast blank and forming the .machined edge I5. It will lbe, understood that the machining may take place with two cuts in order to obtain a smoothly machined surface and an accurate thickness 'of the blank. When the machining has been completed, the plunger I 'I is lifted still further to clear the upper surface of the wall I6 whereupon the blank Ill is pushed to one side and is ready for extrusion.

An example of the relation of the blank I6 to the extrusion apparatus is shown in Fig. 5. Inl this figure the blank III is placed in a lower or recessed die 2| having a cylindrical recess 22, the lower part of which is sloped at 23 to correspond to the shoulder portion of a tube to be formed, and having a. lower cylindrical recess 24 corresponding to the neck-of the tube.- 'I'he disc I0' is positioned in the extruding recess with the inclined or rounded edge I3 fitting the inclined edge 23 of the die recess. .then brought downwardly from V*the position shown in Fig. 5 into the recess of the die 2l.

`, recess. Depending from the lower end of the frusto-conical surface 2l is an extension or post 26 adapted to lit into the recess 24 with a clearance corresponding to the thickness of the neck of the tube.

As the plunger 25 is forced into the die recess in which the blank I@ is placed, the neck projecaeoasvc metal is poured to form the blank I6.' There- The plunger' die 25 is tion or post 28 passes into the central opening I of the blank.' .The opening II need not be of th exact dimension of the part 26, but is suilicientl close to the dimension asto avoid 'displacemen of any considerable metal until the plunger 2 is in a position to confine the metal of the blan I6. As the plunger 25 moves into the reces: therefore, it presses the metal against the Vin clined walls 23 until the cylindrical part 26 enterg or is about to enter, the cylindrical wall of th recess 22. Inasmuch as the post 28 enters thi opening II, there is no substantial displacemen of any metal from one part of the blank to an` other until the metal is confined and the cylin' drical part 26 enters the die recess. Thereupox the pressure causesthe metal to flow in thi minute slit between the plunger 25 and the recessed edge, and to move upwardly over the wal lof the plunger, forming the body of the tube.

Owing to the accurate formation of the blank and to the provision of the openingvII, the extrusion takesl place from a b1ank in which metal has not been forced from one part of the blank to another unconi'lned part and there is, therefore, no irregularity in the blank at the time it is confined by the plunger and thento be extruded from the recess. Consequently, th'e formation of the wall of the tube is uniform and accurately gauged and a blank of minimum weight or volume may be employed.

What I claim` is: I

1. A circular collapsible tube blank of soft, highly ductile metal, having parallel flat faces and a central opening, one of said at faces being machined to -a sharp edge 'at the periphery and at the opening, and the peripheral edge of the op- 4 posite face being rounded.

2. A collapsible -tube blank of soft, highly ductile metal having a,central opening and a substantially fiat machined face, a face opposite said iat face and parallel thereto and having a peripheral margin inclined to correspond to a shoulder of a tube, and having a centralopening.

PAUL