US2579691A

US2579691A - Strip forming mold

Info

Publication number: US2579691A
Application number: US131164A
Authority: US
Inventors: Anton H Narrow
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-12-05
Filing date: 1949-12-05
Publication date: 1951-12-25
Anticipated expiration: 1968-12-25

Description

Dec. 25, 1951 A, H, NARROW 2,579,691

STRIP FORMING MOLD Filed DeC. 5, 1949 (Ittomeg Patented Dec. 25, A1951 UNITED STATES PATENT OFFICE STRIP FORMING MOLD Anton H. Narrow, Memphis, Tenn.

Application December 5, 1949, Serial No..13'1,14

(Cl. 22l36) Claims. l

This invention relates to certain new and use ful improvements in a mold or die for forming a continuous strip or bar `of soft metal, partcularly of type metal and similar alloys, which mold may be used in connection with an extrusion process or may be used in a process in which the cast metal may be drawn or pulled from the die as it emerges, or such extrusion or pulling action may be combined.

Specifically the present invention relates 4to new and useful improvements in the spacing members, conventionally heretofore employed in connection with similar dies or molds and in a new entrance arrangement into the channel forming the interior of the mold.

Heretofore `molds of the same general character have been employed in the formation of strips of the character mentioned, particularly for use in the printing art inthe formation of rules, lines and the like, and the strips thus formed have essentially constituted 'ribbon-like. fiat, continuous members formed by the solidification of the molten type-metal or other alloy within the mold, the finished strip being withdrawn or extruded from the exit end of the mold.

In the preparation of such strips for use as rules in printing by which a thin straight line is imprinted upon a page as desired, it has been customary to form along one edge of the strip a bevel or shaped edge with the apex of the bevel forming the portion used to imprint the line upon the page. It has been found, due to the properties of the alloys commonly used in type-metal, that, unlike other metals, there is an expansion of such type-metal alloys upon cooling from molten state to a solid state with the result that it has heretofore been customary to provide a microscopic divergence between the upper and lower' edges of the channel of the previous molds to compensate for such expansion and to permit ease of operation in the continuous production of the desired strips. It is frequently found that the strips, formed in molds of conventional type having such diverging upper and lower edges, are improperly burnished and the printing edge of the prepared strip has frequently been found to be pitted and otherwise defective in a manner undesirable 'in connection with the printing art.

The principal object of this invention is to provide a mold for forming strips of type-metal which includes means for burnishing the printing edgeof the formed strip to eliminate therefrom any undesired pits and other irregularities.

A further object of the invention is to improve the arrangement of the entrance to such molds through which molten metal is introduced into the mold so as to insure the introduction of the molten metal to the printing-"edgeeforming portion of said mold.

A further object of the invention is to provide a mold for forming strips which includes opposite side members forming sides of the mold channel and upper and lower longitudinal spacers spacing the side members apart and constituting the upper and lower edges of the mold channel, 'in which one of the spacers is scarred 'for the formation of a fine line printingsurface along one edge of the formed strip and the scarfed spacer adjacent the exit end of the channel converges toward the opposite spacer to reduce the width of the channel, the cast strip being drawn beyond the reduced width portion.

A further object of the invention is to provide such a mold in which the aforesaid scarfed spacer and converging `end section is disposed as the upper spacer of the mold.

A further objectvof the invention is to provide such a mold in which the scaried spacer is converged toward the opposite spacer along a gradual arc.

A further object of the invention is to provide a mold for forming strips in which the entrance to the mold channel is restricted Aby a block member, which block member lies intermediate Athe upper and lower spacers and is spaced `from both oation upon reference to the accompanying drawings, in which:

Fig. 1 is a side elevational view of the mold of the present invention with a strip shown emerging therefrom.

Fig. 2 is a sectional elevational View taken on the line II-II of Fig. 1.

Fig. 3 is a sectional view taken on the line III-III of Fig. 2.

Fig. 4 is a fragmentary view similar to Fig. 3 on a greatly enlarged scale illustrating a preferred embodiment of the converging longitudinal spacer of the present invention; and

Fig. 5 is a view similar to Fig. 4 of a variation in the embodiment of the converging spacer.

Referring now to the drawings in which the various parts 'are indicated 'by numerals, the

mold of the present invention consists of a pair of side members II which are substantially identical, but which, as indicated in Fig. 2, may be of differing thicknesses, and to each of which is preferably affixed a side channel face or liner I3, liners I3 being preferably separate elements substantially identical with those shown in my co-pending application, Serial No. 115,541, although it `will be understood that insofar as the present invention is concerned it may be used equally as well in connection with those molds in which the inner liners I3 are integral with side members II and are employed as the sides of the mold channel. Interposed between the channel liners I3 and betweenY the side members II are longitudinal upper and lower spacers I5, IE which are preferably of substantially rectangular shape, extend from end` to end of the mold, maintain spacing between the-,channel liners I3 and` respectively form the upper and lower edges of the mold channel. It will be seen that channel liners I3 and spacers I5, I6 form a channel extending from end to end of the mold and terminating in an exit opening I1.

Preferably lower spacer I6 is provided with a flat straight upper edge I8 `so as to form a relatively straight edge along the lower edge of a strip formed in the mold'. The lower edge l5 of upper spacer I is preferably scarfed as at ISA to form a beveled elongated recess along the lower edge I9 which is effective to impose a sharpened printing edge 2D on the strip 2I formed in the mold and to thereby provide for the printing of a line line when strip 2l is so employed.

Preferably, as is conventional, lower edge I9 of upper spacer I5 diver-ges minutely away from upper edge I8 of lower spacer I5 through a majority of the length of the respective liners. Adjacent the exit end I1 of the channel formed in the mold, lower edge- I9 of upper spacer i5 is provided with a curved portion 22 which converges toward upper edgeA I8 4of lower spacer i@ so as to restrict exit opening I1, with the maximum' restriction being preferably formed closely adjacent opening I1 as at 23.

It will be observed that in the drawings illustrating the present invention the curvature of curved end portion 22 of lower edge i3 of spacer I5 is preferably a microscopic curvature', being substantially exaggerated in the drawings for the purpose of illustration. It will, however, be understood that although the microscopic character of this curvature is preferred it is not intended that the present invention be limited to such microscopic dimension. It has been found that the spacing between the respective edges I9, I8 of upper and lower spacers I5, le is preferably narrowed from the point of beginning of curved portion 22 to the point 23 of maximum curvature in a range lying between .003

passageway 21 intimately associated with the scarfedV edge of' spacer I5, so that the upper edge of passageway 21 is longitudinally alined with the scarfed edge, and the lower edge of the block is also spaced above upper edge I8 of spacer I6 to form a conventional lower inlet passageway 29. Block 25 is preferably maintained in position by suitable dowel pins 3| which extend through the block and maintain it in alinement. Preferably additional dowels 33 are provided to maintain the alinement of spacers I5, I5, and the entire device is preferably detachably secured by suitable screws 35.

in the use of the device it is assembled as described and molten type-metal is introduced as through a suitable spout 31 into the entrance endof the device. Preferably the molten metal is supplied to spout 31 by a suitable pressure device, not shown, so that it is introduced through

passages

21, 29 into the interior of the mold under a suitable pressure.

VThe molten metal flowing through upper passageway 21 isv enabled to oW directly into the scarng I9A of lower edge I9 of upper spacer I5 and is enabled to quickly and properly ll the beveled scarring so as to begin the proper formation of printing edge 2G without depending upon the inward flow of molten metal introduced through passage 29. In this manner introduction of the molten metal into the scarfed edge-forming portion is insured. As the introduction of molten metal through spout 31 is continued the metal is advanced along the interior of the channel between liners i3 and upper and lower spacers I5, I5. The metal continues in a molten state for a substantial distance in its passage through the mold and begins to solidify, preferably beyond the mid point of movement toward discharge end I1 and emerges from the discharge end in solid strip form. Preferably an intermittent pulling force is applied to the emerged end of strip 2 I, a symbolic pulling device being indicated at 39.

As strip 2I passes from the mold, printing edge 20 frictionally contacts the converging curved portion 22 of upper spacer I5 and as the strip is drawn therebeyond the printing edge is eifectively burnished by the frictional engagement with the curved portion.

It will readily be seen that in view of the relatively soft characteristics of the alloys employed conventionally in type-metal the above described frictional contact is highly effective to apply a burnish and polish to the printing edge 20 and t0 eliminate therefrom irregularitiesy pits or other defects which have frequently characterized printing strips produced by conventional molds. In some instances it is considered desirable to converge the terminal end of spacer I5 more abruptly than along the gradual arc of curved portion 22. Under such conditions a more sharply arced portion 22A may be provided adjacent the discharge opening I1. Portion 22A obviously functions in manner substantially identical to that lalready described in connection with portion 22.

It will be understood thatthe foregoing speci- I; cation has described the physical aspects of the preferred embodiment of the present invention, but that other forms and embodiments thereof may be readily accomplished without departing from the scope of :the invention, and it will, there- To fore, be understood that the present invention is not intended to be limited to the precise embodiment shown, except as defined in the appended claims.

I claim:

1. In a mold for forming metallic strips which comprises a pair of sides, a pair of fiat, inwardly facing, side liners, respectively supported by said sides, an yupper spacer and a lower spacer, said spacers extending longitudinally of and being interposed between said liners to space said liners apart horizontally and being vertically spaced apart, said liners and the proximate edges of said spacers defining ,a flat, strip-forming channel, having an entrance end and a discharge end, the said proximate edges diverging from said entrance end throughout a majority of the length of said spacers, one of said spacer edges remote from said entrance end having a minor portion converging toward the other said spacer, the other said spacer edge being straight throughout its length from end to end of said channel.

2. A device in accordance With claim 1 in which said converging portion is curved along a gradual arc.

3.l A device in raccordance with claim 1 in which 1said upper spacer includes said converging porion.

4. In a mold for forming metallic strips Which comprises a pair of sides, a `first spacer, a second spacer spaced from the rst spacer, said spacers extending longitudinally of and being interposed between said sides to space said sides apart, said sides and the proximate edges of said spacers dening a fiat, strip-forming channel having an entrance end and a discharge end, one only of said spacer edges remote from said entrance end and adjacent said discharge end having a minor portion converging toward the other said spacer, the said other spacer being straight throughout its length from end to end of said channel, whereby to restrict said discharge end with the restriction being located on one edge only of the discharge end lto burnishingly contact one edge of a strip passing through said discharge end.

5. A device in accordance with claim 4 in which .said minor converging portion is an arcuately curved portion.

ANTON H. NARROW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,476,967 Hedly Dec. 11, 1923 1,567,363 Elrod 1 Dec. 29, 1925 1,567,431 Elrod Dec. 29, 1925 1,946,488 Dahl Feb, 13, 1934 2,007,301 Lemieux July 9, 1935 2,131,307 Behrendt Sept. 27, 1938 2,135,465 Eldred Nov. 1, 1938 2,187,720 Williams Jan. 23, 1940 2,225,373 Goss Dec. 17, 1940 2,310,805 Mueller Feb. 9, 1943 2,371,604 Brennan -..n Mar. 20, 1945