US1440087A - Typographical casting machine - Google Patents

Description

ra :2 a t ii p e we e DAVID S. KENNEDY, OF BROOKLYN, YORK, ASSIGNOB TO lv'fERGENTHALER LINO- TYPE COMPANY, A COEORATION 01% NEW YORK.

TYPOGRAPHICAL CASTING I/IACHIN'E.

Application filed. February 16, 1922. Serial No. 536,884.

To (JZZ whom it may concern.

Be it known that I, DAvn) ti Knivnnnr, a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Typographical Casting Machines, of which the following is a specification, reference being had therein to the accompanying drawing. 7

This invention relates to typographical casting machines, such as linotype machines of the general organization represented in U. S. Letters Patent to O. Mergenthaler No. 436,532, wherein a melting pot is arranged to deliver molten metal into a slotted mold and up against a composed line of matrices to produce a type bar or slug bearing on its edge type characters corresponding to the intaglio characters of the matrices. In these machines, it is important to provide for the escape of air from the mold, as otherwise the slugs (and particularly their type characters) will be cast in a ragged or porous condition. For this reason, it has been the practise for many years past to provide the mouthpiece of the melting pot with shallow grooves or passages to allow the air to escape during the casting operation. Such an arrangement is fairly satisfactory for the casting of the smaller slugs,.but it is altogether inadequate for the casting of the larger slugs, such for instance as those formed with headletter or display characters. The difiiculty is that the air, in order to escape, must travel back over or through the molten metal as it is injected into the mold, with the result that a considerable portion is inevitably trapped in the mold, thereby producing air pockets or pores which mar the printing face of the type characters. The old arrangementis also open to other objections, one of which, for example, is the leakage or squirting of the molten metal through the air passages due to the failure of the metal to chill quickly enough to seal these passages.

The present invention is intended to obviate the above and other objections and contemplates a construction whereby the air may. be completely expelled. from the mold during the casting operation so that the slugs may be cast in as perfect condition as possible- To this end, it is proposed to form the air vents directly in the mold, and preferably in its front or matrix engaging face, so that the molten metal which is injected into the mold from the rear, may drive the contained air before it and expel it through the vents at the front. In this way, the molten metal, instead of hindering the escape of the air, acts positively to expel it from the mold. The molten metal will of course flow into the air passages, but any leakage or squirting of the metal .is prevented by its sudden chilling or solidification in the air passages due tothe cold condition of the metallic surfaces. The fins cast in the air passages will be carried away on the slug when the latter is ejected from the mold and then removed by the customary trimming knives. The exact form and arrangement of the parts Wlll be fully pointed out in the detailed description to follow:

Although equally applicable to a plainor unrecessed mold, the invention has been herein illustrated asapplied to a mold of the recessed or headletter variety, which is the form commonly employed for the casting of the larger slugs. As shown, the mold comprises the body portion A, the cap portion A and the intermediate liners A and A these parts being held together in assembled relation by the studs A projecting up from the body portion A and engaging in notches formed in the opposite ends of the cap portion. The cap portion A is formed in its front face with the longitudinal groove A and in its under face with the series of transverse grooves A, leaving the blocks or core sections A projecting into the mold cavity proper. As thus constructed, the mold will cast a slug like that shown in Fig. 4, which comprises the relatively thin body portion B, the overhanging face-portion or self B upon which the type characters are formed, and the series of transverse ribs B projecting from the body portion and giving support to the overhanging shelf. In thls connection, it is pointed out that the grooves A are somewhat deeper than the longitudinal groove A (Fig. 2), so that theribs B view of the mold (Fig. 4:) are slightly raised with respect to the'overhanging shelf B and extend across the same to its outer face. These raised ribs are later dressed down by the trimming knife in the customary way.

In accordance with the present invention, the mold is provided with a series of air vents or passages in the form of relatively wide and shallow channels a cut through the front face of the cap portion A and disposed in vertical alignment with the transverse grooves 1%.. During casting, the mold is closed at the rear by the mouthpiece of a melting pot and at the front by a composed line of matrices, in the manner indicated by the dotted lines in Fig. 2. Owing to the presence of the air vents a, however, the mold is left open to the atmosphere at the front, so that when the molten metal is in jected into it from the rear, the contained air will be completely expelled therefrom through the vents and thus allow the molten metal entirely to fill up. the mold and the matrix cavities. As the mold is thus constructed, it has been found in practice that the slugs may be cast in practically perfect condition and with type characters sharply and clearly defined and free from objectionable pores or other imperfections.

During casting, the molten metal necessarily flows into the air vents a, but it almost instantaneously chills and solidifies therein, so that no leakage or squirting; can take place. Such instantaneous chilling of the molten metal is due primarily to the location of the vents at the front, where the steel surfaces of the mold keep cold, but the action is considerably aided by reason of their comparatively small dimensions. However, it is equally important that the vents be such that the fins Z) (Fig. l). cast therein may be carried away with the slug; as the latter is ejected from the mold. It is for this reason that the vents are made relatively wide and narrow, as before mentioned, as thereby the fins are cast with sufficient strength to be drawn out without becoming broken.

The location of the air vents is also im portant, since the this I) must be completely removed from the slug after casting. In the present instance, and as before noted, the vents are aligned with and lead from the transverse grooves A, so that the fins are actually cast on the raised portions of the ribs B see Fig. 4. Consequently, during the trimming of the slug, the knife does not act directly upon the fins, which in such circumstances would simply bend over or break, but cuts into the ribs slightly below the points of juncture of the fins therewith,

thus allowing the fins to be carried off as a part of the shavings from the ribs.

In the accompanying drawing, the invention has been shown merely in preferred form and by way of example and as applied to a specific kind of machi e, but obviously many changes and alterations may be made therein and in its mode of application without departing from its spirit. Thus, the invention is applicable to any form of typo graphical casting machine, whether the product of such machine be a slug or a single type or logotype, although, as has been seen, it is particularly applicable to a slug casting machine. Again, the air vents, instead of being formed in the cap portion of the mold, might be out in the body portion of the mold, or any other suitable portion, so long as they are capable of functioning in the manner set forth. In this connection, it may be stated that, in many instances, the grooves A. and A are out in a special liner which is made separate from the cap portion; and in such case, the air vents might be formed in the liner rather than in the cap portion. These and various othermodifications will readily suggest themselves to those skilled in the art and still be comprised within the scope of the invention. It should be understood, therefore, that the invention is not limited to any specific form or embodiment except in so far as such limitations are specified in the claims.

Having thus described my invention what 1 claim is:

1. In or for a typographical casting ma chine, a mold open at one side for the injection of molten metal and formed at the opposite side with an air vent.

2. In or fora typographical casting machine, a mold formed in its matrix engaging face with an air vent leading from the mold cavity.

In or for a slug casting machine, a longitudinally slotted mold formed in its matrix engaging face with a series of air vents leading from the mold slot.

4. In or for a slug casting machine, a longitudinally slotted mold comprising side and end walls, one of the side walls being formed in its matrix engaging face with a series of air vents leading from the-mold slot.

5. A linotype mold cap formed in its front face with a series of air vents extending therethrough.

6. In, or for a slug casting machine, a longitudinally slotted mold comprising side and end walls, one of the side walls being formed in its casting face with a series of transverse grooves and in its matrix engaging face with a series of air vents aligned with and leading from said transverse grooves.

7. A linotype mold cap formed in its under face with a series of transverse grooves and in its front face with a series of air vents aligned with and leading from said grooves.

8. In or for a slug casting machine, a longitudinally slotted mold comprising side and end walls, one of the side Walls being formed in its matrix engaging face With a longitudinal groove opening into the mold slot and. in its casting face With a series of transverse grooves of slightly greater depth than that of the longitudinal groove, said side well being further formed in its matrix engaging face with a series of air vents aligned with and leading from the transverse grooves.

9. A linotype mold cap formed in its front face with a longitudinal groove and in its under face with a series of transverse grooves, the said cap being further formed in its front face with a series of air vents aligned withand leading from the transverse grooves.

10. A mold constructed according to any one of the foregoing claims characterized by the fact that the air vents therein referred to are in the form of relatively Wide and shallow channels, for the purpose described. In testimony whereof, I have affixed my signature hereto.

DAVID S. KENNEDY.

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