US2600559A - Mold for casting printers' rules, leads, and the like - Google Patents

Description

June 17, 1952 J. c. MOCAULEY MOLD FOR CASTING PRINTERS RULES, LEADS, AND THE LIKE Filed Jan. 31, 1950 INVENTOR.

ATTORWL-V Patented June 17, 1952 MOLD FOR CASTING PRINTERS RULES, LEADS, AND THE LIKE John C. McCauley, Mattapan, Mass., assignor to Ludlow Typograph Company, Chicago, 111., a corporation of Illinois 7 7 Application January 31, 1950, Serial No..141,376

2 Claims. 1

The present invention relates to improvements in the production of metal strips in the form known in the printing art as rules, leads and the like, such strips being formed directly from a body of molten metal by the casting of a continuous strip through a mold. The casting preferably is supplemented by a feeding device which forces metal into the mold and a, device which applies a pull to the finished strip as it emerges from the mold.

Molten metal is forced into the base end of a channel in the mold, within which the metal is cooled and set, and is moved gradually out through the outer open end of the channel as an integral part of the finished strip. In order to ensure rapid cooling and setting of the metal, and thereby to increase the permissible rate of feed, the mold is cooled, usually by means of a Water jacket extending around the mold.

The molds employed in the manufacture of printers leads and rules, in accordance with the continuous or intermittent casting process above referred to, are required to be strongly and accurately constructed to withstand the extreme fluctuations of heat and cooling, and at the same time to produce a metal strip which will meet rigid specifications of measurement and uniformity.

The present invention is an improvement upon a mold of the general type which comprises a pair of plates separated by two liners or spacers which form the sides of the mold, these parts being rigidly secured together by machine screws. Because the assembly and accurate adjustment of these molds requires factory supervision and facilities, it has been found desirable to provide separate molds for each different shape and thickness of lead or rule.

Objects of the present invention are to provide a, novel and improved mold for use in the manufacture of printers leads, rules, and the like strip material, which is more strongly and efficiently constructed than the molds previously available in the art, which is further constructed and arranged to permit of a more rapid rate of cooling and of setting the molten metal, and a substantially faster rate of extrusion of the finished strip from the mold, and which is well adapted to be taken apart and reassembled in the field and adjusted for the production of rules and leads of difierent dimension, without loss of accuracy or effectiveness in use.

With these'and other objects in view as hereinafter may appear, the several features of the invention consist of the devices, combinations,

2 and arrangement of parts hereinafter described and claimed which, together with the advantages to be obtained thereby, will be readily understood by one skilled in the art from the following description taken in connection with the accompanying drawings, in which Fig. 1 is a side view of a mold illustrating in a preferred form the several features of the invention;

Fig. 2 is a sectional view taken on a line 2- 2 of Fig. 1;

Fig. 3 is an exploded view of the mold comprising the mating mold members, and a pair of shims;

Fig. 4 is a sectional view taken on .a line 3-4 of Fig. 2 to illustrate particularly the arrangement of the cooling conduits in the male mold member; and

Fig. 5 is a sectional view of the mold taken on a line 5-5 of Fig. 4.

The mold illustrated in the drawing as embodying in a preferred form the several features of the invention comprises a pair of plates l9 and 12 which are constructed and arranged to provide the mating elements of an adjustable mold. The plate H] has mounted on the inner face thereof a block H which forms the male element of the mold. The block I4 is secured to the plate H] by means of aseries of four machine screws E5. The plate l2 has mounted along the edges of the inner face thereof two bars 16 and I3 which provide the side wall members of the casting channel of the mold. The bar I8 is l.- shaped, being provided at one end with a transverse extension 20 which may be formed integrally with the bar [8, or as .a separate piece and which extends across the face of the mold member I2 into engagement with the barv l5, and forms an end wall, or closure, for the base end of the casting channel. The bars (6 and lorespectively are rigidly secured to the plate 12 by means of a series of machine screws 24, the heads of which are recessed into the surface of the bars I 6 and 18 respectively. A conduit 26 cut through the transverse extension '20 of the bar IQ of the mold provides an entrance or gateway through which molten metal is forced into the casting channel of the mold. It will be understood that while the mold in the preferred form is constructed to include an end wall having a conduit out therethrough, the invention in "the broader aspects is not limited to the specific construction shown. Theend wall 20 may, for example, be omitted and the supply nozzle connected directly across an open base end of the casting channel.

For adjustment of the thickness or point rating of the strip material cast in the mold, two shims or spacers 28 and 3B are provided between opposed faces of the side wall bars I6 and I8 respectively, and the recessed edges formed by the inner face of the plate In at each side of the block I4. The parts of the mold, including the plates I2 and I4, and spacers 28 and 36, are held rigidly together by means of a. series of machine screws 32 arranged with the head portions thereof recessed into plate In and with their opposite ends threaded into plate I2. Adjustment of the thickness or point rating of the finished strip is determined by the choice of spacer members 28 and 30 which in turn de termine the position of the inner face of the block I4 with relation to the opposed inner face of the plate l2.

To avoid sticking or the cast metal to the mold and to assist generally the process of extruding the cast strip from the mold, the cross-sectional area of the metal receiving and casting channel is increased in each dimension by approximately two thousandths of an inch (.002) along the length of the channel, from the base, or receiving end, to the outer end from which the finished strip is projected. This increase in the vertical cross-sectional dimension is obtained by diverging the opposed walls of bars I6 and I8. Variation of the shorter transverse cross-sectional dimension is obtained by the shaping of the inner face of the block I4 so that it diverges with respect to the opposed face of the plate l2. The top and bottom edge of the block 14 are similarly formed in a diverging relation to one another in order to ensure a snug fit between the edges of the block I4 and adjacent walls of the bars l3 and I8. It will be understood that the desired dive ge ce of the faces of block 14 and plate I2 may be obtained in any alternative manner as for example by the use of tapered spacer members.

To insure that the corners of the cast metal strip may be accurately formed, and in order to prevent leakage of the molten metal, a very close fit with a minimum tolerance is required between the sides of the male mold member I4, and side bars I6 and IB forming the side walls of the mold. The slight taper of the member 14 above noted, is of considerable value in assembling the parts of the mold since the narrowed portion of the block I4 can be fitted between the relatively more separated outer ends of the side walls of the channel provided by the bars and I8 and thereafter moved lengthwise into position.

In carrying out the present invention, a water cooling system is provided which takes the form of passages in the block [4 and in the plate I2, which supply water or other coolant directly to the face portions of the mold in contact with the molten metal. The plate I4 is formed with two longitudinally extending drilled conduits 34, 39, and a vertically connecting drilled conduit 3? which may be formed preferably with a number 38 drill. The ends of the conduits are then sealed off or plugged.

Supply and exist connections for the coolant are provided at the open end of the mold. These connections take the form of a transverse bar 39 and gasket 40, secured to the exterior surface of the mold plate In at its outer end.

Transverse drills extending inwardly through the transverse bar 39 and mold plate I0, and into the block I4 are arranged to intersect with the longitudinal conduits 34, 36. To avoid any possibility of leakage, a coolant supply tube 46, and a coolant return tube 48 are fitted into said transverse drills and intersect with the longitudinal passages 34, 36. In order to insure an open connection between the supply tube 46 and passage 34, and similarly between return tube 48 and passage 36, passages 34, 36 are preferably drilled after the tubes 46, 48 are in place thus causing the drill to cut away obstructing portions of the tubes.

Coolant is supplied in a similar manner to cool the inner surface of mold plate I2 through longitudinal passages 50, 52, a vertical passage 54 (see Fig. 5), a coolant supply tube 56 and a coolant return tube 58. A vertically disposed supporting plate 60 and a gasket 62 are secured to the outer surface of the mold plate I2 at its outer end by means of machine screws 64 and 66. The coolant supply and the coolant return tubes 56, 58 are inserted into transverse drills passing through the supporting plate 66 and mold plate l2 to intersect the longitudinal passages 50, 52. It will be understood that applicant is not limited to the specific construction of the coolant supply conduits shown, and that, if so desired, the transverse bars and gaskets could be omitted in'favor of a direct connection of the supply conduits to the male and female mold members respectively.

The improved mold assembly above described has a number of very important advantages over extrusion molds provided by the prior art. The construction and arrangement of the mold members is such that the coolant is more efficiently shielded from the casting channel of the mold, and those surfaces of the mold members engaging the shims or spacers 28, 30 which are employed to control the thickness or point rating of the cast strip, are free from contact with either the molten metal or with the coolant along the length of the casting channel. As will be readily evident from an inspection of the drawing, the molten metal is entirely contained by the mating elements of the mold within a casting channel which comprises the plate I2, the side wall members [6,

l8, and end wall 20, and the block I4 which is closely fitted thereto.

The arrangement above described of the coolant supply and return tubes which serve as linings for the supply and return conduits, and which bridge certain contacting surfaces of the parts from which the mold members .are constructed, has been found to entirely eliminate leakage of coolant, which might otherwise result from any separation of these contacting surfaces caused by heat induced expansion or contraction of mold members when in use,

A highly rigid and efiicient construction of the mold assembly is provided by the arrangement of the adjustable mold members and associated spacer members in which the shims or spacers 28, 3B, are well removed from the casting channel and need not be fitted together with the care required for previous constructions to maintain smooth surfaces and tight joints in the casting channel, and in which the mold plateswith the side walls and spacer members there between are rigidly secured together by screws passing through the side walls and spacer members of the mold.

The arrangement of the male and female mold members in which the side walls I6, I8 of the female member and the sides of the block I4 engaging therewith diverge slightly toward the open end of the casting channel is of substantial importance in the illustrated construction in that it permits the mold to be taken apart and readily assembled into a tight fitting unit by even an unskilled workman who in assembling the mold will insert the block [4 between the side walls IS, IS toward the open end of the casting channel and thereafter slide it lengthwise into position toward the base end of the mold.

It will be understood that the invention is not limited to the specific embodiment shown, and that various deviations may be made therefrom without departing from the spirit and scope of the appended claims.

What is claimed is:

1. A mold for use in the casting of continuous printers leads, rules-and the like strip material which comprises a female mold member providing a fiat casting channel having an open discharge end, and a base inlet end for molten metal with side walls of a height greater than the greatest thickness of lead to be cast in the mold, a male mold member comprising a block arranged to extend between and closely fitted to said side walls and having recessed outwardly extending edge portions overlying said side walls, spacers of predetermined thickness interposed between said side walls and said recessed overlying edge portions of the male mold member, and fastenings passing through the edge portions of said mold members including said spacers and walls for fastening together the male and female mold members.

2. A mold for use in the casting of continuous printers leads, rules and the like strip material which comprises a female mold member providing a fiat casting channel having an open discharge end and a base inlet end for molten metal with the opposite walls thereof diverging slightly from the base inlet end to the open discharge end including divergent side walls of a height greater than the greatest thickness of lead to be JOHN C. MCCAULEY.

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

UNITED STATES PATENTS Number Name Date 257,307 Fitzsimons May 2, 1882 1,476,967 Hedly Dec. 11, 1923 1,503,479 Coats Aug. 5, 1924 1,567,431 Elrod Dec. 29, 1925 1,671,088 Dahl May 22, 1928 1,804,275 Redmann May 5, 1931 1,862,982 Redmann June 14, 1932 1,946,488 Dahl Feb. 13, 1934 2,251,858 Snell Aug. 5, 1941

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