US453343A - Stereotype backing powder or filling - Google Patents

Description

. UNITED STATES PATENT OFFICE.

THOMAS MANGAN,OF OARTI-IAGE, ASSIGNOR OF ONE-HALF TO IVILLIAM WV. PEASE, OF ELMWOOD PLACE, OHIO.

STEREO'T-"YPE BACKING POWDER OR FILLING.

$PECIFIGATION forming part of Letters Patent No. 453,343, dated June 2, 1891.

Application filed December 18,1890. Serial No. 375,122. (No specimens.)

To all whom/it may concern.-

Be it known that I, THOMAS MANGAN, a citizen of the United States, residing at Carthage, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Stereotype Backing Powder or Filling, of which the following is a full, clear, and exact description.

My invention relates to an improved backing or filling'powder to be used in the preparation of stereotype matrices for the purpose of re-enforcing and stiffening the same; and its novelty will be hereinafter set forth, and specifically pointed out in the claim.

The process of preparing stereotype-matrices is substantially as follows: The previously-moistened soft and spongy paper is placed on the type and forced into all of the spaces and interstices thereof by a brush or other proper instrument. The filling-powder or other material, of which there are several kinds now in use, is then applied to fill up all the cavities and interstices of the paper and a backing of paper or straw board is laid on, pressed down, and the whole dried, after which the matrix is removed, andis ready for use in casting the stereotype-plate. The great desiderata in fillings of this character are that they shall dry quickly, so as to require the least possible time in the manufacture of the matrices, and that they shall have the requisite consistency and hardness to withstand the weight of the stereotype metal when poured, so as to give clear and sharp impressions. Most of the fillings now in use are faulty in one or the other or both of the above requirements, and my invention seeks to remedy thesedefects by substantially a new filling material in place of those before used. To that end I prepare a powder composed of about forty-three parts of marble-dust and about seven parts of ordinary wheat flour or other flour containing a glutinous substance, and with this mixture in a dry state I make the filling in the usual manner.

iVhile other proportions of the same ingredients may be used, I have found the proportions named to give the most satisfactory results, both as to quick drying and requisite hardness to withstand the pouring of the stereotype metal and to give sharp prints from the stereotyped plate.

Matrices made in this way may be used a number of times, if desired.

I am aware that clay, plaster-of-paris, and lime combined with a glutinous substance have been before used for fillings, but these substances were more or less imperfect in one or the other or both of the respects above pointed-out and not equal in point of resistance and hardness to marble-dust and flour used in substantially the proportions which I have indicated.

Having thus fully described my invention, 1 claim- As an article of manufacture, a filling or backing for stereotype-matrices composed of or containing as essential ingredients marbledust and flour, substantially as and for the purpose described.

THOMAS MANGAN.

Witnesses:

J. THOMSON ORoss, G. S. WENTwoRTH.