US30691A - Improvement in making plow-plates from molten steel - Google Patents

Description

UNITED STATES PATENT Ormea.

F. Fi SMITH, OF MOMENOE, ILLINOIS.

IMPROVEMENT IN MAKING PLOW-PLATES FROM IVIOLTEN STEEL.

Specilication Ibrmingpart of Letters Patent No. 30,691, dated November 20, 1860.

To all whom it may concern: the other parts. Fig. 7 is a perspective View Be it known that I, F. F. SMITH, of Moof the casting constituting the moldboard O mence, in the county of Kankakee and State and standard B. Fig. Sis a perspective view of Illinois, have invented a new and useful of the landside D. Improvement in Steel Flows; and I do hereby rIhe casting B O is made with a flange, a, at declare that the following is a full, clear, and the foot and back of the standard for the atexact description of the same, reference being tachment of the landside D by rivets or bolts had to the accompanying drawings, forming b b, countersunk on the outside of D, said part of this specification. flange being thrown back under the mold- All steel plows heretofore known or used board, as shown in Figs. 3 and 4, to enable have beeninade of plate or rolled steel worked the landside to be brought fiush with the into shape by bending, welding, and other standard and corresponding edge of the share. forging operations, and owing to the difleulr The said casting I3 C is also made with a ties which present themselves in this mode of fiange, c, of similar character to a in front of manufacturing them have not only had many the standard, and has a rabbet, d, (see Figs. serious defects, but have been very expensive. 2, 3, and 4,) formed along its front or lower One of the greatest defects has been that the edge, that the back or upper edge of the share parts have been made of nearly equal thickmay lap over it in such manner that the faces ness, and as the wear comes most on the botof the mold-board and share come together tom and pointthose partshave been frequently with a flush joint. rlhe share is secured by worn out by use, while the mold-board has rivets or bolts e e passing through the rabbeen barely polished. Another defect has bet dandcountersunk on the outside. Each arisen from the diflieulty of fashioning the casting is made by pouring the molten steel parts to the exact shape desired, owing to from a crncible or other vessel into a "mold theirhaving been ofnecessityformed byhand, whose cavity is of the desired form. The no system of dies having been found suitable I molds are made of cast-iron. for the purpose. I I do not consider it necessary for the iu- The object of my invention is to make a struction of those skilled in the art of casting steel plow free from such defects at a greatly l metals to explain the form and construction I reduced cost; and to this end my invention of these iron-molds further than to make the consists in the manufacture ofthe plow-that following remarks, viz: first, that the tube is to say, those parts of it commonly made of formed for the reception of the molten steel steel-viz., the share, the landside, and the and its conveyance to the cavity of the mold mold-board--by pouring the steel in a molten should be so arranged that the steel will not state into molds of the required shape, by strike upon the interior surface of the cavity,

which process I am enabled to proportion the but will flow into it from one side, for in striki thickness of the several parts to the work and ing upon any portion of the interior surface wear to which they are subject, and to obtain it will cut or melt away that portion and renexactly and infallibly the form desired. der the mold worthless after one or two cast- In the manufacture of the molded steel plow ings have been made second, that the ventila- I propose, for the sake of greater convenience tion of the mold should be made by extremely of casting, as well as of insuring the greater narrow openings, which will prevent the steel solidity of the metal and freedom from honescaping, but yet permit the escape of the air. ey-comb,77 to make it of two or more castings. These openings I make` by placing pieces of The accompanying drawings represent a thin hoop-iron between the joints of the mold plow whose share A is made of one casting, or by making very shallow grooves in the its mold-board B and standard O of another, faces of the joints. and its landside D of a third. The molded cast-steel plow, when the east- Figuresi and 2 are opposite side views of ing is effected in iron molds, possesses anthe plow. Fig. 3 is a back view of the same. other advantage not stated in the commence Fig. 4l is a bottom view of the same. Fig. 5 ment of this s])ecificationthat is to say, by is a top view of the same. Fig. 6 is a perbeing chilled in the casting it becomes so hard spective view of the share A separate from as to be capable of wearing for a very long time. It is necessary, as soon as the steel is vpoured into the molds, and before the metal has cooled enough to contract, to` open the molds and detach the casting from the sprue, because if not detached before the shrinkage takes place the plate is apt to crack. The iianges and undercut parts of the plates, too, cling to the parts of the molds where they receive their peculiar forms, and not being able to shrink in all directions in cooling require the utmost care in freeing the casting from the sprue and molds. The molds themselves being of iron cannot yield to compensate for shrinkage, and hence I open the molds as soon vas the metal is poured into them. It is important, also, that the molds be ventilated to allow the gases to escape. This Vl". accomplish either by the permanent openings at the joints of the mold or by driving in-thin pieces of metal or other material at the joint to raise or separate the molds slightly. The clamps for securing the molds should be so made and united as to be readily detached, as the utmost expedition must be had in raising the mold to detach the sprue from the plate.

The steel used may be that of commerce, and in case of its being of a high quality7 it may be reduced by mixing with it a portion of iron. To determine when the steel is sufiiciently limped or fluid to pour into the molds, a rod of iron is inserted in the molten steel, and by the quantity of steel that adheres to the rod its iluidity may be correctly ascertained, the smaller the. quantity of steel that adheres to .seen from the the rod the more suitable its condition for being poured into the. molds. It will thus be nicety with which each and every ope-ration must be watched and attended to that the casting of steel plates for plows, which have varied forms and thicknesses, is entirely different from that of casting iron in molds.

Heretofore in casting articles of steel in iron molds the molds were first highly heated, and after the metal was poured into them they were,

, with their metal in them, put into an oven or furnace and heated upto a cherry-red heat, and then allowed to cool gradually to prevent cracking by shrinkage. VThis process so anneals and softens the steel as to make it comparatively of little value for plow -plates, While it greatly adds to the expense of making the plates. The contour of the mold gives the form to the plow-plate, and this form may be varied to suit the fashion of the plows to be made, or the particular parts thereof that are to be made of steel.

What I claim as my invention, and desire to secure by Letters Patent, is-v Making plow-plates of irregular forms and of variable thicknesses by pouring molten steel into iron molds in the manner. and for the purposes herein set forth.

F. F. SMITH.

Vitne-sses:

NOAH R. L. BRIs'ror., Anson W. BRISTOL.

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