US51366A - Improvement in manufacture of molders match-plates - Google Patents

Description

CHARLES TRUESDALE AND ABNER J. SENNETT, OF CINCINNATI, OHIO.

IMPROVEMENT IN MANUFACTURE OF lVlOLDEBS MATCH-PLATES.

Specification forming part of Letters Patent No. 5 El,346, dated December 5', 1865.

To all lwhom it may concern:

Be it known that wia-CHARLES TRUESDALE and ABNER J. SENNETT, of Cincinnati, Hamilton county, Ohio, have invented a new and Improved lrocess for the Manufacture of Patterns and Match-Plates; and we do hereby dc- Clare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawings, making part ot' this specification.

Our invention relates to a mode of obtaining the reverse side from pattern-blocks for ornamental castings or relieves, stove-designs, patterns, 85e.

Figuresl to 7, inclusive, represent successive stages of our process.

Upon a pattern-block, A, having the customary guide eyes or plates, we place a drag, B, and pour over the block A sufficient plaster-of-paris to form a preliminary matrix, and ram in behind with sand. (See Fig. 1.) \/Ve then turn the drag and pattern -block, withdraw the block from the plaster cast, put the cope C on the drag, lill the cope with molding-sand, and compress the sand iu the usual way. (See Fig. 2.) We then lift or separate the cope C from the drag B, destroy the preliminary matrix, and return the drag B to the pattern-block A, and again lill thedragB, but this time wholly with molding-sand. (SeeFig.3.) Wethen turn the drag and pattern-block and withdraw the blockfrom the drag. We then reverse the drag and place upon it an open wooden frame, D, having suitable eyes to tit the pins of the drag, and a gate, d,forthe reception ofa mastic com posed of two parts of mineral pitch, one part of pnlverized soapstone or brick-dust, and one part of sawdust or other suitable molding composition, which is then poured in, the entire flask being set at a suitable cant to insure the entrance of the composition without washing away the face ofthe mold. (See Fig. 4.) The composition cast, having sufficiently cooled, is then withdrawn, frame and all, from thelask, and its obverse surface D is coated with wax, or a mixture of paint and sand or other suitable substance, to a corresponding thickness with that desired for the ultimate cast or pattern. (See Fig. 5.)

The cast E thus obtained is a permanent and durable fac-simile of the block A, the delicate outlines of which, being usually workedin putty or wax, are very fragile and easily injured.

By the process described the most delicate outlines are preserved in a durableI form, and not liable to injury by workmen.

The blocliA can be preserved or worked over for other purposes.

A complete composition castmay `now be obtained by taking a sand mold ol' Fig. 5, as at Fig. G, and replacing the plate D E with an empty frame, F, and running com position therein. (Sec Fig. 7.) We have then a permanent and exclusively composition eastot' both surfaces ofthe object, which cast may be used for-f4 any length of ti me in the Ordin ary way of using match-plates.

To obtain either castings or metallic patterns from the composition casts made in the manner described above, they are molded in the usual way that sin gle and double faced matchplates are.

rEhe usual way of obtaining a reverse side from a pattern-block is to take the block and inclose it with a frame with the customary pins and guide-eyes and take a cast therefromA in plaster, then remove the cast and put a thickness on the plaster with wax or with a composition of paint and sand. A reverse obtained in this way is subject to the following among other disadvantages:

First, when the cast is taken the wood absorbs a portion ofthe moisture from the plaster and expands before the plaster sets, and when dry the wood contracts. Thus the frame becomes lower than the plaster cast, and to a certain extent loose therefrom, thereby rendering it impossible to obtain a perfect castiu g. It can only be used with success before the wood contracts.

Second, a reverse obtained in this way isliable to absorb moisture from the atmosphere and natural dampness of foundries, which causes it to easily crumble.

Third, the waste of material. Owing to the causes stated above, new reverse sides to pattern-blocks, such as desirable designs for stovepatterns, have to be frequently taken, and each cast so take-n must have athickness put on the reverse, the old material being thrown out as refuse.

The following are among the many advantages of a composition cast made in the manner described:

First, it will not change from the effects of atmosphericheat or cold land is impervious to moisture.

Second, it is easily prepared for use. If

the thickness.

properly made, is ready for the molder after being cast,Withenoy other labor thaneputtingon (See Fig. 5.)

Third, an original being cast and the thickness put on, it can be copied or duplicated to any extent desirable, andvis ready for use after being cast, With no' other labor.

Fourth, the composition tenacionsly adheres to Wood, never liable-,to becomeloose, and. if by accident the casts should beinjured the m aterial can be remelted and used again.

Onr process may be slightly modified by applying the thickness of wax or paint and sand to the plaster matrix, (see Fig. 1,) so as to dispense withvthe operations shown in Figs. 5, 6,

Images