US2435657A - Inspecting wire drawing die - Google Patents

Description

Feb. 10, 1948.

R. H. SAVIERS INSPECTING WIRE DRAWING DIE Filed Sept. 15, 1944 [mm afar: F0556? Have) 54mm,

i atenterl Feb. l0, 194$ INSPECTING WIRE DRAWING me Robert Henry Saviers, Morrisville, Pa.,assignor to The American Steel and Wire Company of New I Jersey, a corporation of New Jersey 7 Application September 15, 1944, Serial No. 554,304

2 Claims. (01. 18-55) This invention is concerned with inspecting wire drawing dies to determine. whether their various parts are properly made.

A specific example of the invention is illustrated by the accompanying drawings, in which:

- Figure 1 is a vertical section of apparatus suitable for carrying out the invention;

Figure 2 is a longitudinal section of a die; and Figure, 3 is a detail involved in inspecting the die of Figure 2.

' More specifically, these drawings illustrate a tungsten carbide die having'the usual steel shell I, with a ground and polished cylindrical outside, mounting the tungsten carbide insert 2 in which thedie hole is formed to provide the bell section 3, the smoothing out section 4, the constricted bearing section 5 and the countersunk section 6, with the ends I and 8 of the steel shell I ground and polished to form right angular planes respecting the cylindrical outside of the steel shell I and the axis of the die hole, and with the die hole axis concentric with the axis of this cylindrical outside. These various parts bear these relative relations, and the various sections have predetermined shapes and a proper finish, in the case of a properly made die, and deviations, characterizing an improperly made die, cause wire drawing trouble. Therefore, it is desirable to inspect such wire drawing dies to determine whether they are properly made. I

. According to the present invention, a metal cylinder 9 is provided with an internal bore III that is ground and polished to fit the outside of thesteel shell I, of the die, as closely as is possible while permitting the die to slide in the bore. This cylinder 9 is then set on end, on the ram ll of a vertically acting press, with the bottom end of the bore l0 closed by a cylindrical metal plug l2 having at least its top surface ground and finished as truly as possible at right angles to its side and with the latter ground and polished to fit the inside of the bore it! as does the steel shell I of .the die. Thermoplastic material [3 is then placed in the bore ill on top of the plug [2, a separator I4 is stufied into the bearing section of the wire drawing die, with this separator made of material inert to the thermoplastic material l3, the die is then slid into the bore ID, on top of this thermoplastic material l3, more of this material is placed on top of the die, inside the bore 10, and a cylindrical metal piston l5,

having its side ground and finished to fit the bore ill, in the same fashion as described in connection with the plug l2 and the die, and with at least its bottom surface ground and finished in the same manner as the topof the plug I2, is then slid in the bore with this bottomsuriace on the material. The thermoplastic material l3 may be one of the synthetic resin products, commonly used for the purpose of mounting metal specimens for microscopic examination, which are provided the art in the form of a powder which becomes plastic when properly heated. The resin product may be either of the type which is permanently thermoplastic or which becomes infusible,aiter heating and compression, and is preferably opaque. Furthermore, the press, providing theram ll, may be a specimen mounting press of the type commercially available for mounting metal specimens in such plastic material for microscopic examination.

Continuing, heat is next applied the thermoplastic material l3, as by means of a heater l6 encircling the outside of the cylinder 9, and pressure is applied to the thermoplastic material on both sides of the die and directed toward the die, as by operation of the ram If so that it raises until the top of the piston l5 contacts an immovable crosshead 11, force being applied'to the ram H in any fashion. The pressure applied to the material l3, on opposite sides of the die, should be sufficient so that as the material becomes plastic, due to its heating by the heater [6, it is forced against both ends of the die and into the die hole thereof under adequately heavy pressure to assure complete contact of the material with all parts of the die which it can possibly contact. The manufacturers of synthetic resin thermoplastic products provide instructions as to the temperature and pressure their use requires, and these instructions may be followed in determining the proper temperature and pressure required to mold the plastic masses firmly against both ends of the die and into its die hole.

After properly carrying out the above phase, the pressure is released by lowering the ram H and the material is cooled as by turning off the heater 16. After cooling, the piston I5 is withdrawn from the cylinder 9 and the molded plastic impressions, resulting from the described procedure, are removed from the cylinder 9. These molded impressions will be found to be stuck to both sides of the die, and by pulling gently on them they can be separately removed axially of the die hole due to the separator l4 separating the impressions at the die hole bearing section. Incidentally, this separator may be satisfactorily made from cotton since this has been found to be non-reactive to most synthetic resin thermoplastic materials.

Now, since the side of the plug l2, the outside of the steel shell I, of the die, and the piston [5 all formed precision fits with the bore I ll, and since the top of the plug l2 and the bottom of the piston I5 were, within precision limits, at true right angles to the various cylindrical parts, the separated impressions may he set on the flat mounting stage of api'ojectioii microscope and examined for any deviations from that relationship of the parts which should prevail if the die is properly made. Thus, in the case of the illustrated impression, the bottom-; l 8 represents a flat surface that is at right angles to the cy lindrical outside of the steeljlieli -l 'Tlie opposite surface I 9 of this impression is ,plajllel to the surface [8 only in case the end "I "of the steel shell of the die was at xielitsanglesetqthe shells cylindrical outside. The die-hole portion of the impression provides a means for determining whether the die hole is axially concentric with the cylindrical outside of the -steel shell I, this", being do'iie b 'ii'iea u'rin'g whether the axis of the die hole impre n is at right'a'ngles to the bottomfo'f the ifn" ss'io'ii and by rotation of the impression to'determ'ine 6fist.- Finally, the i hole port on 01' the impress on provides a means for measuring the diameters and angularities'of th (rariti s dle hole secti ns, since the part 2( l fof th ejfimpres'sioh was 'ii'iolded by the el p t is e. whit ewes por 21 was m uedbythfe smofothifig'out section 4, While the fragmentary nib 1 22 was moldedby the bearer yibus y explained, it is coniiei fecti nst e rest 0 n: of a projectio Q cro'sco n a ed i hllfii ?bififiBPW i o a screen dir ei iv 't han m as rem s a Although the for o 5 explains the mode of inspectin'g'ithe fet" en {of the die,-it is obi js t t th Pres i ;ie r m. h exitehd or the die'proyihes a-ineans idr'mspectme that end.

;I claim:

wire dr'awin 1. 'A metho ti install-lg the we we re v efsaid'die liaving 'a sheli withfa cylindrical outer I surge; e, "the 'fs hell mounting fan i e in wlv ie ttlieidi ho i orm d concentric with'the ut'er -surtae for, h shelhthe die hole having afc'onjstric Q Q P e dst e the mold at both ends of the die in amounts more than sui'licient to fill the respective ends of the tic impressions when solidified axially from the h mpres'sion'hy means 0 De of the typeeasting an die hole 2. A method 'of inspecting the die hole of a.

wire drawing die said die having a shell with a ylind-ri'cai outer surface, the shell mounting an insert in which the die hole is formed congentricwith the outer surface of the shell, the die hole having a constricted bearing section inwardly of the ends thereof, said method comprising inserting a separator to which thermoplastic resin .is iionereactive completely across the die 'h'ole constricted bearing section, placing the die in a mold h'a-vingh cylindrical bore closely fittng the outer cylindrical surface of the shell, the die fbingtplace'd in the mold intermediate the ends of such mold, vinserting thermoplastic resin in the mold at both ends 'of the die in amounts more thanasuflicient "to fill the respective ends of the die-"hole, applying pressure and heat to such resin by means of surfaces at right angles to the bore-of the mold to force the resin against the die ends "and :into the idle hole, to make an impression 'of the die hole that is separable into two parts for removaLhecause "of said separat ing material, releas'ing such pressure, removing the die from the mold, and removing the two plastic impressions "when solidified axially from the die'hole, the 'q'uantity of resin introdu'ced into the'r'n'oldion each'slde of the die being suflicient to"formpedestals on the ends of the plastic impressionsof the die hole.

ROBERT HENRY SAVIERS.

7 REFERENCES CITED I, The refer'r'ices are of record in the file of this "patent:

UNITED STATES PATENTS

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