US2464574A - Holder for use in reclaiming broken cutting tools - Google Patents

Description

March 15, 1949. J, HENGSTLER 2,464,574

HOLDER FOR USE IN RECLAIMING BROKEN CUTTING-TOOLS Original Filed Nov. 25, 1944 2 Sheds-Sheet 1 March 15, 194g. HENGSTLER 2,464,574

HOLDER FOR USE IN RECLAIMING BROKEN CUTTING-TOOLS Original Filed Nov. 25, 1944 2 Sheets-Sheet 2 WITNESSES INVENTOR;

BY flaw/W A TTORNEYS.

Jobizfienysfleg I Patented Mar. 15, 1949 r HOLDER FOR USE IN RECLAIMING BROKEN CUTTING TOOLS John Hengstler, Altoona, Pa., assignor to The Pennsylvania Railroad Company, Philadelphia, Pa., a corporation of Pennsylvania.

Original application November 23, 1944, Serial Divided and this application December 27, 1945, Serial No. 637,434

This invention has general reference to the restoration of broken, or otherwise damaged, metal articles to their former state or condition of usefulness; while it relates more particularly to the reclaiming of broken milling-cutters or the like and the instant case is a division of my prior application Serial Number 564,864, filed November 23, 1944.

Heretofore attempts have been made to reclaim broken slab milling-cutters, but such attempts have proven unsatisfactory owing to the reduction in the requisite hardness, so vital to successful usage of such cutters, and their inability to hold a good cutting edge. More specifically slab milling-cutters frequently break into two, or more, pieces during milling of the active face, and I have endeavored to repair the same with low temperature melting alloy welding wire and flux, in the manner prescribed by manufacturers thereof, with the result that the cutter became softened during the reclamation process to such an extent that it would not hold a good cutting edge when re-sharpened.

The primary aim of this invention is to provide a novel holder means whereby the above noted disadvantages are positively overcome. Another aim is to effect reclamation of broken milling-cutters, and other ferrous articles, which can be carried out with pre-assurance the said cutter, or other article, will be definitely restored to serviceable condition.

A further aim of this invention is to provide a novel holder or jig for use in the reclamation of the broken parts of a high speed steel millingcutter by heat-treatment and welding, whereby said parts are effectively and evenly integrated together at the junctures.

While the foregoing stated aims are indicative of the objects of this invention, others with ancillary advantages will be evident to those skilled in the art upon a full understanding of the holder means hereinafter disclosed; but it is to be likewise appreciated that said invention is susceptible of variation and modification coming equally within the terms and scope of the concluding claims.

In the accompanying drawings:

Fig. 1 is a top plan view of a convenient means or jig, preferably adapted for holding the broken parts of a spiral milling-cutter together during re-integration of said broken parts into unified assembly.

Fig. 2 is an elevation of the same, or as viewed from below Fig. 1.

Fig. 3 is a vertical section, taken approximately as indicated by the angled arrows III-III in Fig. 2; and,

2 Claims. (Cl. 113-99) Fig. 4 is a similar section taken on the plane IV-IV of Figs. 1 and 3.

In describing the form of this invention exemplified in the two sheets of drawings herewith, specific terms will be employed for the sake of clarity, but it is to be understood the scope of said invention is not thereby limited; each such term being intended to embrace all reasonable equivalents which perform the same function for an analogous purpose.

In carrying out my invention as adapted for the reclamation of broken slab milling-cutters, which it is here remarked usually split lengthwise into two or three parts. As a concrete example, and assuming that a conventional steel milling-cutter eight and one-quarter inches long, having an outside diameter of five inches with a bore of two and one-half inches diameter, to have been split lengthwise at approximately diametrically-opposed points, indicated by irregular lines to define fracture surfaces 1, 1, Figs. 3 and 4, into two parts 8, 8. I first take the two parts 8, 8 and remove all grease and other foreign substances therefrom; and then apply or coat the fracture surfaces 1, 1 only with a suitable flux, and place said two parts in a gas furnace, for example, such furnace having a heat about 1200 F. After being in the furnace for about twenty minutes, to volatilize the flux, the two parts 8, 8 are withdrawn and an appropriate welding deposit heat applied entirely over the fracture faces 1, with incidental driving of the volatilized flux from off said fracture surfaces; whereupon the two parts 8, 8 are placed with the respective fracture surfaces 1, 1, in mutual confronting engagement, and tack welded together, preferably at the ends, to prevent relative separation or movement out of registration; all as set forth in my hereinbefore referred to prior application Serial No. 564,864.

The re-assembled cutter, hereinafter comprehensively designated 9, is now placed in the jig, referred to generally as id, now to be described. This jig Ill conveniently, although not essentially, comprises a box-like structure including end and side walls ll, i2 respectively, all of rectangular contour. The end walls H are vertically spaced with the rectangularly-related side walls l2 united thereto by fillet-welds l3 intermediate the opposedly-beveled edges 14 of the 1 walls l2 and the relatively confronting vertical side edges of the end walls H, as best understood on an examination of Figs; 1 and 2. The jig Ii! also includes a bottom I, Fig. 3, consisting of two plate elements "5, l1, preferably disposed at an angle of ninety-degrees to insure the cutter 9 being properly centralized when placed therein and said plate elements are respectively united to the lower edges of the side walls Ii by fillet welds l8, aswwelleas-to' vonelanotherby a similar weld l8. Opposed apertures or peep-holes iii are provided in the side walls l2. In addition, it will be seen the jig end walls II are each formed A with an upward projection or lug 32L, .havingpanw aperture 22 therethrough, and whereby theijig' I can be lifted, carried or otherwise manipulated, when in use.

23 designates a top or closure for the jig lt," the same being of a contour for free movementinto position between the end and sidewalls ll,

l2 respectively, while it is formedlwithsa centralembossment 24, for a purpose later explainedhl l The closure 23 is provided with dependentlom. gitudinally-spaced chocks 25, conveniently" se--' cured thereto by fillet welds 2G, for seating on the 'cuttenil, as readily-understood from Fig-.23, more particularly.

To ecure the closure 23 ineffective engagementon topof the cutter- 9; while "the latter is in the jig HJJ I 'preierably .provide'the side walls with opposedupstanding projection -27; havingrectangular slots'28 therethrough for passageof a cotter-or clampingkey-member 29 2 Attention is directed-to the fact that-the horizontal-lower edge 30 of said member seats on the closure-em bossment 24 above referred to, whereas the un- I per" inclined: edge 3 l ofthe member 29' oo-acts with the' complemcntarily" sloped upper faces of the rectangularslots2th" It isalso to be noted the clampingmember295 'in use, is'free of engag-ement with-the lower=-faces--33? of the slots 28,

Wherebythe' clamping pressure is longitudinally;

directedand evenly distributed lengthwise: of

the cutter d, as/readilyunderstandable by those conversant with the art- Having describedth'e structural features of' the 1 jigelll and-upon placement-of the tacked together. hereinbefore men tio'ned,=-it is to be particularly noted --'that the broken *cutten fi therein; A as longitudinahfracture"faces-l, T conveniently registemwith ithe: peep-holes- 251 whereupon the top 1 next'zinserted through "the rectangular slots 231 of :the jig:v projections 2?, and. slightly drifted*- or cclosure 223 is put-:in' place; the member 23 is so ethattelittle: or very-slightclamping pressure is exertedonwthe pre-heatedand assembled parts of the cutter 9;! Incidentally this insertion of thetacked-zbroken'parts ll into thefjigl it "is'only" resorted: rto Jor the: :purpose of I better ensuring thatzthelfracture:surfacesZ, of the respective: broken ;partsf:8,lmutually=register without any 'overlapiofirtheir respective surrounding edges:

ThetvfjigV 10 s'conta-ining the tacked ."cutter'Q is placed 'inz-ranzeleotric furnace heated to a temperature of 900 F., with the temperature slowly raised-eat; determined interval periodsto"150 F.;-" and (SIlbSGQIlEIIC thEI'GtS' said temperature is rapidlytraisedito- 2200? F. This temperature of 220Q?;:'F; is :he-ld. .for about eighteen =minutes for all-ecutters-less than three-inchesin diameter,

andflontwentyi-fourminutes for all cutters three Incidentallmthetemperature periods;referred to inz th'e preceding-paragraphlfrom 900: F. upward-)Jaregoverned by the thickness of the cutnoteworthy that at the 1850 Fi'heat, the weld actualz: welding -cycle;

Them. -Jig!.= -l'0= is then removed" from the electricfurnace and the key-member 29 driven tight to clamp, and lock, the fracture faces 1 in tight mutual registration; when'xsaid "jig? ill with the enclosed cutter 9 "is allowed to cooldown' to a temperature of between 400 R, and 700 F. depending on the type of the steel forming the cutter When the desirable'cooling temperature, intervening 400 F. and 700 F., is reached the jig Ill and enclosed cutter 93 is again placed in the electric furnace, at a temperature of 900 F. and said temperature is then slowly raised to 1 00 F. or 1300? F2, for aboutone-hour for the purpose of drawing and tempering the cutter. When the lie? lc'l' 'and cutter it are finally removed from the furnace they are preferably allowed to cool to room temperature; whereupon the cutter El is taken out of said jlgr and later sharpened by grinding in the known mannerw Obviously, :a

second drawing teinpering period may bezrequi-i siteto obtain'the' proper hardness for'rthe re serves to retire fact said cutter is'restrained at four oircumfera entially spaced or opposins ipointsrbyi the partsx:

5, 37 and: 25'."

While the holder' or jig,v llrhas been-more specifically described in connection. with there-v.

clamation of broken slab;milling-cutters, I cer:--.'

tain features thereof are of morexgeneral utility; and it'is therefore to be understood; saidinven tion in its broader aspect-is not limitedto the'ex act-means; shown and described.

Having thus described my inventiomrl claims-.1; 1. A holder for use in Welding brokenLmillingn-v cutters comprising:=vertically+spaced rectanguezlarlyerelated side send walls integratedxwget-her by fillet welds beveled edges of'thesidawalls and. the relatively con-frontin vertical edgesof' the end walls slottedprojectionsonthaside Walls, and: end

walls including: apertured cal i tom'of said holder comprising twoplateelements with intervening angle of ninety degrees, and-1 said-elements being integrated together andptoxv the lower edges of the side wallshy-filletwelds; "1

a closureior the holder-in theform of a rcctangus, lar plate with an embossinent on'its' outer face andangularly dependent chocks'integrated toiits 1 inner face; and means'forclamping the closure: to the holder with concurrent restraintofthet.

cutter therein against relative movement.

2.The inventioniof'claim 1 wherein therclosm'e is provided witha central-embossmenty: wherein termediatef the opposedly I opposedside Walls of the holderhave upstand-av ing projections with vertical slots therethrough;v wherein the clampmeans consists of a key'havs: ing an inclined upperedge; and wherein .thezkeyu' seats on theembossmentand is arranged. for operation iintermediatethe ernbossment and the upper edges of the vertical slots aforesaid.

J GEN HE'NGSTLER.

REFERENGES :CITED- The following references are file of this patent:

U NITED. STATES PATENTS Number Name Date" 552,951 Boweri; Jan.:'14, -1896' 2,381,584 Fulleton Aug; 7, ,1945 1-5:

of record in the

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