US2571350A - Method of forming hand-operated striking tools - Google Patents

Description

Oct. 16, 1951 O E$Tw|NG 2,571,350

METHOD OF FORMING HAND OPERATED STRIKING TOOLS Filed Nov. 16, 1950 fliiomeys Patented Oct. 16, 1951 -ME-THOD' OF FORMING HAND 'OPERATED v STRIKINGFIOGIJS Ernest Q..E'stwing, Rockford, Ill., assignor to Estwin'g Manufacturing Company, Incorporated, Rockford, 111., a; corporationof'lllinois Application'November 1s, 1950, Serial No. 195,988

This invention relates. to the formation. offhand :operated striking tools such as hammers, hatchets and the like and moreparticularly to a methodior producing thatqclass of tools in which the handle, shank and head are integral one with theother.

Tools of the above character as they have heretofore been madehave exhibited 'a lack of uniformity in quality which, though smallincomparison to the number ..'of such toolsv made and used, is nonetheless undesirable.

.I have foundthrough the manufacture or such tools over a period of yearsv in'accordance with the method disclosed in my prior U. 1S; Patent No. 1,669,701, that in spite .of .all reasonable precau- 1; Claims. (01. reins? tionsmanufacture a certain percentage of'the tools will, while rm use,.hreak in the shank, though .on .final inspection at the plant they appeared 'to be. perfect. Uponfinspection avgreatshare of the breaks appeared first as cracks-extending. in

a direction, crosswise of the shank, apparently developing as a result of the vibration andstrain 'occasione'di'hy repeated use of the tool. fThrough the years it has seemed probab1e"that thistbreakage resulted from some defect inthe tool 'as'it left the factory but rigid inspection, and study 'fail'ed'to reveal the cause. "Sometimesthe break- "age would" occur shortly after'the tooPwas-plac'e'd "in "service 'while'at 'others it would not occur until the tool had been in severe longed period of time. v v I A"'solution to theproblem' has been a difii'cult jmatter in part because the cause was unknown. ItiSjl'IOt possible, from a practical standpointgto increase the "cross sectional "area of theslank without increasing the weight and impairing the balance of the tool the latter of which is-"an irnservice over: a "proportan't property of s-uch tool's. -'Fur thermore, it seemed apparent that the cross sectional-area was adequate when the tool was properly con- -'s'trueted as evidenced by the fact that fa'il mre occurred in only a small proportion -o'f the total production.

An important object of the invention the provision :of animprovedxmethod of manufac- "ituring tools of the; character described capable of producing .the. same r.=substantially iiree rof :the "defects heretofore associated therewith. I

Another object of the invention is theprovisiocn -'0f a methodior making tools-:ofthe character --described wherein faults physical structure 'resultingfrom-prior used- -irom the tool.

methods are eliminated A vfurtherobj-ectsisthe provision-of a method of making tools of the aforesaid character'whieh results in improved -grai-n structure the *izital shanhportionof the; tool.

' shamans handle.

invention. 35

and described the method asit applies to the making offlan ordinary-=oarpenters hammer,- but it will .Ibevunderstood that the essential steps-of :the methodras.defined inthe claims are equally zapplicable toflthe' making of other hand'str-iking Stools. such as hatchets, picks, and other similar tools 'Wherethe head integral. 1 e

A still further object is the provision of a method .for making tools of the character described at Ya more ..rapid and uniform rate vso that the necessary operations may all be performed while themetal is still hot enough to be worked without extensivescale formation.

Another object 'is the provision of a method "for making tools of the. character .described'iby which workmen oflesserskill mayproduce products o'fthehighest quality.

Another important object of the inv'ention-is the provision of -a method ,for makinga hand striking tool wherein the metal is hot processed during successive shaping operations to provide improved properties in the head and] shank by drop forging the .headportion of the tool transverselyof'theheadand by rolling the metal. of

the 'shank'intoelo'ngated form to produce "the Further objects'will be apparent from the following specification, appended claims and drawings'thereofl'in which Figured shows the forging dies of a .drop'hammer for performing operations resulting in the structuresshownin Figs. 6 and 7 in the formation of a'striking'toofhandle;

r Fig. Zshows a pair of rolls for'perforrningoperations on the handle; resulting inthestructure shown in Figs. 5;

Fig. 3*shows-a-series of forging-and shearing dies for 'performing operations hot forming'operations on' the toolhead; and: 4 1

Figs. 4 through .11 show successive steps in the formation "of '-'a hammer in accordance with *the For purposes of illustration I have herein show-n and :shank :of the tool -are -lEteferring to the drawings, .Figure 1 vshows "a ipairitoftmatingwdieiplates l0 and SH which in use are mountedrin arr ordinary power .driven drop hammer not shown. Forconvenience. these die -plates-.have:a-seriesof matingcavities for periorm-ing a number-"of operations but-vif-desired "eachpairef cavities maybe on separate plates supported-in"differentmachines. The plateshave .mating cavities JZior-med therein-of a shape and size. to convert ,a heated. .billet -l:3 --(E-ig. 4) into workable form..- This billet tisgripp ed 2by apa'ir of tongs fluheld by an operator.

To produce .a shape as shown .i 11.Fig..4-,;the;end

3 of a heated billet is inserted over the cavity I! by means of the tongs and the drop hammer is operated to deliver a blow on the hot billet. As the die plates I and II separate, the work is given a quarter turn, in the same relative position, and the drop hammer is again operated to deliver further blows on the work to produce the shape shown in Fig. 4.

This processed shape comprises an enlarged circular body portion [6, a flattened tongue I] extending from one face of the body portion,- and a reduced neck [8 separating the unused part of the billet from the formed body. E

The operator then inserts thetongue'll between the mating rolls [9 and 20, Fig. 2, which are power driven at a constant speed and in a direction to eject the work placed between them toward the operator. These rolls are secured to the driven shafts 2| and 22 which are geared together so they rotate at the same speed and in the same relationship to each other. These rolls are machined with surface areas having different radii from the axis to form the areas 23 of smaller radius providing a clearance area between the rolls and the areas 24 of the larger radius which provide mating die faces for operating upon the piece being processed. Ra-

dial shoulders 25 and 25 define the areas of The faces of areas 24 are machined to provid the circumferential grooves 21, 28 and 29 which extend from the leading shoulders 25 to the trailing shoulders 25. These grooves have the corners rounded where they meet the die face and shoulders 25 and 25, and are of different cross sectional areas. The grooves 21 have the largest cross sectional area, the grooves 25 have a smaller cross sectional area, and the grooves 29 have the smallest cross sectional area. The grooves 29 are provided with depressions 30 at a predetermined distance from the shoulder 25 so that the stem 3| as shown in Fig. 5 has the nub 32 formed thereon, in this roove.

In forming the stem 3| the operator inserts the hot shape shown in Fig. 4 between the rolls l9 and 20 when the areas 23 are contiguous and in line with the mating grooves 21 so that as the rolls rotate, the mating grooves 21 impinge on the tongue ll adjacent the body portion I6 and roll it to conform with the grooves 21. Meanwhile the operator moves his hands toward him as the processed piece is advanced by the action of the rolls, and when the piece is free from the rolls, the piece is given a quarter turn and again inserted between the rolls in line with grooves 28. piece and swage it down to a size determined by the cross sectional area of these grooves. The operator again moves his hands toward him as the piece is being processed and when the piece Again the grooves 28 engage theis free, he again turns the piece one quarter turn 'formed into a flange on the finished handle to locate a hand grip placed on the handle. However, while it is preferred to provide this nub, 75

it is not essential as the forming rails is and 20 may be separated slightly to allow more metal in the rolled stem 3| which can later be flowed to produce the flange.

To provide for locating the piece as it is inserted between the rolls l9 and 20, stops 33, 34 and 35 are adjustably mounted in a cross member 31. By adjusting the nuts 38 on the threaded stems 39, the proper setting for each of the stops may be had. Each of these stops comprises a guard 40 which is bent U-shaped and welded onto the stem 39.

p In processing the piece through the rolls, the

operator moves quickly and while he may become very adept at locating the piece, these stops facilitate in locating the work to the proper groove, and also in locating the work upon insertion between the rolls to the proper length of swaging action.

" After the structure of Fig. 5 has been completed, th piece, still supported by the tongs is placed between the die plates in and II, over the cavity 4! and the drop hammer is again operated to deliver a blow on the piece and force it into the mating cavities 4| to produce a rough shape as shown in Fig. 6.

The piece is then turned over while being held by the tongs l4 and placed over the lower mating cavity 42 formed in die plate It. The drop hammer is again operated to shape the piece to conform with the mating cavities 42, the excess metal flowing as a flashing 43 all around the formed piece. This flashing allows flaws and defects which might occur along the edges of the shank or handle to be squeezed out beyond the resultant edges of the shank or handle and minimizes the possibility of a cold shut remaining in a vital spot of the handle. This produces a piecesimilar to that shown in Fig. 7. In this operation the tool head 44 is formed, the shank 45 has been reduced to its rough shape and size, the flare 41 for the hand grip has been shaped and the handle 48 has been given its I beam shape.

From the cavity 42, the piece is moved to another machine and placed on the form 48 carried by a die plate 50 where the shear 5| carried by the plate 52 trims the flashing 45 from the formed tool as shown in Fig. 8. Thereafter the head is placed in a forming die 55, as shown in Fig. 3, to groove the head in the clawformation. This die is formed in a block 54 which may be secured to the platen of the press, not shown. A block 55 carries a forming tool 51 adapted to engage the head and start the formation of the claws by spreading the metal. This results in the structure shown in Fig. 9.

The tool is then moved to a forming die 5|, formed in the block 59 and as the press is operated a slitting and forming tool 50 carried by a block 5| engages the claw end of the head and produces the separated claws. The block 59 is attached to the platen of the press, and the block Si is carried by the movable head. The tool now resembles that shown in Fig. 10, with the claws 52 extending almost straight from the the head.

In the final operation the tool is inverted and placed in the forming die 53, also carried by the frame of the press and a mating die 54 carried by the movable head of the press moves down to bend the claws 52 to a desired shape'as shown in Fig. 11.

At this time, the metal has cooled considerably and the tool is allowed to cool, after which it is ground and polished on the exposed surfaces, and a hand grip is pressed on the handle up to the flare 41 and held in place by a retaining plate as well known in the art.

It will be understood that where the method is applied to the manufacture of other tools such as hatchets, picks or other types of hammers, the die cavities M and 42 will have correspondingly different shapes and the final shaping of the head will vary depending upon the shape of the head required for the tool. However, in each case the essential steps will be the same in that the head portion will be produced by hammer forging and the shank and handle portion are produced by rolling the metal.

I have found that tools produced in this way are substantially free from the latent defects heretofore present in a certain proportion of tools made in accordance with prior art practice. While all of the reasons for the improved results produced by this method are not entirely plain, it is my belief that they result primarily from two causes.

In prior art practice the tools were made by drop forging the entire structure including the shank and handle portion. The elongated stem 3| was produced by imparting to the metal a succession of blows in a direction transverse to the axis of the stem to elongate this portion in step fashion. This, in my opinion tended to dis- 7 rupt and break up the grain structure and thus produce a discontinuity along the length of the shank, whereas such discontinuity is avoided by drop forging the head portion and rolling the shank and handle portion to elongate the grain structure in this area.

The operation of forging the stem 3| also required great skill on the part of the operator in order to keep the reduction as uniform as possible along the length of the stem. However, even with the most skillful operation irregular nubs are formed on the stem. It is my belief that when the stem thus formed is later plastically deformed to shape in the cavities AI and 42, these nubs occasionally fold over in flattened layers instead of flowing or flattening out into a body of the stem thus producing a flaw undetectable by normal inspection methods.

I claim:

1. The method of rough forming a striking tool, comprising forging one end of a heated billet into a workable form having an enlarged circular head and a tongue extending therefrom, roll forming said tongue by a series of passes into an elongated small cross sectional area stem, l

forging said enlarged circular head and said elongated stem into a tool form having lateral extensions from said stem for the head of the tool, forging said tool form into a specific tool shape having the excess metal flow as flashing from said tool form and removing said flashing from said tool shape.

2. The method of rough forming a striking tool comprising forging one end of a heated billet into a workable form having an enlarged circular head and a tongue extending therefrom, roll forming said tongue by a series of passes into an elongated small cross sectional area stem, forging said enlarged circular head and said elongated stem into a tool form having lateral extensions from said stem for the head of the tool, forging said tool form into a specific tool shape and causing the excess metal to flow as flashing from said tool form, and thereafter shearing said flashing from said rough tool shape.

3. The method of rough forming a striking tool, comprising forging one end of a heated billet into a workable form having an enlarged circular head and a tongue extending therefrom, hot roll forming said tongue by a series of passes into an elongated small cross sectional area stem, rotating the work one-quarter turn between each of said passes, forging said enlarged circular head and said stem into a tool form, forging said tool form into a specific tool shape and causing the excess metal to flow as flashing from said tool form to wash away minute cold shuts from said tool form and shearing said flashing from said tool shape to present a rough finished tool.

4. The method of rough forming a striking tool, comprising forging one end of a heated billet into a workable form having an enlarged circular head and a tongue extending therefrom, hot roll forming said tongue by a series of passes into an elongated small cross sectional area stem, rotating the Work one-quarter turn between each of said passes, forming a nub on said stem during the last pass through the rolls, forging said enlarged head and said elongated stem to flow the metal of said circular head transversely to the metal in said stem to form a tool head integrally on said stem, forging said tool form into a specific tool shape and simultaneously causing the excess metal to flow as flashing from said tool shape to flow minute defects from said tool form, and shearing said flashing from said tool shape, all of the aforesaid steps being conducted without reheating of the workpiece.

5. The method of rough forming a striking tool, comprising forging one end of a heated billet into a workable form having a predetermined amount of metal therein and having an enlarged circular head and a tongue extending therefrom, hot roll forming said tongue by a series of passes into an elongated small cross sectional area stem, rotating the work one-quarter turn between each of said passes forming a lateral nub on said stem during the last of said passes, forging said enlarged circular head and said elongated stem into a tool form by flowing the metal of said circular head transversely in opposite directions to form a tool head, and flowing the metal in said nub into a flange on said stem, forging said tool form into a specific tool shape having the excess metal flow as flashing from said tool form and shearing said flashing from said tool shape to produce a rough tool, all of the aforesaid steps being conducted on the workpiece in rapid succession and without reheating the same.

6. The method of forming a striking tool comprising forging one end of a heated billet in a forming die into a workable form having an amount of metal therein in excess of that required in the tool and having an enlarged circular head and a tongue extending therefrom, hot roll forming said tongue by a series of passes into an elongated small cross sectional area stem, drop forging said enlarged circular head and said elongated stem in a forming die into a tool form by flowing metal in said head transversely with respect to said stem to form a tool head, further forging said tool form in a forming die into a specific tool shape having the excess metal flow as flashing from said tool form, shearing said flashing from said tool shape, and subsequently shaping said head to flnal shape.

ERNEST O. ESTWING.

No references cited.

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