US1578502A - Hand tool - Google Patents

Description

March 30,1926. 7 1,578,502

E. O. ESTWING HAND TOOL Filed July 17 1924 Patented Mar. 39, 1926.

, ,"UNITED STATES ERNEST onsrwme, or nocxronn, ILLInoIs, AssIenoa-I'o nsrw'me MANUFAGTUR- me COMPANY, INO.,'0F nocxronn, ILLINOIS, A CORPORATION or ILLINOIS.

To aZZ whom it may concern:

Be it known that I, ERNESTO. Es'rWING,

a citizen of the United States, residing at Rockford, in the county of \Vinnebago and State of Illinois, have invented certain new .1 T and useful lIHPI'OVQl'DQIlbS inHand Tools, of

which the following is a specification.

Thls invention relates to' hand striking tools and Implements and has more particular reference to axes, hammers and hatchets.

The primary purpose of the invention is.

to provide an improved hand tool,.such for example as an-axe,,hammer or. hatched-in which the head and handle are drp-forged in one piece and so shaped and treated that maximum strength is obtained with mini-.

mum weight and material and the tool iswell balanced and substantially unbreakable. By

this I mean-that it is-unbreakable when'used in the manner and for the purposes intended for tools of this kind. making the handle [and head in one piece the many objections to the conventional construction,employing fastening means or devices of some sort ior duced cross-section throwsthe center of gravity in the header close'thereto, accord- .ing to the style of the tool, whlch gives a highly desirable balance. This balance -enables more eflicient use of the tool because the greatest weight being in the head enables the greatest degree of manual effort to be.

' thereis the least lost effort due to the 'bal- .40

transmitted in the blow. With such a tool ance of handle and head and consequently the tool is less tiring to use and the strokes are more efiectivethan withthe conventional style of tool. The foregoing results are attained to better advantage when the handle -is tapered in thickness gradually from the head to its remote end, thus further throw-- ing the'center of gravity close to the head and providing the greatest strength adjacent thereto, at which point the greatest strain and stress occurs from the efiects of, the

blowp Another advantage-resulting. from,

a tool shaped as described is that it may be used ,very efi'ectively as a pry for splittmg wood and in some instances as acrow barby sidewis'e pressure onfthe handle after-the HAND 001.. p

. Application filed July 17, 1924. Serial No. 726,433.

blade has i been inserted between for driven into the parts to be separated. In order to fill out the hand grip suitable scalesjor grips are riveted or otherwisesecured to the sides of the handle.

The foregoing features of construction are v 1,578,502 PA EN QFFI'CE."

made possible in a commercially practical tool by reason of the method employed in,

1 manufacturing it. According to my inventiontheaxe, hammeror hatchet is formed or shaped in one pieceby drop-forging. The

forgings or tool blanks arethen normalized to reduce internal strainfinlthe structure or to establish equilibrium of the constituents.

The tool blanks are then annealed for 'ma-. chineability and following this are hardened heat. treatment as will beexplai'ned more fully hereinafter. P I Otherobjects and attendant advantages will be appreciated by those skilled in this art as the invention becomes betterfunderstood byreference to the following d'escrip-.

tion when considered in connection with i the accompanying draw ng, in wh ch v .Figure 1, IS a side elevation of a scouting or outdoor are or hatchet, embodying'my invention; i I I I a, i Fig. 2,.is' an end view of the head. of said hatchet," W W i a Figs. 3,4,5 and 6 are sections taken on the :lines 3-3, H, 55 and 6 6 respectively, ofFig. l; I

V Fig. .7, is a side elevation of a carpenters hatchet embodying my invention; I p 7 Fig. 8,.1s an end v ew of the head shown in Fig." 7; and

from another,flis applicable to all tools of} this type. 1 I

Considering first the structural characteristics common to these tools, my invention provides a metal head and a handle in one piece. The head, designated generally by] Fig,g9, is a section taken on the line 99 I 11, may. be of any suitablefshape, such as" f an -axe head, hammer head orhatchet head, I

except that according to my invention the head may-be comparatively narrow .ior ve'ffective cleavage becauscnoeye font-he ban dle or helve is necessary. This is especially desirable in carpenters hatchets as shown in Fig. 8, and is also desirable in scouting or outdoor 'h'atchets as shown in Fig. 2. The handle, designated ge'nerallyrby 12' is elon-v gated in cross-section substantially from end to end in a plane parallel with the plane-of the head, as shown in Figs.r3, andv5. This that the reductionin' sectional area is' caramount of metal.

reduces wind resistance to a iiiininiuni and gives maximum strength in' the I plane in which mostv stresses 'occur when using the tool n striking. The greatest cross-sectionalarea is at the juncture of the head andhandle, as shown in Figs. 3 and 6, so that thegreatest strength is at the point-of great-v;

est-stress. The handle tapers in thickness toward its outer end and is therefore of a gradually reducing cross-section as clearly shown'in said- Figures 3 to 5 inclusive. This reduced crosssection although not necessarily tapered, is an essentialfeatur'e of my invention for the 'reasonthat it throws the center of gravity forward 'to or in proximity to the head with consequent advantages as described above and for the further reason ried out in a way so that it provides the greatest requisite strength withthe "least The reduced cross-section is made, possible by the method of manufacture here nafter described and 1s,;there- I fore, dependent on such method in so far as the production of a commercially practical and salable tool is concerned. In orderto fill outjth-e hand grip portion of the handle wooden scales or-grips 13' are secured to the sides thereof by suitable means such as rivets 14. The grips'niay however, ,beof any suit- 7 facture of a striking tool by forming and" one-piece tool.

' able. or preferred material which is light in weight and durable. L r It will'be observed from the foregoing that my invention contemplates the manushaping the striking. head "and handle by :forging operations to, produce an integral,

Thetool is forged into a novel shape characterized by its comparatively flat, narrow handle which: coniprises'aweb portion to which the. grips or scales 13 are attached and a shank port on interme- V diate this and the striking head. The forgingand hammering operations alsocoinpress and reduce the size of the grain of thesteel fto give greater strength. It will be noted. that the cross-section: of the handle through out both the shank and web portions is re duced transversely and elongated in a plane parallelwith the major axis of they striking head and is further reducedpor tapered lon gitudinally at bothsides'graduallyfroni the strikingj'liead to the opposite endLflBy reason of this narrow cross-section less metal isl mployed in the handle which, consequent sly; is of less weight than 111 any prior 'strik- 1s tool having ahead, handle shankjand axe, hatchet, hammer or the like.

a they are of wood;

handle web in one piece, whether it be in an This is accomplished without impairing the shape and usefulness of the tool;;;;.andi moreover,

it enables .a betteridistributioni ofgthe metal for strength and balance for the reason that the handle crosssection is comparatively both sides of the handle web at either one or both ends thereof. These fillets. merely serve to fill 1n the'space between the ends of the grips: and the handle shank or web so as to give a smooth outside surface and to protect the ends of the grips especially when of other shapes and materials might be used.

It will beobserved that in actual practice the handle shank and web portions are thinner or narrower in transverse cros's section than shown iii the drawings, in proportion to the size of each tool shown. That is, the

drawings show the handle shank and web cross-'sectionsthicker in order to more clearly*illustrate the longitudinal transverse taper. 1. 1 The foregoi ig novel characteristics as to the shape of the tool are made possible in a practical tool onlylby.combining therewith certain determined physical properties in The fillets are 11Qt'tl1GI'C fore, 'BSSGIltlEl-l to myinvention because grips the molecular structure ofthe' steel. To.

this end my invention contemplates heat treatment of the forged tool to remove-all strains incident .to the forging operations andto uneven cooling of the shaped tool, to 7 refine the inicrostructure characteristic of the metal, and to increase the tensile strength, raisethe elastic limitand reduce ductility. By coinbiningthe above-mentioned charac teristics 'of-f-shape 'and definite physical.

properties by reason of this method of manufacture I obtain a new result, namely. a hand striking tool which is substantially unbreakable for the purposes intended and has less. material in the handle and better'balance and feelthan any prior one-piece metal too], so .far as I am aware.

Furthermore, a striking tool made in accordance withniy invention is far more useful than prior tools otthis kind that is, it

can be used for more purposes'an'd'can be the-tool, flhis is due primarily to theunusual strength in the handle and its adapta- [tion to prying, splitting and pulling beyond the range of tools-of this character on the market. s c r V 1 I The method of manufacture is as follows subjected to harder use without damaging A high carbon steel should be used, preferably one having the following chemical comfrom non-metallic inclusions when examined under the microscope. The tool will be formed and shaped by drop-forging operations, it being noted that the forging temperatures should be closely observed and kept within the range of from 1900 .to

2100 F. The forgings are then normalized to establish equilibrium by heating to 1550 F. and quenching in oil. The next step is to anneal for machinability, that is, for rough grinding and drilling the rivet holes. obtaining a Brinell hardness of 190-200.

. Following this the tool-blanks will be hardened by heat treatment. The first stepis to heat the blanks to 1450 F., then quench in mineral oil, 'thus obtaining a martensitic condition on the cutting edge and atroostito- 'martensitic condition in the body and han- .dle.

The blanks will then be drawn at 406 F. in oil, whereby the cutting edge is converted .to troostite-martensite condition and the handle to sorbotroostite, after which the edge may be ground and, the tool finished as by applying the handle grips, polishing, etc. This gives the most desirable physical structure for a tool of this-kind and makes pos sible the use ofthe reduced,cross-section'in the handle above described. I By reason of the foregoing method of.

manufacture a high'grade tool may be pro duced andsold at areasonable price. Furthermore, the finishedproduct has superior qualities becausethere is; no danger or trouble incidental to the head loosening and 'the handle is unbreakable when put to the uses intended for tools of this kind. As a result of said method the physical properties of the steel after it has been normalized and annealed are approximately: tensile strength 120,000 lbs. per square inch, yield point 90,-

' 000 lbs. per square inch, reduction of area 20% and elongation 15% and after the heat treatment operations approximately the following physical properties are obtained in.

thefinished tool: tensile strength 180,000'1bs. per square inch, yield .point 150,000 lbs. per square inch, reduction of area 5%. and elongation 5%. I L

lVhile the foregoing describes a preferred method of practicing my invention, the particular steps taken and the examples showing' proportions used are merely for purpose of illustration. It should therefore, be understood that 111 manufacturing striking tools in accordance with my invention changes may be made in'details of construction, as for example, when applying the invention to the manufacture of different tools such as axes, hatchets, hammers and the like, also that any suitable or equivalent steps and operations might be employed for securing the desired physical properties in the metal of the finished tool,'without destrength in the plane in which most stresses occur in striking with the tool and also to reduce wind resistance and secure minimum weight, the handle having also a gradually reducing thickness from the head endto the holding end so that greater strength is thrown toward the head end of the handle where the striking strain tends to concentrate While lightening the handle as the strain diminishes. V p o.

. 2. A forged and tempered hand striking tool having .an integral striking head and handle, the handle having from end to end a cross-section elongated in a Plane parallel with the plane of the head to secure maxi- ;mum strength in the plane in which most also to secure minimum weight, the handle having also a gradually reducing thickness vention as expressed in the appended claims,

fromjthe head end to the handleend so that greater strengthis thrown toward'the head I end of the handle Wherethe striking strain tends to concentrate whiledightenmg the" handle as the strain diminishes, the tempering permitting the maximum reduction in cross-section for lightness while retaining strength. v

3. A hand striking tool comprising a forged one-piece striking head and handle, the handle having substantially from end to end a cross-section elongated in a plane'par allel with the plane of the head to secure the maximum strength in the plane in which most stresses occur in striking with the to 11 and also being so proportioned in cross-section that greater strength is thrown toward the head end of the handle where the striking strain tends to concentrate while lightening the handle as the strain diminishes, the

.tool being heat treated to permit maximum lightness while reduction in cross-section for retaining strength.

ERNEST of. ESTWING.

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