US2905214A - Hatchet - Google Patents

Description

Sept 22, 1959 T. J. TRETHEWAY 2,905,214

HATCHET Filed Aug. 5. 1957' INVENTOR. Thomas J.Trethewoy Attorneys HATCHET Thomas J. Tretheway, Seattle, Wash., assigner of onehalf to Paul Bromley, Seattle, Wash.

Application AugustS, 1957, Serial No. 676,157

1 Claim. (Cl. 145-2) This invention relates to hatchets or, more broadly, chopping implements in general. It is one object of the invention to form such hatchet, configuration considered, so that the same will perform a chopping function more effectively than has been heretofore possible.

The invention has the further object of providing a hatchet whose head is composed of two parts, one a tip cast from a metal of such characteristics as will permit the tip to take and hold a cutting edge, and the other a backing for such tip cast from a dead metal producing little or no recoil upon impact of the hatchet with an object being chopped.

As a further object still the invention aims to provide a hatchet so made as to be unusually light in Weight and thus particularly adapting itself to inclusion in a survival kit, and wherein such light weight is attributed in part to a hollow construction enabling the implement to be easily weighted, if desired, by loading the interior with wet sand.

The foregoing, with yet additional objects and advantages in view will appear and be understood in the course of the following description, the invention consisting in the new method of producing a hatchet and in the novel construction, adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawings:

Figure 1 is a side elevational view, with parts broken away and in section, illustrating a hatchet constructed in accordance with the teachings of the present invention.

Fig. 2 is a transverse vertical sectional view drawn to an enlarged scale on line 2-2 of Fig. l.

Fig. 3 is a transverse vertical sectional view on line 3 3 of Fig. l, employing the same scale as Fig. 2.

Fig. 4 is a rear end view of the hatchet; and

Fig. 5 is an elevational view portraying the tip Which forms the cutting edge for the hatchet.

With reference being had to said drawing, the numeral designates the hatchet head and 11 the handle. The head is shown as a single-bitted head, but the invention lends itself equally well to a double-bitted head. It is eminently desirable that the head and the handle be integral and while the same are so illustrated it is here furthermore pointed out that the teachings of the invention are applicable in part to the head alone and hence are applicable to a hatchet, or an axe, employing a handle which is removably associated with the head.

The hatchet of the present invention is bimetallic, employing one metal for the head proper and its handle, and a second metal for the cutting edge, shell molding or casting the latter separate and apart from the hatchet and applying the same as an insert 12. Such insert presents a sectionally triangular, or approximately triangular, striking body 13 backed by a tongue 14 extending as a prolongation of the altitude of said triangular figure, and the tip edge 15, the shoulders 16, and the tongues back edge 17 are each curvilinear and parallel to one another. Such curve is developed on a fairly long radius, say 61/2 as it pertains to the tip edge 15. The tongue 2,905,2l4 Patented Sept. 22, 1959 terminates at each end somewhat short of the end limit of the striking body, and piercing this tongue at equidistant closely spaced intervals of the length are a series of holes 18.

The insert 12 is composed of steel. Suitable for the purpose is A.S.T.M.-A-296-49%, Grade CA 15 modified to .20 carbon. After casting, the same is air-quenched to an approximate 40G-425 B-rinell hardness, and is then placed in a permanent mold having the shape of the hatchet, preliminary to the pouring of the second metal. For this latter purpose I prefer to employ an aluminum alloy, and particularly one whose modulus of elasticity will produce a substantial dead metal. Found to be eminently suitable is Tenzaloy (modulus of elasticity 10,300,000) having a nominal composition of 0.8% copper, 8.0% zinc, 0.4% magnesium, and the balance aluminum. ASTM specitications of this alloy, for permanent mold, are Bl08-50T alloy ZCSlB. Tenzaloy, while it can be artificially aged, say at a temperature of 250 over a l0 hour period, can be aged at room temperature to obtain equivalent mechanical properties. The pouring temperature is approximately l400-l450 F. This process of pouring the aluminum alloy on the steel insert 12 within the mold anneals the steel edge to an approximate 350 Brinell hardness. The Brinell hardness of the Tenzaloy is 74 after a l0 to 14 day room temperature period of aging, being 60 after aging one day. Its tensile strength after these periods of aging is 40,000 p.s.i. and 30,000 p.s.i., respectively. The yield strength reaches 27,000 p.s.i. after l0 days of aging.

Both the head and yits integral handle 11 are made hollow to provide connecting chambers 20 and 21, respectively, with the handle being open at the outer end, and a plug 22 having a knurled head 23 is threaded into said end opening as a removable closure therefor. A neoprene washer 24 is employed with said plug. Between the handle and the head, along the back of the former, there is cast into the hatchet a stilening web 25, and there is cast along the sides of the handle, adjacent the outer end, roughened surfaces 26 which augment a thickened butt 27 to assure a firm grip for the user.

Two features have considerable import in a consideration of the shape `of the head. One is -that the cutting edge is so placed that rectilineal line drawn tangent to a perpendicular bisecting the tip edge 15 is substantially parallel with the longitudinal center line of the handle. The significance lies in the fact that a blow centered on the tip edge at a point midway between its ends can be so delivered that maximum leverage is achieved at the exact moment of impact. Conventional hatchets, by comparison, locate .their cutting edges such that a bisecting perpendicular is in acute angular relation to the longitudinal center line of the handle. The other feature is the provision of a wedge-shaped head, namely a head in which the ilanking faces 28 belly outwardly. Having as its function to preclude the head from becoming immovably lodged in wood or other objects being chopped, as not infrequently occurs with a head having conventional concave flanks, the shaping of the head to a double convex configuration, as employed in a splitting wedge, is practical in a hatchet only Where such head is substantially devoid of rebound. The dead metal composing the present head permits the double convex shape to be effectively employed.

The described hatchet is especially adapted to use in a survival kit. The implement is unusually light in weight, and its Kair-tight interior permits safe storage of matches, maps and other items requiring protection from the elements. Having `substantially complete absence of rebound, the hatchet is highly eilicient either as a Weapon or as a chopping tool in its normal empty condition, but should added weight be desired a loading of the interior with wet sand considerably `augments the striking force. The cutting edge is found to be practically indestruotible under normal usage. Extensive tests including the chopping of access openings through sheet metal panelsY have shown that the tool `will withstand severe and even the most abusive treatment. The bond between the steel insert andthe aluminum alloy remains lsecure and there is little evidence of the cutting edge becoming chipped or dulled after very extended usage.

It is believed that the invention Will have been clearly understood from the foregoing detailed description of my illustrated embodiment. Changes in the details of construction, andin the formulations and processing of the metals composing the parts, will suggestthemselves and can be resorted to Without departing from the spirit of the invention. It is accordingly my intention that no limitations be implied and that the hereto annexed claim be given the broadest interpretation to which the employed language admits.

What I claim is:

An yall-metal hatchet having yan integrally cast head and handle of a light-Weight non-ferrous alloy having a low modulus of elasticity in the order of 10,000,000, said head and handle both beingv hollow and having their interiors connecting, `a steel insert locked in said head and providing Va chopping edge, and a removable closure for the outer end of said handle giving access to the interior thereof, said loW modulus of elasticity reducing the rebound characteristic of the hatchet during use thereof.

References Cited inthe le of this patent UNITED STATES PATENTS D. 140,408 Henkel Feb. 20, 1945 27,227 Lippincott Feb. 21, 1860 297,716 Rex Apr. 29, 1884 684,098 Regan Oct. 8, 1901 1,441,903 Blazuik Jan. 9, 1923 1,446,046 Johnson Feb. 20, 1923 2,692,626- Martin Oct. 26, 1954 2,738,815 Hoeldtke Mar. 20, 1956

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