US1552867A - Hatchet head and process of heat treating it and other articles - Google Patents

Description

Sept. 8, 1925.

G. G. MITCHELL HATCHET HEAD AND PROCESS OF HEAT TREATING IT AND OTHER AR ICLES Filed Jan. 26, 1924 Patented Sept. 8, 1925.

UNITED STATES GEORGE G. MITCHELL, OF UNION, NEW JERSEY, ASSIGNOR TO I. A. SAYBE &

CORPORATION OF NEW JERSEY.

HATCHET HEAD AND PROCESS OF HEAT TREATING IT AND OTHER ARTICLES.

V 1,552,867 PATENT OFFICE. f

Application filed January 26, 1924. Serial No. 888,875.

To all whom it may concern:

Be it known that I, GEORGE Gr.v MITCHELL, a citizen of the United States, and a resident of the town of Union, in the county of Union and State of New Jersey, have invented new and useful Improvements in Hatchet Heads and Processes of Heat Treating Them and Other Articles, of which the following is a specification.

This invention relates particularly to hatchets, although it may be employed in the heat treating of any tool which is similar to a hatchet in having a head with a thin blade or bit and an opposite striking portion or poll, with an intermediate eye, and I do not wish to be understood as limiting the use of my invention to any particular tool. In fact the invention is applicable to the heat treatment of any article which is desired to have opposite hardened portions and an intermediate portion somewhat temper drawn with respect to; such opposite portions.

The objects of the invention are in general to heat treat an article so as to secure in it opposite hardened portions and an intermediate temper drawn portion'with no istinct or sharp dividing line between the different grain structures of the steel, or in other words to secure a gradual transit-ion from one grain structure to another; more particularly to so treat a hatchet head or other article having an intermediate portion such as the eye of the hatchet which P is desired to be somewhat'temper drawn with respect to the striking port-ion or poll and the blade or bit of the hatchet; to thus secure a hatchet head or the like which is stronger and less liable to breakage; to secure a hatchet in which the blade or hit can be used back toward the eye a maximum distance, and to obtain other advantages and results as may be brought out by the following'description. 1

Referring to the accompanying drawings, in which like numerals of reference indicate the same parts throughout the several views,

Figure 1 illustrates the heating of an entire hatchet head for hardening the blade;

Figure 2 illustrates the quenching of the Whole hatchet head in hardening the blade;

Figure 3 illustrates the heating of the striking portion or poll preparatory to hardeningit, and at the same time temper drawing the steel about the eye and the bit, and

Fi ure 4 illustrates the quenching striklng portion or poll in hardening ltm" In said drawings, 1 indicates the headof a? a lathers hatchet to be heat treated by my improved process, said head having an eye 2, and a blade or'bit 3 and striking, portion or poll 4 at opposite sides of said eye.

It will be understood that the blade or hit I such hardening extending or penetrating only slightly into such striking portion or poll, and then to harden the blade or bit only about three-quarters of an inch from the cutting edge to prevent drawing of the temper from'the poll, thus leaving the major portion of the steel in the poll and bit and around the eye without proper heat treatment. This hardening of the poll and bit, moreover,--left distinct dividing lines between the ditlerent grain structures of the steel, particularly near thebase of the blade or bit, so that said blade or bit was likely to break at, the dividing line and was not hard enough to be used beyond said dividing line. a

In carrying out my improved process of heat treating, I first harden the .whole hatchet with a view to getting the proper hardness in the blade or bit, and then I harden the striking portion or poll with particular attention thereto. Describing the process more in detail, I first heat the entire hatchet head, as illustrated in Figure 1, to a temperature desired for hardening the blade orbit, as by submerging it in a liquid 1 heating bath 5, and then I quench the whole hatchet head by dipping it, blade down, in a quenching medium, such as oil 6, as illustrated in Figure 2, so as to give to said blade or bitthe hardness it is desired to have. Subsequentl the striking portion or poll 4, only, of the hatchet head is heated in the liquid heating bath 5, as shown in Figure 3, to the 1proper tein erature for hardening said po 1, and suc draw from around the eye 2 some of the temper or hardness already imparted thereto,

heating serves to t so as to leave the hatchet head highly temper'drawn around its eye as is desirable. Then the striking portion or poll is uenched in a jet of water 7, as shown in igure 4, so as to obtain. in it, and particularly its .face, the hardness desired.

'By my improved process of heat treating, therefore, a hatchet head is secured with ain structures which gradually change rom the highly temper drawn middle ortion around the eye 2 to the hardened b ade or hit 3' and the hardened poll or strikingportion/L and particularly the face thereof. Thereare no distinct dividing lines between the different grain structures, with conse 'quent weakness thereof, but maximum strength and durability are secured and the blade or hit can be made of minimum thickness. .1 201i. Obviously while I have described my imroved processas applied to the heat treatmg of a hatchet, it can be applied to other articles of similar nature, or indeed to any article having opposite hardened portions 2 w 'th an intermediate temper drawn port-ion, without departing from the spirit or scope of the invention, and I do not wish to be understood as limiting myself except as required by the following claims when construed in the light ofthe prior art.

Having thus described the invention, what I claim is: v i 1. A process of "heat treating an article to secure opposite hardened portions and an intermediate temper drawn portion, consisting in hardening the article as desired for one of said opposite portions, heating the other of said opposite portions to a temperature for hardening it which Will draw temper from the intermediate portion, and quenching said heated opposite portion.

2. A process of heat treating an article to secure opposite hardened portions and an intermediate temper drawn portion, consisting in heatingthe article to a proper temperature for hardening one of said opposite portions, quenching it, heating the other of said opposite portions to a proper temperature for hardening it and temper-drawing the intermediate portion, and quenching the last-heated opposite portion.

. 3. A process of heat treating a hatchet head or the like to secure a temper drawn eye and differently hardened portions at op;

posite sides of said eye, consisting in heating the head to the proper temperature for hardening the portlon at one side of said eye, quenching the head, heating the ortion at the other side of said eye to t e proper temperature for hardening it and'temperdrawing the eye, and quenching said lastheated portion.

,4. A process of heat treating a hatchet head or the like, consisting in heating the head to a proper temperature for hardening the blade or hit, quenching it, heating the poll or striking portion to a proper temperaturtle for hardening it, and quenching said pol 5. A process of heat treating ahatchet head or the like, consisting in heating the head to a proper temperature for hardening the blade-or bit, quenching it, heating the poll or striking )ortion to the proper temperature for hardening it and temper-drawing the eye, and quenching said poll or striking portion.

6. A hatchet head or the like having a hardened blade or hit, a hardened striking portion or poll and a temper drawn eye portion between said blade and poll, with the grain structure changing gradually from one of said parts to another, whereby a distinct dividing line upon which breakage may occur is avoided.

7 A hatchet head comprising a hardened blade or bit, a differently hardened striking portion or poll and a temper drawn eye portion between said blade and poll, with the grain structure changing gradually from oneof said parts" to another, whereby a distinct dividing line upon which breakage may occur is avoided.

'8. A processof heat treating a hatchethead or the like having a blade or bit, a striking portion or poll and an eye between said blade and poll, which consists in hardening the blade and eye suitably for said blade, heating the poll to a proper temperature for hardening it and temper-drawing said eye, and quenching said poll.

9. A process of heat treatin a hatchet head or the like having a blade or bit, a striking portion or poll and an eye between said blade and poll, which consists in hardening the head suitably for said blade,,heating the poll to a proper temperature for hardening it 'and temper-drawmg said eye, and quenching said poll.

GEORGE e. MITCHELL.

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