US2355641A - Soft hammer - Google Patents

Description

" Aug. 15, 1944.

F. A GALLANT 2,355,641 'so FT HAMMER I Filed Feb. 27; 1942 'INVENTOR Frauds/l. G'aZ/anf ATTORNEY:

Patented Aug. 15, 1944 sor'r HAMMER Francis A. Gallant, East Orange, N. J., assignor to Victory Safety Hammer Corporation, East Orange, N. J., a corporation of New Jersey Application February 27, 1942, Serial No. 432,614

Claims.

This invention relates to soft hammers or the like and aims to provide certain improvements therein.

Hammers constructed with relatively soft heads have a wide diversity of use in the industries and also in the operation of many machines. Generally speaking, they are used for the purpose of delivering blows against machine parts or other objects when it is desired to loosen or tighten the same without injuring the object struck, either by affecting its finish, or chipping or shattering the object. Such hammers have a wide range of utility and a very considerable variation in size and weight, and to some extent in shape. In hammers of this type as heretofore constructed, the head of the hammer has usually been made of metal which is relatively soft as compared with the work upon which it is to be used. Such hammers as a rule follow the old construction of double-ended hammers or sledges, differing only from the latter in the character of the metal used. As heretofore constructed, all of the soft metal hammers with which I am acquainted have the disadvantage that after they have been in use for a short time, the striking faces begin to mushroom, or spread very much in the same manner as the end of a rivet is upset. This creates a circular fin around the striking face, which fin is very apt to crack off in use and fly into the face of the user or nearby operatives, and many painful and serious accidents have occurred from this cause. is often seriously affected by the wearing away of the metal of the head in this fashion.

According to the present invention I provide a hammer of this type which is not subject to the foregoing disadvantages, but which, on the contrary, maintains a relatively smooth external contour, without substantial fins or projections, and also retains its balance until the hammer has lived out its useful life. The invention is applicable to soft-headed hammers of all types, sizes, and configurations, running from the ordinary single-handed type to the heavier sledges and mauls.

In the drawing, wherein I have shown the preferred form of the invention Figure 1 is a side elevation of a conventional size of hammer, showing the head or striking portion in elevation and the interior construction in dotted lines;

Fig. 2 is a section of a part of Fig. 1, showing the head of the hammer, the section being taken substantially on the line 22 of Fig. 1;

Furthermore. the balance of the hammer Fig. 3 is a section of the head of the hammer taken on the line 3-3 in Fig. 2; and

Fig. 4 is an end view of the hammer head.

Referring to the drawing, let A indicate the hammer head and B its handle of any suitable form or shape. The hammerhead is shown as of the double-ended type, having striking faces C and D, the head being illustrated with a thickened middle portion formed .with the eye E through which the end of the handle projects and is secured in the ordinary manner. Preferably the hammer head tapers in both directions from the central thickened portion to the striking faces. Any of these features may be changed at will.

The general object of hammers of this type is to provide a hammer head of sufficient mass to exert the required force against the part struck without creating an impact which would mar the finish or endanger the safety of the part in question. In other words, the general purpose of a soft-headed hammer is to cushion the blow by the yielding of the material of which the hammer head is composed. This yielding of the hammer head, where the blow is substantial, creates a plastic deformation of the metal of the head. Except for a restricted amount of compressibility of the metal of the head, it is obvious that the deformation, which is permanent, will displace the metal in some direction or other. With the solid-headed hammers now in use, this displacement of the metal causes it to upset in the manner hereinbefore referred to. According to the present invention I provide a hammer head in which provisions are made for displacement of the metal in the interior of the head. To this end I provide the hammer head with cored-out or hollow portions such as the chamber F, best located as is seen in the drawing, and this corded portion is duplicated at G when the hammer is double-headed. For ease in casting, the chambers F and G are connected up with the eye E by passages H and I, as shown.

The location and shape of the chamber F with relation to the exterior shape of the hammer are of some considerable importance. Preferably the chamber follows the general cross-section of the head. In the particular form shown in the drawing the head is, generally speaking, square in cross-section and the chamber is, hence, formed with a similar cross-section. This provides side walls J of substantially uniform thickness around the chamber. The supporting walls K for the striking faces C and D are preferably, however, of greater thickness than the surroundconsideration the size and shape of the chamher.

When the hammer provided by the invention is put into use, I believe that there almost immediately begins a very slow collapse or yielding of the side walls into the chamber F (or G, as the case may be). This yielding or deformation of the hammer head is able to progress symmetrically because of the fact that the chamber provides a space into which the metal can flow. The exterior of the hammer head preserves in general its symmetrical shape and balance because of the orderly collapse of the walls. There are substantially no fins formed on the exterior, and prolonged use gradually flattens or collapses the working portions of the head, which maintain in general a smooth exterior shape. This is accompanied, as in the case of all soft metal hammers, by a certain wearing away of the metal at the striking faces.

The particular metal selected for the hammer head depends largely upon the purpose to which it is to be put. As a general proposition, copper is a very efficient metal, having the proper degree of softness for many operations. This may, however, be further softened, if desired, by the use of lead or lead and zinc; or it may, if necessary, be hardened by the use of proper alloy metals. The invention does not exclude, however, the use of any metal, or, in some instances, other soft materials, which have the requisite degree of hardness and plasticity for the special purpose involved. Properly selected metals will not spark on contact with steel and iron or other materials upon which it may be used, and hence do not constitute a hazard in the employment of the present invention where explosives are present. Copper is one such metal.

While I have shown and described one form of the invention, it will be understood that I do not wish to be limited thereto, since various changes may be made therein without departing from the spirit of the invention. While the ham mer head is best formed as a single casting, it is, of course, possible to construct it in several parts connected by welding, brazing, or in any other suitable way, to make a unitary construction. While I have shown the invention as applied to the head of a hammer of conventional type, having a handle, it will be understood that I wish to include any striking part where the same functioning is desirabl or necessary, irrespective of how the part may be mounted or whether it may b designed for manual or other use. It will also be understood that, broadly speaking, the invention covers heads in which the metal can become displaced inwardly as described by a plastic flowing action, and, while an empty cham ber is best suited for this purpose, the invention covers other constructions which have means for permitting this action.

What I claim is:

'1. A hammer having a handle, a head of unitary construction mounted on said handle, said head being composed of a material which has the requisite mass, degree of hardness and plasticity, and having a striking portion of no greater area than the cross-sectional area of the head rearwardly of the striking portion and of sufficient thickness to absorb a large part of the shocks of use and undergo severe plastic deformation in continued use, said head having an interior chamber inwardly of the striking portion and lying back of a substantial part of said striking portion-the side walls of said head surrounding the chamber inwardly of the striking portion being of less thickness than the striking portionl, and said chamber being adapted to receive a part of the striking portion as the material thereof undergoes such plastic deformation in use, whereby to avoid mushrooming of the material of the striking portion around the exterior edges of its striking face.

2. A hammer according to claim 1, wherein the head is of generally tapered form having its smallest cross-sectional area at the striking end of the head.

3. A hammer according to claim 1, wherein the chamber within the head inwardly of the striking portion is in general of the same transverse cross-section as the head and has rounded edges.

4. A hammer according to claim 1, wherein the head is composed of soft metal.

5. A hammer of soft metal comprising a body having a tapering striking head and a handleengaging socket, a chamber in said head, and a passage connecting the chamber and socket, the chamber and passage providing a tubular wall about said chamber and passage increasing in thickness toward the socket, said striking head having a striking portion thicker than the adjacent portion of said tubular side wall, the thickness of said striking portion and the thickness and taper of the side walls being so proportioned that during use of said hammer said striking head will be deformed without mushrooming, the spread of the metal being accommodated by said chamber.

FRANCIS A. GALLANT.

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