US3640324A

US3640324A - Hammer head having an antislip and wear-resistant striking face surface

Info

Publication number: US3640324A
Application number: US876300A
Authority: US
Inventors: Laurence W Porter
Original assignee: Vaughan and Bushnell Manufacturing Co
Current assignee: Vaughan and Bushnell Manufacturing Co
Priority date: 1969-11-13
Filing date: 1969-11-13
Publication date: 1972-02-08
Anticipated expiration: 1989-02-08

Abstract

A forged steel hammer head including an impact head proper having a striking face on one end thereof is provided with a layer of tungsten carbide electrodeposited on the end, forming an outer surface on the striking face and penetrating the impact head proper, thereby providing an antislip and wear-resistant surface on the striking face.

Description

. w. r mm States atet H 1 9 Porter Feb. fi, 11972 [54] HAMMER HEAD HAVENG AN ANTISLIP [56] References Cited AND WEAR-RESISTANT STRIKING FAC SURFAE UNITED STATES PATENTS ml Pom-r, Hem 5338'53 351323 Z3135???:JJJJ::JJ::JJJJJJJJJJJJJJJ:@1233? 3 [73] Assignee: Vaughan & Bushnell Mfg. (30., l-lebron, Ill.

Primary Examiner-Andrew R. Juhasz Flled: 13, 1969 Assistant ExaminerMichael Koczo, Jr. [21] AppL No: 876,300 Attorney-Norman H. Gerlach [57] ABSTRACT [52] 11.8. Cl ..145/29 R, 76/DIG. 11 A forged Steel hammer head including an impact head propel, having a face on one end thereof is provided a [58] Field 01: Search 145/29; 76/DIG. 1 115 g 2130; layer oftungsten carbide electrodeposited on the and, forming an outer surface on the striking face and penetrating the impact head proper, thereby providing an antislip and wear-resistant surface on the striking face.

1 Claims, 4 Drawing Figures PATENIED FEB 8872 131 49 324 FIG] INVENTOR LAURENCE W. PORTER ATTORNEY HAMMER HEAD HAVING AN ANTISLIP AND WEAR-- RESISTANT STRIKING FACE SURFACE This invention relates to portable impact tools and has particular reference to a hammer construction.

It has long been considered desirable to provide on the forged steel head of a hammer a striking or impact surface which will reduce or minimize the tendency for the hammer head to slip or skid off of the head of a nail or other fastener when struck with the hammer, and thereby minimize nail bending. For this purpose, hammer heads used for driving nails and the like, such as employed in carpenters hammers, are conventionally provided with a milled or scored striking face. However, the milled face heads are in general limited to use in rough work, for example, structural framing and assembly of forms. The milled face heads are generally unsuitable for finishing work inasmuch as the milled striking surface mars the surface of the wood or other material into which the nails are driven. Consequently, it is necessary to use two hammers, employing a hammer with a milled face head where suitable to obtain the advantages of an antislip surface, and changing to a hammer with a smooth face head to preserve the surface of the wood or other material in finishing work. It would be a great advantage to be able to employ the same hammer for both rough and finishing work while minimizing hammer head slippage on the nail head during both types of work and preserving the finish of the work surface in the latter instance.

The milled face hammer heads also have the disadvantages that they wear more rapidly and are damaged more readily, inasmuch as the area of the striking surface is markedly reduced owing to the removal of metal by milling and also because the striking surface constitutes a series of small protrusions rather than a continuous smooth solid surface. Consequently, their performance level falls more rapidly and the hammers must be replaced more frequently than hammers having smooth face heads.

It is an object of the present invention to provide a forged steel hammer head, and a hammer embodying the same, having an antislip and wear-resistant striking face surface which satisfies the need for an antislip hammer head suitable for both rough and finishing work and which also has high wearability and durability.

A particular object is to provide a hammer head having a striking face surface that has antislip characteristics while not marring the surface of the work upon impact.

Another particular object is to provide a hammer head having such striking face surface that also eliminates the wear and durability problems of milled face heads and further provides increased wear resistance over smooth face heads.

A specific object is to provide in a forged steel hammer head including an impact head proper having a striking face on one end thereof, a layer of tungsten carbide electrodeposited on the end forming an outer surface on the striking face and penetrating the impact head proper, thereby providing an antislip and wear-resistant surface on the striking face.

An additional object is to provide a hammer head accomplishing the foregoing objects which is readily and economically constructed, requiring but a very simple operation on an otherwise finished tool.

These and other objects, advantages and functions of the invcntion will be apparent on reference to specification and to the accompanying drawings, in which like parts are identified by like reference symbols in each of the views, and in which:

FIG. I is a perspective view of a carpenters claw hammer provided with a head having an antislip and wear-resistant striking face surface in accordance with the invention;

FIG. 2 is an enlarged elevational view of the striking face surface on the hammer head shown in FIG. 1;

FIG. 3 is an enlarged view partly in cross section and partly in side elevation of a portion of the impact head proper of the hammer head shown in FIG. 1; and

FIG. 4 is a view like FIG. 2 illustrating another embodiment of the invention.

Referring to the drawings, particularly FIG. I, a carpenter's straight claw or ripping hammer 10 is illustrated, and it includes a wooden handle 12 and a forged steel hammer head 14 constructed in accordance with the invention. The invention is equally applicable to various other styles and types of portable or manual hammers and the heads thereof, employed for driv ing nails or other fastening means, including curved claw or nail hammers, claw hammers having welded steel or tubular steel handles, and hammers designed to accomplish other functions while having a striking face on the hammer head employed to a greater or lesser extent for driving nails or other fastening means, or for striking other surfaces or objects where antislip or wear resistance properties are desirable.

The illustrative hammer head 14 is of the bell-faced type, and it includes a medial body portion or region 16 and, projecting outwardly from opposite ends thereof, an impact head proper l8 and a claw portion or region 20. The impact head proper 18 is integrally joined to the medial body portion 16 by a constricted portion 22 of polygonal cross section. The medial body portion 16 is provided with a generally rectangular socket or opening 24 extending transversely therethrough. The socket 24 receives a distal connecting section 26 of the handle 12 therein, where the handle is secured in place by wedges, not shown. The handle also includes a proximal grip section 30, by which the hammer 10 is held during use.

The impact head proper l8 constitutes a substantially cylindrical portion of the hammer head 14, and it terminates at its outer impact end 28 in a circular, slightly convex striking face 32. Alternatively, the striking face 32 may be flat. A peripheral bevel edge or face 34 around the periphery of the striking face 32 serves to minimize chipping. The claw portion 20 is integral with the medial body portion 16, and is bifurcated at 36 to provide a pair of divergent claws 38 of conventional structure.

The hammer head 14 is constructed of forged steel, suitably heated, annealed, ground, hardened and finished, to provide the proper degrees of hardness and toughness in respective portions thereof. The illustrative and other suitable hammer heads may be constructed of the various steels conventionally employed therein, including, for example, high carbon steel (e.g., about 0.8 percent carbon as in AISI No. 1,078 or 1,080 steel) and alloy steels such as chromium-vanadium alloy steels (e.g., AISI No. 6150). A claw hammer, such as illustrated, is heat-treated to provide a Rockwell C hardness of 50-60 on the striking face 32, and 40-55 on the claws 38.

The hammer head 14 includes a layer or coat 40 of tungsten carbide electrodeposited on the outer impact end 28 of the head proper 18. The tungsten carbide layer 40 forms an outer surface 44 on the striking face 32, and the layer also penetrates the head proper 18, as illustrated in FIG. 3. Electrodeposition causes molecular tungsten carbide to penetrate the striking face 32, forming deposits within the head proper 18. Also, carbide deposits build up on the surface of the striking face 32, thereby forming the outer surface 44 thereon. In the preferred practice of the invention, the layer 40 formed by such carbide deposits penetrates the head proper 18 for about one-half of the layer depth. It is also preferred that the depth or thickness of the layer 40 be on the order of 0.004 inch, with the layer extending into the head proper 18 for about 0.002 inch.

FIG. 4 illustrates another embodiment of the invention, wherein a tungsten carbide layer 46 like the layer 40 is electrodeposited on the bevel edge portion of the outer impact end 28, in the same manner. The layer 46 forms an outer surface 48 on the bevel edge 34, and the layer also penetrates the head proper 18. The characteristics of the layer 46, including penetration and depth, are the same as described above for the layer 40 on the striking face 32 portion of the outer impact end 28.

The

tungsten carbide layers

40 and 46 are applied in a very simple, convenient and rapid manner employing conventional equipment for electrodeposition of the carbide, which is commercially available. The layers are applied by means of a spark discharge from a tungsten carbide electrode subjected to an electrical potential, in a hand-held electromagnetic vibratory electrical tool, which interrupts the current at a regular frequency, e.g., 120 pulses per minute. The electrode is placed against or closely adjacent to the surface of the striking face 32 or the bevel edge 34, and tungsten carbide is discharged from the electrode and deposited beneath and on the adjacent surface, in a depth or thickness depending upon the spark gap and the potential. The electrode is moved over the surface of the striking face 32 or of the bevel edge 34, to form the

layer

40 or 46 thereover. The tungsten carbide is fused into the head proper l8 and deposited thereon without overheating the surfaces thereof and affecting their properties.

Available equipment includes Model 312 Rocklinizer (Rocklin Manufacturing Co), which is employed at its maximum dial setting to provide a

tungsten carbide layer

40 or 46 of about 0.004 inch depth. It is preferred to provide such layer depth corresponding to the capacity of the particular equipment, although lesser depths may be provided while yet achieving improved results in accordance with the invention. Greater layer depths may be provided but do not appear to be needed. Another brand of available equipment is identified as Carbumatic (Mercuria Company, Inc.). The commercial equipment was previously employed for coating machine tools and dies.

The outer tungsten carbide surface 44 on the striking face 32 has very desirable antislip characteristics, apparently due to the presence of hard tungsten carbide deposits forming a roughened or pitted surface tending to prevent relative movement between the hammer head and the nail head. While being rough relative to a smooth surface striking face, the outer surface 44 is relatively even as compared to a milled face, so that the surface of the work is not marred. The antislip and finish retaining characteristics of the hammer 10 were demonstrated in construction work, where the carpenters found that they could work down nails without slip or skidding off of the nail heads, and in addition, they could change from rough framing to finishing work using the same hammer without marring the wood, which was a marked advantage.

The outer tungsten carbide surface 44, being formed by hard, closely adjacent carbide deposits, also is very wear-resistant and durable, in contrast to the reduced wearability and durability ofa milled face. Further, the carbide surface 44 has enhanced wear resistance as compared to an uncoated striking face 32, especially desirable for work under abrasive conditions, as in concrete work. The invention thus provides the multiple functions of minimizing slip, preserving the finish of the work surface, and increasing wear resistance.

The outer surface 48 of the tungsten carbide layer 46 on the bevel edge 34 likewise is very wear-resistant and durable. In the absence of the layer 46, the bevel edge tends to round off, into the striking face 32, which reduces the area of the striking face. The additional wear resistance imparted by the layer 46 is also especially desirable for work under abrasive conditions.

The invention thus provides a hammer head having a most advantageous antislip and wear-resistant striking surface, which can be used more efficiently where hammer head slip is a factor, as in driving nails or other fastening means, is a dual purpose tool suitable for both rough and fine work, and is very serviceable and long-lasting. While preferred embodiments of the invention have been described and illustrated, it will be ap parent to those skilled in the art that various changes and modifications may be made within the spirit and scope of the invention. It is intended that such changes and modifications be included within the scope of the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

1. In a forged steel claw hammer head including a medial body portion, a claw portion integral with said body portion and projecting outwardly from one end thereof, and an impact head proper integral with said body portion and projecting outwardly from the opposite end thereof, said impact head proper having a striking face on its outer end, said striking face having a minimum Rockwell C hardness of about 50, a layer of tungsten carbide having a depth on the order of 0.004

inch electrodeposited on said outer end forming an outer sur face on said striking face and penetrating said impact head proper for about one-half of the layer depth, said layer being deposited by a spark discharge from tungsten carbide electrode to preserve the striking face properties, thereby providing an antislip and wear-resistant surface on said striking face.

Claims

1. In a forged steel claw hammer head including a medial body portion, a claw portion integral with said body portion and projecting outwardly from one end thereof, and an impact head proper integral with said body portion and projecting outwardly from the opposite end thereof, said impact head proper having a striking face on its outer end, said striking face having a minimum Rockwell C hardness of about 50, a layer of tungsten carbide having a depth on the order of 0.004 inch electrodeposited on said outer end forming an outer surface on said striking face and penetrating said impact head proper for about one-half of the layer depth, said layer being deposited by a spark discharge from tungsten carbide electrode to preserve the striking face properties, thereby providing an antislip and wearresistant surface on said striking face.