Expanded – threaded – driven – headed – tool-deformed – or locked-thr – Impact driven fastener – e.g. – nail – spike – tack – etc. – Having means to facilitate explosive driving
Reexamination Certificate
1997-12-19
2001-01-09
Saether, Flemming (Department: 3627)
Expanded, threaded, driven, headed, tool-deformed, or locked-thr
Impact driven fastener, e.g., nail, spike, tack, etc.
Having means to facilitate explosive driving
Reexamination Certificate
active
06171042
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention pertains to a steel pin for axial, non-rotational penetration into a steel, concrete, or masonry substrate, to a fastener comprising such a pin and a steel washer, and to a steel washer useful in the fastener. This invention also pertains to a method of making such a pin.
BACKGROUND OF THE INVENTION
As exemplified in Almeras et al. U.S. Pat. No. 4,824,003, which issued to Societe de Prospection et d'Inventions Techniques S.P.I.T. of Paris, France, it is known to provide a steel pin, having a head, a shank, and a point, with a steel washer, having an outer diameter equal approximately to the outer diameter of the head, for guiding the steel pin in the muzzle, barrel, or nosepiece of a driving or setting tool. The steel washer is carried on the shank, in axially spaced relation to the head, and is movable toward the head when the pin with the washer is forcibly driven into a substrate, either directly or through a workpiece, so that the washer bears against the substrate or the workpiece. As exemplified therein, the steel washer also performs an energy-absorbing function.
As exemplified by a steel pin made and sold by Societe de Prospection et d'Inventions Techniques S.P.I.T., supra, under Product Designation SBR 14, it is known for the steel pin to have a head, an ogival point, a knurled shank, which is not tapered, and a transition zone having a tapered portion between the knurled shank and the head. The SBR 14 pin is made from carbon steel having a carbon content in a range from 0.58 percent to 0.62 percent.
As known heretofore, the steel pin can be made from a predetermined length of carbon steel wire, which has a carbon content not less than 0.35 percent and which can be surface hardened or through hardened. AISI C 1038 steel, which has a carbon content in a range from 0.35 percent to 0.41 percent, can thus be used. Moreover, the predetermined length of carbon steel wire is formed in an initial step so as to form an intermediate part, which has a head to become the head of the steel pin, a shank to become the shank of the steel pin, and an end portion, on which the point is formed in a further step. As known heretofore, the point is formed by rotary swaging or by so-called “pinch pointing”, which refers to forging between two forging dies.
SUMMARY OF THE INVENTION
This invention provides improvements in a steel pin for axial, non-rotational penetration into a steel, concrete, or masonry substrate, in a steel washer useful with the steel pin, in a fastener comprising the steel pin and the steel washer, and in a method of making the steel pin. The fastener is designed to be forcibly driven so that the steel pin is driven into a steel, concrete, or masonry substrate, either directly or through a workpiece.
As improved by this invention, the steel pin is made from a predetermined length of carbon steel wire having an initial diameter and having a carbon content in a range from about the carbon content of AISI C 1038 steel to about the carbon content of AISI C 1065 steel. AISI C 1062 steel wire is preferred for the predetermined length of carbon steel wire. Broadly, the steel pin comprises a head, a tapered shank, a point, and a transition zone.
The head of the steel pin has an outer diameter at least about 2.6 times greater than the initial diameter of the predetermined length of carbon steel wire. Thus, the steel pin differs materially from the prior pin sold under Product Designation SBR 14, in which the head had an outer diameter about 2.3 times the initial diameter of the predetermined length of carbon steel wire used to make the prior pin sold thereunder. Heretofore, it was thought that the maximum diameter of the head of a pin in this carbon range was about 2.3 times the initial diameter, because the pins would be inconsistent due to non-round heads or to cracks caused by over work-hardening.
The tapered shank of the steel pin defines a comparatively smaller conical angle and has a smaller end and a larger end. Its smaller end has a diameter smaller than the initial diameter of the predetermined length of carbon steel wire, preferably being about 0.6 times the initial diameter thereof. Preferably, the larger end of the tapered shank has a diameter about 0.7 times the initial diameter of the predetermined length of carbon steel wire. The tapered shank pin is especially useful in attaching to a bar joist because it develops sufficient holding power by continuously sizing the hole that it forms in the bar joist.
Being joined unitarily to the smaller end of the tapered shank, the point conforms substantially to an ogive, preferably to a tangent ogive, which is tangent to the tapered shank. Although the point conforms substantially to an ogive, the point may have a rounded tip.
The transition zone has a tapered portion defining a comparatively larger conical angle between the tapered shank and the head. The tapered portion of the transition zone has a smaller end joined unitarily to the larger end of the tapered shank. The tapered portion thereof has a larger end joined unitarily to the head.
Preferably, the larger end of the tapered portion of the transition zone has a diameter about 1.1 times the initial diameter of the predetermined length of carbon steel wire. Preferably, the tapered shank defines a conical angle (total taper) in a range from about 2° to about 4°, and the axial length of the transition zone is less than about one half of the axial length of the tapered shank.
As improved by this invention, the steel washer is annular and has an annular periphery and a central aperture, which has a margin with a novel configuration. The margin of the central aperture defines plural projections with pin-engaging surfaces spaced angularly from one another. Each pin-engaging surface conforms essentially to a cylindrical section. Collectively, the pin-engaging surfaces encompass a minor portion of a complete cylinder, not less than about one third of a complete cylinder.
Preferably, the margin of the central aperture of the washer defines exactly four of the pin-engaging surfaces, which are spaced regularly from one another. Preferably, moreover, each pin-engaging surface is configured so as to encompass about one twelfth of a complete cylinder.
The steel washer improved by this invention can be advantageously combined with a steel pin, such as the steel pin improved by this invention, to provide an improved fastener. In the improved fastener, the annular periphery of the washer has an outer diameter equal approximately to the outer diameter of the head and wherein the central aperture of the washer enables the washer to be tightly fitted over the tapered shank, near the smaller end of the tapered shank, when the pin and the washer are assembled. Thus, when the fastener is forcibly driven so that the pin is driven into a steel, concrete, or masonry substrate, the washer and the head are arranged to guide the fastener through the muzzle, barrel, or nosepiece of the driving or setting tool and the washer is arranged to be forcibly moved along the tapered shank, toward the larger end of the tapered shank, as the pin enters the substrate.
As improved by this invention, the method of making a steel pin for axial, non-rotational penetration of a steel, concrete, or masonry substrate, such as the steel pin improved by this invention, contemplates making the steel pin from a predetermined length of carbon steel wire with an initial diameter and with a carbon content in a range from about the carbon content of AISI C 1038 steel to about the carbon content of AISI C 1065 steel, preferably from a predetermined length of AISI C 1062 steel wire, by successive forming, rolling, and heat treating steps.
In the forming step, which may be also called a heading step, the predetermined length of carbon steel wire is formed so as to form an intermediate part, which is elongate and which has a head on one end and a shank between its ends. If the shank is tapered, it is generally tapered in the forming step. In the rolling step, the intermed
Olvera Gilbert
Velan George M.
Illinois Tool Works Inc.
Saether Flemming
Schwartz & Weinrieb
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